Files
86Box/src/machine/m_at_grid.c
2025-07-27 15:23:43 +02:00

356 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 the GRiD GRiDcase 1520
*
* The GRiDcase 1520 is a 286-based portable.
* These are HDDs supported by GRiD1520 (and probably other 15XX) BIOS
* "CP3022",5
* "CP3024",5, 615,4,17 BIOS table type 2
* "CP344",6,
* "CP3044",9, 980,5,17 BIOS table type 17
* "CP3042",9
* "CP3104",7, 776,8,33 extended type 224 (separate entry outside BIOS table)
* The only way to run unpatched BIOS is to run exactly that (or larger)
* geometry and report model name correctly in response to IDENTYIFY command.
* Alternatively you can use RomBuster to patch the BIOS.
* https://classicbits.net/coding-and-software/my-software/rombuster/
*/
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <86box/86box.h>
#include "cpu.h"
#include <86box/timer.h>
#include <86box/device.h>
#include <86box/fdd.h>
#include <86box/fdc.h>
#include <86box/fdc_ext.h>
#include <86box/io.h>
#include <86box/keyboard.h>
#include <86box/machine.h>
#include <86box/mem.h>
#include <86box/rom.h>
#include <86box/vid_cga.h>
#include <86box/plat_unused.h>
#define GRID_APPROM_SELECT 0x440
#define GRID_APPROM_ENABLE 0x405
/*
approm mapping regs?
XXX_7FA equ 7FAh
XXX_7F8 equ 7F8h
XXX_7F9 equ 7F9h
XXX_BD0 equ 0BD0h
XXX_BD1 equ 0BD1h
*/
#define GRID_EMS_PAGE_0 0x0258
#define GRID_EMS_PAGE_1 0x4258
#define GRID_EMS_PAGE_2 0x8258
#define GRID_EMS_PAGE_3 0xC258
#define GRID_TURBO 0x416
#define GRID_UNUSED_424 0x424
#define GRID_426 0x426
#define GRID_HIGH_ENABLE 0xFFF
#define GRID_ROM_SUBSYSTEM 0x6F8
// EMS window
#define GRID_EMS_BASE 0xE0000
#define GRID_EMS_PAGE_SIZE 0x4000
#define GRID_EMS_PAGE_MASK 0x3FFF
#define GRID_EMS_PAGE_SHIFT 14
// physical base of extended memory
#define GRID_EXTENDED_BASE 0xA0000
#define GRID_1M 0x100000
typedef struct {
uint8_t grid_unknown;
uint8_t grid_unused_424;
uint8_t grid_426;
uint8_t grid_high_enable;
uint8_t grid_ems_page[4];
mem_mapping_t grid_ems_mapping[4];
uint8_t grid_turbo;
uint8_t grid_rom_enable;
uint8_t grid_rom_select;
} grid_t;
static uint32_t get_grid_ems_paddr(grid_t *dev, uint32_t addr) {
uint32_t slot = (addr >> GRID_EMS_PAGE_SHIFT) & 0x3;
uint32_t paddr = addr;
if (dev->grid_ems_page[slot] & 0x80)
paddr = GRID_EXTENDED_BASE + ((uint32_t)(dev->grid_ems_page[slot] & 0x7F) << GRID_EMS_PAGE_SHIFT) + (addr & GRID_EMS_PAGE_MASK);
return paddr;
}
static void grid_ems_mem_write8(uint32_t addr, uint8_t val, void *priv) {
grid_t *dev = (grid_t *) priv;
addr = get_grid_ems_paddr(dev, addr);
if (addr < (mem_size << 10))
ram[addr] = val;
}
static uint8_t grid_ems_mem_read8(uint32_t addr, void *priv) {
grid_t *dev = (grid_t *) priv;
uint8_t val = 0xFF;
addr = get_grid_ems_paddr(dev, addr);
if (addr < (mem_size << 10))
val = ram[addr];
return val;
}
static void grid_ems_mem_write16(uint32_t addr, uint16_t val, void *priv) {
grid_t *dev = (grid_t *) priv;
addr = get_grid_ems_paddr(dev, addr);
if (addr < (mem_size << 10))
