mappers/mapper_066_0.c


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__attribute__((section(".mapper_066_0")))
static uint8_t mapper_066_0_prg_rom_read(struct nes_state *state, uint32_t addr) {
	struct mapper_066_0 *mapper = &state->mapper_data.m066_0;

	if(addr >= 0x8000) {
		return state->prg_rom[addr & 0x7fff];
	}
	return 0;
}

__attribute__((section(".mapper_066_0")))
static void mapper_066_0_prg_rom_write(struct nes_state *state, uint32_t addr, uint8_t value) {
	struct mapper_066_0 *mapper = &state->mapper_data.m066_0;

	if(addr >= 0x8000) {
		uint32_t prg_bank = (value >> 4) & 3;
		uint32_t chr_bank = (value >> 0) & 3;

		mapper->prg_offset = state->prg_rom + (prg_bank * 0x8000);
		mapper->chr_offset = state->chr_rom + (chr_bank * 0x2000);
	}
}

__attribute__((section(".mapper_066_0")))
static uint8_t mapper_066_0_chr_read(struct nes_state *state, uint32_t addr) {
	struct mapper_066_0 *mapper = &state->mapper_data.m066_0;
	return mapper->chr_offset[addr];
}

__attribute__((section(".mapper_066_0")))
static void mapper_066_0_init(struct nes_state *state) {
	struct mapper_066_0 *mapper = &state->mapper_data.m066_0;

	mapper->prg_offset = state->prg_rom;
	mapper->chr_offset = state->chr_rom;

	state->mapper_function.prg_rom_read		= mapper_066_0_prg_rom_read;
	state->mapper_function.prg_rom_write	= mapper_066_0_prg_rom_write;
	state->mapper_function.chr_read			= mapper_066_0_chr_read;
}