86Box/src/video/vid_cl54xx.c

/*
 * 86Box    A hypervisor and IBM PC system emulator that specializes in
 *          running old operating systems and software designed for IBM
 *          PC systems and compatibles from 1981 through fairly recent
 *          system designs based on the PCI bus.
 *
 *          This file is part of the 86Box distribution.
 *
 *          Emulation of select Cirrus Logic cards (CL-GD 5428,
 *          CL-GD 5429, CL-GD 5430, CL-GD 5434 and CL-GD 5436 are supported).
 *
 *
 *
 * Authors: Miran Grca, <mgrca8@gmail.com>
 *          tonioni,
 *          TheCollector1995,
 *
 *          Copyright 2016-2020 Miran Grca.
 *          Copyright 2020      tonioni.
 *          Copyright 2016-2020 TheCollector1995.
 */
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdarg.h>
#include <stdlib.h>
#include <wchar.h>
#include <86box/86box.h>
#include "cpu.h"
#include <86box/io.h>
#include <86box/mca.h>
#include <86box/mem.h>
#include <86box/pci.h>
#include <86box/rom.h>
#include <86box/device.h>
#include <86box/timer.h>
#include <86box/video.h>
#include <86box/i2c.h>
#include <86box/vid_ddc.h>
#include <86box/vid_svga.h>
#include <86box/vid_svga_render.h>
#include <86box/plat_fallthrough.h>
#include <86box/plat_unused.h>

#define BIOS_GD5401_PATH                "roms/video/cirruslogic/avga1.rom"
#define BIOS_GD5402_PATH                "roms/video/cirruslogic/avga2.rom"
#define BIOS_GD5402_ONBOARD_PATH        "roms/machines/cmdsl386sx25/c000.rom"
#define BIOS_GD5420_PATH                "roms/video/cirruslogic/5420.vbi"
#define BIOS_GD5422_PATH                "roms/video/cirruslogic/cl5422.bin"
#define BIOS_GD5426_DIAMOND_A1_ISA_PATH "roms/video/cirruslogic/diamond5426.vbi"
#define BIOS_GD5426_MCA_PATH            "roms/video/cirruslogic/Reply.BIN"
#define BIOS_GD5428_DIAMOND_B1_VLB_PATH "roms/video/cirruslogic/Diamond SpeedStar PRO VLB v3.04.bin"
#define BIOS_GD5428_ISA_PATH            "roms/video/cirruslogic/5428.bin"
#define BIOS_GD5428_MCA_PATH            "roms/video/cirruslogic/SVGA141.ROM"
#define BIOS_GD5428_PATH                "roms/video/cirruslogic/vlbusjapan.BIN"
#define BIOS_GD5428_BOCA_ISA_PATH_1     "roms/video/cirruslogic/boca_gd5428_1.30b_1.bin"
#define BIOS_GD5428_BOCA_ISA_PATH_2     "roms/video/cirruslogic/boca_gd5428_1.30b_2.bin"
#define BIOS_GD5429_PATH                "roms/video/cirruslogic/5429.vbi"
#define BIOS_GD5430_DIAMOND_A8_VLB_PATH "roms/video/cirruslogic/diamondvlbus.bin"
#define BIOS_GD5430_ORCHID_VLB_PATH     "roms/video/cirruslogic/orchidvlbus.bin"
#define BIOS_GD5430_PATH                "roms/video/cirruslogic/pci.bin"
#define BIOS_GD5434_DIAMOND_A3_ISA_PATH "roms/video/cirruslogic/Diamond Multimedia SpeedStar 64 v2.02 EPROM Backup from ST M27C256B-12F1.BIN"
#define BIOS_GD5434_PATH                "roms/video/cirruslogic/gd5434.BIN"
#define BIOS_GD5436_PATH                "roms/video/cirruslogic/5436.vbi"
#define BIOS_GD5440_PATH                "roms/video/cirruslogic/BIOS.BIN"
#define BIOS_GD5446_PATH                "roms/video/cirruslogic/5446bv.vbi"
#define BIOS_GD5446_STB_PATH            "roms/video/cirruslogic/stb nitro64v.BIN"
#define BIOS_GD5480_PATH                "roms/video/cirruslogic/clgd5480.rom"

#define CIRRUS_ID_CLGD5401              0x88
#define CIRRUS_ID_CLGD5402              0x89
#define CIRRUS_ID_CLGD5420              0x8a
#define CIRRUS_ID_CLGD5422              0x8c
#define CIRRUS_ID_CLGD5424              0x94
#define CIRRUS_ID_CLGD5426              0x90
#define CIRRUS_ID_CLGD5428              0x98
#define CIRRUS_ID_CLGD5429              0x9c
#define CIRRUS_ID_CLGD5430              0xa0
#define CIRRUS_ID_CLGD5432              0xa2
#define CIRRUS_ID_CLGD5434_4            0xa4
#define CIRRUS_ID_CLGD5434              0xa8
#define CIRRUS_ID_CLGD5436              0xac
#define CIRRUS_ID_CLGD5440              0xa0 /* Yes, the 5440 has the same ID as the 5430. */
#define CIRRUS_ID_CLGD5446              0xb8
#define CIRRUS_ID_CLGD5480              0xbc

/* sequencer 0x07 */
#define CIRRUS_SR7_BPP_VGA           0x00
#define CIRRUS_SR7_BPP_SVGA          0x01
#define CIRRUS_SR7_BPP_MASK          0x0e
#define CIRRUS_SR7_BPP_8             0x00
#define CIRRUS_SR7_BPP_16_DOUBLEVCLK 0x02
#define CIRRUS_SR7_BPP_24            0x04
#define CIRRUS_SR7_BPP_16            0x06
#define CIRRUS_SR7_BPP_32            0x08
#define CIRRUS_SR7_ISAADDR_MASK      0xe0

/* sequencer 0x12 */
#define CIRRUS_CURSOR_SHOW      0x01
#define CIRRUS_CURSOR_HIDDENPEL 0x02
#define CIRRUS_CURSOR_LARGE     0x04 /* 64x64 if set, 32x32 if clear */

/* sequencer 0x17 */
#define CIRRUS_BUSTYPE_VLBFAST   0x10
#define CIRRUS_BUSTYPE_PCI       0x20
#define CIRRUS_BUSTYPE_VLBSLOW   0x30
#define CIRRUS_BUSTYPE_ISA       0x38
#define CIRRUS_MMIO_ENABLE       0x04
#define CIRRUS_MMIO_USE_PCIADDR  0x40 /* 0xb8000 if cleared. */
#define CIRRUS_MEMSIZEEXT_DOUBLE 0x80

/* control 0x0b */
#define CIRRUS_BANKING_DUAL            0x01
#define CIRRUS_BANKING_GRANULARITY_16K 0x20 /* set:16k, clear:4k */

/* control 0x30 */
#define CIRRUS_BLTMODE_BACKWARDS       0x01
#define CIRRUS_BLTMODE_MEMSYSDEST      0x02
#define CIRRUS_BLTMODE_MEMSYSSRC       0x04
#define CIRRUS_BLTMODE_TRANSPARENTCOMP 0x08
#define CIRRUS_BLTMODE_PATTERNCOPY     0x40
#define CIRRUS_BLTMODE_COLOREXPAND     0x80
#define CIRRUS_BLTMODE_PIXELWIDTHMASK  0x30
#define CIRRUS_BLTMODE_PIXELWIDTH8     0x00
#define CIRRUS_BLTMODE_PIXELWIDTH16    0x10
#define CIRRUS_BLTMODE_PIXELWIDTH24    0x20
#define CIRRUS_BLTMODE_PIXELWIDTH32    0x30

/* control 0x31 */
#define CIRRUS_BLT_BUSY      0x01
#define CIRRUS_BLT_START     0x02
#define CIRRUS_BLT_RESET     0x04
#define CIRRUS_BLT_FIFOUSED  0x10
#define CIRRUS_BLT_PAUSED    0x20
#define CIRRUS_BLT_APERTURE2 0x40
#define CIRRUS_BLT_AUTOSTART 0x80

/* control 0x33 */
#define CIRRUS_BLTMODEEXT_BACKGROUNDONLY   0x08
#define CIRRUS_BLTMODEEXT_SOLIDFILL        0x04
#define CIRRUS_BLTMODEEXT_COLOREXPINV      0x02
#define CIRRUS_BLTMODEEXT_DWORDGRANULARITY 0x01

#define CL_GD5428_SYSTEM_BUS_MCA           5
#define CL_GD5428_SYSTEM_BUS_VESA          6
#define CL_GD5428_SYSTEM_BUS_ISA           7

#define CL_GD5429_SYSTEM_BUS_VESA          5
#define CL_GD5429_SYSTEM_BUS_ISA           7

#define CL_GD543X_SYSTEM_BUS_PCI           4
#define CL_GD543X_SYSTEM_BUS_VESA          6
#define CL_GD543X_SYSTEM_BUS_ISA           7

typedef struct gd54xx_t {
    mem_mapping_t mmio_mapping;
    mem_mapping_t linear_mapping;
    mem_mapping_t aperture2_mapping;
    mem_mapping_t vgablt_mapping;

    svga_t svga;

    int   has_bios;
    int   rev;
    int   bit32;
    rom_t bios_rom;

    uint32_t vram_size;
    uint32_t vram_mask;

    uint8_t vclk_n[4];
    uint8_t vclk_d[4];

    struct {
        uint8_t state;
        int     ctrl;
    } ramdac;

    struct {
        uint16_t width;
        uint16_t height;
        uint16_t dst_pitch;
        uint16_t src_pitch;
        uint16_t trans_col;
        uint16_t trans_mask;
        uint16_t height_internal;
        uint16_t msd_buf_pos;
        uint16_t msd_buf_cnt;

        uint8_t status;
        uint8_t mask;
        uint8_t mode;
        uint8_t rop;
        uint8_t modeext;
        uint8_t ms_is_dest;
        uint8_t msd_buf[32];

        uint32_t fg_col;
        uint32_t bg_col;
        uint32_t dst_addr_backup;
        uint32_t src_addr_backup;
        uint32_t dst_addr;
        uint32_t src_addr;
        uint32_t sys_src32;
        uint32_t sys_cnt;

        /* Internal state */
        int pixel_width;
        int pattern_x;
        int x_count;
        int y_count;
        int xx_count;
        int dir;
        int unlock_special;
    } blt;

    struct {
        int      mode;
        uint16_t stride;
        uint16_t r1sz;
        uint16_t r1adjust;
        uint16_t r2sz;
        uint16_t r2adjust;
        uint16_t r2sdz;
        uint16_t wvs;
        uint16_t wve;
        uint16_t hzoom;
        uint16_t vzoom;
        uint8_t  occlusion;
        uint8_t  colorkeycomparemask;
        uint8_t  colorkeycompare;
        int      region1size;
        int      region2size;
        int      colorkeymode;
        uint32_t ck;
    } overlay;

    int pci;
    int vlb;
    int mca;
    int countminusone;
    int vblank_irq;
    int vportsync;

    uint8_t pci_regs[256];
    uint8_t int_line;
    uint8_t unlocked;
    uint8_t status;
    uint8_t extensions;
    uint8_t crtcreg_mask;

    uint8_t fc; /* Feature Connector */

    int id;

    uint8_t pci_slot;
    uint8_t irq_state;

    uint8_t pos_regs[8];

    uint32_t lfb_base;
    uint32_t vgablt_base;

    int mmio_vram_overlap;

    uint32_t extpallook[256];
    PALETTE  extpal;

    void *i2c;
    void *ddc;
} gd54xx_t;

static video_timings_t timing_gd54xx_isa = { .type = VIDEO_ISA, .write_b = 3, .write_w = 3, .write_l = 6, .read_b = 8, .read_w = 8, .read_l = 12 };
static video_timings_t timing_gd54xx_vlb = { .type = VIDEO_BUS, .write_b = 4, .write_w = 4, .write_l = 8, .read_b = 10, .read_w = 10, .read_l = 20 };
static video_timings_t timing_gd54xx_pci = { .type = VIDEO_PCI, .write_b = 4, .write_w = 4, .write_l = 8, .read_b = 10, .read_w = 10, .read_l = 20 };

static void
gd543x_mmio_write(uint32_t addr, uint8_t val, void *priv);
static void
gd543x_mmio_writeb(uint32_t addr, uint8_t val, void *priv);
static void
gd543x_mmio_writew(uint32_t addr, uint16_t val, void *priv);
static void
gd543x_mmio_writel(uint32_t addr, uint32_t val, void *priv);
static uint8_t
gd543x_mmio_read(uint32_t addr, void *priv);
static uint16_t
gd543x_mmio_readw(uint32_t addr, void *priv);
static uint32_t
gd543x_mmio_readl(uint32_t addr, void *priv);

static void
gd54xx_recalc_banking(gd54xx_t *gd54xx);

static void
gd543x_recalc_mapping(gd54xx_t *gd54xx);

static void
gd54xx_reset_blit(gd54xx_t *gd54xx);
static void
gd54xx_start_blit(uint32_t cpu_dat, uint32_t count, gd54xx_t *gd54xx, svga_t *svga);

#define CLAMP(x)                      \
    do {                              \
        if ((x) & ~0xff)              \
            x = ((x) < 0) ? 0 : 0xff; \
    } while (0)

#define DECODE_YCbCr()                      \
    do {                                    \
        int c;                              \
                                            \
        for (c = 0; c < 2; c++) {           \
            uint8_t y1, y2;                 \
            int8_t  Cr, Cb;                 \
            int     dR, dG, dB;             \
                                            \
            y1 = src[0];                    \
            Cr = src[1] - 0x80;             \
            y2 = src[2];                    \
            Cb = src[3] - 0x80;             \
            src += 4;                       \
                                            \
            dR = (359 * Cr) >> 8;           \
            dG = (88 * Cb + 183 * Cr) >> 8; \
            dB = (453 * Cb) >> 8;           \
                                            \
            r[x_write] = y1 + dR;           \
            CLAMP(r[x_write]);              \
            g[x_write] = y1 - dG;           \
            CLAMP(g[x_write]);              \
            b[x_write] = y1 + dB;           \
            CLAMP(b[x_write]);              \
                                            \
            r[x_write + 1] = y2 + dR;       \
            CLAMP(r[x_write + 1]);          \
            g[x_write + 1] = y2 - dG;       \
            CLAMP(g[x_write + 1]);          \
            b[x_write + 1] = y2 + dB;       \
            CLAMP(b[x_write + 1]);          \
                                            \
            x_write = (x_write + 2) & 7;    \
        }                                   \
    } while (0)

/*Both YUV formats are untested*/
#define DECODE_YUV211()                  \
    do {                                 \
        uint8_t y1, y2, y3, y4;          \
        int8_t  U, V;                    \
        int     dR, dG, dB;              \
                                         \
        U  = src[0] - 0x80;              \
        y1 = (298 * (src[1] - 16)) >> 8; \
        y2 = (298 * (src[2] - 16)) >> 8; \
        V  = src[3] - 0x80;              \
        y3 = (298 * (src[4] - 16)) >> 8; \
        y4 = (298 * (src[5] - 16)) >> 8; \
        src += 6;                        \
                                         \
        dR = (309 * V) >> 8;             \
        dG = (100 * U + 208 * V) >> 8;   \
        dB = (516 * U) >> 8;             \
                                         \
        r[x_write] = y1 + dR;            \
        CLAMP(r[x_write]);               \
        g[x_write] = y1 - dG;            \
        CLAMP(g[x_write]);               \
        b[x_write] = y1 + dB;            \
        CLAMP(b[x_write]);               \
                                         \
        r[x_write + 1] = y2 + dR;        \
        CLAMP(r[x_write + 1]);           \
        g[x_write + 1] = y2 - dG;        \
        CLAMP(g[x_write + 1]);           \
        b[x_write + 1] = y2 + dB;        \
        CLAMP(b[x_write + 1]);           \
                                         \
        r[x_write + 2] = y3 + dR;        \
        CLAMP(r[x_write + 2]);           \
        g[x_write + 2] = y3 - dG;        \
        CLAMP(g[x_write + 2]);           \
        b[x_write + 2] = y3 + dB;        \
        CLAMP(b[x_write + 2]);           \
                                         \
        r[x_write + 3] = y4 + dR;        \
        CLAMP(r[x_write + 3]);           \
        g[x_write + 3] = y4 - dG;        \
        CLAMP(g[x_write + 3]);           \
        b[x_write + 3] = y4 + dB;        \
        CLAMP(b[x_write + 3]);           \
                                         \
        x_write = (x_write + 4) & 7;     \
    } while (0)

#define DECODE_YUV422()                      \
    do {                                     \
        int c;                               \
                                             \
        for (c = 0; c < 2; c++) {            \
            uint8_t y1, y2;                  \
            int8_t  U, V;                    \
            int     dR, dG, dB;              \
                                             \
            U  = src[0] - 0x80;              \
            y1 = (298 * (src[1] - 16)) >> 8; \
            V  = src[2] - 0x80;              \
            y2 = (298 * (src[3] - 16)) >> 8; \
            src += 4;                        \
                                             \
            dR = (309 * V) >> 8;             \
            dG = (100 * U + 208 * V) >> 8;   \
            dB = (516 * U) >> 8;             \
                                             \
            r[x_write] = y1 + dR;            \
            CLAMP(r[x_write]);               \
            g[x_write] = y1 - dG;            \
            CLAMP(g[x_write]);               \
            b[x_write] = y1 + dB;            \
            CLAMP(b[x_write]);               \
                                             \
            r[x_write + 1] = y2 + dR;        \
            CLAMP(r[x_write + 1]);           \
            g[x_write + 1] = y2 - dG;        \
            CLAMP(g[x_write + 1]);           \
            b[x_write + 1] = y2 + dB;        \
            CLAMP(b[x_write + 1]);           \
                                             \
            x_write = (x_write + 2) & 7;     \
        }                                    \
    } while (0)

#define DECODE_RGB555()                                                      \
    do {                                                                     \
        int c;                                                               \
                                                                             \
        for (c = 0; c < 4; c++) {                                            \
            uint16_t dat;                                                    \
                                                                             \
            dat = *(uint16_t *) src;                                         \
            src += 2;                                                        \
                                                                             \
            r[x_write + c] = ((dat & 0x001f) << 3) | ((dat & 0x001f) >> 2);  \
            g[x_write + c] = ((dat & 0x03e0) >> 2) | ((dat & 0x03e0) >> 7);  \
            b[x_write + c] = ((dat & 0x7c00) >> 7) | ((dat & 0x7c00) >> 12); \
        }                                                                    \
        x_write = (x_write + 4) & 7;                                         \
    } while (0)

#define DECODE_RGB565()                                                      \
    do {                                                                     \
        int c;                                                               \
                                                                             \
        for (c = 0; c < 4; c++) {                                            \
            uint16_t dat;                                                    \
                                                                             \
            dat = *(uint16_t *) src;                                         \
            src += 2;                                                        \
                                                                             \
            r[x_write + c] = ((dat & 0x001f) << 3) | ((dat & 0x001f) >> 2);  \
            g[x_write + c] = ((dat & 0x07e0) >> 3) | ((dat & 0x07e0) >> 9);  \
            b[x_write + c] = ((dat & 0xf800) >> 8) | ((dat & 0xf800) >> 13); \
        }                                                                    \
        x_write = (x_write + 4) & 7;                                         \
    } while (0)

#define DECODE_CLUT()                                  \
    do {                                               \
        int c;                                         \
                                                       \
        for (c = 0; c < 4; c++) {                      \
            uint8_t dat;                               \
                                                       \
            dat = *(uint8_t *) src;                    \
            src++;                                     \
                                                       \
            r[x_write + c] = svga->pallook[dat] >> 0;  \
            g[x_write + c] = svga->pallook[dat] >> 8;  \
            b[x_write + c] = svga->pallook[dat] >> 16; \
        }                                              \
        x_write = (x_write + 4) & 7;                   \
    } while (0)

#define OVERLAY_SAMPLE()                \
    do {                                \
        switch (gd54xx->overlay.mode) { \
            case 0:                     \
                DECODE_YUV422();        \
                break;                  \
            case 2:                     \
                DECODE_CLUT();          \
                break;                  \
            case 3:                     \
                DECODE_YUV211();        \
                break;                  \
            case 4:                     \
                DECODE_RGB555();        \
                break;                  \
            case 5:                     \
                DECODE_RGB565();        \
                break;                  \
        }                               \
    } while (0)

static int
gd54xx_interrupt_enabled(gd54xx_t *gd54xx)
{
    return !gd54xx->pci || (gd54xx->svga.gdcreg[0x17] & 0x04);
}

static int
gd54xx_vga_vsync_enabled(gd54xx_t *gd54xx)
{
    if (!(gd54xx->svga.crtc[0x11] & 0x20) && (gd54xx->svga.crtc[0x11] & 0x10) && gd54xx_interrupt_enabled(gd54xx))
        return 1;
    return 0;
}

static void
gd54xx_update_irqs(gd54xx_t *gd54xx)
{
    if (!gd54xx->pci)
        return;

    if ((gd54xx->vblank_irq > 0) && gd54xx_vga_vsync_enabled(gd54xx))
        pci_set_irq(gd54xx->pci_slot, PCI_INTA, &gd54xx->irq_state);
    else
        pci_clear_irq(gd54xx->pci_slot, PCI_INTA, &gd54xx->irq_state);
}

static void
gd54xx_vblank_start(svga_t *svga)
{
    gd54xx_t *gd54xx = (gd54xx_t *) svga->priv;
    if (gd54xx->vblank_irq >= 0) {
        gd54xx->vblank_irq = 1;
        gd54xx_update_irqs(gd54xx);
    }
}

/* Returns 1 if the card is a 5422+ */
static int
gd54xx_is_5422(svga_t *svga)
{
    if (svga->crtc[0x27] >= CIRRUS_ID_CLGD5422)
        return 1;
    else
        return 0;
}

static void
gd54xx_overlay_draw(svga_t *svga, int displine)
{
    const gd54xx_t *gd54xx = (gd54xx_t *) svga->priv;
    int             shift  = (svga->crtc[0x27] >= CIRRUS_ID_CLGD5446) ? 2 : 0;
    int             h_acc  = svga->overlay_latch.h_acc;
    int             r[8];
    int             g[8];
    int             b[8];
    int             x_read = 4;
    int             x_write = 4;
    uint32_t       *p;
    uint8_t        *src         = &svga->vram[(svga->overlay_latch.addr << shift) & svga->vram_mask];
    int             bpp         = svga->bpp;
    int             bytesperpix = (bpp + 7) / 8;
    uint8_t        *src2        = &svga->vram[(svga->ma - (svga->hdisp * bytesperpix)) & svga->vram_display_mask];
    int             occl;
    int             ckval;

    p = &(svga->monitor->target_buffer->line[displine])[gd54xx->overlay.region1size + svga->x_add];
    src2 += gd54xx->overlay.region1size * bytesperpix;