*(uint16_t *)&(ram[addr]) = val;
}
static uint16_t grid_ems_mem_read16(uint32_t addr, void *priv) {
grid_t *dev = (grid_t *) priv;
uint16_t val = 0xFFFF;
addr = get_grid_ems_paddr(dev, addr);
if (addr < (mem_size << 10))
val = *(uint16_t *)&(ram[addr]);
return val;
}
static void grid_ems_update_mapping(grid_t *dev, uint32_t slot) {
uint32_t vaddr = GRID_EMS_BASE + (slot << GRID_EMS_PAGE_SHIFT);
if (dev->grid_ems_page[slot] & 0x80) {
uint32_t paddr;
mem_mapping_enable(&dev->grid_ems_mapping[slot]);
paddr = get_grid_ems_paddr(dev, vaddr);
mem_mapping_set_exec(&dev->grid_ems_mapping[slot], ram + paddr);
} else {
mem_mapping_disable(&dev->grid_ems_mapping[slot]);
}
}
static void grid_io_write(uint16_t port, uint8_t val, void *priv) {
grid_t *dev = (grid_t *) priv;
switch (port) {
case GRID_426:
dev->grid_426 = val;
break;
case GRID_UNUSED_424:
dev->grid_unused_424 = val;
break;
case GRID_ROM_SUBSYSTEM:
case GRID_ROM_SUBSYSTEM+1:
case GRID_ROM_SUBSYSTEM+2:
case GRID_ROM_SUBSYSTEM+3:
case GRID_ROM_SUBSYSTEM+4:
case GRID_ROM_SUBSYSTEM+5:
case GRID_ROM_SUBSYSTEM+6:
case GRID_ROM_SUBSYSTEM+7:
break;
case GRID_APPROM_SELECT:
dev->grid_rom_select = val;
break;
case GRID_APPROM_ENABLE:
dev->grid_rom_enable = val;
break;
case GRID_TURBO:
if ((dev->grid_turbo ^ val) & 1) {
dev->grid_turbo = val;
if (dev->grid_turbo)
cpu_dynamic_switch(cpu);
else
cpu_dynamic_switch(0); /* 286/6 */
}
break;
case GRID_EMS_PAGE_0:
case GRID_EMS_PAGE_1:
case GRID_EMS_PAGE_2:
case GRID_EMS_PAGE_3: {
uint32_t slot = (port >> 14) & 0x3;
if (dev->grid_ems_page[slot] == val)
break; // no change
dev->grid_ems_page[slot] = val;
if (dev->grid_high_enable & 0x1)
break; // XMS is enabled
grid_ems_update_mapping(dev, slot);
flushmmucache();
break;
}
case GRID_HIGH_ENABLE: {
if (((val ^ dev->grid_high_enable) & 0x1) == 0)
break; // no change
dev->grid_high_enable = val;
if (dev->grid_high_enable & 0x1) {
for (uint8_t i = 0; i < 4; i++)
mem_mapping_disable(&dev->grid_ems_mapping[i]);
mem_mapping_enable(&ram_high_mapping);
} else {
mem_mapping_disable(&ram_high_mapping);
for (uint8_t i = 0; i < 4; i++)
grid_ems_update_mapping(dev, i);
}
flushmmucache();
break;
}
default:
break;
}
}
static uint8_t grid_io_read(uint16_t port, void *priv) {
grid_t *dev = (grid_t *) priv;
switch (port) {
case GRID_426:
return dev->grid_426;
break;
case GRID_UNUSED_424:
return dev->grid_unused_424;
break;
case GRID_ROM_SUBSYSTEM:
return 0x99;
break;
case GRID_ROM_SUBSYSTEM+1:
case GRID_ROM_SUBSYSTEM+2:
case GRID_ROM_SUBSYSTEM+3:
case GRID_ROM_SUBSYSTEM+4:
case GRID_ROM_SUBSYSTEM+5:
case GRID_ROM_SUBSYSTEM+6:
case GRID_ROM_SUBSYSTEM+7:
break;
case GRID_APPROM_SELECT:
return dev->grid_rom_select;
case GRID_APPROM_ENABLE:
return dev->grid_rom_enable;
case GRID_TURBO:
return dev->grid_turbo;
case GRID_HIGH_ENABLE:
return dev->grid_high_enable;
case GRID_EMS_PAGE_0:
case GRID_EMS_PAGE_1:
case GRID_EMS_PAGE_2:
case GRID_EMS_PAGE_3: {
uint32_t slot = (port >> 14) & 0x3;
