168 lines
3.8 KiB
C
168 lines
3.8 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.
|
|
*
|
|
* Emulation of C&T CS8230 ("386/AT") chipset.
|
|
*
|
|
*
|
|
*
|
|
* Authors: Sarah Walker, <http://pcem-emulator.co.uk/>
|
|
*
|
|
* Copyright 2020 Sarah Walker.
|
|
*/
|
|
#include <stdio.h>
|
|
#include <stdint.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <wchar.h>
|
|
#include <86box/86box.h>
|
|
#include "cpu.h"
|
|
#include <86box/timer.h>
|
|
#include <86box/io.h>
|
|
#include <86box/device.h>
|
|
#include <86box/mem.h>
|
|
#include <86box/fdd.h>
|
|
#include <86box/fdc.h>
|
|
#include <86box/chipset.h>
|
|
|
|
|
|
typedef struct
|
|
{
|
|
int idx;
|
|
uint8_t regs[256];
|
|
} cs8230_t;
|
|
|
|
|
|
static void
|
|
shadow_control(uint32_t addr, uint32_t size, int state)
|
|
{
|
|
switch (state) {
|
|
case 0x00:
|
|
mem_set_mem_state(addr, size, MEM_READ_INTERNAL | MEM_WRITE_INTERNAL);
|
|
break;
|
|
case 0x01:
|
|
mem_set_mem_state(addr, size, MEM_READ_EXTANY | MEM_WRITE_INTERNAL);
|
|
break;
|
|
case 0x10:
|
|
mem_set_mem_state(addr, size, MEM_READ_INTERNAL | MEM_WRITE_EXTANY);
|
|
break;
|
|
case 0x11:
|
|
mem_set_mem_state(addr, size, MEM_READ_EXTANY | MEM_WRITE_EXTANY);
|
|
break;
|
|
}
|
|
|
|
flushmmucache_nopc();
|
|
}
|
|
|
|
|
|
static void
|
|
rethink_shadow_mappings(cs8230_t *cs8230)
|
|
{
|
|
int c;
|
|
|
|
for (c = 0; c < 32; c++) {
|
|
/* Addresses 40000-bffff in 16k blocks */
|
|
if (cs8230->regs[0xa + (c >> 3)] & (1 << (c & 7)))
|
|
mem_set_mem_state(0x40000 + (c << 14), 0x4000, MEM_READ_EXTERNAL | MEM_WRITE_EXTERNAL); /* I/O channel */
|
|
else
|
|
mem_set_mem_state(0x40000 + (c << 14), 0x4000, MEM_READ_INTERNAL | MEM_WRITE_INTERNAL); /* System board */
|
|
}
|
|
|
|
for (c = 0; c < 16; c++) {
|
|
/* Addresses c0000-fffff in 16k blocks. System board ROM can be mapped here */
|
|
if (cs8230->regs[0xe + (c >> 3)] & (1 << (c & 7)))
|
|
mem_set_mem_state(0xc0000 + (c << 14), 0x4000, MEM_READ_EXTANY | MEM_WRITE_EXTANY); /* I/O channel */
|
|
else
|
|
shadow_control(0xc0000 + (c << 14), 0x4000, (cs8230->regs[9] >> (3 - (c >> 2))) & 0x11);
|
|
}
|
|
}
|
|
|
|
|
|
static uint8_t
|
|
cs8230_read(uint16_t port, void *p)
|
|
{
|
|
cs8230_t *cs8230 = (cs8230_t *) p;
|
|
uint8_t ret = 0xff;
|
|
|
|
if (port & 1) {
|
|
switch (cs8230->idx) {
|
|
case 0x04: /* 82C301 ID/version */
|
|
ret = cs8230->regs[cs8230->idx] & ~0xe3;
|
|
break;
|
|
|
|
case 0x08: /* 82C302 ID/Version */
|
|
ret = cs8230->regs[cs8230->idx] & ~0xe0;
|
|
break;
|
|
|
|
case 0x05: case 0x06: /* 82C301 registers */
|
|
case 0x09: case 0x0a: case 0x0b: case 0x0c: /* 82C302 registers */
|
|
case 0x0d: case 0x0e: case 0x0f:
|
|
case 0x10: case 0x11: case 0x12: case 0x13:
|
|
case 0x28: case 0x29: case 0x2a:
|
|
ret = cs8230->regs[cs8230->idx];
|
|
break;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
|
|
static void
|
|
cs8230_write(uint16_t port, uint8_t val, void *p)
|
|
{
|
|
cs8230_t *cs8230 = (cs8230_t *)p;
|
|
|
|
if (!(port & 1))
|
|
cs8230->idx = val;
|
|
else {
|
|
cs8230->regs[cs8230->idx] = val;
|
|
switch (cs8230->idx) {
|
|
case 0x09: /* RAM/ROM Configuration in boot area */
|
|
case 0x0a: case 0x0b: case 0x0c: case 0x0d: case 0x0e: case 0x0f: /* Address maps */
|
|
rethink_shadow_mappings(cs8230);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
static void
|
|
cs8230_close(void *priv)
|
|
{
|
|
cs8230_t *cs8230 = (cs8230_t *)priv;
|
|
|
|
free(cs8230);
|
|
}
|
|
|
|
|
|
static void
|
|
*cs8230_init(const device_t *info)
|
|
{
|
|
cs8230_t *cs8230 = (cs8230_t *)malloc(sizeof(cs8230_t));
|
|
memset(cs8230, 0, sizeof(cs8230_t));
|
|
|
|
io_sethandler(0x0022, 0x0002, cs8230_read, NULL, NULL, cs8230_write, NULL, NULL, cs8230);
|
|
|
|
if (mem_size > 768) {
|
|
mem_mapping_set_addr(&ram_mid_mapping, 0xa0000, mem_size > 1024 ? 0x60000 : 0x20000 + (mem_size - 768) * 1024);
|
|
mem_mapping_set_exec(&ram_mid_mapping, ram + 0xa0000);
|
|
}
|
|
|
|
return cs8230;
|
|
}
|
|
|
|
|
|
const device_t cs8230_device = {
|
|
"C&T CS8230 (386/AT)",
|
|
0,
|
|
0,
|
|
cs8230_init, cs8230_close, NULL,
|
|
{ NULL }, NULL, NULL,
|
|
NULL
|
|
};
|