    OVERLAY_SAMPLE();

    for (int x = 0; (x < gd54xx->overlay.region2size) && ((x + gd54xx->overlay.region1size) < svga->hdisp); x++) {
        if (gd54xx->overlay.occlusion) {
            occl  = 1;
            ckval = gd54xx->overlay.ck;
            if (bytesperpix == 1) {
                if (*src2 == ckval)
                    occl = 0;
            } else if (bytesperpix == 2) {
                if (*((uint16_t *) src2) == ckval)
                    occl = 0;
            } else
                occl = 0;
            if (!occl)
                *p++ = r[x_read] | (g[x_read] << 8) | (b[x_read] << 16);
            src2 += bytesperpix;
        } else
            *p++ = r[x_read] | (g[x_read] << 8) | (b[x_read] << 16);

        h_acc += gd54xx->overlay.hzoom;
        if (h_acc >= 256) {
            if ((x_read ^ (x_read + 1)) & ~3)
                OVERLAY_SAMPLE();
            x_read = (x_read + 1) & 7;

            h_acc -= 256;
        }
    }

    svga->overlay_latch.v_acc += gd54xx->overlay.vzoom;
    if (svga->overlay_latch.v_acc >= 256) {
        svga->overlay_latch.v_acc -= 256;
        svga->overlay_latch.addr += svga->overlay.pitch << 1;
    }
}

static void
gd54xx_update_overlay(gd54xx_t *gd54xx)
{
    svga_t *svga = &gd54xx->svga;
    int     bpp  = svga->bpp;

    svga->overlay.cur_ysize     = gd54xx->overlay.wve - gd54xx->overlay.wvs + 1;
    gd54xx->overlay.region1size = 32 * gd54xx->overlay.r1sz / bpp + (gd54xx->overlay.r1adjust * 8 / bpp);
    gd54xx->overlay.region2size = 32 * gd54xx->overlay.r2sz / bpp + (gd54xx->overlay.r2adjust * 8 / bpp);

    gd54xx->overlay.occlusion = (svga->crtc[0x3e] & 0x80) != 0 && svga->bpp <= 16;

    /* Mask and chroma key ignored. */
    if (gd54xx->overlay.colorkeymode == 0)
        gd54xx->overlay.ck = gd54xx->overlay.colorkeycompare;
    else if (gd54xx->overlay.colorkeymode == 1)
        gd54xx->overlay.ck = gd54xx->overlay.colorkeycompare | (gd54xx->overlay.colorkeycomparemask << 8);
    else
        gd54xx->overlay.occlusion = 0;
}

/* Returns 1 if the card supports the 8-bpp/16-bpp transparency color or mask. */
static int
gd54xx_has_transp(svga_t *svga, int mask)
{
    if (((svga->crtc[0x27] == CIRRUS_ID_CLGD5446) || (svga->crtc[0x27] == CIRRUS_ID_CLGD5480)) && !mask)
        return 1; /* 5446 and 5480 have mask but not transparency. */
    if ((svga->crtc[0x27] == CIRRUS_ID_CLGD5426) || (svga->crtc[0x27] == CIRRUS_ID_CLGD5428))
        return 1; /* 5426 and 5428 have both. */
    else
        return 0; /* The rest have neither. */
}

/* Returns 1 if the card is a 5434, 5436/46, or 5480. */
static int
gd54xx_is_5434(svga_t *svga)
{
    if (svga->crtc[0x27] >= CIRRUS_ID_CLGD5434)
        return 1;
    else
        return 0;
}

static void
gd54xx_out(uint16_t addr, uint8_t val, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;
    uint8_t   old;
    uint8_t   o;
    uint8_t   index;
    uint32_t  o32;

    if (((addr & 0xfff0) == 0x3d0 || (addr & 0xfff0) == 0x3b0) && !(svga->miscout & 1))
        addr ^= 0x60;

    switch (addr) {
        case 0x3c0:
        case 0x3c1:
            if (!svga->attrff) {
                svga->attraddr = val & 31;
                if ((val & 0x20) != svga->attr_palette_enable) {
                    svga->fullchange          = 3;
                    svga->attr_palette_enable = val & 0x20;
                    svga_recalctimings(svga);
                }
            } else {
                o                                   = svga->attrregs[svga->attraddr & 31];
                svga->attrregs[svga->attraddr & 31] = val;
                if (svga->attraddr < 16)
                    svga->fullchange = changeframecount;
                if (svga->attraddr == 0x10 || svga->attraddr == 0x14 || svga->attraddr < 0x10) {
                    for (uint8_t c = 0; c < 16; c++) {
                        if (svga->attrregs[0x10] & 0x80)
                            svga->egapal[c] = (svga->attrregs[c] & 0xf) | ((svga->attrregs[0x14] & 0xf) << 4);
                        else
                            svga->egapal[c] = (svga->attrregs[c] & 0x3f) | ((svga->attrregs[0x14] & 0xc) << 4);
                    }
                }
                /* Recalculate timings on change of attribute register 0x11 (overscan border color) too. */
                if (svga->attraddr == 0x10) {
                    if (o != val)
                        svga_recalctimings(svga);
                } else if (svga->attraddr == 0x11) {
                    if (!(svga->seqregs[0x12] & 0x80)) {
                        svga->overscan_color = svga->pallook[svga->attrregs[0x11]];
                        if (o != val)
                            svga_recalctimings(svga);
                    }
                } else if (svga->attraddr == 0x12) {
                    if ((val & 0xf) != svga->plane_mask)
                        svga->fullchange = changeframecount;
                    svga->plane_mask = val & 0xf;
                }
            }
            svga->attrff ^= 1;
            return;

        case 0x3c4:
            svga->seqaddr = val;
            break;
        case 0x3c5:
            if ((svga->seqaddr == 2) && !gd54xx->unlocked) {
                o = svga->seqregs[svga->seqaddr & 0x1f];
                svga_out(addr, val, svga);
                if (svga->gdcreg[0xb] & 0x04)
                    svga->seqregs[svga->seqaddr & 0x1f] = (o & 0xf0) | (val & 0x0f);
                return;
            } else if ((svga->seqaddr > 6) && !gd54xx->unlocked)
                return;

            if (svga->seqaddr > 5) {
                o                                   = svga->seqregs[svga->seqaddr & 0x1f];
                svga->seqregs[svga->seqaddr & 0x1f] = val;
                switch (svga->seqaddr) {
                    case 6:
                        val &= 0x17;
                        if (val == 0x12)
                            svga->seqregs[6] = 0x12;
                        else
                            svga->seqregs[6] = 0x0f;
                        if (svga->crtc[0x27] < CIRRUS_ID_CLGD5429)
                            gd54xx->unlocked = (svga->seqregs[6] == 0x12);
                        break;
                    case 0x08:
                        if (gd54xx->i2c)
                            i2c_gpio_set(gd54xx->i2c, !!(val & 0x01), !!(val & 0x02));
                        break;
                    case 0x0b:
                    case 0x0c:
                    case 0x0d:
                    case 0x0e: /* VCLK stuff */
                        gd54xx->vclk_n[svga->seqaddr - 0x0b] = val;
                        break;
                    case 0x1b:
                    case 0x1c:
                    case 0x1d:
                    case 0x1e: /* VCLK stuff */
                        gd54xx->vclk_d[svga->seqaddr - 0x1b] = val;
                        break;
                    case 0x10:
                    case 0x30:
                    case 0x50:
                    case 0x70:
                    case 0x90:
                    case 0xb0:
                    case 0xd0:
                    case 0xf0:
                        svga->hwcursor.x = (val << 3) | (svga->seqaddr >> 5);
                        break;
                    case 0x11:
                    case 0x31:
                    case 0x51:
                    case 0x71:
                    case 0x91:
                    case 0xb1:
                    case 0xd1:
                    case 0xf1:
                        svga->hwcursor.y = (val << 3) | (svga->seqaddr >> 5);
                        break;
                    case 0x12:
                        svga->ext_overscan = !!(val & 0x80);
                        if (svga->ext_overscan && (svga->crtc[0x27] >= CIRRUS_ID_CLGD5426))
                            svga->overscan_color = gd54xx->extpallook[2];
                        else
                            svga->overscan_color = svga->pallook[svga->attrregs[0x11]];
                        svga_recalctimings(svga);
                        svga->hwcursor.ena = val & CIRRUS_CURSOR_SHOW;
                        if (svga->crtc[0x27] >= CIRRUS_ID_CLGD5422)
                            svga->hwcursor.cur_xsize = svga->hwcursor.cur_ysize = ((val & CIRRUS_CURSOR_LARGE) && (svga->crtc[0x27] >= CIRRUS_ID_CLGD5422)) ? 64 : 32;
                        else
                            svga->hwcursor.cur_xsize = 32;

                        if ((svga->seqregs[0x12] & CIRRUS_CURSOR_LARGE) && (svga->crtc[0x27] >= CIRRUS_ID_CLGD5422))
                            svga->hwcursor.addr = ((gd54xx->vram_size - 0x4000) + ((svga->seqregs[0x13] & 0x3c) * 256));
                        else
                            svga->hwcursor.addr = ((gd54xx->vram_size - 0x4000) + ((svga->seqregs[0x13] & 0x3f) * 256));
                        break;
                    case 0x13:
                        if ((svga->seqregs[0x12] & CIRRUS_CURSOR_LARGE) && (svga->crtc[0x27] >= CIRRUS_ID_CLGD5422))
                            svga->hwcursor.addr = ((gd54xx->vram_size - 0x4000) + ((val & 0x3c) * 256));
                        else
                            svga->hwcursor.addr = ((gd54xx->vram_size - 0x4000) + ((val & 0x3f) * 256));
                        break;
                    case 0x07:
                        svga->packed_chain4 = svga->seqregs[7] & 1;
                        svga_recalctimings(svga);
                        if (gd54xx_is_5422(svga))
                            gd543x_recalc_mapping(gd54xx);
                        else
                            svga->seqregs[svga->seqaddr] &= 0x0f;
                        if (svga->crtc[0x27] >= CIRRUS_ID_CLGD5429)
                            svga->set_reset_disabled = svga->seqregs[7] & 1;
                        break;
                    case 0x17:
                        if (gd54xx_is_5422(svga))
                            gd543x_recalc_mapping(gd54xx);
                        else
                            return;
                        break;

                    default:
                        break;
                }
                return;
            }
            break;
        case 0x3c6:
            if (!gd54xx->unlocked)
                break;
            if (gd54xx->ramdac.state == 4) {
                gd54xx->ramdac.state = 0;
                gd54xx->ramdac.ctrl  = val;
                svga_recalctimings(svga);
                return;
            }
            gd54xx->ramdac.state = 0;
            break;
        case 0x3c7:
        case 0x3c8:
            gd54xx->ramdac.state = 0;
            break;
        case 0x3c9:
            gd54xx->ramdac.state = 0;
            svga->dac_status     = 0;
            svga->fullchange     = changeframecount;
            switch (svga->dac_pos) {
                case 0:
                    svga->dac_r = val;
                    svga->dac_pos++;
                    break;
                case 1:
                    svga->dac_g = val;
                    svga->dac_pos++;
                    break;
                case 2:
                    index = svga->dac_addr & 0xff;
                    if (svga->seqregs[0x12] & 2) {
                        index &= 0x0f;
                        gd54xx->extpal[index].r   = svga->dac_r;
                        gd54xx->extpal[index].g   = svga->dac_g;
                        gd54xx->extpal[index].b   = val;
                        gd54xx->extpallook[index] = makecol32(video_6to8[gd54xx->extpal[index].r & 0x3f], video_6to8[gd54xx->extpal[index].g & 0x3f], video_6to8[gd54xx->extpal[index].b & 0x3f]);
                        if (svga->ext_overscan && (index == 2)) {
                            o32                  = svga->overscan_color;
                            svga->overscan_color = gd54xx->extpallook[2];
                            if (o32 != svga->overscan_color)
                                svga_recalctimings(svga);
                        }
                    } else {
                        svga->vgapal[index].r = svga->dac_r;
                        svga->vgapal[index].g = svga->dac_g;
                        svga->vgapal[index].b = val;
                        svga->pallook[index]  = makecol32(video_6to8[svga->vgapal[index].r & 0x3f], video_6to8[svga->vgapal[index].g & 0x3f], video_6to8[svga->vgapal[index].b & 0x3f]);
                    }
                    svga->dac_addr = (svga->dac_addr + 1) & 255;
                    svga->dac_pos  = 0;
                    break;

                default:
                    break;
            }
            return;
        case 0x3ce:
            /* Per the CL-GD 5446 manual: bits 0-5 are the GDC register index, bits 6-7 are reserved. */
            svga->gdcaddr = val /* & 0x3f*/;
            return;
        case 0x3cf:
            if ((svga->gdcaddr > 0x1f) && ((svga->crtc[0x27] <= CIRRUS_ID_CLGD5422) || (svga->crtc[0x27] == CIRRUS_ID_CLGD5424)))
                return;

            o = svga->gdcreg[svga->gdcaddr];

            if ((svga->gdcaddr < 2) && !gd54xx->unlocked)
                svga->gdcreg[svga->gdcaddr] = (svga->gdcreg[svga->gdcaddr] & 0xf0) | (val & 0x0f);
            else if ((svga->gdcaddr <= 8) || gd54xx->unlocked)
                svga->gdcreg[svga->gdcaddr] = val;

            if (svga->gdcaddr <= 8) {
                switch (svga->gdcaddr) {
                    case 0:
                        gd543x_mmio_write(0xb8000, val, gd54xx);
                        break;
                    case 1:
                        gd543x_mmio_write(0xb8004, val, gd54xx);
                        break;
                    case 2:
                        svga->colourcompare = val;
                        break;
                    case 4:
                        svga->readplane = val & 3;
                        break;
                    case 5:
                        if (svga->gdcreg[0xb] & 0x04)
                            svga->writemode = val & 7;
                        else
                            svga->writemode = val & 3;
                        svga->readmode    = val & 8;
                        svga->chain2_read = val & 0x10;
                        break;
                    case 6:
                        if ((o ^ val) & 0x0c)
                            gd543x_recalc_mapping(gd54xx);
                        break;
                    case 7:
                        svga->colournocare = val;
                        break;

                    default:
                        break;
                }

                if ((svga->crtc[0x27] == CIRRUS_ID_CLGD5422) || (svga->crtc[0x27] == CIRRUS_ID_CLGD5424))
                    svga->fast = (svga->gdcreg[8] == 0xff && !(svga->gdcreg[3] & 0x18) && !svga->gdcreg[1]) && ((svga->chain4 && svga->packed_chain4) || svga->fb_only) && !(svga->adv_flags & FLAG_ADDR_BY8); /*TODO: needs verification on other Cirrus chips*/
                else
                    svga->fast = (svga->gdcreg[8] == 0xff && !(svga->gdcreg[3] & 0x18) && !svga->gdcreg[1]) && ((svga->chain4 && svga->packed_chain4) || svga->fb_only);
                if (((svga->gdcaddr == 5) && ((val ^ o) & 0x70)) || ((svga->gdcaddr == 6) && ((val ^ o) & 1)))
                    svga_recalctimings(svga);
            } else {
                switch (svga->gdcaddr) {
                    case 0x0b:
                        svga->adv_flags = 0;
                        if (svga->gdcreg[0xb] & 0x01)
                            svga->adv_flags = FLAG_EXTRA_BANKS;
                        if (svga->gdcreg[0xb] & 0x02)
                            svga->adv_flags |= FLAG_ADDR_BY8;
                        if (svga->gdcreg[0xb] & 0x04)
                            svga->adv_flags |= FLAG_EXT_WRITE;
                        if (svga->gdcreg[0xb] & 0x08)
                            svga->adv_flags |= FLAG_LATCH8;
                        if ((svga->gdcreg[0xb] & 0x10) && (svga->adv_flags & FLAG_EXT_WRITE))
                            svga->adv_flags |= FLAG_ADDR_BY16;
                        if (svga->gdcreg[0xb] & 0x04)
                            svga->writemode = svga->gdcreg[5] & 7;
                        else if (o & 0x4) {
                            svga->gdcreg[5] &= ~0x04;
                            svga->writemode = svga->gdcreg[5] & 3;
                            svga->adv_flags &= (FLAG_EXTRA_BANKS | FLAG_ADDR_BY8 | FLAG_LATCH8);
                            if (svga->crtc[0x27] != CIRRUS_ID_CLGD5436) {
                                svga->gdcreg[0] &= 0x0f;
                                gd543x_mmio_write(0xb8000, svga->gdcreg[0], gd54xx);
                                svga->gdcreg[1] &= 0x0f;
                                gd543x_mmio_write(0xb8004, svga->gdcreg[1], gd54xx);
                            }
                            svga->seqregs[2] &= 0x0f;
                        }
                        fallthrough;
                    case 0x09:
                    case 0x0a:
                        gd54xx_recalc_banking(gd54xx);
                        break;

                    case 0x0c:
                        gd54xx->overlay.colorkeycompare = val;
                        gd54xx_update_overlay(gd54xx);
                        break;
                    case 0x0d:
                        gd54xx->overlay.colorkeycomparemask = val;
                        gd54xx_update_overlay(gd54xx);
                        break;

                    case 0x0e:
                        if (svga->crtc[0x27] >= CIRRUS_ID_CLGD5429) {
                            svga->dpms = (val & 0x06) && ((svga->miscout & ((val & 0x06) << 5)) != 0xc0);
                            svga_recalctimings(svga);
                        }
                        break;

                    case 0x10:
                        gd543x_mmio_write(0xb8001, val, gd54xx);
                        break;
                    case 0x11:
                        gd543x_mmio_write(0xb8005, val, gd54xx);
                        break;
                    case 0x12:
                        gd543x_mmio_write(0xb8002, val, gd54xx);
                        break;
                    case 0x13:
                        gd543x_mmio_write(0xb8006, val, gd54xx);
                        break;
                    case 0x14:
                        gd543x_mmio_write(0xb8003, val, gd54xx);
                        break;
                    case 0x15:
                        gd543x_mmio_write(0xb8007, val, gd54xx);
                        break;

                    case 0x20:
                        gd543x_mmio_write(0xb8008, val, gd54xx);
                        break;
                    case 0x21:
                        gd543x_mmio_write(0xb8009, val, gd54xx);
                        break;
                    case 0x22:
                        gd543x_mmio_write(0xb800a, val, gd54xx);
                        break;
                    case 0x23:
                        gd543x_mmio_write(0xb800b, val, gd54xx);
                        break;
                    case 0x24:
                        gd543x_mmio_write(0xb800c, val, gd54xx);
                        break;
                    case 0x25:
                        gd543x_mmio_write(0xb800d, val, gd54xx);
                        break;
                    case 0x26:
                        gd543x_mmio_write(0xb800e, val, gd54xx);
                        break;
                    case 0x27:
                        gd543x_mmio_write(0xb800f, val, gd54xx);
                        break;

                    case 0x28:
                        gd543x_mmio_write(0xb8010, val, gd54xx);
                        break;
                    case 0x29:
                        gd543x_mmio_write(0xb8011, val, gd54xx);
                        break;
                    case 0x2a:
                        gd543x_mmio_write(0xb8012, val, gd54xx);
                        break;

                    case 0x2c:
                        gd543x_mmio_write(0xb8014, val, gd54xx);
                        break;
                    case 0x2d:
                        gd543x_mmio_write(0xb8015, val, gd54xx);
                        break;
                    case 0x2e:
                        gd543x_mmio_write(0xb8016, val, gd54xx);
                        break;

                    case 0x2f:
                        gd543x_mmio_write(0xb8017, val, gd54xx);
                        break;
                    case 0x30:
                        gd543x_mmio_write(0xb8018, val, gd54xx);
                        break;

                    case 0x32:
                        gd543x_mmio_write(0xb801a, val, gd54xx);
                        break;

                    case 0x33:
                        gd543x_mmio_write(0xb801b, val, gd54xx);
                        break;

                    case 0x31:
                        gd543x_mmio_write(0xb8040, val, gd54xx);
                        break;

                    case 0x34:
                        gd543x_mmio_write(0xb801c, val, gd54xx);
                        break;

                    case 0x35:
                        gd543x_mmio_write(0xb801d, val, gd54xx);
                        break;

                    case 0x38:
                        gd543x_mmio_write(0xb8020, val, gd54xx);
                        break;

                    case 0x39:
                        gd543x_mmio_write(0xb8021, val, gd54xx);
                        break;

                    default:
                        break;
                }
            }
            return;

        case 0x3d4:
            svga->crtcreg = val & gd54xx->crtcreg_mask;
            return;
        case 0x3d5:
            if (((svga->crtcreg == 0x19) || (svga->crtcreg == 0x1a) || (svga->crtcreg == 0x1b) || (svga->crtcreg == 0x1d) || (svga->crtcreg == 0x25) || (svga->crtcreg == 0x27)) && !gd54xx->unlocked)
                return;
            if ((svga->crtcreg == 0x25) || (svga->crtcreg == 0x27))
                return;
            if ((svga->crtcreg < 7) && (svga->crtc[0x11] & 0x80))
                return;
            if ((svga->crtcreg == 7) && (svga->crtc[0x11] & 0x80))
                val = (svga->crtc[7] & ~0x10) | (val & 0x10);
            old                       = svga->crtc[svga->crtcreg];
            svga->crtc[svga->crtcreg] = val;

            if (svga->crtcreg == 0x11) {
                if (!(val & 0x10)) {
                    if (gd54xx->vblank_irq > 0)
                        gd54xx->vblank_irq = -1;
                } else if (gd54xx->vblank_irq < 0)
                    gd54xx->vblank_irq = 0;
                gd54xx_update_irqs(gd54xx);
                if ((val & ~0x30) == (old & ~0x30))
                    old = val;
            }

