Files
86Box/src/chipset/82c100.c
Jasmine Iwanek 998cfe5cc8 Constification
2023-07-25 17:59:24 -04:00

401 lines
11 KiB
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.
*
* Implementation of Chips&Technology's 82C100 chipset.
*
*
*
* Authors: Miran Grca, <mgrca8@gmail.com>
*
* Copyright 2021 Miran Grca.
*/
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <wchar.h>
#define HAVE_STDARG_H
#include <86box/86box.h>
#include <86box/device.h>
#include "cpu.h"
#include "x86.h"
#include <86box/io.h>
#include <86box/mem.h>
#include <86box/nmi.h>
#include <86box/plat_unused.h>
#include <86box/port_92.h>
#include <86box/rom.h>
#include <86box/chipset.h>
typedef struct ems_page_t {
int enabled;
uint32_t virt;
uint32_t phys;
} ems_page_t;
typedef struct ct_82c100_t {
uint8_t index;
uint8_t access;
uint16_t ems_io_base;
uint32_t ems_window_base;
uint8_t ems_page_regs[4];
uint8_t regs[256];
ems_page_t ems_pages[4];
mem_mapping_t ems_mappings[4];
} ct_82c100_t;
#ifdef ENABLE_CT_82C100_LOG
int ct_82c100_do_log = ENABLE_CT_82C100_LOG;
static void
ct_82c100_log(const char *fmt, ...)
{
va_list ap;
if (ct_82c100_do_log) {
va_start(ap, fmt);
pclog_ex(fmt, ap);
va_end(ap);
}
}
#else
# define ct_82c100_log(fmt, ...)
#endif
static void
ct_82c100_ems_pages_recalc(ct_82c100_t *dev)
{
uint32_t page_base;
for (uint8_t i = 0; i < 4; i++) {
page_base = dev->ems_window_base + (i << 14);
if ((i == 1) || (i == 2))
page_base ^= 0xc000;
if (dev->ems_page_regs[i] & 0x80) {
dev->ems_pages[i].virt = page_base;
dev->ems_pages[i].phys = 0xa0000 + (((uint32_t) (dev->ems_page_regs[i] & 0x7f)) << 14);
ct_82c100_log("Enabling EMS page %i: %08X-%08X -> %08X-%08X\n", i,
dev->ems_pages[i].virt, dev->ems_pages[i].virt + 0x00003fff,
dev->ems_pages[i].phys, dev->ems_pages[i].phys + 0x00003fff);
mem_mapping_set_addr(&(dev->ems_mappings[i]), dev->ems_pages[i].virt, 0x4000);
mem_mapping_set_exec(&(dev->ems_mappings[i]), &(ram[dev->ems_pages[i].phys]));
mem_set_mem_state_both(page_base, 0x00004000, MEM_READ_INTERNAL | MEM_WRITE_INTERNAL);
} else {
ct_82c100_log("Disabling EMS page %i\n", i);
mem_mapping_disable(&(dev->ems_mappings[i]));
mem_set_mem_state_both(page_base, 0x00004000, MEM_READ_EXTANY | MEM_WRITE_EXTANY);
}
}
flushmmucache_nopc();
}
static void
ct_82c100_ems_out(uint16_t port, uint8_t val, void *priv)
{
ct_82c100_t *dev = (ct_82c100_t *) priv;
ct_82c100_log("[%04X] dev->ems_page_regs[%i] = %02X\n", port, port >> 14, val);
dev->ems_page_regs[port >> 14] = val;
ct_82c100_ems_pages_recalc(dev);
}
static uint8_t
ct_82c100_ems_in(uint16_t port, void *priv)
{
const ct_82c100_t *dev = (ct_82c100_t *) priv;
uint8_t ret = 0xff;
ret = dev->ems_page_regs[port >> 14];
return ret;
}
static void
ct_82c100_ems_update(ct_82c100_t *dev)
{
for (uint8_t i = 0; i < 4; i++) {
ct_82c100_log("Disabling EMS I/O handler %i at %04X\n", i, dev->ems_io_base + (i << 14));
io_handler(0, dev->ems_io_base + (i << 14), 1,
ct_82c100_ems_in, NULL, NULL, ct_82c100_ems_out, NULL, NULL, dev);