return dev->grid_ems_page[slot];
}
default:
break;
}
return 0xff;
}
static void *
grid_init(UNUSED(const device_t *info))
{
grid_t *dev = calloc(1, sizeof(grid_t));
io_sethandler(GRID_ROM_SUBSYSTEM, 0x0008, grid_io_read, NULL, NULL, grid_io_write, NULL, NULL, dev);
io_sethandler(GRID_UNUSED_424, 0x0001, grid_io_read, NULL, NULL, grid_io_write, NULL, NULL, dev);
io_sethandler(GRID_426, 0x0001, grid_io_read, NULL, NULL, grid_io_write, NULL, NULL, dev);
io_sethandler(GRID_APPROM_SELECT, 0x0001, grid_io_read, NULL, NULL, grid_io_write, NULL, NULL, dev);
io_sethandler(GRID_APPROM_ENABLE, 0x0001, grid_io_read, NULL, NULL, grid_io_write, NULL, NULL, dev);
io_sethandler(GRID_TURBO, 0x0001, grid_io_read, NULL, NULL, grid_io_write, NULL, NULL, dev);
dev->grid_turbo = 0x1;
io_sethandler(GRID_HIGH_ENABLE, 0x0001, grid_io_read, NULL, NULL, grid_io_write, NULL, NULL, dev);
io_sethandler(GRID_EMS_PAGE_0, 0x0001, grid_io_read, NULL, NULL, grid_io_write, NULL, NULL, dev);
io_sethandler(GRID_EMS_PAGE_1, 0x0001, grid_io_read, NULL, NULL, grid_io_write, NULL, NULL, dev);
io_sethandler(GRID_EMS_PAGE_2, 0x0001, grid_io_read, NULL, NULL, grid_io_write, NULL, NULL, dev);
io_sethandler(GRID_EMS_PAGE_3, 0x0001, grid_io_read, NULL, NULL, grid_io_write, NULL, NULL, dev);
dev->grid_high_enable = 1;
for (uint8_t slot = 0; slot < 4; slot++) {
dev->grid_ems_page[slot] = 0;
mem_mapping_add(&dev->grid_ems_mapping[slot], GRID_EMS_BASE + (slot << GRID_EMS_PAGE_SHIFT), GRID_EMS_PAGE_SIZE, grid_ems_mem_read8, grid_ems_mem_read16, NULL,
grid_ems_mem_write8, grid_ems_mem_write16, NULL, ram + GRID_EXTENDED_BASE + (slot << GRID_EMS_PAGE_SHIFT), MEM_MAPPING_EXTERNAL, dev);
mem_mapping_disable(&dev->grid_ems_mapping[slot]);
}
flushmmucache();
return dev;
}
static void grid_close(void *priv) {
grid_t *dev = (grid_t *) priv;
free(dev);
}
static void grid_reset(void *priv) {
grid_t *dev = (grid_t *) priv;
dev->grid_high_enable = 1;
mem_mapping_enable(&ram_high_mapping);
dev->grid_turbo = 0x1;
for (uint8_t slot = 0; slot < 4; slot++) {
dev->grid_ems_page[slot] = 0;
mem_mapping_disable(&dev->grid_ems_mapping[slot]);
}
flushmmucache();
dev->grid_unknown = 0;
dev->grid_unused_424 = 0;
dev->grid_426 = 0;
dev->grid_rom_enable = 0;
dev->grid_rom_select = 0;
}
const device_t grid_device = {
.name = "GRiDcase 1520 chipset",
.internal_name = "grid1520",
.flags = 0,
.local = 0,
.init = grid_init,
.close = grid_close,
.reset = grid_reset,
.available = NULL,
.speed_changed = NULL,
.force_redraw = NULL,
.config = NULL
};
int machine_at_grid1520_init(const machine_t *model) {
int ret = 0;
ret = bios_load_linear("roms/machines/grid1520/grid1520_891025.rom",
0x000f8000, 0x8000, 0);
if (bios_only || !ret)
return ret;
machine_at_common_ide_init(model);
mem_remap_top(384);
device_add(&kbc_at_device);
// for now just select CGA with amber monitor
//device_add(&cga_device);
if (fdc_current[0] == FDC_INTERNAL)
device_add(&fdc_at_device);
device_add(&grid_device);
return ret;
}