--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sft_mapper.c	Mon Dec 12 20:51:19 2022 -0800
@@ -0,0 +1,27 @@
+#include "genesis.h"
+
+void* sft_wukong_write_b(uint32_t address, void *context, uint8_t value)
+{
+	if (!(address & 1)) {
+		return context;
+	}
+	m68k_context *m68k = context;
+	genesis_context *gen = m68k->system;
+	printf("wukong mapper write: %X - %X\n", address, value);
+	uint16_t *old = m68k->mem_pointers[gen->mapper_start_index];
+	if (value & 0x80) {
+		m68k->mem_pointers[gen->mapper_start_index] = gen->cart;
+	} else {
+		m68k->mem_pointers[gen->mapper_start_index] = gen->cart + 1 * 1024 * 1024;
+	}
+	if (old != m68k->mem_pointers[gen->mapper_start_index]) {
+		m68k_invalidate_code_range(m68k, 0x200000, 0x3C0000);
+	}
+
+	return context;
+}
+
+void* sft_wukong_write_w(uint32_t address, void *context, uint16_t value)
+{
+	return sft_wukong_write_b(address | 1, context, value);
+}