}
dev->ems_io_base = 0x0208 + (dev->regs[0x4c] & 0xf0);
for (uint8_t i = 0; i < 4; i++) {
ct_82c100_log("Enabling EMS I/O handler %i at %04X\n", i, dev->ems_io_base + (i << 14));
io_handler(1, dev->ems_io_base + (i << 14), 1,
ct_82c100_ems_in, NULL, NULL, ct_82c100_ems_out, NULL, NULL, dev);
}
dev->ems_window_base = 0xc0000 + (((uint32_t) (dev->regs[0x4c] & 0x0f)) << 14);
ct_82c100_ems_pages_recalc(dev);
}
static void
ct_82c100_reset(void *priv)
{
ct_82c100_t *dev = (ct_82c100_t *) priv;
ct_82c100_log("Reset\n");
memset(dev->regs, 0x00, sizeof(dev->regs));
memset(dev->ems_page_regs, 0x00, sizeof(dev->ems_page_regs));
dev->index = dev->access = 0x00;
/* INTERNAL CONFIGURATION/CONTROL REGISTERS */
dev->regs[0x40] = 0x01; /* Defaults to 8086/V30 mode. */
dev->regs[0x43] = 0x30;
dev->regs[0x48] = 0x01;
use_custom_nmi_vector = 0;
ct_82c100_ems_update(dev);
/* ADDITIONAL I/O REGISTERS */
}
static void
ct_82c100_out(uint16_t port, uint8_t val, void *priv)
{
ct_82c100_t *dev = (ct_82c100_t *) priv;
if (port == 0x0022) {
dev->index = val;
dev->access = 1;
} else if (port == 0x0023) {
if (dev->access) {
switch (dev->index) {
/* INTERNAL CONFIGURATION/CONTROL REGISTERS */
case 0x40:
dev->regs[0x40] = val & 0xc7;
/* TODO: Clock stuff - needs CPU speed change functionality that's
going to be implemented in 86box v4.0.
Bit 0 is 0 for 8088/V20 and 1 for 8086/V30. */
break;
case 0x41:
dev->regs[0x41] = val & 0xed;
/* TODO: Where is the Software Reset Function that's enabled by
setting bit 6 to 1? */
break;
case 0x42:
dev->regs[0x42] = val & 0x01;
break;
case 0x43:
dev->regs[0x43] = val;
break;
case 0x44:
dev->regs[0x44] = val;
custom_nmi_vector = (custom_nmi_vector & 0xffffff00) | ((uint32_t) val);
break;
case 0x45:
dev->regs[0x45] = val;
custom_nmi_vector = (custom_nmi_vector & 0xffff00ff) | (((uint32_t) val) << 8);
break;
case 0x46:
dev->regs[0x46] = val;
custom_nmi_vector = (custom_nmi_vector & 0xff00ffff) | (((uint32_t) val) << 16);
break;
case 0x47:
dev->regs[0x47] = val;
custom_nmi_vector = (custom_nmi_vector & 0x00ffffff) | (((uint32_t) val) << 24);
break;
case 0x48:
case 0x49:
dev->regs[dev->index] = val;
break;
case 0x4b:
dev->regs[0x4b] = val;
use_custom_nmi_vector = !!(val & 0x40);
break;
case 0x4c:
ct_82c100_log("CS4C: %02X\n", val);
dev->regs[0x4c] = val;
ct_82c100_ems_update(dev);
break;
default:
break;
}
dev->access = 0;
}
} else if (port == 0x72)
dev->regs[0x72] = val & 0x7e;
else if (port == 0x7e)
dev->regs[0x7e] = val;
else if (port == 0x7f) {
/* Bit 3 is Software Controlled Reset, asserted if set. Will be
done in the feature/machine_and_kb branch using hardresetx86(). */
dev->regs[0x7f] = val;
if ((dev->regs[0x41] & 0x40) && (val & 0x08)) {
softresetx86();
cpu_set_edx();
ct_82c100_reset(dev);
}
}
}
static uint8_t
ct_82c100_in(uint16_t port, void *priv)
{
ct_82c100_t *dev = (ct_82c100_t *) priv;
uint8_t ret = 0xff;
if (port == 0x0022)
ret = dev->index;
else if (port == 0x0023) {
if (dev->access) {
