nese/src/map/mmc1.c

#include "map.h"


typedef struct {
    uint8_t* prg_rom;
    int prg_rom_size;
    uint8_t* prg_ram;
    int prg_ram_size;
    uint8_t* chr_rom;
    int chr_rom_size;

    uint8_t reg_shift;
    uint8_t reg_control;
    uint8_t reg_chr_0;
    uint8_t reg_chr_1;
    uint8_t reg_prg;
} mmc1_mapper;

/*
int mmc1_init(nes_mapper* nes_map, nes_cart* cart) {
    nrom_mapper* map = malloc(sizeof(nrom_mapper));
    nes_map->data = map;
    if (NULL != map) {
        map->prg_rom      = cart->prg_rom;
        map->prg_rom_size = cart->prg_rom_size;
        map->chr_rom      = cart->chr_rom;
        map->chr_rom_size = cart->chr_rom_size;
        map->prg_ram      = cart->wram;
        map->prg_ram_size = nes_mem_wram_size;

        map->shift_reg = 0;
    }
    return (NULL == map ? -1 : 0);
}

void nrom_done(nes_mapper* nes_map) {
    free(nes_map->data);
}

static inline uint8_t* nrom_prg_addr(nrom_mapper* map,
                                     uint16_t addr) {
    if (addr > map->prg_rom_size) {
        addr &= 0x3FFF;
    }
    return &(map->prg_rom[addr]);
}

uint8_t nrom_prg_read(nes_mapper* map, uint16_t addr) {
    return *(nrom_prg_addr((nrom_mapper*)map->data, addr));
}

void nrom_prg_write(nes_mapper* map, uint16_t addr, uint8_t val) {
    // No ROM writes.
}

uint8_t* nrom_chr_addr(nes_mapper* nes_map, uint16_t addr) {
    nrom_mapper* map = (nrom_mapper*)nes_map->data;
    return &map->chr_rom[addr % map->chr_rom_size];
}

*/

nes_mapper mapper_mmc1 = {
/*
    .init = mmc1_init,
    .done = mmc1_done,
    .prg_read = mmc1_prg_read,
    .prg_write = mmc1_prg_write,
    .chr_addr = mmc1_chr_addr,
    .vram_addr = mmc1_chr_addr,
*/
};