2ca4ead570
Misc ViRGE fixes. Changes to memory mapping. Changes to PCI handling. Disabled 'AMI WinBIOS 486 PCI' due to incomplete chipset emulation. Invalid GUS register reads no longer kill the emulator.
86 lines
2.7 KiB
C
86 lines
2.7 KiB
C
#include <string.h>
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#include "ibm.h"
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#include "io.h"
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#include "mem.h"
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#include "cpu.h"
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#include "ali1429.h"
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static int ali1429_index;
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static uint8_t ali1429_regs[256];
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static void ali1429_recalc()
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{
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int c;
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for (c = 0; c < 8; c++)
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{
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uint32_t base = 0xc0000 + (c << 15);
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if (ali1429_regs[0x13] & (1 << c))
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{
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switch (ali1429_regs[0x14] & 3)
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{
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case 0:
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mem_set_mem_state(base, 0x8000, MEM_READ_EXTERNAL | MEM_WRITE_EXTERNAL);
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break;
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case 1:
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mem_set_mem_state(base, 0x8000, MEM_READ_INTERNAL | MEM_WRITE_EXTERNAL);
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break;
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case 2:
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mem_set_mem_state(base, 0x8000, MEM_READ_EXTERNAL | MEM_WRITE_INTERNAL);
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break;
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case 3:
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mem_set_mem_state(base, 0x8000, MEM_READ_INTERNAL | MEM_WRITE_INTERNAL);
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break;
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}
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}
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else
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mem_set_mem_state(base, 0x8000, MEM_READ_EXTERNAL | MEM_WRITE_EXTERNAL);
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}
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flushmmucache();
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}
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void ali1429_write(uint16_t port, uint8_t val, void *priv)
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{
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int c;
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if (!(port & 1))
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ali1429_index = val;
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else
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{
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ali1429_regs[ali1429_index] = val;
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// pclog("ALI1429 write %02X %02X %04X:%04X %i\n",ali1429_index,val,CS,pc,ins);
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switch (ali1429_index)
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{
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case 0x13:
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ali1429_recalc();
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break;
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case 0x14:
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shadowbios = val & 1;
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shadowbios_write = val & 2;
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ali1429_recalc();
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break;
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}
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}
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}
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uint8_t ali1429_read(uint16_t port, void *priv)
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{
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if (!(port & 1))
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return ali1429_index;
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if ((ali1429_index >= 0xc0 || ali1429_index == 0x20) && cpu_iscyrix)
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return 0xff; /*Don't conflict with Cyrix config registers*/
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return ali1429_regs[ali1429_index];
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}
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void ali1429_reset()
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{
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memset(ali1429_regs, 0xff, 256);
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}
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void ali1429_init()
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{
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io_sethandler(0x0022, 0x0002, ali1429_read, NULL, NULL, ali1429_write, NULL, NULL, NULL);
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}
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