            if (old != val) {
                /* Overlay registers */
                switch (svga->crtcreg) {
                    case 0x1d:
                        if (((old >> 3) & 7) != ((val >> 3) & 7)) {
                            gd54xx->overlay.colorkeymode = (val >> 3) & 7;
                            gd54xx_update_overlay(gd54xx);
                        }
                        break;
                    case 0x31:
                        gd54xx->overlay.hzoom = val == 0 ? 256 : val;
                        gd54xx_update_overlay(gd54xx);
                        break;
                    case 0x32:
                        gd54xx->overlay.vzoom = val == 0 ? 256 : val;
                        gd54xx_update_overlay(gd54xx);
                        break;
                    case 0x33:
                        gd54xx->overlay.r1sz &= ~0xff;
                        gd54xx->overlay.r1sz |= val;
                        gd54xx_update_overlay(gd54xx);
                        break;
                    case 0x34:
                        gd54xx->overlay.r2sz &= ~0xff;
                        gd54xx->overlay.r2sz |= val;
                        gd54xx_update_overlay(gd54xx);
                        break;
                    case 0x35:
                        gd54xx->overlay.r2sdz &= ~0xff;
                        gd54xx->overlay.r2sdz |= val;
                        gd54xx_update_overlay(gd54xx);
                        break;
                    case 0x36:
                        gd54xx->overlay.r1sz &= 0xff;
                        gd54xx->overlay.r1sz |= (val << 8) & 0x300;
                        gd54xx->overlay.r2sz &= 0xff;
                        gd54xx->overlay.r2sz |= (val << 6) & 0x300;
                        gd54xx->overlay.r2sdz &= 0xff;
                        gd54xx->overlay.r2sdz |= (val << 4) & 0x300;
                        gd54xx_update_overlay(gd54xx);
                        break;
                    case 0x37:
                        gd54xx->overlay.wvs &= ~0xff;
                        gd54xx->overlay.wvs |= val;
                        svga->overlay.y = gd54xx->overlay.wvs;
                        break;
                    case 0x38:
                        gd54xx->overlay.wve &= ~0xff;
                        gd54xx->overlay.wve |= val;
                        gd54xx_update_overlay(gd54xx);
                        break;
                    case 0x39:
                        gd54xx->overlay.wvs &= 0xff;
                        gd54xx->overlay.wvs |= (val << 8) & 0x300;
                        gd54xx->overlay.wve &= 0xff;
                        gd54xx->overlay.wve |= (val << 6) & 0x300;
                        gd54xx_update_overlay(gd54xx);
                        break;
                    case 0x3a:
                        svga->overlay.addr &= ~0xff;
                        svga->overlay.addr |= val;
                        gd54xx_update_overlay(gd54xx);
                        break;
                    case 0x3b:
                        svga->overlay.addr &= ~0xff00;
                        svga->overlay.addr |= val << 8;
                        gd54xx_update_overlay(gd54xx);
                        break;
                    case 0x3c:
                        svga->overlay.addr &= ~0x0f0000;
                        svga->overlay.addr |= (val << 16) & 0x0f0000;
                        svga->overlay.pitch &= ~0x100;
                        svga->overlay.pitch |= (val & 0x20) << 3;
                        gd54xx_update_overlay(gd54xx);
                        break;
                    case 0x3d:
                        svga->overlay.pitch &= ~0xff;
                        svga->overlay.pitch |= val;
                        gd54xx_update_overlay(gd54xx);
                        break;
                    case 0x3e:
                        gd54xx->overlay.mode = (val >> 1) & 7;
                        svga->overlay.ena    = (val & 1) != 0;
                        gd54xx_update_overlay(gd54xx);
                        break;

                    default:
                        break;
                }

                if (svga->crtcreg < 0xe || svga->crtcreg > 0x10) {
                    if ((svga->crtcreg == 0xc) || (svga->crtcreg == 0xd)) {
                        svga->fullchange = 3;
                        svga->ma_latch   = ((svga->crtc[0xc] << 8) | svga->crtc[0xd]) + ((svga->crtc[8] & 0x60) >> 5);
                    } else {
                        svga->fullchange = changeframecount;
                        svga_recalctimings(svga);
                    }
                }
            }
            break;

        default:
            break;
    }
    svga_out(addr, val, svga);
}

static uint8_t
gd54xx_in(uint16_t addr, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;

    uint8_t index;
    uint8_t ret = 0xff;

    if (((addr & 0xfff0) == 0x3d0 || (addr & 0xfff0) == 0x3b0) && !(svga->miscout & 1))
        addr ^= 0x60;

    switch (addr) {
        case 0x3c2:
            ret = svga_in(addr, svga);
            ret |= gd54xx->vblank_irq > 0 ? 0x80 : 0x00;
            break;

        case 0x3c4:
            if (svga->seqregs[6] == 0x12) {
                ret = svga->seqaddr;
                if ((ret & 0x1e) == 0x10) {
                    if (ret & 1)
                        ret = ((svga->hwcursor.y & 7) << 5) | 0x11;
                    else
                        ret = ((svga->hwcursor.x & 7) << 5) | 0x10;
                }
            } else
                ret = svga->seqaddr;
            break;

        case 0x3c5:
            if ((svga->seqaddr == 2) && !gd54xx->unlocked)
                ret = svga_in(addr, svga) & 0x0f;
            else if ((svga->seqaddr > 6) && !gd54xx->unlocked)
                ret = 0xff;
            else if (svga->seqaddr > 5) {
                ret = svga->seqregs[svga->seqaddr & 0x3f];
                switch (svga->seqaddr) {
                    case 6:
                        ret = svga->seqregs[6];
                        break;
                    case 0x08:
                        if (gd54xx->i2c) {
                            ret &= 0x7b;
                            if (i2c_gpio_get_scl(gd54xx->i2c))
                                ret |= 0x04;
                            if (i2c_gpio_get_sda(gd54xx->i2c))
                                ret |= 0x80;
                        }
                        break;
                    case 0x0a: /*Scratch Pad 1 (Memory size for 5402/542x)*/
                        ret = svga->seqregs[0x0a] & ~0x1a;
                        if (svga->crtc[0x27] == CIRRUS_ID_CLGD5402) {
                            ret |= 0x01; /*512K of memory*/
                        } else if (svga->crtc[0x27] > CIRRUS_ID_CLGD5402) {
                            switch (gd54xx->vram_size >> 10) {
                                case 512:
                                    ret |= 0x08;
                                    break;
                                case 1024:
                                    ret |= 0x10;
                                    break;
                                case 2048:
                                    ret |= 0x18;
                                    break;

                                default:
                                    break;
                            }
                        }
                        break;
                    case 0x0b:
                    case 0x0c:
                    case 0x0d:
                    case 0x0e:
                        ret = gd54xx->vclk_n[svga->seqaddr - 0x0b];
                        break;
                    case 0x0f: /*DRAM control*/
                        ret = svga->seqregs[0x0f] & ~0x98;
                        switch (gd54xx->vram_size >> 10) {
                            case 512:
                                ret |= 0x08; /*16-bit DRAM data bus width*/
                                break;
                            case 1024:
                                ret |= 0x10; /*32-bit DRAM data bus width for 1M of memory*/
                                break;
                            case 2048:
                                ret |= (gd54xx_is_5434(svga)) ? 0x98 : 0x18; /*32-bit (Pre-5434)/64-bit (5434 and up) DRAM data bus width for 2M of memory*/
                                break;
                            case 4096:
                                ret |= 0x98; /*64-bit (5434 and up) DRAM data bus width for 4M of memory*/
                                break;

                            default:
                                break;
                        }
                        break;
                    case 0x15: /*Scratch Pad 3 (Memory size for 543x)*/
                        ret = svga->seqregs[0x15] & ~0x0f;
                        if (svga->crtc[0x27] >= CIRRUS_ID_CLGD5430) {
                            switch (gd54xx->vram_size >> 20) {
                                case 1:
                                    ret |= 0x02;
                                    break;
                                case 2:
                                    ret |= 0x03;
                                    break;
                                case 4:
                                    ret |= 0x04;
                                    break;

                                default:
                                    break;
                            }
                        }
                        break;
                    case 0x17:
                        ret = svga->seqregs[0x17] & ~(7 << 3);
                        if (svga->crtc[0x27] <= CIRRUS_ID_CLGD5429) {
                            if ((svga->crtc[0x27] == CIRRUS_ID_CLGD5428) || (svga->crtc[0x27] == CIRRUS_ID_CLGD5426)) {
                                if (gd54xx->vlb)
                                    ret |= (CL_GD5428_SYSTEM_BUS_VESA << 3);
                                else if (gd54xx->mca)
                                    ret |= (CL_GD5428_SYSTEM_BUS_MCA << 3);
                                else
                                    ret |= (CL_GD5428_SYSTEM_BUS_ISA << 3);
                            } else {
                                if (gd54xx->vlb)
                                    ret |= (CL_GD5429_SYSTEM_BUS_VESA << 3);
                                else
                                    ret |= (CL_GD5429_SYSTEM_BUS_ISA << 3);
                            }
                        } else {
                            if (gd54xx->pci)
                                ret |= (CL_GD543X_SYSTEM_BUS_PCI << 3);
                            else if (gd54xx->vlb)
                                ret |= (CL_GD543X_SYSTEM_BUS_VESA << 3);
                            else
                                ret |= (CL_GD543X_SYSTEM_BUS_ISA << 3);
                        }
                        break;
                    case 0x18:
                        ret = svga->seqregs[0x18] & 0xfe;
                        break;
                    case 0x1b:
                    case 0x1c:
                    case 0x1d:
                    case 0x1e:
                        ret = gd54xx->vclk_d[svga->seqaddr - 0x1b];
                        break;

                    default:
                        break;
                }
                break;
            } else
                ret = svga_in(addr, svga);
            break;
        case 0x3c6:
            if (!gd54xx->unlocked)
                ret = svga_in(addr, svga);
            else if (gd54xx->ramdac.state == 4) {
                /* CL-GD 5428 does not lock the register when it's read. */
                if (svga->crtc[0x27] != CIRRUS_ID_CLGD5428)
                    gd54xx->ramdac.state = 0;
                ret = gd54xx->ramdac.ctrl;
            } else {
                gd54xx->ramdac.state++;
                if (gd54xx->ramdac.state == 4)
                    ret = gd54xx->ramdac.ctrl;
                else
                    ret = svga_in(addr, svga);
            }
            break;
        case 0x3c7:
        case 0x3c8:
            gd54xx->ramdac.state = 0;
            ret                  = svga_in(addr, svga);
            break;
        case 0x3c9:
            gd54xx->ramdac.state = 0;
            svga->dac_status     = 3;
            index                = (svga->dac_addr - 1) & 0xff;
            if (svga->seqregs[0x12] & 2)
                index &= 0x0f;
            switch (svga->dac_pos) {
                case 0:
                    svga->dac_pos++;
                    if (svga->seqregs[0x12] & 2)
                        ret = gd54xx->extpal[index].r & 0x3f;
                    else
                        ret = svga->vgapal[index].r & 0x3f;
                    break;
                case 1:
                    svga->dac_pos++;
                    if (svga->seqregs[0x12] & 2)
                        ret = gd54xx->extpal[index].g & 0x3f;
                    else
                        ret = svga->vgapal[index].g & 0x3f;
                    break;
                case 2:
                    svga->dac_pos  = 0;
                    svga->dac_addr = (svga->dac_addr + 1) & 255;
                    if (svga->seqregs[0x12] & 2)
                        ret = gd54xx->extpal[index].b & 0x3f;
                    else
                        ret = svga->vgapal[index].b & 0x3f;
                    break;

                default:
                    break;
            }
            break;
        case 0x3ce:
            ret = svga->gdcaddr & 0x3f;
            break;
        case 0x3cf:
            if (svga->gdcaddr >= 0x10) {
                if ((svga->gdcaddr > 8) && !gd54xx->unlocked)
                    ret = 0xff;
                else if ((svga->gdcaddr > 0x1f) && ((svga->crtc[0x27] <= CIRRUS_ID_CLGD5422) || (svga->crtc[0x27] == CIRRUS_ID_CLGD5424)))
                    ret = 0xff;
                else
                    switch (svga->gdcaddr) {
                        case 0x10:
                            ret = gd543x_mmio_read(0xb8001, gd54xx);
                            break;
                        case 0x11:
                            ret = gd543x_mmio_read(0xb8005, gd54xx);
                            break;
                        case 0x12:
                            ret = gd543x_mmio_read(0xb8002, gd54xx);
                            break;
                        case 0x13:
                            ret = gd543x_mmio_read(0xb8006, gd54xx);
                            break;
                        case 0x14:
                            ret = gd543x_mmio_read(0xb8003, gd54xx);
                            break;
                        case 0x15:
                            ret = gd543x_mmio_read(0xb8007, gd54xx);
                            break;

                        case 0x20:
                            ret = gd543x_mmio_read(0xb8008, gd54xx);
                            break;
                        case 0x21:
                            ret = gd543x_mmio_read(0xb8009, gd54xx);
                            break;
                        case 0x22:
                            ret = gd543x_mmio_read(0xb800a, gd54xx);
                            break;
                        case 0x23:
                            ret = gd543x_mmio_read(0xb800b, gd54xx);
                            break;
                        case 0x24:
                            ret = gd543x_mmio_read(0xb800c, gd54xx);
                            break;
                        case 0x25:
                            ret = gd543x_mmio_read(0xb800d, gd54xx);
                            break;
                        case 0x26:
                            ret = gd543x_mmio_read(0xb800e, gd54xx);
                            break;
                        case 0x27:
                            ret = gd543x_mmio_read(0xb800f, gd54xx);
                            break;

                        case 0x28:
                            ret = gd543x_mmio_read(0xb8010, gd54xx);
                            break;
                        case 0x29:
                            ret = gd543x_mmio_read(0xb8011, gd54xx);
                            break;
                        case 0x2a:
                            ret = gd543x_mmio_read(0xb8012, gd54xx);
                            break;

                        case 0x2c:
                            ret = gd543x_mmio_read(0xb8014, gd54xx);
                            break;
                        case 0x2d:
                            ret = gd543x_mmio_read(0xb8015, gd54xx);
                            break;
                        case 0x2e:
                            ret = gd543x_mmio_read(0xb8016, gd54xx);
                            break;

                        case 0x2f:
                            ret = gd543x_mmio_read(0xb8017, gd54xx);
                            break;
                        case 0x30:
                            ret = gd543x_mmio_read(0xb8018, gd54xx);
                            break;

                        case 0x32:
                            ret = gd543x_mmio_read(0xb801a, gd54xx);
                            break;

                        case 0x33:
                            ret = gd543x_mmio_read(0xb801b, gd54xx);
                            break;

                        case 0x31:
                            ret = gd543x_mmio_read(0xb8040, gd54xx);
                            break;

                        case 0x34:
                            ret = gd543x_mmio_read(0xb801c, gd54xx);
                            break;

                        case 0x35:
                            ret = gd543x_mmio_read(0xb801d, gd54xx);
                            break;

                        case 0x38:
                            ret = gd543x_mmio_read(0xb8020, gd54xx);
                            break;

                        case 0x39:
                            ret = gd543x_mmio_read(0xb8021, gd54xx);
                            break;

                        case 0x3f:
                            if (svga->crtc[0x27] == CIRRUS_ID_CLGD5446)
                                gd54xx->vportsync = !gd54xx->vportsync;
                            ret = gd54xx->vportsync ? 0x80 : 0x00;
                            break;

                        default:
                            break;
                    }
            } else {
                if ((svga->gdcaddr < 2) && !gd54xx->unlocked)
                    ret = (svga->gdcreg[svga->gdcaddr] & 0x0f);
                else {
                    if (svga->gdcaddr == 0)
                        ret = gd543x_mmio_read(0xb8000, gd54xx);
                    else if (svga->gdcaddr == 1)
                        ret = gd543x_mmio_read(0xb8004, gd54xx);
                    else
                        ret = svga->gdcreg[svga->gdcaddr];
                }
            }
            break;
        case 0x3d4:
            ret = svga->crtcreg;
            break;
        case 0x3d5:
            ret = svga->crtc[svga->crtcreg];
            if (((svga->crtcreg == 0x19) || (svga->crtcreg == 0x1a) || (svga->crtcreg == 0x1b) || (svga->crtcreg == 0x1d) || (svga->crtcreg == 0x25) || (svga->crtcreg == 0x27)) && !gd54xx->unlocked)
                ret = 0xff;
            else
                switch (svga->crtcreg) {
                    case 0x22: /*Graphics Data Latches Readback Register*/
                        /*Should this be & 7 if 8 byte latch is enabled? */
                        ret = svga->latch.b[svga->gdcreg[4] & 3];
                        break;
                    case 0x24: /*Attribute controller toggle readback (R)*/
                        ret = svga->attrff << 7;
                        break;
                    case 0x26: /*Attribute controller index readback (R)*/
                        ret = svga->attraddr & 0x3f;
                        break;
                    case 0x27:                  /*ID*/
                        ret = svga->crtc[0x27]; /*GD542x/GD543x*/
                        break;
                    case 0x28: /*Class ID*/
                        if ((svga->crtc[0x27] == CIRRUS_ID_CLGD5430) || (svga->crtc[0x27] == CIRRUS_ID_CLGD5440))
                            ret = 0xff; /*Standard CL-GD5430/40*/
                        break;

                    default:
                        break;
                }
            break;
        default:
            ret = svga_in(addr, svga);
            break;
    }

    return ret;
}

static void
gd54xx_recalc_banking(gd54xx_t *gd54xx)
{
    svga_t *svga = &gd54xx->svga;

    if (!gd54xx_is_5422(svga)) {
        svga->extra_banks[0] = (svga->gdcreg[0x09] & 0x7f) << 12;

        if (svga->gdcreg[0x0b] & CIRRUS_BANKING_DUAL)
            svga->extra_banks[1] = (svga->gdcreg[0x0a] & 0x7f) << 12;
        else
            svga->extra_banks[1] = svga->extra_banks[0] + 0x8000;
    } else {
        if ((svga->gdcreg[0x0b] & CIRRUS_BANKING_GRANULARITY_16K) && (svga->crtc[0x27] >= CIRRUS_ID_CLGD5426) && (svga->crtc[0x27] != CIRRUS_ID_CLGD5424))
            svga->extra_banks[0] = svga->gdcreg[0x09] << 14;
        else
            svga->extra_banks[0] = svga->gdcreg[0x09] << 12;

        if (svga->gdcreg[0x0b] & CIRRUS_BANKING_DUAL) {
            if ((svga->gdcreg[0x0b] & CIRRUS_BANKING_GRANULARITY_16K) && (svga->crtc[0x27] >= CIRRUS_ID_CLGD5426) && (svga->crtc[0x27] != CIRRUS_ID_CLGD5424))
                svga->extra_banks[1] = svga->gdcreg[0x0a] << 14;
            else
                svga->extra_banks[1] = svga->gdcreg[0x0a] << 12;
        } else
            svga->extra_banks[1] = svga->extra_banks[0] + 0x8000;
    }

    svga->write_bank = svga->read_bank = svga->extra_banks[0];
}

static void
gd543x_recalc_mapping(gd54xx_t *gd54xx)
{
    svga_t  *svga = &gd54xx->svga;
    uint32_t base;
    uint32_t size;

    if (gd54xx->pci && (!(gd54xx->pci_regs[PCI_REG_COMMAND] & PCI_COMMAND_MEM))) {
        mem_mapping_disable(&svga->mapping);
        mem_mapping_disable(&gd54xx->linear_mapping);
        mem_mapping_disable(&gd54xx->mmio_mapping);
        return;
    }

    gd54xx->mmio_vram_overlap = 0;

    if (!gd54xx_is_5422(svga) || !(svga->seqregs[7] & 0xf0) || !(svga->seqregs[0x07] & 0x01)) {
        mem_mapping_disable(&gd54xx->linear_mapping);
        mem_mapping_disable(&gd54xx->aperture2_mapping);
        switch (svga->gdcreg[6] & 0x0c) {
            case 0x0: /*128k at A0000*/
                mem_mapping_set_addr(&svga->mapping, 0xa0000, 0x20000);
                svga->banked_mask = 0xffff;
                break;
            case 0x4: /*64k at A0000*/
                mem_mapping_set_addr(&svga->mapping, 0xa0000, 0x10000);
                svga->banked_mask = 0xffff;
                break;
            case 0x8: /*32k at B0000*/
                mem_mapping_set_addr(&svga->mapping, 0xb0000, 0x08000);
                svga->banked_mask = 0x7fff;
                break;
            case 0xC: /*32k at B8000*/
                mem_mapping_set_addr(&svga->mapping, 0xb8000, 0x08000);
                svga->banked_mask         = 0x7fff;
                gd54xx->mmio_vram_overlap = 1;
                break;

            default:
                break;
        }

        if ((svga->seqregs[0x17] & CIRRUS_MMIO_ENABLE) && (svga->seqregs[0x07] & 0x01) && (svga->crtc[0x27] >= CIRRUS_ID_CLGD5429)) {
            if (gd54xx->mmio_vram_overlap) {
                mem_mapping_disable(&svga->mapping);
                mem_mapping_set_addr(&gd54xx->mmio_mapping, 0xb8000, 0x08000);
            } else
                mem_mapping_set_addr(&gd54xx->mmio_mapping, 0xb8000, 0x00100);
        } else
            mem_mapping_disable(&gd54xx->mmio_mapping);
    } else {
        if ((svga->crtc[0x27] <= CIRRUS_ID_CLGD5429) || (!gd54xx->pci && !gd54xx->vlb)) {
            if (svga->gdcreg[0x0b] & CIRRUS_BANKING_GRANULARITY_16K) {
                base = (svga->seqregs[7] & 0xf0) << 16;
                size = 1 * 1024 * 1024;
            } else {
                base = (svga->seqregs[7] & 0xe0) << 16;
                size = 2 * 1024 * 1024;
            }
        } else if (gd54xx->pci) {
            base = gd54xx->lfb_base;
#if 0
            if (svga->crtc[0x27] == CIRRUS_ID_CLGD5480)
                size = 32 * 1024 * 1024;
            else
#endif
            if (svga->crtc[0x27] >= CIRRUS_ID_CLGD5436)
                size = 16 * 1024 * 1024;
            else
                size = 4 * 1024 * 1024;
        } else { /*VLB/ISA/MCA*/
            base = 128 * 1024 * 1024;
            if (svga->crtc[0x27] >= CIRRUS_ID_CLGD5436)
                size = 16 * 1024 * 1024;
            else
                size = 4 * 1024 * 1024;
        }

        mem_mapping_disable(&svga->mapping);
        mem_mapping_set_addr(&gd54xx->linear_mapping, base, size);
        if ((svga->seqregs[0x17] & CIRRUS_MMIO_ENABLE) && (svga->crtc[0x27] >= CIRRUS_ID_CLGD5429)) {
            if (svga->seqregs[0x17] & CIRRUS_MMIO_USE_PCIADDR)
                mem_mapping_disable(&gd54xx->mmio_mapping); /* MMIO is handled in the linear read/write functions */
            else
                mem_mapping_set_addr(&gd54xx->mmio_mapping, 0xb8000, 0x00100);
        } else
            mem_mapping_disable(&gd54xx->mmio_mapping);

        if ((svga->crtc[0x27] >= CIRRUS_ID_CLGD5436) && (gd54xx->blt.status & CIRRUS_BLT_APERTURE2) && ((gd54xx->blt.mode & (CIRRUS_BLTMODE_COLOREXPAND | CIRRUS_BLTMODE_MEMSYSSRC)) == (CIRRUS_BLTMODE_COLOREXPAND | CIRRUS_BLTMODE_MEMSYSSRC))) {
            if (svga->crtc[0x27] == CIRRUS_ID_CLGD5480)
                mem_mapping_set_addr(&gd54xx->aperture2_mapping, gd54xx->lfb_base + 16777216, 16777216);
            else
                mem_mapping_set_addr(&gd54xx->aperture2_mapping, 0xbc000, 0x04000);
        } else
            mem_mapping_disable(&gd54xx->aperture2_mapping);
    }
}

