mirror of https://github.com/mlaux/gb6.git
82 lines
2.3 KiB
C
82 lines
2.3 KiB
C
#include <stdio.h>
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#include "cpu.h"
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#include "rom.h"
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#include "lcd.h"
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#include "dmg.h"
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#include "types.h"
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#include "bootstrap.h"
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void dmg_new(struct dmg *dmg, struct cpu *cpu, struct rom *rom, struct lcd *lcd)
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{
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dmg->cpu = cpu;
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dmg->rom = rom;
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dmg->lcd = lcd;
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}
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u8 dmg_read(void *_dmg, u16 address)
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{
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struct dmg *dmg = (struct dmg *) _dmg;
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if (address < 0x100) {
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return dmg_boot_rom[address];
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} else if (address < 0x4000) {
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return dmg->rom->data[address];
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} else if (address < 0x8000) {
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// TODO switchable rom bank
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return dmg->rom->data[address];
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} else if (address < 0xa000) {
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return dmg->video_ram[address - 0x8000];
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} else if (address < 0xc000) {
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// TODO switchable ram bank
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return 0;
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} else if (address < 0xe000) {
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return dmg->main_ram[address - 0xc000];
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} else if (lcd_is_valid_addr(address)) {
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return lcd_read(dmg->lcd, address);
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} else if (address >= 0xff80 && address <= 0xfffe) {
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return dmg->zero_page[address - 0xff80];
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} else {
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// not sure about any of this yet
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fprintf(stderr, "don't know how to read 0x%04x\n", address);
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return 0;
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}
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}
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void dmg_write(void *_dmg, u16 address, u8 data)
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{
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struct dmg *dmg = (struct dmg *) _dmg;
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if (address < 0x4000) {
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printf("warning: writing 0x%04x in rom\n", address);
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dmg->rom->data[address] = data;
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} else if (address < 0x8000) {
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// TODO switchable rom bank
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printf("warning: writing 0x%04x in rom\n", address);
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dmg->rom->data[address] = data;
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} else if (address < 0xa000) {
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dmg->video_ram[address - 0x8000] = data;
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} else if (address < 0xc000) {
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// TODO switchable ram bank
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} else if (address < 0xe000) {
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dmg->main_ram[address - 0xc000] = data;
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} else if (lcd_is_valid_addr(address)) {
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lcd_write(dmg->lcd, address, data);
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} else if (address >= 0xff80 && address <= 0xfffe) {
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dmg->zero_page[address - 0xff80] = data;
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} else {
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// not sure about any of this yet
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}
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}
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void dmg_step(void *_dmg)
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{
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struct dmg *dmg = (struct dmg *) _dmg;
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// order of dependencies? i think cpu needs to step first then update
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// all other hw
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cpu_step(dmg->cpu);
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if (dmg->cpu->pc % 456 == 0) {
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// each line takes 456 cycles
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lcd_step(dmg->lcd);
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}
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} |