62 lines
1.6 KiB
C
62 lines
1.6 KiB
C
/* Copyright holders: Sarah Walker
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see COPYING for more details
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*/
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#include "../ibm.h"
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#include "../cpu/cpu.h"
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#include "../io.h"
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#include "../mem.h"
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#include "machine_at.h"
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#include "machine_at_headland.h"
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static int headland_index;
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static uint8_t headland_regs[256];
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static void headland_write(uint16_t addr, uint8_t val, void *priv)
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{
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if (addr & 1)
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{
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if (headland_index == 0xc1 && !is486) val = 0;
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headland_regs[headland_index] = val;
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if (headland_index == 0x82)
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{
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shadowbios = val & 0x10;
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shadowbios_write = !(val & 0x10);
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if (shadowbios)
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mem_set_mem_state(0xf0000, 0x10000, MEM_READ_INTERNAL | MEM_WRITE_DISABLED);
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else
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mem_set_mem_state(0xf0000, 0x10000, MEM_READ_EXTERNAL | MEM_WRITE_INTERNAL);
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}
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}
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else
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headland_index = val;
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}
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static uint8_t headland_read(uint16_t addr, void *priv)
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{
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if (addr & 1)
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{
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if ((headland_index >= 0xc0 || headland_index == 0x20) && cpu_iscyrix)
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return 0xff; /*Don't conflict with Cyrix config registers*/
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return headland_regs[headland_index];
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}
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return headland_index;
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}
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static void headland_init(void)
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{
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io_sethandler(0x0022, 0x0002, headland_read, NULL, NULL, headland_write, NULL, NULL, NULL);
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}
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void machine_at_headland_init(void)
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{
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machine_at_ide_init();
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headland_init();
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}
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