static void
gd54xx_recalctimings(svga_t *svga)
{
    const gd54xx_t *gd54xx = (gd54xx_t *) svga->priv;
    uint8_t         clocksel;
    uint8_t         rdmask;
    uint8_t         linedbl = svga->dispend * 9 / 10 >= svga->hdisp;

    svga->rowoffset = (svga->crtc[0x13]) | (((int) (uint32_t) (svga->crtc[0x1b] & 0x10)) << 4);

    svga->interlace = (svga->crtc[0x1a] & 0x01);

    if (!(svga->gdcreg[6] & 1) && !(svga->attrregs[0x10] & 1)) { /*Text mode*/
        svga->interlace = 0;
    }

    svga->map8 = svga->pallook;
    if (svga->seqregs[7] & CIRRUS_SR7_BPP_SVGA) {
        if (linedbl)
            svga->render = svga_render_8bpp_lowres;
        else {
            svga->render = svga_render_8bpp_highres;
            if ((svga->dispend == 512) && !svga->interlace && gd54xx_is_5434(svga))
                svga->hdisp <<= 1;
        }
    } else if (svga->gdcreg[5] & 0x40)
        svga->render = svga_render_8bpp_lowres;

    svga->ma_latch |= ((svga->crtc[0x1b] & 0x01) << 16) | ((svga->crtc[0x1b] & 0xc) << 15);

    svga->bpp = 8;

    if (gd54xx->ramdac.ctrl & 0x80) {
        if (gd54xx->ramdac.ctrl & 0x40) {
            if ((svga->crtc[0x27] >= CIRRUS_ID_CLGD5428) || (svga->crtc[0x27] == CIRRUS_ID_CLGD5426))
                rdmask = 0xf;
            else
                rdmask = 0x7;

            switch (gd54xx->ramdac.ctrl & rdmask) {
                case 0:
                    svga->bpp = 15;
                    if (linedbl) {
                        if (gd54xx->ramdac.ctrl & 0x10)
                            svga->render = svga_render_15bpp_mix_lowres;
                        else
                            svga->render = svga_render_15bpp_lowres;
                    } else {
                        if (gd54xx->ramdac.ctrl & 0x10)
                            svga->render = svga_render_15bpp_mix_highres;
                        else
                            svga->render = svga_render_15bpp_highres;
                    }
                    break;

                case 1:
                    svga->bpp = 16;
                    if (linedbl)
                        svga->render = svga_render_16bpp_lowres;
                    else
                        svga->render = svga_render_16bpp_highres;
                    break;

                case 5:
                    if (gd54xx_is_5434(svga) && (svga->seqregs[7] & CIRRUS_SR7_BPP_32)) {
                        svga->bpp = 32;
                        if (linedbl)
                            svga->render = svga_render_32bpp_lowres;
                        else
                            svga->render = svga_render_32bpp_highres;
                        if (svga->crtc[0x27] < CIRRUS_ID_CLGD5436) {
                            svga->rowoffset *= 2;
                        }
                    } else {
                        svga->bpp = 24;
                        if (linedbl)
                            svga->render = svga_render_24bpp_lowres;
                        else
                            svga->render = svga_render_24bpp_highres;
                    }
                    break;

                case 8:
                    svga->bpp  = 8;
                    svga->map8 = video_8togs;
                    if (linedbl)
                        svga->render = svga_render_8bpp_lowres;
                    else
                        svga->render = svga_render_8bpp_highres;
                    break;

                case 9:
                    svga->bpp  = 8;
                    svga->map8 = video_8to32;
                    if (linedbl)
                        svga->render = svga_render_8bpp_lowres;
                    else
                        svga->render = svga_render_8bpp_highres;
                    break;

                case 0xf:
                    switch (svga->seqregs[7] & CIRRUS_SR7_BPP_MASK) {
                        case CIRRUS_SR7_BPP_32:
                            if (svga->crtc[0x27] >= CIRRUS_ID_CLGD5430) {
                                svga->bpp = 32;
                                if (linedbl)
                                    svga->render = svga_render_32bpp_lowres;
                                else
                                    svga->render = svga_render_32bpp_highres;
                                svga->rowoffset *= 2;
                            }
                            break;

                        case CIRRUS_SR7_BPP_24:
                            svga->bpp = 24;
                            if (linedbl)
                                svga->render = svga_render_24bpp_lowres;
                            else
                                svga->render = svga_render_24bpp_highres;
                            break;

                        case CIRRUS_SR7_BPP_16:
                            if ((svga->crtc[0x27] >= CIRRUS_ID_CLGD5428) || (svga->crtc[0x27] == CIRRUS_ID_CLGD5426)) {
                                svga->bpp = 16;
                                if (linedbl)
                                    svga->render = svga_render_16bpp_lowres;
                                else
                                    svga->render = svga_render_16bpp_highres;
                            }
                            break;

                        case CIRRUS_SR7_BPP_16_DOUBLEVCLK:
                            svga->bpp = 16;
                            if (linedbl)
                                svga->render = svga_render_16bpp_lowres;
                            else
                                svga->render = svga_render_16bpp_highres;
                            break;

                        case CIRRUS_SR7_BPP_8:
                            svga->bpp = 8;
                            if (linedbl)
                                svga->render = svga_render_8bpp_lowres;
                            else
                                svga->render = svga_render_8bpp_highres;
                            break;

                        default:
                            break;
                    }
                    break;

                default:
                    break;
            }
        } else {
            svga->bpp = 15;
            if (linedbl) {
                if (gd54xx->ramdac.ctrl & 0x10)
                    svga->render = svga_render_15bpp_mix_lowres;
                else
                    svga->render = svga_render_15bpp_lowres;
            } else {
                if (gd54xx->ramdac.ctrl & 0x10)
                    svga->render = svga_render_15bpp_mix_highres;
                else
                    svga->render = svga_render_15bpp_highres;
            }
        }
    }

    clocksel = (svga->miscout >> 2) & 3;

    if (!gd54xx->vclk_n[clocksel] || !gd54xx->vclk_d[clocksel])
        svga->clock = (cpuclock * (float) (1ULL << 32)) / ((svga->miscout & 0xc) ? 28322000.0 : 25175000.0);
    else {
        int     n    = gd54xx->vclk_n[clocksel] & 0x7f;
        int     d    = (gd54xx->vclk_d[clocksel] & 0x3e) >> 1;
        uint8_t m    = gd54xx->vclk_d[clocksel] & 0x01 ? 2 : 1;
        float   freq = (14318184.0F * ((float) n / ((float) d * m)));
        if (gd54xx_is_5422(svga)) {
            switch (svga->seqregs[7] & (gd54xx_is_5434(svga) ? 0xe : 6)) {
                case 2:
                    freq /= 2.0F;
                    break;
                case 4:
                    if (!gd54xx_is_5434(svga))
                        freq /= 3.0F;
                    break;

                default:
                    break;
            }
        }
        svga->clock = (cpuclock * (double) (1ULL << 32)) / freq;
    }

    svga->vram_display_mask = (svga->crtc[0x1b] & 2) ? gd54xx->vram_mask : 0x3ffff;

    if (!(svga->gdcreg[6] & 1) && !(svga->attrregs[0x10] & 1)) { /*Text mode*/
        if (svga->seqregs[1] & 8) {
            svga->render = svga_render_text_40;
        } else
            svga->render = svga_render_text_80;
    }
}

static void
gd54xx_hwcursor_draw(svga_t *svga, int displine)
{
    const gd54xx_t *gd54xx = (gd54xx_t *) svga->priv;
    int             comb;
    int             b0;
    int             b1;
    uint8_t         dat[2];
    int             offset  = svga->hwcursor_latch.x - svga->hwcursor_latch.xoff;
    int             pitch   = (svga->hwcursor.cur_xsize == 64) ? 16 : 4;
    uint32_t        bgcol   = gd54xx->extpallook[0x00];
    uint32_t        fgcol   = gd54xx->extpallook[0x0f];
    uint8_t         linedbl = svga->dispend * 9 / 10 >= svga->hdisp;

    offset <<= linedbl;

    if (svga->interlace && svga->hwcursor_oddeven)
        svga->hwcursor_latch.addr += pitch;

    for (int x = 0; x < svga->hwcursor.cur_xsize; x += 8) {
        dat[0] = svga->vram[svga->hwcursor_latch.addr & svga->vram_display_mask];
        if (svga->hwcursor.cur_xsize == 64)
            dat[1] = svga->vram[(svga->hwcursor_latch.addr + 0x08) & svga->vram_display_mask];
        else
            dat[1] = svga->vram[(svga->hwcursor_latch.addr + 0x80) & svga->vram_display_mask];
        for (uint8_t xx = 0; xx < 8; xx++) {
            b0   = (dat[0] >> (7 - xx)) & 1;
            b1   = (dat[1] >> (7 - xx)) & 1;
            comb = (b1 | (b0 << 1));
            if (offset >= svga->hwcursor_latch.x) {
                switch (comb) {
                    case 0:
                        /* The original screen pixel is shown (invisible cursor) */
                        break;
                    case 1:
                        /* The pixel is shown in the cursor background color */
                        (svga->monitor->target_buffer->line[displine])[offset + svga->x_add] = bgcol;
                        break;
                    case 2:
                        /* The pixel is shown as the inverse of the original screen pixel
                           (XOR cursor) */
                        (svga->monitor->target_buffer->line[displine])[offset + svga->x_add] ^= 0xffffff;
                        break;
                    case 3:
                        /* The pixel is shown in the cursor foreground color */
                        (svga->monitor->target_buffer->line[displine])[offset + svga->x_add] = fgcol;
                        break;

                    default:
                        break;
                }
            }

            offset++;
        }
        svga->hwcursor_latch.addr++;
    }

    if (svga->hwcursor.cur_xsize == 64)
        svga->hwcursor_latch.addr += 8;

    if (svga->interlace && !svga->hwcursor_oddeven)
        svga->hwcursor_latch.addr += pitch;
}

static void
gd54xx_rop(gd54xx_t *gd54xx, uint8_t *res, uint8_t *dst, const uint8_t *src)
{
    switch (gd54xx->blt.rop) {
        case 0x00:
            *res = 0x00;
            break;
        case 0x05:
            *res = *src & *dst;
            break;
        case 0x06:
            *res = *dst;
            break;
        case 0x09:
            *res = *src & ~*dst;
            break;
        case 0x0b:
            *res = ~*dst;
            break;
        case 0x0d:
            *res = *src;
            break;
        case 0x0e:
            *res = 0xff;
            break;
        case 0x50:
            *res = ~*src & *dst;
            break;
        case 0x59:
            *res = *src ^ *dst;
            break;
        case 0x6d:
            *res = *src | *dst;
            break;
        case 0x90:
            *res = ~(*src | *dst);
            break;
        case 0x95:
            *res = ~(*src ^ *dst);
            break;
        case 0xad:
            *res = *src | ~*dst;
            break;
        case 0xd0:
            *res = ~*src;
            break;
        case 0xd6:
            *res = ~*src | *dst;
            break;
        case 0xda:
            *res = ~(*src & *dst);
            break;

        default:
            break;
    }
}

static uint8_t
gd54xx_mem_sys_dest_read(gd54xx_t *gd54xx)
{
    uint8_t ret = 0xff;

    if (gd54xx->blt.msd_buf_cnt != 0) {
        ret = gd54xx->blt.msd_buf[gd54xx->blt.msd_buf_pos++];
        gd54xx->blt.msd_buf_cnt--;

        if (gd54xx->blt.msd_buf_cnt == 0) {
            if (gd54xx->countminusone == 1) {
                gd54xx->blt.msd_buf_pos = 0;
                if ((gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND) && !(gd54xx->blt.modeext & CIRRUS_BLTMODEEXT_DWORDGRANULARITY))
                    gd54xx_start_blit(0xff, 8, gd54xx, &gd54xx->svga);
                else
                    gd54xx_start_blit(0xffffffff, 32, gd54xx, &gd54xx->svga);
            } else
                gd54xx_reset_blit(gd54xx); /* End of blit, do no more. */
        }
    }

    return ret;
}

static void
gd54xx_mem_sys_src_write(gd54xx_t *gd54xx, uint8_t val)
{
    gd54xx->blt.sys_src32 &= ~(0xff << (gd54xx->blt.sys_cnt << 3));
    gd54xx->blt.sys_src32 |= (val << (gd54xx->blt.sys_cnt << 3));
    gd54xx->blt.sys_cnt = (gd54xx->blt.sys_cnt + 1) & 3;

    if (gd54xx->blt.sys_cnt == 0) {
        if ((gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND) && !(gd54xx->blt.modeext & CIRRUS_BLTMODEEXT_DWORDGRANULARITY)) {
            for (uint8_t i = 0; i < 32; i += 8)
                gd54xx_start_blit((gd54xx->blt.sys_src32 >> i) & 0xff, 8, gd54xx, &gd54xx->svga);
        } else
            gd54xx_start_blit(gd54xx->blt.sys_src32, 32, gd54xx, &gd54xx->svga);
    }
}

static void
gd54xx_write(uint32_t addr, uint8_t val, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;

    if (gd54xx->countminusone && !gd54xx->blt.ms_is_dest && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
        gd54xx_mem_sys_src_write(gd54xx, val);
        return;
    }

    if ((svga->seqregs[0x07] & 0x01) == 0) {
        svga_write(addr, val, svga);
        return;
    }

    addr = (addr & 0x7fff) + svga->extra_banks[(addr >> 15) & 1];

    svga_write_linear(addr, val, svga);
}

static void
gd54xx_writew(uint32_t addr, uint16_t val, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;

    if (gd54xx->countminusone && !gd54xx->blt.ms_is_dest && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
        gd54xx_write(addr, val, gd54xx);
        gd54xx_write(addr + 1, val >> 8, gd54xx);
        return;
    }

    if ((svga->seqregs[0x07] & 0x01) == 0) {
        svga_writew(addr, val, svga);
        return;
    }

    addr = (addr & 0x7fff) + svga->extra_banks[(addr >> 15) & 1];

    if (svga->writemode < 4)
        svga_writew_linear(addr, val, svga);
    else {
        svga_write_linear(addr, val, svga);
        svga_write_linear(addr + 1, val >> 8, svga);
    }
}

static void
gd54xx_writel(uint32_t addr, uint32_t val, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;

    if (gd54xx->countminusone && !gd54xx->blt.ms_is_dest && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
        gd54xx_write(addr, val, gd54xx);
        gd54xx_write(addr + 1, val >> 8, gd54xx);
        gd54xx_write(addr + 2, val >> 16, gd54xx);
        gd54xx_write(addr + 3, val >> 24, gd54xx);
        return;
    }

    if ((svga->seqregs[0x07] & 0x01) == 0) {
        svga_writel(addr, val, svga);
        return;
    }

    addr = (addr & 0x7fff) + svga->extra_banks[(addr >> 15) & 1];

    if (svga->writemode < 4)
        svga_writel_linear(addr, val, svga);
    else {
        svga_write_linear(addr, val, svga);
        svga_write_linear(addr + 1, val >> 8, svga);
        svga_write_linear(addr + 2, val >> 16, svga);
        svga_write_linear(addr + 3, val >> 24, svga);
    }
}

/* This adds write modes 4 and 5 to SVGA. */
static void
gd54xx_write_modes45(svga_t *svga, uint8_t val, uint32_t addr)
{
    uint32_t i;
    uint32_t j;

    switch (svga->writemode) {
        case 4:
            if (svga->adv_flags & FLAG_ADDR_BY16) {
                addr &= svga->decode_mask;

                for (i = 0; i < 8; i++) {
                    if (val & svga->seqregs[2] & (0x80 >> i)) {
                        svga->vram[addr + (i << 1)]     = svga->gdcreg[1];
                        svga->vram[addr + (i << 1) + 1] = svga->gdcreg[0x11];
                    }
                }
            } else {
                addr <<= 1;
                addr &= svga->decode_mask;

                for (i = 0; i < 8; i++) {
                    if (val & svga->seqregs[2] & (0x80 >> i))
                        svga->vram[addr + i] = svga->gdcreg[1];
                }
            }
            break;

        case 5:
            if (svga->adv_flags & FLAG_ADDR_BY16) {
                addr &= svga->decode_mask;

                for (i = 0; i < 8; i++) {
                    j = (0x80 >> i);
                    if (svga->seqregs[2] & j) {
                        svga->vram[addr + (i << 1)]     = (val & j) ? svga->gdcreg[1] : svga->gdcreg[0];
                        svga->vram[addr + (i << 1) + 1] = (val & j) ? svga->gdcreg[0x11] : svga->gdcreg[0x10];
                    }
                }
            } else {
                addr <<= 1;
                addr &= svga->decode_mask;

                for (i = 0; i < 8; i++) {
                    j = (0x80 >> i);
                    if (svga->seqregs[2] & j)
                        svga->vram[addr + i] = (val & j) ? svga->gdcreg[1] : svga->gdcreg[0];
                }
            }
            break;

        default:
            break;
    }

    svga->changedvram[addr >> 12] = changeframecount;
}

static uint8_t
gd54xx_get_aperture(uint32_t addr)
{
    uint32_t ap = addr >> 22;
    return (uint8_t) (ap & 0x03);
}

static int
gd54xx_aperture2_enabled(gd54xx_t *gd54xx)
{
    const svga_t *svga = &gd54xx->svga;

    if (svga->crtc[0x27] < CIRRUS_ID_CLGD5436)
        return 0;

    if (!(gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND))
        return 0;

    if (!(gd54xx->blt.status & CIRRUS_BLT_APERTURE2))
        return 0;

    return 1;
}

static uint8_t
gd54xx_readb_linear(uint32_t addr, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;

    uint8_t ap = gd54xx_get_aperture(addr);
    addr &= 0x003fffff; /* 4 MB mask */

    if ((svga->seqregs[0x07] & 0x01) == 0)
        return svga_read_linear(addr, svga);

    if ((addr >= (svga->vram_max - 256)) && (addr < svga->vram_max)) {
        if ((svga->seqregs[0x17] & CIRRUS_MMIO_ENABLE) && (svga->seqregs[0x17] & CIRRUS_MMIO_USE_PCIADDR))
            return gd543x_mmio_read(addr & 0x000000ff, gd54xx);
    }

    /* Do mem sys dest reads here if the blitter is neither paused, nor is there a second aperture. */
    if (gd54xx->countminusone && gd54xx->blt.ms_is_dest && !gd54xx_aperture2_enabled(gd54xx) && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED))
        return gd54xx_mem_sys_dest_read(gd54xx);

    switch (ap) {
        default:
        case 0:
            break;
        case 1:
            /* 0 -> 1, 1 -> 0, 2 -> 3, 3 -> 2 */
            addr ^= 0x00000001;
            break;
        case 2:
            /* 0 -> 3, 1 -> 2, 2 -> 1, 3 -> 0 */
            addr ^= 0x00000003;
            break;
        case 3:
            return 0xff;
    }

    return svga_read_linear(addr, svga);
}

static uint16_t
gd54xx_readw_linear(uint32_t addr, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;

    uint8_t  ap = gd54xx_get_aperture(addr);
    uint16_t temp;

    addr &= 0x003fffff; /* 4 MB mask */

    if ((svga->seqregs[0x07] & 0x01) == 0)
        return svga_readw_linear(addr, svga);

    if ((addr >= (svga->vram_max - 256)) && (addr < svga->vram_max)) {
        if ((svga->seqregs[0x17] & CIRRUS_MMIO_ENABLE) && (svga->seqregs[0x17] & CIRRUS_MMIO_USE_PCIADDR)) {
            temp = gd543x_mmio_readw(addr & 0x000000ff, gd54xx);
            return temp;
        }
    }

    /* Do mem sys dest reads here if the blitter is neither paused, nor is there a second aperture. */
    if (gd54xx->countminusone && gd54xx->blt.ms_is_dest && !gd54xx_aperture2_enabled(gd54xx) && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
        temp = gd54xx_readb_linear(addr, priv);
        temp |= gd54xx_readb_linear(addr + 1, priv) << 8;
        return temp;
    }

    switch (ap) {
        default:
        case 0:
            return svga_readw_linear(addr, svga);
        case 2:
            /* 0 -> 3, 1 -> 2, 2 -> 1, 3 -> 0 */
            addr ^= 0x00000002;
            fallthrough;
        case 1:
            temp = svga_readb_linear(addr + 1, svga);
            temp |= (svga_readb_linear(addr, svga) << 8);

            if (svga->fast)
                cycles -= svga->monitor->mon_video_timing_read_w;

            return temp;
        case 3:
            return 0xffff;
    }
}

static uint32_t
gd54xx_readl_linear(uint32_t addr, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;

    uint8_t  ap = gd54xx_get_aperture(addr);
    uint32_t temp;

    addr &= 0x003fffff; /* 4 MB mask */

    if ((svga->seqregs[0x07] & 0x01) == 0)
        return svga_readl_linear(addr, svga);

    if ((addr >= (svga->vram_max - 256)) && (addr < svga->vram_max)) {
        if ((svga->seqregs[0x17] & CIRRUS_MMIO_ENABLE) && (svga->seqregs[0x17] & CIRRUS_MMIO_USE_PCIADDR)) {
            temp = gd543x_mmio_readl(addr & 0x000000ff, gd54xx);
            return temp;
        }
    }

