make dma honour banking

[picodrive.git] / pico / memory.h

diff --git a/pico/memory.h b/pico/memory.h
index 4421371..4260a35 100644 (file)
--- a/pico/memory.h
+++ b/pico/memory.h
@@ -45,7 +45,8 @@ void cpu68k_map_set(uptr *map, int start_addr, int end_addr,
 void cpu68k_map_all_ram(int start_addr, int end_addr, void *ptr, int is_sub);
 void m68k_map_unmap(int start_addr, int end_addr);
 
-#define map_flag_set(x) ((x) & ((uptr)1 << (sizeof(uptr) * 8 - 1)))
+#define MAP_FLAG ((uptr)1 << (sizeof(uptr) * 8 - 1))
+#define map_flag_set(x) ((x) & MAP_FLAG)
 
 #define MAKE_68K_READ8(name, map)               \
 u32 name(u32 a)                                 \
@@ -132,6 +133,17 @@ void name(u32 a, u32 d)                         \
   }                                             \
 }
 
+static __inline void *m68k_dma_source(u32 a)
+{
+  uptr v;
+  a &= 0x00fffffe;
+  v = m68k_read16_map[a >> M68K_MEM_SHIFT];
+  if (map_flag_set(v))
+    return NULL;
+  else
+    return (void *)((v << 1) + a);
+}
+
 // 32x
 typedef struct {
   uptr addr; // stores (membase >> 1) or ((handler >> 1) | (1<<31))