1 files changed, 63 insertions, 0 deletions
diff --git a/mappers/mapper.c b/mappers/mapper.c
new file mode 100644
index 0000000..d63e2a0
--- /dev/null
+++ b/mappers/mapper.c
@@ -0,0 +1,63 @@
+
+static uint8_t mapper_default_ciram_read(struct nes_state *state, uint32_t addr) {
+	if(state->ines.mirroring == 0) { // Horizontal
+		addr = (addr & 0x800) | (addr & 0x3ff);
+	} else { // Vertical (default fallback)
+		addr = addr & 0x7ff;
+	}
+
+	return state->ciram[addr];
+}
+
+static void mapper_default_ciram_write(struct nes_state *state, uint32_t addr, uint8_t value) {
+	if(state->ines.mirroring == 0) {
+		addr = (addr & 0x800) | (addr & 0x3ff);
+	} else {
+		addr = addr & 0x7ff;
+	}
+	state->ciram[addr] = value;
+}
+
+static void mapper_default_prg_write(struct nes_state *state, uint32_t addr, uint8_t value) { }
+static void mapper_default_chr_write(struct nes_state *state, uint32_t addr, uint8_t value) { }
+static void mapper_default_tick(struct nes_state *state) { }
+
+#include "mapper_000_0.c"
+#include "mapper_002_2.c"
+#include "mapper_003_0.c"
+#include "mapper_007_2.c"
+#include "mapper_011_0.c"
+#include "mapper_066_0.c"
+
+#define MAPPER_ID(mapper, submapper) (((mapper) << 4) | (submapper))
+
+static void (*mapper_table[4096])(struct nes_state *state) = {
+	[MAPPER_ID( 0, 0)] = mapper_000_0_init,
+	[MAPPER_ID( 2, 2)] = mapper_002_2_init,
+	[MAPPER_ID( 3, 0)] = mapper_003_0_init,
+	[MAPPER_ID( 7, 2)] = mapper_007_2_init,
+	[MAPPER_ID(11, 0)] = mapper_011_0_init,
+	[MAPPER_ID(66, 0)] = mapper_011_0_init,
+};
+
+static void mapper_reset(struct nes_state *state) {
+	state->mapper.prg_read = 0;
+	state->mapper.prg_write = mapper_default_prg_write;
+	state->mapper.chr_read = 0;
+	state->mapper.chr_write = mapper_default_chr_write;
+	state->mapper.ciram_read = mapper_default_ciram_read;
+	state->mapper.ciram_write = mapper_default_ciram_write;
+	state->mapper.tick = mapper_default_tick;
+}
+
+static void mapper_setup(struct nes_state *state) {
+	uint32_t mapper = state->ines.mapper << 4 | state->ines.submapper;
+	mapper_reset(state);
+	if(mapper_table[mapper]) {
+		mapper_table[mapper](state);
+	} else {
+		printf("Unsupported mapper %d_%x, falling back to NROM\n", state->ines.mapper, state->ines.submapper);
+		mapper_table[0](state);
+	}
+}
+