    /* Do mem sys dest reads here if the blitter is neither paused, nor is there a second aperture. */
    if (gd54xx->countminusone && gd54xx->blt.ms_is_dest && !gd54xx_aperture2_enabled(gd54xx) && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
        temp = gd54xx_readb_linear(addr, priv);
        temp |= gd54xx_readb_linear(addr + 1, priv) << 8;
        temp |= gd54xx_readb_linear(addr + 2, priv) << 16;
        temp |= gd54xx_readb_linear(addr + 3, priv) << 24;
        return temp;
    }

    switch (ap) {
        default:
        case 0:
            return svga_readl_linear(addr, svga);
        case 1:
            temp = svga_readb_linear(addr + 1, svga);
            temp |= (svga_readb_linear(addr, svga) << 8);
            temp |= (svga_readb_linear(addr + 3, svga) << 16);
            temp |= (svga_readb_linear(addr + 2, svga) << 24);

            if (svga->fast)
                cycles -= svga->monitor->mon_video_timing_read_l;

            return temp;
        case 2:
            temp = svga_readb_linear(addr + 3, svga);
            temp |= (svga_readb_linear(addr + 2, svga) << 8);
            temp |= (svga_readb_linear(addr + 1, svga) << 16);
            temp |= (svga_readb_linear(addr, svga) << 24);

            if (svga->fast)
                cycles -= svga->monitor->mon_video_timing_read_l;

            return temp;
        case 3:
            return 0xffffffff;
    }
}

static uint8_t
gd5436_aperture2_readb(UNUSED(uint32_t addr), void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;

    if (gd54xx->countminusone && gd54xx->blt.ms_is_dest && gd54xx_aperture2_enabled(gd54xx) && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED))
        return gd54xx_mem_sys_dest_read(gd54xx);

    return 0xff;
}

static uint16_t
gd5436_aperture2_readw(uint32_t addr, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    uint16_t  ret    = 0xffff;

    if (gd54xx->countminusone && gd54xx->blt.ms_is_dest && gd54xx_aperture2_enabled(gd54xx) && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
        ret = gd5436_aperture2_readb(addr, priv);
        ret |= gd5436_aperture2_readb(addr + 1, priv) << 8;
        return ret;
    }

    return ret;
}

static uint32_t
gd5436_aperture2_readl(uint32_t addr, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    uint32_t  ret    = 0xffffffff;

    if (gd54xx->countminusone && gd54xx->blt.ms_is_dest && gd54xx_aperture2_enabled(gd54xx) && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
        ret = gd5436_aperture2_readb(addr, priv);
        ret |= gd5436_aperture2_readb(addr + 1, priv) << 8;
        ret |= gd5436_aperture2_readb(addr + 2, priv) << 16;
        ret |= gd5436_aperture2_readb(addr + 3, priv) << 24;
        return ret;
    }

    return ret;
}

static void
gd5436_aperture2_writeb(UNUSED(uint32_t addr), uint8_t val, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;

    if (gd54xx->countminusone && !gd54xx->blt.ms_is_dest
        && gd54xx_aperture2_enabled(gd54xx) && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED))
        gd54xx_mem_sys_src_write(gd54xx, val);
}

static void
gd5436_aperture2_writew(uint32_t addr, uint16_t val, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;

    if (gd54xx->countminusone && !gd54xx->blt.ms_is_dest
        && gd54xx_aperture2_enabled(gd54xx) && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
        gd5436_aperture2_writeb(addr, val, gd54xx);
        gd5436_aperture2_writeb(addr + 1, val >> 8, gd54xx);
    }
}

static void
gd5436_aperture2_writel(uint32_t addr, uint32_t val, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;

    if (gd54xx->countminusone && !gd54xx->blt.ms_is_dest
        && gd54xx_aperture2_enabled(gd54xx) && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
        gd5436_aperture2_writeb(addr, val, gd54xx);
        gd5436_aperture2_writeb(addr + 1, val >> 8, gd54xx);
        gd5436_aperture2_writeb(addr + 2, val >> 16, gd54xx);
        gd5436_aperture2_writeb(addr + 3, val >> 24, gd54xx);
    }
}

static void
gd54xx_writeb_linear(uint32_t addr, uint8_t val, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;

    uint8_t ap = gd54xx_get_aperture(addr);

    if ((svga->seqregs[0x07] & 0x01) == 0) {
        svga_write_linear(addr, val, svga);
        return;
    }

    addr &= 0x003fffff; /* 4 MB mask */

    if ((addr >= (svga->vram_max - 256)) && (addr < svga->vram_max)) {
        if ((svga->seqregs[0x17] & CIRRUS_MMIO_ENABLE) && (svga->seqregs[0x17] & CIRRUS_MMIO_USE_PCIADDR)) {
            gd543x_mmio_write(addr & 0x000000ff, val, gd54xx);
            return;
        }
    }

    /* Do mem sys src writes here if the blitter is neither paused, nor is there a second aperture. */
    if (gd54xx->countminusone && !gd54xx->blt.ms_is_dest && !gd54xx_aperture2_enabled(gd54xx) && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
        gd54xx_mem_sys_src_write(gd54xx, val);
        return;
    }

    switch (ap) {
        default:
        case 0:
            break;
        case 1:
            /* 0 -> 1, 1 -> 0, 2 -> 3, 3 -> 2 */
            addr ^= 0x00000001;
            break;
        case 2:
            /* 0 -> 3, 1 -> 2, 2 -> 1, 3 -> 0 */
            addr ^= 0x00000003;
            break;
        case 3:
            return;
    }

    svga_write_linear(addr, val, svga);
}

static void
gd54xx_writew_linear(uint32_t addr, uint16_t val, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;

    uint8_t ap = gd54xx_get_aperture(addr);

    if ((svga->seqregs[0x07] & 0x01) == 0) {
        svga_writew_linear(addr, val, svga);
        return;
    }

    addr &= 0x003fffff; /* 4 MB mask */

    if ((addr >= (svga->vram_max - 256)) && (addr < svga->vram_max)) {
        if ((svga->seqregs[0x17] & CIRRUS_MMIO_ENABLE) && (svga->seqregs[0x17] & CIRRUS_MMIO_USE_PCIADDR)) {
            gd543x_mmio_writew(addr & 0x000000ff, val, gd54xx);
            return;
        }
    }

    /* Do mem sys src writes here if the blitter is neither paused, nor is there a second aperture. */
    if (gd54xx->countminusone && !gd54xx->blt.ms_is_dest && !gd54xx_aperture2_enabled(gd54xx) && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
        gd54xx_writeb_linear(addr, val, gd54xx);
        gd54xx_writeb_linear(addr + 1, val >> 8, gd54xx);
        return;
    }

    if (svga->writemode < 4) {
        switch (ap) {
            default:
            case 0:
                svga_writew_linear(addr, val, svga);
                return;
            case 2:
                addr ^= 0x00000002;
            case 1:
                svga_writeb_linear(addr + 1, val & 0xff, svga);
                svga_writeb_linear(addr, val >> 8, svga);

                if (svga->fast)
                    cycles -= svga->monitor->mon_video_timing_write_w;
                return;
            case 3:
                return;
        }
    } else {
        switch (ap) {
            default:
            case 0:
                svga_write_linear(addr, val & 0xff, svga);
                svga_write_linear(addr + 1, val >> 8, svga);
                return;
            case 2:
                addr ^= 0x00000002;
                fallthrough;
            case 1:
                svga_write_linear(addr + 1, val & 0xff, svga);
                svga_write_linear(addr, val >> 8, svga);
                return;
            case 3:
                return;
        }
    }
}

static void
gd54xx_writel_linear(uint32_t addr, uint32_t val, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;

    uint8_t ap = gd54xx_get_aperture(addr);

    if ((svga->seqregs[0x07] & 0x01) == 0) {
        svga_writel_linear(addr, val, svga);
        return;
    }

    addr &= 0x003fffff; /* 4 MB mask */

    if ((addr >= (svga->vram_max - 256)) && (addr < svga->vram_max)) {
        if ((svga->seqregs[0x17] & CIRRUS_MMIO_ENABLE) && (svga->seqregs[0x17] & CIRRUS_MMIO_USE_PCIADDR)) {
            gd543x_mmio_writel(addr & 0x000000ff, val, gd54xx);
            return;
        }
    }

    /* Do mem sys src writes here if the blitter is neither paused, nor is there a second aperture. */
    if (gd54xx->countminusone && !gd54xx->blt.ms_is_dest && !gd54xx_aperture2_enabled(gd54xx) && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
        gd54xx_writeb_linear(addr, val, gd54xx);
        gd54xx_writeb_linear(addr + 1, val >> 8, gd54xx);
        gd54xx_writeb_linear(addr + 2, val >> 16, gd54xx);
        gd54xx_writeb_linear(addr + 3, val >> 24, gd54xx);
        return;
    }

    if (svga->writemode < 4) {
        switch (ap) {
            default:
            case 0:
                svga_writel_linear(addr, val, svga);
                return;
            case 1:
                svga_writeb_linear(addr + 1, val & 0xff, svga);
                svga_writeb_linear(addr, val >> 8, svga);
                svga_writeb_linear(addr + 3, val >> 16, svga);
                svga_writeb_linear(addr + 2, val >> 24, svga);
                return;
            case 2:
                svga_writeb_linear(addr + 3, val & 0xff, svga);
                svga_writeb_linear(addr + 2, val >> 8, svga);
                svga_writeb_linear(addr + 1, val >> 16, svga);
                svga_writeb_linear(addr, val >> 24, svga);
                return;
            case 3:
                return;
        }
    } else {
        switch (ap) {
            default:
            case 0:
                svga_write_linear(addr, val & 0xff, svga);
                svga_write_linear(addr + 1, val >> 8, svga);
                svga_write_linear(addr + 2, val >> 16, svga);
                svga_write_linear(addr + 3, val >> 24, svga);
                return;
            case 1:
                svga_write_linear(addr + 1, val & 0xff, svga);
                svga_write_linear(addr, val >> 8, svga);
                svga_write_linear(addr + 3, val >> 16, svga);
                svga_write_linear(addr + 2, val >> 24, svga);
                return;
            case 2:
                svga_write_linear(addr + 3, val & 0xff, svga);
                svga_write_linear(addr + 2, val >> 8, svga);
                svga_write_linear(addr + 1, val >> 16, svga);
                svga_write_linear(addr, val >> 24, svga);
                return;
            case 3:
                return;
        }
    }
}

static uint8_t
gd54xx_read(uint32_t addr, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;

    if ((svga->seqregs[0x07] & 0x01) == 0)
        return svga_read(addr, svga);

    if (gd54xx->countminusone && gd54xx->blt.ms_is_dest && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED))
        return gd54xx_mem_sys_dest_read(gd54xx);

    addr = (addr & 0x7fff) + svga->extra_banks[(addr >> 15) & 1];
    return svga_read_linear(addr, svga);
}

static uint16_t
gd54xx_readw(uint32_t addr, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;
    uint16_t  ret;

    if ((svga->seqregs[0x07] & 0x01) == 0)
        return svga_readw(addr, svga);

    if (gd54xx->countminusone && gd54xx->blt.ms_is_dest && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
        ret = gd54xx_read(addr, priv);
        ret |= gd54xx_read(addr + 1, priv) << 8;
        return ret;
    }

    addr = (addr & 0x7fff) + svga->extra_banks[(addr >> 15) & 1];
    return svga_readw_linear(addr, svga);
}

static uint32_t
gd54xx_readl(uint32_t addr, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;
    uint32_t  ret;

    if ((svga->seqregs[0x07] & 0x01) == 0)
        return svga_readl(addr, svga);

    if (gd54xx->countminusone && gd54xx->blt.ms_is_dest && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
        ret = gd54xx_read(addr, priv);
        ret |= gd54xx_read(addr + 1, priv) << 8;
        ret |= gd54xx_read(addr + 2, priv) << 16;
        ret |= gd54xx_read(addr + 3, priv) << 24;
        return ret;
    }

    addr = (addr & 0x7fff) + svga->extra_banks[(addr >> 15) & 1];
    return svga_readl_linear(addr, svga);
}

static int
gd543x_do_mmio(svga_t *svga, uint32_t addr)
{
    if (svga->seqregs[0x17] & CIRRUS_MMIO_USE_PCIADDR)
        return 1;
    else
        return ((addr & ~0xff) == 0xb8000);
}

static void
gd543x_mmio_write(uint32_t addr, uint8_t val, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;
    uint8_t   old;

    if (gd543x_do_mmio(svga, addr)) {
        switch (addr & 0xff) {
            case 0x00:
                if (gd54xx_is_5434(svga))
                    gd54xx->blt.bg_col = (gd54xx->blt.bg_col & 0xffffff00) | val;
                else
                    gd54xx->blt.bg_col = (gd54xx->blt.bg_col & 0xff00) | val;
                break;
            case 0x01:
                if (gd54xx_is_5434(svga))
                    gd54xx->blt.bg_col = (gd54xx->blt.bg_col & 0xffff00ff) | (val << 8);
                else
                    gd54xx->blt.bg_col = (gd54xx->blt.bg_col & 0x00ff) | (val << 8);
                break;
            case 0x02:
                if (gd54xx_is_5434(svga))
                    gd54xx->blt.bg_col = (gd54xx->blt.bg_col & 0xff00ffff) | (val << 16);
                break;
            case 0x03:
                if (gd54xx_is_5434(svga))
                    gd54xx->blt.bg_col = (gd54xx->blt.bg_col & 0x00ffffff) | (val << 24);
                break;

            case 0x04:
                if (gd54xx_is_5434(svga))
                    gd54xx->blt.fg_col = (gd54xx->blt.fg_col & 0xffffff00) | val;
                else
                    gd54xx->blt.fg_col = (gd54xx->blt.fg_col & 0xff00) | val;
                break;
            case 0x05:
                if (gd54xx_is_5434(svga))
                    gd54xx->blt.fg_col = (gd54xx->blt.fg_col & 0xffff00ff) | (val << 8);
                else
                    gd54xx->blt.fg_col = (gd54xx->blt.fg_col & 0x00ff) | (val << 8);
                break;
            case 0x06:
                if (gd54xx_is_5434(svga))
                    gd54xx->blt.fg_col = (gd54xx->blt.fg_col & 0xff00ffff) | (val << 16);
                break;
            case 0x07:
                if (gd54xx_is_5434(svga))
                    gd54xx->blt.fg_col = (gd54xx->blt.fg_col & 0x00ffffff) | (val << 24);
                break;

            case 0x08:
                gd54xx->blt.width = (gd54xx->blt.width & 0xff00) | val;
                break;
            case 0x09:
                gd54xx->blt.width = (gd54xx->blt.width & 0x00ff) | (val << 8);
                if (gd54xx_is_5434(svga))
                    gd54xx->blt.width &= 0x1fff;
                else
                    gd54xx->blt.width &= 0x07ff;
                break;
            case 0x0a:
                gd54xx->blt.height = (gd54xx->blt.height & 0xff00) | val;
                break;
            case 0x0b:
                gd54xx->blt.height = (gd54xx->blt.height & 0x00ff) | (val << 8);
                if (svga->crtc[0x27] >= CIRRUS_ID_CLGD5436)
                    gd54xx->blt.height &= 0x07ff;
                else
                    gd54xx->blt.height &= 0x03ff;
                break;
            case 0x0c:
                gd54xx->blt.dst_pitch = (gd54xx->blt.dst_pitch & 0xff00) | val;
                break;
            case 0x0d:
                gd54xx->blt.dst_pitch = (gd54xx->blt.dst_pitch & 0x00ff) | (val << 8);
                gd54xx->blt.dst_pitch &= 0x1fff;
                break;
            case 0x0e:
                gd54xx->blt.src_pitch = (gd54xx->blt.src_pitch & 0xff00) | val;
                break;
            case 0x0f:
                gd54xx->blt.src_pitch = (gd54xx->blt.src_pitch & 0x00ff) | (val << 8);
                gd54xx->blt.src_pitch &= 0x1fff;
                break;

            case 0x10:
                gd54xx->blt.dst_addr = (gd54xx->blt.dst_addr & 0xffff00) | val;
                break;
            case 0x11:
                gd54xx->blt.dst_addr = (gd54xx->blt.dst_addr & 0xff00ff) | (val << 8);
                break;
            case 0x12:
                gd54xx->blt.dst_addr = (gd54xx->blt.dst_addr & 0x00ffff) | (val << 16);
                if (gd54xx_is_5434(svga))
                    gd54xx->blt.dst_addr &= 0x3fffff;
                else
                    gd54xx->blt.dst_addr &= 0x1fffff;

                if ((svga->crtc[0x27] >= CIRRUS_ID_CLGD5436) && (gd54xx->blt.status & CIRRUS_BLT_AUTOSTART) && !(gd54xx->blt.status & CIRRUS_BLT_BUSY)) {
                    gd54xx->blt.status |= CIRRUS_BLT_BUSY;
                    gd54xx_start_blit(0, 0xffffffff, gd54xx, svga);
                }
                break;

            case 0x14:
                gd54xx->blt.src_addr = (gd54xx->blt.src_addr & 0xffff00) | val;
                break;
            case 0x15:
                gd54xx->blt.src_addr = (gd54xx->blt.src_addr & 0xff00ff) | (val << 8);
                break;
            case 0x16:
                gd54xx->blt.src_addr = (gd54xx->blt.src_addr & 0x00ffff) | (val << 16);
                if (gd54xx_is_5434(svga))
                    gd54xx->blt.src_addr &= 0x3fffff;
                else
                    gd54xx->blt.src_addr &= 0x1fffff;
                break;

            case 0x17:
                gd54xx->blt.mask = val;
                break;
            case 0x18:
                gd54xx->blt.mode = val;
                gd543x_recalc_mapping(gd54xx);
                break;

            case 0x1a:
                gd54xx->blt.rop = val;
                break;

            case 0x1b:
                if (svga->crtc[0x27] >= CIRRUS_ID_CLGD5436)
                    gd54xx->blt.modeext = val;
                break;

            case 0x1c:
                gd54xx->blt.trans_col = (gd54xx->blt.trans_col & 0xff00) | val;
                break;
            case 0x1d:
                gd54xx->blt.trans_col = (gd54xx->blt.trans_col & 0x00ff) | (val << 8);
                break;

            case 0x20:
                gd54xx->blt.trans_mask = (gd54xx->blt.trans_mask & 0xff00) | val;
                break;
            case 0x21:
                gd54xx->blt.trans_mask = (gd54xx->blt.trans_mask & 0x00ff) | (val << 8);
                break;

            case 0x40:
                old                = gd54xx->blt.status;
                gd54xx->blt.status = val;
                gd543x_recalc_mapping(gd54xx);
                if (!(old & CIRRUS_BLT_RESET) && (gd54xx->blt.status & CIRRUS_BLT_RESET))
                    gd54xx_reset_blit(gd54xx);
                else if (!(old & CIRRUS_BLT_START) && (gd54xx->blt.status & CIRRUS_BLT_START)) {
                    gd54xx->blt.status |= CIRRUS_BLT_BUSY;
                    gd54xx_start_blit(0, 0xffffffff, gd54xx, svga);
                }
                break;

            default:
                break;
        }
    } else if (gd54xx->mmio_vram_overlap)
        gd54xx_write(addr, val, gd54xx);
}

static void
gd543x_mmio_writeb(uint32_t addr, uint8_t val, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;

    if (!gd543x_do_mmio(svga, addr) && !gd54xx->blt.ms_is_dest && gd54xx->countminusone && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
        gd54xx_mem_sys_src_write(gd54xx, val);
        return;
    }

    gd543x_mmio_write(addr, val, priv);
}

static void
gd543x_mmio_writew(uint32_t addr, uint16_t val, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;

    if (gd543x_do_mmio(svga, addr)) {
        gd543x_mmio_write(addr, val & 0xff, gd54xx);
        gd543x_mmio_write(addr + 1, val >> 8, gd54xx);
    } else if (gd54xx->mmio_vram_overlap) {
        if (gd54xx->countminusone && !gd54xx->blt.ms_is_dest && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
            gd543x_mmio_write(addr, val & 0xff, gd54xx);
            gd543x_mmio_write(addr + 1, val >> 8, gd54xx);
        } else {
            gd54xx_write(addr, val, gd54xx);
            gd54xx_write(addr + 1, val >> 8, gd54xx);
        }
    }
}

static void
gd543x_mmio_writel(uint32_t addr, uint32_t val, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;

    if (gd543x_do_mmio(svga, addr)) {
        gd543x_mmio_write(addr, val & 0xff, gd54xx);
        gd543x_mmio_write(addr + 1, val >> 8, gd54xx);
        gd543x_mmio_write(addr + 2, val >> 16, gd54xx);
        gd543x_mmio_write(addr + 3, val >> 24, gd54xx);
    } else if (gd54xx->mmio_vram_overlap) {
        if (gd54xx->countminusone && !gd54xx->blt.ms_is_dest && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
            gd543x_mmio_write(addr, val & 0xff, gd54xx);
            gd543x_mmio_write(addr + 1, val >> 8, gd54xx);
            gd543x_mmio_write(addr + 2, val >> 16, gd54xx);
            gd543x_mmio_write(addr + 3, val >> 24, gd54xx);
        } else {
            gd54xx_write(addr, val, gd54xx);
            gd54xx_write(addr + 1, val >> 8, gd54xx);
            gd54xx_write(addr + 2, val >> 16, gd54xx);
            gd54xx_write(addr + 3, val >> 24, gd54xx);
        }
    }
}

static uint8_t
gd543x_mmio_read(uint32_t addr, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;
    uint8_t   ret    = 0xff;

    if (gd543x_do_mmio(svga, addr)) {
        switch (addr & 0xff) {
            case 0x00:
                ret = gd54xx->blt.bg_col & 0xff;
                break;
            case 0x01:
                ret = (gd54xx->blt.bg_col >> 8) & 0xff;
                break;
            case 0x02:
                if (gd54xx_is_5434(svga))
                    ret = (gd54xx->blt.bg_col >> 16) & 0xff;
                break;
            case 0x03:
                if (gd54xx_is_5434(svga))
                    ret = (gd54xx->blt.bg_col >> 24) & 0xff;
                break;

            case 0x04:
                ret = gd54xx->blt.fg_col & 0xff;
                break;
            case 0x05:
                ret = (gd54xx->blt.fg_col >> 8) & 0xff;
                break;
            case 0x06:
                if (gd54xx_is_5434(svga))
                    ret = (gd54xx->blt.fg_col >> 16) & 0xff;
                break;
            case 0x07:
                if (gd54xx_is_5434(svga))
                    ret = (gd54xx->blt.fg_col >> 24) & 0xff;
                break;

            case 0x08:
                ret = gd54xx->blt.width & 0xff;
                break;
            case 0x09:
                if (gd54xx_is_5434(svga))
                    ret = (gd54xx->blt.width >> 8) & 0x1f;
                else
                    ret = (gd54xx->blt.width >> 8) & 0x07;
                break;
            case 0x0a:
                ret = gd54xx->blt.height & 0xff;
                break;
            case 0x0b:
                if (svga->crtc[0x27] >= CIRRUS_ID_CLGD5436)
                    ret = (gd54xx->blt.height >> 8) & 0x07;
                else
                    ret = (gd54xx->blt.height >> 8) & 0x03;
                break;
            case 0x0c:
                ret = gd54xx->blt.dst_pitch & 0xff;
                break;
            case 0x0d:
                ret = (gd54xx->blt.dst_pitch >> 8) & 0x1f;
                break;
            case 0x0e:
                ret = gd54xx->blt.src_pitch & 0xff;
                break;
            case 0x0f:
                ret = (gd54xx->blt.src_pitch >> 8) & 0x1f;
                break;

            case 0x10:
                ret = gd54xx->blt.dst_addr & 0xff;
                break;
            case 0x11:
                ret = (gd54xx->blt.dst_addr >> 8) & 0xff;
                break;
            case 0x12:
                if (gd54xx_is_5434(svga))
                    ret = (gd54xx->blt.dst_addr >> 16) & 0x3f;
                else
                    ret = (gd54xx->blt.dst_addr >> 16) & 0x1f;
                break;

