mappers/mapper_003_2.c


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__attribute__((section(".mapper_003_2"), hot))
static uint8_t mapper_003_2_prg_read(struct nes_state *state, uint32_t addr) {
	return state->prg_rom[addr & 0x7fff];
}

__attribute__((section(".mapper_003_2"), hot))
static void mapper_003_2_prg_write(struct nes_state *state, uint32_t addr, uint8_t value) {
	struct mapper_003_2 *mapper = (struct mapper_003_2 *)&state->map;

	if(addr >= 0x8000) {
		value &= state->prg_rom[addr & 0x7fff];
		mapper->chr_ptr = state->chr_rom + (value & 3) * 0x2000;
	}
}

__attribute__((section(".mapper_003_2"), hot))
static uint8_t mapper_003_2_chr_read(struct nes_state *state, uint32_t addr) {
	struct mapper_003_2 *mapper = (struct mapper_003_2 *)&state->map;
	return mapper->chr_ptr[addr];
}

__attribute__((section(".mapper_003_2")))
static void mapper_003_2_init(struct nes_state *state) {
	struct mapper_003_2 *mapper = (struct mapper_003_2 *)&state->map;

	mapper->chr_ptr = state->chr_rom;

	state->mapper.prg_read	= mapper_003_2_prg_read;
	state->mapper.prg_write	= mapper_003_2_prg_write;
	state->mapper.chr_read	= mapper_003_2_chr_read;
}