gb6/src/dmg.c

63 lines
1.8 KiB
C

#include <stdio.h>
#include "cpu.h"
#include "rom.h"
#include "dmg.h"
#include "types.h"
#include "bootstrap.h"
void dmg_new(struct dmg *dmg, struct cpu *cpu, struct rom *rom)
{
dmg->cpu = cpu;
dmg->rom = rom;
}
u8 dmg_read(void *_dmg, u16 address)
{
struct dmg *dmg = (struct dmg *) _dmg;
if (address < 0x100) {
return dmg_boot_rom[address];
}
if (address < 0x4000) {
return dmg->rom->data[address];
} else if (address < 0x8000) {
// TODO switchable rom bank
return dmg->rom->data[address];
} else if (address < 0xa000) {
return dmg->video_ram[address - 0x8000];
} else if (address < 0xc000) {
// TODO switchable ram bank
return 0;
} else if (address < 0xe000) {
return dmg->main_ram[address - 0xc000];
} else if (address >= 0xff80 && address <= 0xfffe) {
return dmg->zero_page[address - 0xff80];
} else {
// not sure about any of this yet
return 0;
}
}
void dmg_write(void *_dmg, u16 address, u8 data)
{
struct dmg *dmg = (struct dmg *) _dmg;
if (address < 0x4000) {
printf("warning: writing 0x%04x in rom\n", address);
dmg->rom->data[address] = data;
} else if (address < 0x8000) {
// TODO switchable rom bank
printf("warning: writing 0x%04x in rom\n", address);
dmg->rom->data[address] = data;
} else if (address < 0xa000) {
dmg->video_ram[address - 0x8000] = data;
} else if (address < 0xc000) {
// TODO switchable ram bank
} else if (address < 0xe000) {
dmg->main_ram[address - 0xc000] = data;
} else if (address >= 0xff80 && address <= 0xfffe) {
dmg->zero_page[address - 0xff80] = data;
} else {
// not sure about any of this yet
}
}