            case 0x14:
                ret = gd54xx->blt.src_addr & 0xff;
                break;
            case 0x15:
                ret = (gd54xx->blt.src_addr >> 8) & 0xff;
                break;
            case 0x16:
                if (gd54xx_is_5434(svga))
                    ret = (gd54xx->blt.src_addr >> 16) & 0x3f;
                else
                    ret = (gd54xx->blt.src_addr >> 16) & 0x1f;
                break;

            case 0x17:
                ret = gd54xx->blt.mask;
                break;
            case 0x18:
                ret = gd54xx->blt.mode;
                break;

            case 0x1a:
                ret = gd54xx->blt.rop;
                break;

            case 0x1b:
                if (svga->crtc[0x27] >= CIRRUS_ID_CLGD5436)
                    ret = gd54xx->blt.modeext;
                break;

            case 0x1c:
                ret = gd54xx->blt.trans_col & 0xff;
                break;
            case 0x1d:
                ret = (gd54xx->blt.trans_col >> 8) & 0xff;
                break;

            case 0x20:
                ret = gd54xx->blt.trans_mask & 0xff;
                break;
            case 0x21:
                ret = (gd54xx->blt.trans_mask >> 8) & 0xff;
                break;

            case 0x40:
                ret = gd54xx->blt.status;
                break;

            default:
                break;
        }
    } else if (gd54xx->mmio_vram_overlap)
        ret = gd54xx_read(addr, gd54xx);
    else if (gd54xx->countminusone && gd54xx->blt.ms_is_dest && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
        ret = gd54xx_mem_sys_dest_read(gd54xx);
    }

    return ret;
}

static uint16_t
gd543x_mmio_readw(uint32_t addr, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;
    uint16_t  ret    = 0xffff;

    if (gd543x_do_mmio(svga, addr))
        ret = gd543x_mmio_read(addr, gd54xx) | (gd543x_mmio_read(addr + 1, gd54xx) << 8);
    else if (gd54xx->mmio_vram_overlap)
        ret = gd54xx_read(addr, gd54xx) | (gd54xx_read(addr + 1, gd54xx) << 8);
    else if (gd54xx->countminusone && gd54xx->blt.ms_is_dest && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
        ret = gd543x_mmio_read(addr, priv);
        ret |= gd543x_mmio_read(addr + 1, priv) << 8;
        return ret;
    }

    return ret;
}

static uint32_t
gd543x_mmio_readl(uint32_t addr, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;
    uint32_t  ret    = 0xffffffff;

    if (gd543x_do_mmio(svga, addr))
        ret = gd543x_mmio_read(addr, gd54xx) | (gd543x_mmio_read(addr + 1, gd54xx) << 8) | (gd543x_mmio_read(addr + 2, gd54xx) << 16) | (gd543x_mmio_read(addr + 3, gd54xx) << 24);
    else if (gd54xx->mmio_vram_overlap)
        ret = gd54xx_read(addr, gd54xx) | (gd54xx_read(addr + 1, gd54xx) << 8) | (gd54xx_read(addr + 2, gd54xx) << 16) | (gd54xx_read(addr + 3, gd54xx) << 24);
    else if (gd54xx->countminusone && gd54xx->blt.ms_is_dest && !(gd54xx->blt.status & CIRRUS_BLT_PAUSED)) {
        ret = gd543x_mmio_read(addr, priv);
        ret |= gd543x_mmio_read(addr + 1, priv) << 8;
        ret |= gd543x_mmio_read(addr + 2, priv) << 16;
        ret |= gd543x_mmio_read(addr + 3, priv) << 24;
        return ret;
    }

    return ret;
}

static void
gd5480_vgablt_write(uint32_t addr, uint8_t val, void *priv)
{
    addr &= 0x00000fff;

    if ((addr >= 0x00000100) && (addr < 0x00000200))
        gd543x_mmio_writeb((addr & 0x000000ff) | 0x000b8000, val, priv);
    else if (addr < 0x00000100)
        gd54xx_out(0x03c0 + addr, val, priv);
}

static void
gd5480_vgablt_writew(uint32_t addr, uint16_t val, void *priv)
{
    addr &= 0x00000fff;

    if ((addr >= 0x00000100) && (addr < 0x00000200))
        gd543x_mmio_writew((addr & 0x000000ff) | 0x000b8000, val, priv);
    else if (addr < 0x00000100) {
        gd5480_vgablt_write(addr, val & 0xff, priv);
        gd5480_vgablt_write(addr + 1, val >> 8, priv);
    }
}

static void
gd5480_vgablt_writel(uint32_t addr, uint32_t val, void *priv)
{
    addr &= 0x00000fff;

    if ((addr >= 0x00000100) && (addr < 0x00000200))
        gd543x_mmio_writel((addr & 0x000000ff) | 0x000b8000, val, priv);
    else if (addr < 0x00000100) {
        gd5480_vgablt_writew(addr, val & 0xffff, priv);
        gd5480_vgablt_writew(addr + 2, val >> 16, priv);
    }
}

static uint8_t
gd5480_vgablt_read(uint32_t addr, void *priv)
{
    uint8_t ret = 0xff;

    addr &= 0x00000fff;

    if ((addr >= 0x00000100) && (addr < 0x00000200))
        ret = gd543x_mmio_read((addr & 0x000000ff) | 0x000b8000, priv);
    else if (addr < 0x00000100)
        ret = gd54xx_in(0x03c0 + addr, priv);

    return ret;
}

static uint16_t
gd5480_vgablt_readw(uint32_t addr, void *priv)
{
    uint16_t ret = 0xffff;

    addr &= 0x00000fff;

    if ((addr >= 0x00000100) && (addr < 0x00000200))
        ret = gd543x_mmio_readw((addr & 0x000000ff) | 0x000b8000, priv);
    else if (addr < 0x00000100) {
        ret = gd5480_vgablt_read(addr, priv);
        ret |= (gd5480_vgablt_read(addr + 1, priv) << 8);
    }

    return ret;
}

static uint32_t
gd5480_vgablt_readl(uint32_t addr, void *priv)
{
    uint32_t ret = 0xffffffff;

    addr &= 0x00000fff;

    if ((addr >= 0x00000100) && (addr < 0x00000200))
        ret = gd543x_mmio_readl((addr & 0x000000ff) | 0x000b8000, priv);
    else if (addr < 0x00000100) {
        ret = gd5480_vgablt_readw(addr, priv);
        ret |= (gd5480_vgablt_readw(addr + 2, priv) << 16);
    }

    return ret;
}

static uint8_t
gd54xx_color_expand(gd54xx_t *gd54xx, int mask, int shift)
{
    uint8_t ret;

    if (gd54xx->blt.mode & CIRRUS_BLTMODE_TRANSPARENTCOMP)
        ret = gd54xx->blt.fg_col >> (shift << 3);
    else
        ret = mask ? (gd54xx->blt.fg_col >> (shift << 3)) : (gd54xx->blt.bg_col >> (shift << 3));

    return ret;
}

static int
gd54xx_get_pixel_width(gd54xx_t *gd54xx)
{
    int ret = 1;

    switch (gd54xx->blt.mode & CIRRUS_BLTMODE_PIXELWIDTHMASK) {
        case CIRRUS_BLTMODE_PIXELWIDTH8:
            ret = 1;
            break;
        case CIRRUS_BLTMODE_PIXELWIDTH16:
            ret = 2;
            break;
        case CIRRUS_BLTMODE_PIXELWIDTH24:
            ret = 3;
            break;
        case CIRRUS_BLTMODE_PIXELWIDTH32:
            ret = 4;
            break;

        default:
            break;
    }

    return ret;
}

static void
gd54xx_blit(gd54xx_t *gd54xx, uint8_t mask, uint8_t *dst, uint8_t target, int skip)
{
    int is_transp;
    int is_bgonly;

    /* skip indicates whether or not it is a pixel to be skipped (used for left skip);
       mask indicates transparency or not (only when transparent comparison is enabled):
        color expand: direct pattern bit; 1 = write, 0 = do not write
                      (the other way around in inverse mode);
        normal 8-bpp or 16-bpp: does not match transparent color = write,
                                matches transparent color = do not write */

    /* Make sure to always ignore transparency and skip in case of mem sys dest. */
    is_transp = (gd54xx->blt.mode & CIRRUS_BLTMODE_MEMSYSDEST) ? 0 : (gd54xx->blt.mode & CIRRUS_BLTMODE_TRANSPARENTCOMP);
    is_bgonly = (gd54xx->blt.mode & CIRRUS_BLTMODE_MEMSYSDEST) ? 0 : (gd54xx->blt.modeext & CIRRUS_BLTMODEEXT_BACKGROUNDONLY);
    skip      = (gd54xx->blt.mode & CIRRUS_BLTMODE_MEMSYSDEST) ? 0 : skip;

    if (is_transp) {
        if ((gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND) && (gd54xx->blt.modeext & CIRRUS_BLTMODEEXT_COLOREXPINV))
            mask = !mask;

        /* If mask is 1 and it is not a pixel to be skipped, write it. */
        if (mask && !skip)
            *dst = target;
    } else if ((gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND) && is_bgonly) {
        /* If mask is 1 or it is not a pixel to be skipped, write it.
           (Skip only background pixels.) */
        if (mask || !skip)
            *dst = target;
    } else {
        /* If if it is not a pixel to be skipped, write it. */
        if (!skip)
            *dst = target;
    }
}

static int
gd54xx_transparent_comp(gd54xx_t *gd54xx, uint32_t xx, uint8_t src)
{
    svga_t *svga = &gd54xx->svga;
    int     ret  = 1;

    if ((gd54xx->blt.pixel_width <= 2) && gd54xx_has_transp(svga, 0)) {
        ret = src ^ ((uint8_t *) &(gd54xx->blt.trans_col))[xx];
        if (gd54xx_has_transp(svga, 1))
            ret &= ~(((uint8_t *) &(gd54xx->blt.trans_mask))[xx]);
        ret = !ret;
    }

    return ret;
}

static void
gd54xx_pattern_copy(gd54xx_t *gd54xx)
{
    uint8_t  target;
    uint8_t  src;
    uint8_t *dst;
    int      pattern_y;
    int      pattern_pitch;
    uint32_t bitmask = 0;
    uint32_t pixel;
    uint32_t srca;
    uint32_t srca2;
    uint32_t dsta;
    svga_t  *svga = &gd54xx->svga;

    pattern_pitch = gd54xx->blt.pixel_width << 3;

    if (gd54xx->blt.pixel_width == 3)
        pattern_pitch = 32;

    if (gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND)
        pattern_pitch = 1;

    dsta = gd54xx->blt.dst_addr & svga->vram_mask;
    /* The vertical offset is in the three low-order bits of the Source Address register. */
    pattern_y = gd54xx->blt.src_addr & 0x07;

    /* Mode             Pattern bytes   Pattern line bytes
       ---------------------------------------------------
       Color Expansion    8              1
       8-bpp             64              8
       16-bpp           128             16
       24-bpp           256             32
       32-bpp           256             32
     */

    /* The boundary has to be equal to the size of the pattern. */
    srca = (gd54xx->blt.src_addr & ~0x07) & svga->vram_mask;

    for (uint16_t y = 0; y <= gd54xx->blt.height; y++) {
        /* Go to the correct pattern line. */
        srca2 = srca + (pattern_y * pattern_pitch);
        pixel = 0;
        for (uint16_t x = 0; x <= gd54xx->blt.width; x += gd54xx->blt.pixel_width) {
            if (gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND) {
                if (gd54xx->blt.modeext & CIRRUS_BLTMODEEXT_SOLIDFILL)
                    bitmask = 1;
                else
                    bitmask = svga->vram[srca2 & svga->vram_mask] & (0x80 >> pixel);
            }
            for (int xx = 0; xx < gd54xx->blt.pixel_width; xx++) {
                if (gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND)
                    src = gd54xx_color_expand(gd54xx, bitmask, xx);
                else {
                    src     = svga->vram[(srca2 + (x % (gd54xx->blt.pixel_width << 3)) + xx) & svga->vram_mask];
                    bitmask = gd54xx_transparent_comp(gd54xx, xx, src);
                }
                dst    = &(svga->vram[(dsta + x + xx) & svga->vram_mask]);
                target = *dst;
                gd54xx_rop(gd54xx, &target, &target, &src);
                if (gd54xx->blt.pixel_width == 3)
                    gd54xx_blit(gd54xx, bitmask, dst, target, ((x + xx) < gd54xx->blt.pattern_x));
                else
                    gd54xx_blit(gd54xx, bitmask, dst, target, (x < gd54xx->blt.pattern_x));
            }
            pixel                                                   = (pixel + 1) & 7;
            svga->changedvram[((dsta + x) & svga->vram_mask) >> 12] = changeframecount;
        }
        pattern_y = (pattern_y + 1) & 7;
        dsta += gd54xx->blt.dst_pitch;
    }
}

static void
gd54xx_reset_blit(gd54xx_t *gd54xx)
{
    gd54xx->countminusone = 0;
    gd54xx->blt.status &= ~(CIRRUS_BLT_START | CIRRUS_BLT_BUSY | CIRRUS_BLT_FIFOUSED);
}

/* Each blit is either 1 byte -> 1 byte (non-color expand blit)
   or 1 byte -> 8/16/24/32 bytes (color expand blit). */
static void
gd54xx_mem_sys_src(gd54xx_t *gd54xx, uint32_t cpu_dat, uint32_t count)
{
    uint8_t *dst;
    uint8_t  exp;
    uint8_t  target;
    int      mask_shift;
    uint32_t byte_pos;
    uint32_t bitmask = 0;
    svga_t  *svga = &gd54xx->svga;

    gd54xx->blt.ms_is_dest = 0;

    if (gd54xx->blt.mode & (CIRRUS_BLTMODE_MEMSYSDEST | CIRRUS_BLTMODE_PATTERNCOPY))
        gd54xx_reset_blit(gd54xx);
    else if (count == 0xffffffff) {
        gd54xx->blt.dst_addr_backup = gd54xx->blt.dst_addr;
        gd54xx->blt.src_addr_backup = gd54xx->blt.src_addr;
        gd54xx->blt.x_count = gd54xx->blt.xx_count = 0;
        gd54xx->blt.y_count                        = 0;
        gd54xx->countminusone                      = 1;
        gd54xx->blt.sys_src32                      = 0x00000000;
        gd54xx->blt.sys_cnt                        = 0;
        return;
    } else if (gd54xx->countminusone) {
        if (!(gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND) || (gd54xx->blt.modeext & CIRRUS_BLTMODEEXT_DWORDGRANULARITY)) {
            if (!gd54xx->blt.xx_count && !gd54xx->blt.x_count)
                byte_pos = (((gd54xx->blt.mask >> 5) & 3) << 3);
            else
                byte_pos = 0;
            mask_shift = 31 - byte_pos;
            if (!(gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND))
                cpu_dat >>= byte_pos;
        } else
            mask_shift = 7;

        while (mask_shift > -1) {
            if (gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND) {
                bitmask = (cpu_dat >> mask_shift) & 0x01;
                exp     = gd54xx_color_expand(gd54xx, bitmask, gd54xx->blt.xx_count);
            } else {
                exp     = cpu_dat & 0xff;
                bitmask = gd54xx_transparent_comp(gd54xx, gd54xx->blt.xx_count, exp);
            }

            dst    = &(svga->vram[gd54xx->blt.dst_addr_backup & svga->vram_mask]);
            target = *dst;
            gd54xx_rop(gd54xx, &target, &target, &exp);
            if ((gd54xx->blt.pixel_width == 3) && (gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND))
                gd54xx_blit(gd54xx, bitmask, dst, target, ((gd54xx->blt.x_count + gd54xx->blt.xx_count) < gd54xx->blt.pattern_x));
            else
                gd54xx_blit(gd54xx, bitmask, dst, target, (gd54xx->blt.x_count < gd54xx->blt.pattern_x));

            gd54xx->blt.dst_addr_backup += gd54xx->blt.dir;

            if (gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND)
                gd54xx->blt.xx_count = (gd54xx->blt.xx_count + 1) % gd54xx->blt.pixel_width;

            svga->changedvram[(gd54xx->blt.dst_addr_backup & svga->vram_mask) >> 12] = changeframecount;

            if (!gd54xx->blt.xx_count) {
                /* 1 mask bit = 1 blitted pixel */
                if (gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND)
                    mask_shift--;
                else {
                    cpu_dat >>= 8;
                    mask_shift -= 8;
                }

                if (gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND)
                    gd54xx->blt.x_count = (gd54xx->blt.x_count + gd54xx->blt.pixel_width) % (gd54xx->blt.width + 1);
                else
                    gd54xx->blt.x_count = (gd54xx->blt.x_count + 1) % (gd54xx->blt.width + 1);

                if (!gd54xx->blt.x_count) {
                    gd54xx->blt.y_count = (gd54xx->blt.y_count + 1) % (gd54xx->blt.height + 1);
                    if (gd54xx->blt.y_count)
                        gd54xx->blt.dst_addr_backup = gd54xx->blt.dst_addr + (gd54xx->blt.dst_pitch * gd54xx->blt.y_count * gd54xx->blt.dir);
                    else {
                        /* If we're here, the blit is over, reset. */
                        gd54xx_reset_blit(gd54xx);
                    }
                    /* Stop blitting and request new data if end of line reached. */
                    return;
                }
            }
        }
    }
}

static void
gd54xx_normal_blit(uint32_t count, gd54xx_t *gd54xx, svga_t *svga)
{
    uint8_t  src   = 0;
    uint8_t  dst;
    uint16_t width = gd54xx->blt.width;
    int      x_max = 0;
    int      shift = 0;
    int      mask = 0;
    uint32_t src_addr = gd54xx->blt.src_addr;
    uint32_t dst_addr = gd54xx->blt.dst_addr;

    x_max = gd54xx->blt.pixel_width << 3;

    gd54xx->blt.dst_addr_backup = gd54xx->blt.dst_addr;
    gd54xx->blt.src_addr_backup = gd54xx->blt.src_addr;
    gd54xx->blt.height_internal = gd54xx->blt.height;
    gd54xx->blt.x_count         = 0;
    gd54xx->blt.y_count         = 0;

    while (count) {
        src  = 0;
        mask = 0;

        if (gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND) {
            mask  = svga->vram[src_addr & svga->vram_mask] & (0x80 >> (gd54xx->blt.x_count / gd54xx->blt.pixel_width));
            shift = (gd54xx->blt.x_count % gd54xx->blt.pixel_width);
            src   = gd54xx_color_expand(gd54xx, mask, shift);
        } else {
            src = svga->vram[src_addr & svga->vram_mask];
            src_addr += gd54xx->blt.dir;
            mask = 1;
        }
        count--;

        dst                                                   = svga->vram[dst_addr & svga->vram_mask];
        svga->changedvram[(dst_addr & svga->vram_mask) >> 12] = changeframecount;

        gd54xx_rop(gd54xx, &dst, &dst, (const uint8_t *) &src);

        if ((gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND) && (gd54xx->blt.modeext & CIRRUS_BLTMODEEXT_COLOREXPINV))
            mask = !mask;

        /* This handles 8bpp and 16bpp non-color-expanding transparent comparisons. */
        if ((gd54xx->blt.mode & CIRRUS_BLTMODE_TRANSPARENTCOMP) && !(gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND) && ((gd54xx->blt.mode & CIRRUS_BLTMODE_PIXELWIDTHMASK) <= CIRRUS_BLTMODE_PIXELWIDTH16) && (src != ((gd54xx->blt.trans_mask >> (shift << 3)) & 0xff)))
            mask = 0;

        if (((gd54xx->blt.width - width) >= gd54xx->blt.pattern_x) && !((gd54xx->blt.mode & CIRRUS_BLTMODE_TRANSPARENTCOMP) && !mask)) {
            svga->vram[dst_addr & svga->vram_mask] = dst;
        }

        dst_addr += gd54xx->blt.dir;
        gd54xx->blt.x_count++;

        if (gd54xx->blt.x_count == x_max) {
            gd54xx->blt.x_count = 0;
            if (gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND)
                src_addr++;
        }

        width--;
        if (width == 0xffff) {
            width    = gd54xx->blt.width;
            dst_addr = gd54xx->blt.dst_addr_backup = gd54xx->blt.dst_addr_backup + (gd54xx->blt.dst_pitch * gd54xx->blt.dir);
            gd54xx->blt.y_count                    = (gd54xx->blt.y_count + gd54xx->blt.dir) & 7;

            if (gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND) {
                if (gd54xx->blt.x_count != 0)
                    src_addr++;
            } else
                src_addr = gd54xx->blt.src_addr_backup = gd54xx->blt.src_addr_backup + (gd54xx->blt.src_pitch * gd54xx->blt.dir);

            dst_addr &= svga->vram_mask;
            gd54xx->blt.dst_addr_backup &= svga->vram_mask;
            src_addr &= svga->vram_mask;
            gd54xx->blt.src_addr_backup &= svga->vram_mask;

            gd54xx->blt.x_count = 0;

            gd54xx->blt.height_internal--;
            if (gd54xx->blt.height_internal == 0xffff) {
                gd54xx_reset_blit(gd54xx);
                return;
            }
        }
    }

    /* Count exhausted, stuff still left to blit. */
    gd54xx_reset_blit(gd54xx);
}

static void
gd54xx_mem_sys_dest(uint32_t count, gd54xx_t *gd54xx, svga_t *svga)
{
    gd54xx->blt.ms_is_dest = 1;

    if (gd54xx->blt.mode & CIRRUS_BLTMODE_PATTERNCOPY) {
        fatal("mem sys dest pattern copy not allowed (see 1994 manual)\n");
        gd54xx_reset_blit(gd54xx);
    } else if (gd54xx->blt.mode & CIRRUS_BLTMODE_COLOREXPAND) {
        fatal("mem sys dest color expand not allowed (see 1994 manual)\n");
        gd54xx_reset_blit(gd54xx);
    } else {
        if (count == 0xffffffff) {
            gd54xx->blt.dst_addr_backup = gd54xx->blt.dst_addr;
            gd54xx->blt.msd_buf_cnt     = 0;
            gd54xx->blt.src_addr_backup = gd54xx->blt.src_addr;
            gd54xx->blt.x_count = gd54xx->blt.xx_count = 0;
            gd54xx->blt.y_count                        = 0;
            gd54xx->countminusone                      = 1;
            count                                      = 32;
        }

        gd54xx->blt.msd_buf_pos = 0;

        while (gd54xx->blt.msd_buf_pos < 32) {
            gd54xx->blt.msd_buf[gd54xx->blt.msd_buf_pos & 0x1f] = svga->vram[gd54xx->blt.src_addr_backup & svga->vram_mask];
            gd54xx->blt.src_addr_backup += gd54xx->blt.dir;
            gd54xx->blt.msd_buf_pos++;

            gd54xx->blt.x_count = (gd54xx->blt.x_count + 1) % (gd54xx->blt.width + 1);

            if (!gd54xx->blt.x_count) {
                gd54xx->blt.y_count = (gd54xx->blt.y_count + 1) % (gd54xx->blt.height + 1);

                if (gd54xx->blt.y_count)
                    gd54xx->blt.src_addr_backup = gd54xx->blt.src_addr + (gd54xx->blt.src_pitch * gd54xx->blt.y_count * gd54xx->blt.dir);
                else
                    gd54xx->countminusone = 2; /* Signal end of blit. */
                /* End of line reached, stop and notify regardless of how much we already transferred. */
                goto request_more_data;
            }
        }

