164 lines
3.9 KiB
C
164 lines
3.9 KiB
C
/*
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* 86Box A hypervisor and IBM PC system emulator that specializes in
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* running old operating systems and software designed for IBM
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* PC systems and compatibles from 1981 through fairly recent
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* system designs based on the PCI bus.
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*
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* This file is part of the 86Box distribution.
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*
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* Implementation of the VLSI VL82c113 Combination I/O Chip.
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*
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* Authors: Miran Grca, <mgrca8@gmail.com>
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*
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* Copyright 2024 Miran Grca.
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*/
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#include <stdio.h>
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#include <stdint.h>
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#include <stdlib.h>
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#include <string.h>
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#include <wchar.h>
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#include <86box/86box.h>
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#include <86box/io.h>
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#include <86box/timer.h>
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#include <86box/device.h>
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#include <86box/keyboard.h>
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#include <86box/nvr.h>
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#include <86box/sio.h>
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typedef struct vl82c113_t {
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uint8_t index;
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uint8_t nvr_enabled;
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uint8_t regs[3];
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uint8_t pad;
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uint16_t nvr_base;
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int cur_reg;
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nvr_t *nvr;
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void *kbc;
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} vl82c113_t;
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static void
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vl82c113_nvr_handler(vl82c113_t *dev)
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{
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const uint8_t nvr_enabled = (dev->regs[0x00]) & 0x01;
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const uint16_t nvr_base = ((dev->regs[0x01] << 8) | dev->regs[0x00]) & 0xfffe;
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if ((nvr_enabled != dev->nvr_enabled) || (nvr_base != dev->nvr_base)) {
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if (dev->nvr_enabled && (dev->nvr_base != 0x0000))
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nvr_at_handler(0, dev->nvr_base, dev->nvr);
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dev->nvr_enabled = nvr_enabled;
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dev->nvr_base = nvr_base;
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if (dev->nvr_enabled && (dev->nvr_base != 0x0000))
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nvr_at_handler(1, dev->nvr_base, dev->nvr);
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}
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}
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static void
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vl82c113_out(uint16_t port, uint8_t val, void *priv)
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{
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vl82c113_t *dev = (vl82c113_t *) priv;
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if (port == 0xec)
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dev->index = val;
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else if ((dev->index >= 0x1b) && (dev->index <= 0x1d)) {
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const uint8_t index = dev->index - 0x1b;
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const uint8_t valxor = dev->regs[index] ^ val;
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dev->regs[index] = val;
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switch (index) {
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default:
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break;
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case 0x00:
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case 0x01:
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if (valxor)
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vl82c113_nvr_handler(dev);
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break;
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case 0x02:
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if (valxor & 0x02)
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kbc_at_set_ps2(dev->kbc, !(val & 0x02));
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break;
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}
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}
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}
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static uint8_t
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vl82c113_in(uint16_t port, void *priv)
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{
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const vl82c113_t *dev = (vl82c113_t *) priv;
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uint8_t ret = 0xff;
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if (port == 0xed) {
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if ((dev->index >= 0x1b) && (dev->index <= 0x1d))
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ret = dev->regs[dev->index - 0x1b];
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else if (dev->index == 0x1f)
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/* REVID */
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ret = 0xc0;
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}
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return ret;
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}
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static void
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vl82c113_reset(void *priv)
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{
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vl82c113_t *dev = (vl82c113_t *) priv;
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memset(dev->regs, 0x00, sizeof(dev->regs));
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dev->regs[0x00] = 0x71;
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dev->regs[0x01] = 0x00;
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dev->regs[0x02] = 0xc3;
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kbc_at_set_ps2(dev->kbc, 0);
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vl82c113_nvr_handler(dev);
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}
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static void
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vl82c113_close(void *priv)
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{
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vl82c113_t *dev = (vl82c113_t *) priv;
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free(dev);
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}
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static void *
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vl82c113_init(const device_t *info)
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{
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vl82c113_t *dev = (vl82c113_t *) calloc(1, sizeof(vl82c113_t));
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dev->nvr = device_add(&at_nvr_device);
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dev->nvr_enabled = 1;
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dev->nvr_base = 0x0070;
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/* Commands are standard. */
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dev->kbc = device_add(&keyboard_at_device);
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vl82c113_reset(dev);
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io_sethandler(0x00ec, 0x0002, vl82c113_in, NULL, NULL, vl82c113_out, NULL, NULL, dev);
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return dev;
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}
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const device_t vl82c113_device = {
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.name = "VLSI VL82c113 Combination I/O",
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.internal_name = "vl82c113",
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.flags = 0,
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.local = 0,
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.init = vl82c113_init,
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.close = vl82c113_close,
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.reset = vl82c113_reset,
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{ .available = NULL },
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.speed_changed = NULL,
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.force_redraw = NULL,
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.config = NULL
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};
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