switch (dev->index) {
/* INTERNAL CONFIGURATION/CONTROL REGISTERS */
case 0x40 ... 0x49:
case 0x4b:
case 0x4c:
ret = dev->regs[dev->index];
break;
default:
break;
}
dev->access = 0;
}
} else if (port == 0x72)
ret = dev->regs[0x72];
else if (port == 0x7e)
ret = dev->regs[0x7e];
else if (port == 0x7f)
ret = dev->regs[0x7f];
return ret;
}
static uint8_t
mem_read_emsb(uint32_t addr, void *priv)
{
const ems_page_t *page = (ems_page_t *) priv;
uint8_t ret = 0xff;
#ifdef ENABLE_CT_82C100_LOG
uint32_t old_addr = addr;
#endif
addr = addr - page->virt + page->phys;
if (addr < (mem_size << 10))
ret = ram[addr];
ct_82c100_log("mem_read_emsb(%08X = %08X): %02X\n", old_addr, addr, ret);
return ret;
}
static uint16_t
mem_read_emsw(uint32_t addr, void *priv)
{
const ems_page_t *page = (ems_page_t *) priv;
uint16_t ret = 0xffff;
#ifdef ENABLE_CT_82C100_LOG
uint32_t old_addr = addr;
#endif
addr = addr - page->virt + page->phys;
if (addr < (mem_size << 10))
ret = *(uint16_t *) &ram[addr];
ct_82c100_log("mem_read_emsw(%08X = %08X): %04X\n", old_addr, addr, ret);
return ret;
}
static void
mem_write_emsb(uint32_t addr, uint8_t val, void *priv)
{
const ems_page_t *page = (ems_page_t *) priv;
#ifdef ENABLE_CT_82C100_LOG
uint32_t old_addr = addr;
#endif
addr = addr - page->virt + page->phys;
if (addr < (mem_size << 10))
ram[addr] = val;
ct_82c100_log("mem_write_emsb(%08X = %08X, %02X)\n", old_addr, addr, val);
}
static void
mem_write_emsw(uint32_t addr, uint16_t val, void *priv)
{
const ems_page_t *page = (ems_page_t *) priv;
#ifdef ENABLE_CT_82C100_LOG
uint32_t old_addr = addr;
#endif
addr = addr - page->virt + page->phys;
if (addr < (mem_size << 10))
*(uint16_t *) &ram[addr] = val;
ct_82c100_log("mem_write_emsw(%08X = %08X, %04X)\n", old_addr, addr, val);
}
static void
ct_82c100_close(void *priv)
{
ct_82c100_t *dev = (ct_82c100_t *) priv;
free(dev);
}
static void *
ct_82c100_init(UNUSED(const device_t *info))
{
ct_82c100_t *dev;
dev = (ct_82c100_t *) malloc(sizeof(ct_82c100_t));
memset(dev, 0x00, sizeof(ct_82c100_t));
ct_82c100_reset(dev);
io_sethandler(0x0022, 2,
ct_82c100_in, NULL, NULL, ct_82c100_out, NULL, NULL, dev);
io_sethandler(0x0072, 1,
ct_82c100_in, NULL, NULL, ct_82c100_out, NULL, NULL, dev);
io_sethandler(0x007e, 2,
ct_82c100_in, NULL, NULL, ct_82c100_out, NULL, NULL, dev);
for (uint8_t i = 0; i < 4; i++) {
mem_mapping_add(&(dev->ems_mappings[i]), (i + 28) << 14, 0x04000,
mem_read_emsb, mem_read_emsw, NULL,
mem_write_emsb, mem_write_emsw, NULL,
ram + 0xa0000 + (i << 14), MEM_MAPPING_INTERNAL, &dev->ems_pages[i]);
mem_mapping_disable(&(dev->ems_mappings[i]));
}
mem_mapping_disable(&ram_mid_mapping);
device_add(&port_92_device);
return dev;
}
const device_t ct_82c100_device = {
.name = "C&T 82C100",
.internal_name = "ct_82c100",
.flags = 0,
.local = 0,
.init = ct_82c100_init,
.close = ct_82c100_close,
.reset = ct_82c100_reset,
{ .available = NULL },
.speed_changed = NULL,
.force_redraw = NULL,
.config = NULL
};