        /* End of while. */
request_more_data:
        /* If the byte count we have blitted are not divisible by 4, round them up. */
        if (gd54xx->blt.msd_buf_pos & 3)
            gd54xx->blt.msd_buf_cnt = (gd54xx->blt.msd_buf_pos & ~3) + 4;
        else
            gd54xx->blt.msd_buf_cnt = gd54xx->blt.msd_buf_pos;
        gd54xx->blt.msd_buf_pos = 0;
        return;
    }
}

static void
gd54xx_start_blit(uint32_t cpu_dat, uint32_t count, gd54xx_t *gd54xx, svga_t *svga)
{
    if ((gd54xx->blt.mode & CIRRUS_BLTMODE_BACKWARDS) && !(gd54xx->blt.mode & (CIRRUS_BLTMODE_PATTERNCOPY | CIRRUS_BLTMODE_COLOREXPAND)) && !(gd54xx->blt.mode & CIRRUS_BLTMODE_TRANSPARENTCOMP))
        gd54xx->blt.dir = -1;
    else
        gd54xx->blt.dir = 1;

    gd54xx->blt.pixel_width = gd54xx_get_pixel_width(gd54xx);

    if (gd54xx->blt.mode & (CIRRUS_BLTMODE_PATTERNCOPY | CIRRUS_BLTMODE_COLOREXPAND)) {
        if (gd54xx->blt.pixel_width == 3)
            gd54xx->blt.pattern_x = gd54xx->blt.mask & 0x1f; /* (Mask & 0x1f) bytes. */
        else
            gd54xx->blt.pattern_x = (gd54xx->blt.mask & 0x07) * gd54xx->blt.pixel_width; /* (Mask & 0x07) pixels. */
    } else
        gd54xx->blt.pattern_x = 0; /* No skip in normal blit mode. */

    if (gd54xx->blt.mode & CIRRUS_BLTMODE_MEMSYSSRC)
        gd54xx_mem_sys_src(gd54xx, cpu_dat, count);
    else if (gd54xx->blt.mode & CIRRUS_BLTMODE_MEMSYSDEST)
        gd54xx_mem_sys_dest(count, gd54xx, svga);
    else if (gd54xx->blt.mode & CIRRUS_BLTMODE_PATTERNCOPY) {
        gd54xx_pattern_copy(gd54xx);
        gd54xx_reset_blit(gd54xx);
    } else
        gd54xx_normal_blit(count, gd54xx, svga);
}

static uint8_t
cl_pci_read(UNUSED(int func), int addr, void *priv)
{
    const gd54xx_t *gd54xx = (gd54xx_t *) priv;
    const svga_t   *svga   = &gd54xx->svga;
    uint8_t         ret    = 0x00;

    if ((addr >= 0x30) && (addr <= 0x33) && (!gd54xx->has_bios))
        ret = 0x00;
    else  switch (addr) {
            case 0x00:
                ret = 0x13; /*Cirrus Logic*/
                break;
            case 0x01:
                ret = 0x10;
                break;

            case 0x02:
                ret = svga->crtc[0x27];
                break;
            case 0x03:
                ret = 0x00;
                break;

            case PCI_REG_COMMAND:
                ret = gd54xx->pci_regs[PCI_REG_COMMAND]; /*Respond to IO and memory accesses*/
                break;

            case 0x07:
                ret = 0x02; /*Fast DEVSEL timing*/
                break;

            case 0x08:
                ret = gd54xx->rev; /*Revision ID*/
                break;
            case 0x09:
                ret = 0x00; /*Programming interface*/
                break;

            case 0x0a:
                ret = 0x00; /*Supports VGA interface*/
                break;
            case 0x0b:
                ret = 0x03;
                break;

            case 0x10:
                ret = 0x08; /*Linear frame buffer address*/
                break;
            case 0x11:
                ret = 0x00;
                break;
            case 0x12:
                ret = 0x00;
                break;
            case 0x13:
                ret = gd54xx->lfb_base >> 24;
                if (svga->crtc[0x27] == CIRRUS_ID_CLGD5480)
                    ret &= 0xfe;
                break;

            case 0x14:
                ret = 0x00; /*PCI VGA/BitBLT Register Base Address*/
                break;
            case 0x15:
                ret = (svga->crtc[0x27] == CIRRUS_ID_CLGD5480) ? ((gd54xx->vgablt_base >> 8) & 0xf0) : 0x00;
                break;
            case 0x16:
                ret = (svga->crtc[0x27] == CIRRUS_ID_CLGD5480) ? ((gd54xx->vgablt_base >> 16) & 0xff) : 0x00;
                break;
            case 0x17:
                ret = (svga->crtc[0x27] == CIRRUS_ID_CLGD5480) ? ((gd54xx->vgablt_base >> 24) & 0xff) : 0x00;
                break;

            case 0x30:
                ret = (gd54xx->pci_regs[0x30] & 0x01); /*BIOS ROM address*/
                break;
            case 0x31:
                ret = 0x00;
                break;
            case 0x32:
                ret = gd54xx->pci_regs[0x32];
                break;
            case 0x33:
                ret = gd54xx->pci_regs[0x33];
                break;

            case 0x3c:
                ret = gd54xx->int_line;
                break;
            case 0x3d:
                ret = PCI_INTA;
                break;

            default:
                break;
    }

    return ret;
}

static void
cl_pci_write(UNUSED(int func), int addr, uint8_t val, void *priv)
{
    gd54xx_t     *gd54xx = (gd54xx_t *) priv;
    const svga_t *svga   = &gd54xx->svga;
    uint32_t      byte;

    if ((addr >= 0x30) && (addr <= 0x33) && (!gd54xx->has_bios))
        return;

    switch (addr) {
        case PCI_REG_COMMAND:
            gd54xx->pci_regs[PCI_REG_COMMAND] = val & 0x23;
            mem_mapping_disable(&gd54xx->vgablt_mapping);
            io_removehandler(0x03c0, 0x0020, gd54xx_in, NULL, NULL, gd54xx_out, NULL, NULL, gd54xx);
            if (val & PCI_COMMAND_IO)
                io_sethandler(0x03c0, 0x0020, gd54xx_in, NULL, NULL, gd54xx_out, NULL, NULL, gd54xx);
            if ((val & PCI_COMMAND_MEM) && (gd54xx->vgablt_base != 0x00000000) && (gd54xx->vgablt_base < 0xfff00000))
                mem_mapping_set_addr(&gd54xx->vgablt_mapping, gd54xx->vgablt_base, 0x1000);
            if ((gd54xx->pci_regs[PCI_REG_COMMAND] & PCI_COMMAND_MEM) && (gd54xx->pci_regs[0x30] & 0x01)) {
                uint32_t addr = (gd54xx->pci_regs[0x32] << 16) | (gd54xx->pci_regs[0x33] << 24);
                mem_mapping_set_addr(&gd54xx->bios_rom.mapping, addr, 0x8000);
            } else
                mem_mapping_disable(&gd54xx->bios_rom.mapping);
            gd543x_recalc_mapping(gd54xx);
            break;

        case 0x13:
            /* 5480, like 5446 rev. B, has a 32 MB aperture, with the second set used for
               BitBLT transfers. */
            if (svga->crtc[0x27] == CIRRUS_ID_CLGD5480)
                val &= 0xfe;
            gd54xx->lfb_base = val << 24;
            gd543x_recalc_mapping(gd54xx);
            break;

        case 0x15:
        case 0x16:
        case 0x17:
            if (svga->crtc[0x27] != CIRRUS_ID_CLGD5480)
                return;
            byte = (addr & 3) << 3;
            gd54xx->vgablt_base &= ~(0xff << byte);
            if (addr == 0x15)
                val &= 0xf0;
            gd54xx->vgablt_base |= (val << byte);
            mem_mapping_disable(&gd54xx->vgablt_mapping);
            if ((gd54xx->pci_regs[PCI_REG_COMMAND] & PCI_COMMAND_MEM) && (gd54xx->vgablt_base != 0x00000000) && (gd54xx->vgablt_base < 0xfff00000))
                mem_mapping_set_addr(&gd54xx->vgablt_mapping, gd54xx->vgablt_base, 0x1000);
            break;

        case 0x30:
        case 0x32:
        case 0x33:
            gd54xx->pci_regs[addr] = val;
            if ((gd54xx->pci_regs[PCI_REG_COMMAND] & PCI_COMMAND_MEM) && (gd54xx->pci_regs[0x30] & 0x01)) {
                uint32_t addr = (gd54xx->pci_regs[0x32] << 16) | (gd54xx->pci_regs[0x33] << 24);
                mem_mapping_set_addr(&gd54xx->bios_rom.mapping, addr, 0x8000);
            } else
                mem_mapping_disable(&gd54xx->bios_rom.mapping);
            return;

        case 0x3c:
            gd54xx->int_line = val;
            return;

        default:
            break;
    }
}

static uint8_t
gd5428_mca_read(int port, void *priv)
{
    const gd54xx_t *gd54xx = (gd54xx_t *) priv;

    return gd54xx->pos_regs[port & 7];
}

static void
gd5428_mca_write(int port, uint8_t val, void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;

    if (port < 0x102)
        return;

    gd54xx->pos_regs[port & 7] = val;
    mem_mapping_disable(&gd54xx->bios_rom.mapping);
    if (gd54xx->pos_regs[2] & 0x01)
        mem_mapping_enable(&gd54xx->bios_rom.mapping);
}

static uint8_t
gd5428_mca_feedb(void *priv)
{
    const gd54xx_t *gd54xx = (gd54xx_t *) priv;

    return gd54xx->pos_regs[2] & 0x01;
}

static void
gd54xx_reset(void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;
    svga_t   *svga   = &gd54xx->svga;

    memset(svga->crtc, 0x00, sizeof(svga->crtc));
    memset(svga->seqregs, 0x00, sizeof(svga->seqregs));
    memset(svga->gdcreg, 0x00, sizeof(svga->gdcreg));
    svga->crtc[0]     = 63;
    svga->crtc[6]     = 255;
    svga->dispontime  = 1000ULL << 32;
    svga->dispofftime = 1000ULL << 32;
    svga->bpp         = 8;

    io_removehandler(0x03c0, 0x0020, gd54xx_in, NULL, NULL, gd54xx_out, NULL, NULL, gd54xx);
    io_sethandler(0x03c0, 0x0020, gd54xx_in, NULL, NULL, gd54xx_out, NULL, NULL, gd54xx);

    mem_mapping_disable(&gd54xx->vgablt_mapping);
    if (gd54xx->has_bios && (gd54xx->pci || gd54xx->mca))
        mem_mapping_disable(&gd54xx->bios_rom.mapping);

    memset(gd54xx->pci_regs, 0x00, 256);

    mem_mapping_set_p(&svga->mapping, gd54xx);
    mem_mapping_disable(&gd54xx->mmio_mapping);
    mem_mapping_disable(&gd54xx->linear_mapping);
    mem_mapping_disable(&gd54xx->aperture2_mapping);
    mem_mapping_disable(&gd54xx->vgablt_mapping);

    gd543x_recalc_mapping(gd54xx);
    gd54xx_recalc_banking(gd54xx);

    svga->hwcursor.yoff = svga->hwcursor.xoff = 0;

    if (gd54xx->id >= CIRRUS_ID_CLGD5420) {
        gd54xx->vclk_n[0] = 0x4a;
        gd54xx->vclk_d[0] = 0x2b;
        gd54xx->vclk_n[1] = 0x5b;
        gd54xx->vclk_d[1] = 0x2f;
        gd54xx->vclk_n[2] = 0x45;
        gd54xx->vclk_d[2] = 0x30;
        gd54xx->vclk_n[3] = 0x7e;
        gd54xx->vclk_d[3] = 0x33;
    } else {
        gd54xx->vclk_n[0] = 0x66;
        gd54xx->vclk_d[0] = 0x3b;
        gd54xx->vclk_n[1] = 0x5b;
        gd54xx->vclk_d[1] = 0x2f;
        gd54xx->vclk_n[2] = 0x45;
        gd54xx->vclk_d[2] = 0x2c;
        gd54xx->vclk_n[3] = 0x7e;
        gd54xx->vclk_d[3] = 0x33;
    }

    svga->extra_banks[1] = 0x8000;

    gd54xx->pci_regs[PCI_REG_COMMAND] = 7;

    gd54xx->pci_regs[0x30] = 0x00;
    gd54xx->pci_regs[0x32] = 0x0c;
    gd54xx->pci_regs[0x33] = 0x00;

    svga->crtc[0x27] = gd54xx->id;

    svga->seqregs[6] = 0x0f;
    if (svga->crtc[0x27] >= CIRRUS_ID_CLGD5429)
        gd54xx->unlocked = 1;
    else
        gd54xx->unlocked = 0;
}

static void *
gd54xx_init(const device_t *info)
{
    gd54xx_t   *gd54xx = malloc(sizeof(gd54xx_t));
    svga_t     *svga   = &gd54xx->svga;
    int         id     = info->local & 0xff;
    int         vram;
    const char *romfn  = NULL;
    const char *romfn1 = NULL;
    const char *romfn2 = NULL;

    memset(gd54xx, 0, sizeof(gd54xx_t));

    gd54xx->pci   = !!(info->flags & DEVICE_PCI);
    gd54xx->vlb   = !!(info->flags & DEVICE_VLB);
    gd54xx->mca   = !!(info->flags & DEVICE_MCA);
    gd54xx->bit32 = gd54xx->pci || gd54xx->vlb;

    gd54xx->rev      = 0;
    gd54xx->has_bios = 1;

    gd54xx->id = id;

    switch (id) {
        case CIRRUS_ID_CLGD5401:
            romfn = BIOS_GD5401_PATH;
            break;

        case CIRRUS_ID_CLGD5402:
            if (info->local & 0x200)
                romfn = BIOS_GD5402_ONBOARD_PATH;
            else
                romfn = BIOS_GD5402_PATH;
            break;

        case CIRRUS_ID_CLGD5420:
            romfn = BIOS_GD5420_PATH;
            break;

        case CIRRUS_ID_CLGD5422:
        case CIRRUS_ID_CLGD5424:
            romfn = BIOS_GD5422_PATH;
            break;

        case CIRRUS_ID_CLGD5426:
            if (info->local & 0x200)
                romfn = NULL;
            else {
                if (info->local & 0x100)
                    romfn = BIOS_GD5426_DIAMOND_A1_ISA_PATH;
                else {
                    if (gd54xx->vlb)
                        romfn = BIOS_GD5428_PATH;
                    else if (gd54xx->mca)
                        romfn = BIOS_GD5426_MCA_PATH;
                    else
                        romfn = BIOS_GD5428_ISA_PATH;
                }
            }
            break;

        case CIRRUS_ID_CLGD5428:
            if (info->local & 0x100)
                if (gd54xx->vlb)
                    romfn = BIOS_GD5428_DIAMOND_B1_VLB_PATH;
                else {
                    romfn1 = BIOS_GD5428_BOCA_ISA_PATH_1;
                    romfn2 = BIOS_GD5428_BOCA_ISA_PATH_2;
                }
            else {
                if (gd54xx->vlb)
                    romfn = BIOS_GD5428_PATH;
                else if (gd54xx->mca)
                    romfn = BIOS_GD5428_MCA_PATH;
                else
                    romfn = BIOS_GD5428_ISA_PATH;
            }
            break;

        case CIRRUS_ID_CLGD5429:
            romfn = BIOS_GD5429_PATH;
            break;

        case CIRRUS_ID_CLGD5432:
        case CIRRUS_ID_CLGD5434_4:
            if (info->local & 0x200) {
                romfn            = NULL;
                gd54xx->has_bios = 0;
            }
            break;

        case CIRRUS_ID_CLGD5434:
            if (info->local & 0x200) {
                romfn            = NULL;
                gd54xx->has_bios = 0;
            } else if (gd54xx->vlb) {
                romfn = BIOS_GD5430_ORCHID_VLB_PATH;
            } else {
                if (info->local & 0x100)
                    romfn = BIOS_GD5434_DIAMOND_A3_ISA_PATH;
                else
                    romfn = BIOS_GD5434_PATH;
            }
            break;

        case CIRRUS_ID_CLGD5436:
            romfn = BIOS_GD5436_PATH;
            break;

        case CIRRUS_ID_CLGD5430:
            if (info->local & 0x400) {
                /* CL-GD 5440 */
                gd54xx->rev = 0x47;
                if (info->local & 0x200) {
                    romfn            = NULL;
                    gd54xx->has_bios = 0;
                } else
                    romfn = BIOS_GD5440_PATH;
            } else {
                /* CL-GD 5430 */
                if (info->local & 0x200) {
                    romfn            = NULL;
                    gd54xx->has_bios = 0;
                } else if (gd54xx->pci)
                    romfn = BIOS_GD5430_PATH;
                else if ((gd54xx->vlb) && (info->local & 0x100))
                    romfn = BIOS_GD5430_ORCHID_VLB_PATH;
                else
                    romfn = BIOS_GD5430_DIAMOND_A8_VLB_PATH;
            }
            break;

        case CIRRUS_ID_CLGD5446:
            if (info->local & 0x100)
                romfn = BIOS_GD5446_STB_PATH;
            else
                romfn = BIOS_GD5446_PATH;
            break;

        case CIRRUS_ID_CLGD5480:
            romfn = BIOS_GD5480_PATH;
            break;

        default:
            break;
    }

    if (info->flags & DEVICE_MCA) {
        if (id == CIRRUS_ID_CLGD5428)
            vram              = 1024;
        else
            vram = device_get_config_int("memory");
        gd54xx->vram_size = vram << 10;
    } else {
        if (id <= CIRRUS_ID_CLGD5428) {
            if ((id == CIRRUS_ID_CLGD5426) && (info->local & 0x200))
                vram = 1024;
            else if (id == CIRRUS_ID_CLGD5401)
                vram = 256;
            else if (id == CIRRUS_ID_CLGD5402)
                vram = 512;
            else
                vram = device_get_config_int("memory");
            gd54xx->vram_size = vram << 10;
        } else {
            vram              = device_get_config_int("memory");
            gd54xx->vram_size = vram << 20;
        }
    }
    gd54xx->vram_mask = gd54xx->vram_size - 1;

    if (romfn)
        rom_init(&gd54xx->bios_rom, romfn, 0xc0000, 0x8000, 0x7fff, 0, MEM_MAPPING_EXTERNAL);
    else if (romfn1 && romfn2)
        rom_init_interleaved(&gd54xx->bios_rom, BIOS_GD5428_BOCA_ISA_PATH_1, BIOS_GD5428_BOCA_ISA_PATH_2, 0xc0000,
                             0x8000, 0x7fff, 0, MEM_MAPPING_EXTERNAL);

    if (info->flags & DEVICE_ISA)
        video_inform(VIDEO_FLAG_TYPE_SPECIAL, &timing_gd54xx_isa);
    else if (info->flags & DEVICE_PCI)
        video_inform(VIDEO_FLAG_TYPE_SPECIAL, &timing_gd54xx_pci);
    else
        video_inform(VIDEO_FLAG_TYPE_SPECIAL, &timing_gd54xx_vlb);

    if (id >= CIRRUS_ID_CLGD5426) {
        svga_init(info, &gd54xx->svga, gd54xx, gd54xx->vram_size,
                  gd54xx_recalctimings, gd54xx_in, gd54xx_out,
                  gd54xx_hwcursor_draw, gd54xx_overlay_draw);
    } else {
        svga_init(info, &gd54xx->svga, gd54xx, gd54xx->vram_size,
                  gd54xx_recalctimings, gd54xx_in, gd54xx_out,
                  gd54xx_hwcursor_draw, NULL);
    }
    svga->vblank_start = gd54xx_vblank_start;
    svga->ven_write    = gd54xx_write_modes45;
    if ((vram == 1) || (vram >= 256 && vram <= 1024))
        svga->decode_mask = gd54xx->vram_mask;

    if (gd54xx->bit32) {
        mem_mapping_set_handler(&svga->mapping, gd54xx_read, gd54xx_readw, gd54xx_readl, gd54xx_write, gd54xx_writew, gd54xx_writel);
        mem_mapping_add(&gd54xx->mmio_mapping, 0, 0,
                        gd543x_mmio_read, gd543x_mmio_readw, gd543x_mmio_readl,
                        gd543x_mmio_writeb, gd543x_mmio_writew, gd543x_mmio_writel,
                        NULL, MEM_MAPPING_EXTERNAL, gd54xx);
        mem_mapping_add(&gd54xx->linear_mapping, 0, 0,
                        gd54xx_readb_linear, gd54xx_readw_linear, gd54xx_readl_linear,
                        gd54xx_writeb_linear, gd54xx_writew_linear, gd54xx_writel_linear,
                        NULL, MEM_MAPPING_EXTERNAL, gd54xx);
        mem_mapping_add(&gd54xx->aperture2_mapping, 0, 0,
                        gd5436_aperture2_readb, gd5436_aperture2_readw, gd5436_aperture2_readl,
                        gd5436_aperture2_writeb, gd5436_aperture2_writew, gd5436_aperture2_writel,
                        NULL, MEM_MAPPING_EXTERNAL, gd54xx);
        mem_mapping_add(&gd54xx->vgablt_mapping, 0, 0,
                        gd5480_vgablt_read, gd5480_vgablt_readw, gd5480_vgablt_readl,
                        gd5480_vgablt_write, gd5480_vgablt_writew, gd5480_vgablt_writel,
                        NULL, MEM_MAPPING_EXTERNAL, gd54xx);
    } else {
        mem_mapping_set_handler(&svga->mapping, gd54xx_read, gd54xx_readw, NULL, gd54xx_write, gd54xx_writew, NULL);
        mem_mapping_add(&gd54xx->mmio_mapping, 0, 0,
                        gd543x_mmio_read, gd543x_mmio_readw, NULL,
                        gd543x_mmio_writeb, gd543x_mmio_writew, NULL,
                        NULL, MEM_MAPPING_EXTERNAL, gd54xx);
        mem_mapping_add(&gd54xx->linear_mapping, 0, 0,
                        gd54xx_readb_linear, gd54xx_readw_linear, NULL,
                        gd54xx_writeb_linear, gd54xx_writew_linear, NULL,
                        NULL, MEM_MAPPING_EXTERNAL, gd54xx);
        mem_mapping_add(&gd54xx->aperture2_mapping, 0, 0,
                        gd5436_aperture2_readb, gd5436_aperture2_readw, NULL,
                        gd5436_aperture2_writeb, gd5436_aperture2_writew, NULL,
                        NULL, MEM_MAPPING_EXTERNAL, gd54xx);
        mem_mapping_add(&gd54xx->vgablt_mapping, 0, 0,
                        gd5480_vgablt_read, gd5480_vgablt_readw, NULL,
                        gd5480_vgablt_write, gd5480_vgablt_writew, NULL,
                        NULL, MEM_MAPPING_EXTERNAL, gd54xx);
    }
    io_sethandler(0x03c0, 0x0020, gd54xx_in, NULL, NULL, gd54xx_out, NULL, NULL, gd54xx);

    if (gd54xx->pci && id >= CIRRUS_ID_CLGD5430) {
        if (romfn == NULL)
            pci_add_card(PCI_ADD_VIDEO, cl_pci_read, cl_pci_write, gd54xx, &gd54xx->pci_slot);
        else
            pci_add_card(PCI_ADD_NORMAL, cl_pci_read, cl_pci_write, gd54xx, &gd54xx->pci_slot);
        mem_mapping_disable(&gd54xx->bios_rom.mapping);
    }

    mem_mapping_set_p(&svga->mapping, gd54xx);
    mem_mapping_disable(&gd54xx->mmio_mapping);
    mem_mapping_disable(&gd54xx->linear_mapping);
    mem_mapping_disable(&gd54xx->aperture2_mapping);
    mem_mapping_disable(&gd54xx->vgablt_mapping);

    svga->hwcursor.yoff = svga->hwcursor.xoff = 0;

    if (id >= CIRRUS_ID_CLGD5420) {
        gd54xx->vclk_n[0] = 0x4a;
        gd54xx->vclk_d[0] = 0x2b;
        gd54xx->vclk_n[1] = 0x5b;
        gd54xx->vclk_d[1] = 0x2f;
        gd54xx->vclk_n[2] = 0x45;
        gd54xx->vclk_d[2] = 0x30;
        gd54xx->vclk_n[3] = 0x7e;
        gd54xx->vclk_d[3] = 0x33;
    } else {
        gd54xx->vclk_n[0] = 0x66;
        gd54xx->vclk_d[0] = 0x3b;
        gd54xx->vclk_n[1] = 0x5b;
        gd54xx->vclk_d[1] = 0x2f;
        gd54xx->vclk_n[2] = 0x45;
        gd54xx->vclk_d[2] = 0x2c;
        gd54xx->vclk_n[3] = 0x7e;
        gd54xx->vclk_d[3] = 0x33;
    }

    svga->extra_banks[1] = 0x8000;

    gd54xx->pci_regs[PCI_REG_COMMAND] = 7;

    gd54xx->pci_regs[0x30] = 0x00;
    gd54xx->pci_regs[0x32] = 0x0c;
    gd54xx->pci_regs[0x33] = 0x00;

    svga->crtc[0x27] = id;

    svga->seqregs[6] = 0x0f;

    if (svga->crtc[0x27] >= CIRRUS_ID_CLGD5429)
        gd54xx->unlocked = 1;

    if (gd54xx->mca) {
        gd54xx->pos_regs[0] = svga->crtc[0x27] == CIRRUS_ID_CLGD5426 ? 0x82 : 0x7b;
        gd54xx->pos_regs[1] = svga->crtc[0x27] == CIRRUS_ID_CLGD5426 ? 0x81 : 0x91;
        mem_mapping_disable(&gd54xx->bios_rom.mapping);
        mca_add(gd5428_mca_read, gd5428_mca_write, gd5428_mca_feedb, NULL, gd54xx);
        io_sethandler(0x46e8, 0x0001, gd54xx_in, NULL, NULL, gd54xx_out, NULL, NULL, gd54xx);
    }

    if (gd54xx_is_5434(svga)) {
        gd54xx->i2c = i2c_gpio_init("ddc_cl54xx");
        gd54xx->ddc = ddc_init(i2c_gpio_get_bus(gd54xx->i2c));
    }

    if (svga->crtc[0x27] >= CIRRUS_ID_CLGD5446)
        gd54xx->crtcreg_mask = 0x7f;
    else
        gd54xx->crtcreg_mask = 0x3f;

    gd54xx->overlay.colorkeycompare = 0xff;

    return gd54xx;
}

static int
gd5401_available(void)
{
    return rom_present(BIOS_GD5401_PATH);
}

static int
gd5402_available(void)
{
    return rom_present(BIOS_GD5402_PATH);
}

static int
gd5420_available(void)
{
    return rom_present(BIOS_GD5420_PATH);
}

static int
gd5422_available(void)
{
    return rom_present(BIOS_GD5422_PATH);
}

static int
gd5426_diamond_a1_available(void)
{
    return rom_present(BIOS_GD5426_DIAMOND_A1_ISA_PATH);
}

static int
gd5428_available(void)
{
    return rom_present(BIOS_GD5428_PATH);
}

static int
gd5428_diamond_b1_available(void)
{
    return rom_present(BIOS_GD5428_DIAMOND_B1_VLB_PATH);
}

static int
gd5428_boca_isa_available(void)
{
    return rom_present(BIOS_GD5428_BOCA_ISA_PATH_1) && rom_present(BIOS_GD5428_BOCA_ISA_PATH_2);
}

static int
gd5428_isa_available(void)
{
    return rom_present(BIOS_GD5428_ISA_PATH);
}

static int
gd5426_mca_available(void)
{
    return rom_present(BIOS_GD5426_MCA_PATH);
}

static int
gd5428_mca_available(void)
{
    return rom_present(BIOS_GD5428_MCA_PATH);
}

static int
gd5429_available(void)
{
    return rom_present(BIOS_GD5429_PATH);
}

static int
gd5430_diamond_a8_available(void)
{
    return rom_present(BIOS_GD5430_DIAMOND_A8_VLB_PATH);
}

static int
gd5430_available(void)
{
    return rom_present(BIOS_GD5430_PATH);
}

static int
gd5434_available(void)
{
    return rom_present(BIOS_GD5434_PATH);
}

static int
gd5434_isa_available(void)
{
    return rom_present(BIOS_GD5434_PATH);
}

static int
gd5430_orchid_vlb_available(void)
{
    return rom_present(BIOS_GD5430_ORCHID_VLB_PATH);
}

static int
gd5434_diamond_a3_available(void)
{
    return rom_present(BIOS_GD5434_DIAMOND_A3_ISA_PATH);
}

static int
gd5436_available(void)
{
    return rom_present(BIOS_GD5436_PATH);
}

static int
gd5440_available(void)
{
    return rom_present(BIOS_GD5440_PATH);
}

static int
gd5446_available(void)
{
    return rom_present(BIOS_GD5446_PATH);
}

static int
gd5446_stb_available(void)
{
    return rom_present(BIOS_GD5446_STB_PATH);
}

static int
gd5480_available(void)
{
    return rom_present(BIOS_GD5480_PATH);
}

void
gd54xx_close(void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;

    svga_close(&gd54xx->svga);

    if (gd54xx->i2c) {
        ddc_close(gd54xx->ddc);
        i2c_gpio_close(gd54xx->i2c);
    }

    free(gd54xx);
}

void
gd54xx_speed_changed(void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;

    svga_recalctimings(&gd54xx->svga);
}

void
gd54xx_force_redraw(void *priv)
{
    gd54xx_t *gd54xx = (gd54xx_t *) priv;

    gd54xx->svga.fullchange = gd54xx->svga.monitor->mon_changeframecount;
}

// clang-format off
static const device_config_t gd542x_config[] = {
    {
        .name = "memory",
        .description = "Memory size",
        .type = CONFIG_SELECTION,
        .selection = {
            {
                .description = "512 KB",
                .value = 512
            },
            {
                .description = "1 MB",
                .value = 1024
            },
            {
                .description = ""
            }
        },
        .default_int = 512
    },
    {
        .type = CONFIG_END
    }
};

static const device_config_t gd5426_config[] = {
    {
        .name = "memory",
        .description = "Memory size",
        .type = CONFIG_SELECTION,
        .selection = {
            {
                .description = "512 KB",
                .value = 512
            },
            {
                .description = "1 MB",
                .value = 1024
            },
            {
                .description = "2 MB",
                .value = 2048
            },
            {
                .description = ""
            }
        },
        .default_int = 2048
    },
    {
        .type = CONFIG_END
    }
};

static const device_config_t gd5428_onboard_config[] = {
    {
        .name = "memory",
        .description = "Onboard memory size",
        .type = CONFIG_SELECTION,
        .selection = {
            {
                .description = "512 KB",
                .value = 512
            },
            {
                .description = "1 MB",
                .value = 1024
            },
            {
                .description = "2 MB",
                .value = 2048
            },
            {
                .description = ""
            }
        },
        .default_int = 2048
    },
    {
        .type = CONFIG_END
    }
};

static const device_config_t gd5429_config[] = {
    {
        .name = "memory",
        .description = "Memory size",
        .type = CONFIG_SELECTION,
        .selection = {
            {
                .description = "1 MB",
                .value = 1
            },
            {
                .description = "2 MB",
                .value = 2
            },
            {
                .description = ""
            }
        },
        .default_int = 2
    },
    {
        .type = CONFIG_END
    }
};

static const device_config_t gd5440_onboard_config[] = {
    {
        .name = "memory",
        .description = "Onboard memory size",
        .type = CONFIG_SELECTION,
        .selection = {
            {
                .description = "1 MB",
                .value = 1
            },
            {
                .description = "2 MB",
                .value = 2
            },
            {
                .description = ""
            }
        },
        .default_int = 2
    },
    {
        .type = CONFIG_END
    }
};

static const device_config_t gd5434_config[] = {
    {
        .name = "memory",
        .description = "Memory size",
        .type = CONFIG_SELECTION,
        .selection = {
            {
                .description = "1 MB",
                .value = 1
            },
            {
                .description = "2 MB",
                .value = 2
            },
            {
                .description = "4 MB",
                .value = 4
            },
            {
                .description = ""
            }
        },
        .default_int = 4
    },
    {
        .type = CONFIG_END
    }
};

static const device_config_t gd5434_onboard_config[] = {
    {
        .name = "memory",
        .description = "Onboard memory size",
        .type = CONFIG_SELECTION,
        .selection = {
            {
                .description = "1 MB",
                .value = 1
            },
            {
                .description = "2 MB",
                .value = 2
            },
            {
                .description = "4 MB",
                .value = 4
            },
            {
                .description = ""
            }
        },
        .default_int = 4
    },
    {
        .type = CONFIG_END
    }
};

static const device_config_t gd5480_config[] = {
    {
        .name = "memory",
        .description = "Memory size",
        .type = CONFIG_SELECTION,
        .selection = {
            {
                .description = "2 MB",
                .value = 2
            },
            {
                .description = "4 MB",
                .value = 4
            },
            {
                .description = ""
            }
        },
        .default_int = 4
    },
    {
        .type = -1
    }
};
// clang-format on

const device_t gd5401_isa_device = {
    .name          = "Cirrus Logic GD5401 (ISA) (ACUMOS AVGA1)",
    .internal_name = "cl_gd5401_isa",
    .flags         = DEVICE_ISA,
    .local         = CIRRUS_ID_CLGD5401,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5401_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = NULL,
};

const device_t gd5402_isa_device = {
    .name          = "Cirrus Logic GD5402 (ISA) (ACUMOS AVGA2)",
    .internal_name = "cl_gd5402_isa",
    .flags         = DEVICE_ISA,
    .local         = CIRRUS_ID_CLGD5402,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5402_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = NULL,
};

const device_t gd5402_onboard_device = {
    .name          = "Cirrus Logic GD5402 (ISA) (ACUMOS AVGA2) (On-Board)",
    .internal_name = "cl_gd5402_onboard",
    .flags         = DEVICE_AT | DEVICE_ISA,
    .local         = CIRRUS_ID_CLGD5402 | 0x200,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = NULL },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = NULL,
};

const device_t gd5420_isa_device = {
    .name          = "Cirrus Logic GD5420 (ISA)",
    .internal_name = "cl_gd5420_isa",
    .flags         = DEVICE_AT | DEVICE_ISA,
    .local         = CIRRUS_ID_CLGD5420,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5420_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd542x_config,
};

const device_t gd5422_isa_device = {
    .name          = "Cirrus Logic GD5422 (ISA)",
    .internal_name = "cl_gd5422_isa",
    .flags         = DEVICE_AT | DEVICE_ISA,
    .local         = CIRRUS_ID_CLGD5422,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5422_available }, /* Common BIOS between 5422 and 5424 */
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd542x_config,
};

const device_t gd5424_vlb_device = {
    .name          = "Cirrus Logic GD5424 (VLB)",
    .internal_name = "cl_gd5424_vlb",
    .flags         = DEVICE_VLB,
    .local         = CIRRUS_ID_CLGD5424,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5422_available }, /* Common BIOS between 5422 and 5424 */
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd542x_config,
};

const device_t gd5426_isa_device = {
    .name          = "Cirrus Logic GD5426 (ISA)",
    .internal_name = "cl_gd5426_isa",
    .flags         = DEVICE_AT | DEVICE_ISA,
    .local         = CIRRUS_ID_CLGD5426,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5428_isa_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5426_config
};

/*According to a Diamond bios file listing and vgamuseum*/
const device_t gd5426_diamond_speedstar_pro_a1_isa_device = {
    .name          = "Cirrus Logic GD5426 (ISA) (Diamond SpeedStar Pro Rev. A1)",
    .internal_name = "cl_gd5426_diamond_a1_isa",
    .flags         = DEVICE_AT | DEVICE_ISA,
    .local         = CIRRUS_ID_CLGD5426 | 0x100,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5426_diamond_a1_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5426_config
};

const device_t gd5426_vlb_device = {
    .name          = "Cirrus Logic GD5426 (VLB)",
    .internal_name = "cl_gd5426_vlb",
    .flags         = DEVICE_VLB,
    .local         = CIRRUS_ID_CLGD5426,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5428_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5426_config
};

const device_t gd5426_onboard_device = {
    .name          = "Cirrus Logic GD5426 (VLB) (On-Board)",
    .internal_name = "cl_gd5426_onboard",
    .flags         = DEVICE_VLB,
    .local         = CIRRUS_ID_CLGD5426 | 0x200,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = NULL },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = NULL
};

const device_t gd5428_isa_device = {
    .name          = "Cirrus Logic GD5428 (ISA)",
    .internal_name = "cl_gd5428_isa",
    .flags         = DEVICE_AT | DEVICE_ISA,
    .local         = CIRRUS_ID_CLGD5428,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5428_isa_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5426_config
};

const device_t gd5428_vlb_device = {
    .name          = "Cirrus Logic GD5428 (VLB)",
    .internal_name = "cl_gd5428_vlb",
    .flags         = DEVICE_VLB,
    .local         = CIRRUS_ID_CLGD5428,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5428_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5426_config
};

/*According to a Diamond bios file listing and vgamuseum*/
const device_t gd5428_diamond_speedstar_pro_b1_vlb_device = {
    .name          = "Cirrus Logic GD5428 (VLB) (Diamond SpeedStar Pro Rev. B1)",
    .internal_name = "cl_gd5428_diamond_b1_vlb",
    .flags         = DEVICE_VLB,
    .local         = CIRRUS_ID_CLGD5428 | 0x100,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5428_diamond_b1_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5426_config
};

const device_t gd5428_boca_isa_device = {
    .name          = "Cirrus Logic GD5428 (ISA) (BOCA Research 4610)",
    .internal_name = "cl_gd5428_boca_isa",
    .flags         = DEVICE_AT | DEVICE_ISA,
    .local         = CIRRUS_ID_CLGD5428 | 0x100,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5428_boca_isa_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5426_config
};

const device_t gd5428_mca_device = {
    .name          = "Cirrus Logic GD5428 (MCA) (IBM SVGA Adapter/A)",
    .internal_name = "ibm1mbsvga",
    .flags         = DEVICE_MCA,
    .local         = CIRRUS_ID_CLGD5428,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5428_mca_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = NULL
};

const device_t gd5426_mca_device = {
    .name          = "Cirrus Logic GD5426 (MCA) (Reply Video Adapter)",
    .internal_name = "replymcasvga",
    .flags         = DEVICE_MCA,
    .local         = CIRRUS_ID_CLGD5426,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5426_mca_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5426_config
};

const device_t gd5428_onboard_device = {
    .name          = "Cirrus Logic GD5428 (ISA) (On-Board)",
    .internal_name = "cl_gd5428_onboard",
    .flags         = DEVICE_AT | DEVICE_ISA,
    .local         = CIRRUS_ID_CLGD5428,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5428_isa_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5428_onboard_config
};

const device_t gd5429_isa_device = {
    .name          = "Cirrus Logic GD5429 (ISA)",
    .internal_name = "cl_gd5429_isa",
    .flags         = DEVICE_AT | DEVICE_ISA,
    .local         = CIRRUS_ID_CLGD5429,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5429_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5429_config
};

const device_t gd5429_vlb_device = {
    .name          = "Cirrus Logic GD5429 (VLB)",
    .internal_name = "cl_gd5429_vlb",
    .flags         = DEVICE_VLB,
    .local         = CIRRUS_ID_CLGD5429,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5429_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5429_config
};

/*According to a Diamond bios file listing and vgamuseum*/
const device_t gd5430_diamond_speedstar_pro_se_a8_vlb_device = {
    .name          = "Cirrus Logic GD5430 (VLB) (Diamond SpeedStar Pro SE Rev. A8)",
    .internal_name = "cl_gd5430_vlb_diamond",
    .flags         = DEVICE_VLB,
    .local         = CIRRUS_ID_CLGD5430,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5430_diamond_a8_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5429_config
};

const device_t gd5430_vlb_device = {
    .name          = "Cirrus Logic GD5430",
    .internal_name = "cl_gd5430_vlb",
    .flags         = DEVICE_VLB,
    .local         = CIRRUS_ID_CLGD5430 | 0x100,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5430_orchid_vlb_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5429_config
};

const device_t gd5430_onboard_vlb_device = {
    .name          = "Cirrus Logic GD5430 (On-Board)",
    .internal_name = "cl_gd5430_onboard_vlb",
    .flags         = DEVICE_VLB,
    .local         = CIRRUS_ID_CLGD5430 | 0x200,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = NULL },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5429_config
};

const device_t gd5430_pci_device = {
    .name          = "Cirrus Logic GD5430 (PCI)",
    .internal_name = "cl_gd5430_pci",
    .flags         = DEVICE_PCI,
    .local         = CIRRUS_ID_CLGD5430,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5430_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5429_config
};

const device_t gd5430_onboard_pci_device = {
    .name          = "Cirrus Logic GD5430 (PCI) (On-Board)",
    .internal_name = "cl_gd5430_onboard_pci",
    .flags         = DEVICE_PCI,
    .local         = CIRRUS_ID_CLGD5430 | 0x200,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = NULL },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5429_config
};

const device_t gd5434_isa_device = {
    .name          = "Cirrus Logic GD5434 (ISA)",
    .internal_name = "cl_gd5434_isa",
    .flags         = DEVICE_AT | DEVICE_ISA,
    .local         = CIRRUS_ID_CLGD5434,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5434_isa_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5434_config
};

/*According to a Diamond bios file listing and vgamuseum*/
const device_t gd5434_diamond_speedstar_64_a3_isa_device = {
    .name          = "Cirrus Logic GD5434 (ISA) (Diamond SpeedStar 64 Rev. A3)",
    .internal_name = "cl_gd5434_diamond_a3_isa",
    .flags         = DEVICE_AT | DEVICE_ISA,
    .local         = CIRRUS_ID_CLGD5434 | 0x100,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5434_diamond_a3_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5429_config
};

const device_t gd5434_onboard_pci_device = {
    .name          = "Cirrus Logic GD5434-4 (PCI) (On-Board)",
    .internal_name = "cl_gd5434_onboard_pci",
    .flags         = DEVICE_PCI,
    .local         = CIRRUS_ID_CLGD5434 | 0x200,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = NULL },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5434_onboard_config
};

const device_t gd5434_vlb_device = {
    .name          = "Cirrus Logic GD5434 (VLB)",
    .internal_name = "cl_gd5434_vlb",
    .flags         = DEVICE_VLB,
    .local         = CIRRUS_ID_CLGD5434,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5430_orchid_vlb_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5434_config
};

const device_t gd5434_pci_device = {
    .name          = "Cirrus Logic GD5434 (PCI)",
    .internal_name = "cl_gd5434_pci",
    .flags         = DEVICE_PCI,
    .local         = CIRRUS_ID_CLGD5434,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5434_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5434_config
};

const device_t gd5436_pci_device = {
    .name          = "Cirrus Logic GD5436 (PCI)",
    .internal_name = "cl_gd5436_pci",
    .flags         = DEVICE_PCI,
    .local         = CIRRUS_ID_CLGD5436,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5436_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5434_config
};

const device_t gd5440_onboard_pci_device = {
    .name          = "Cirrus Logic GD5440 (PCI) (On-Board)",
    .internal_name = "cl_gd5440_onboard_pci",
    .flags         = DEVICE_PCI,
    .local         = CIRRUS_ID_CLGD5440 | 0x600,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = NULL },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5440_onboard_config
};

const device_t gd5440_pci_device = {
    .name          = "Cirrus Logic GD5440 (PCI)",
    .internal_name = "cl_gd5440_pci",
    .flags         = DEVICE_PCI,
    .local         = CIRRUS_ID_CLGD5440 | 0x400,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5440_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5429_config
};

const device_t gd5446_pci_device = {
    .name          = "Cirrus Logic GD5446 (PCI)",
    .internal_name = "cl_gd5446_pci",
    .flags         = DEVICE_PCI,
    .local         = CIRRUS_ID_CLGD5446,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5446_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5434_config
};

const device_t gd5446_stb_pci_device = {
    .name          = "Cirrus Logic GD5446 (PCI) (STB Nitro 64V)",
    .internal_name = "cl_gd5446_stb_pci",
    .flags         = DEVICE_PCI,
    .local         = CIRRUS_ID_CLGD5446 | 0x100,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5446_stb_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5434_config
};

const device_t gd5480_pci_device = {
    .name          = "Cirrus Logic GD5480 (PCI)",
    .internal_name = "cl_gd5480_pci",
    .flags         = DEVICE_PCI,
    .local         = CIRRUS_ID_CLGD5480,
    .init          = gd54xx_init,
    .close         = gd54xx_close,
    .reset         = gd54xx_reset,
    { .available = gd5480_available },
    .speed_changed = gd54xx_speed_changed,
    .force_redraw  = gd54xx_force_redraw,
    .config        = gd5480_config
};