From 7feeb8806243f9f0bc6c3d6e957b97d12cecb7df Mon Sep 17 00:00:00 2001
From: notaz <notasas@gmail.com>
Date: Fri, 22 Sep 2017 02:16:15 +0300
Subject: [PATCH] make dma honour banking

I was sure I had it done before, turns out not.
---
 pico/memory.h    | 11 +++++++++++
 pico/videoport.c |  5 +++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/pico/memory.h b/pico/memory.h
index afca082..4260a35 100644
--- a/pico/memory.h
+++ b/pico/memory.h
@@ -133,6 +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))
diff --git a/pico/videoport.c b/pico/videoport.c
index 9ddc167..35ece48 100644
--- a/pico/videoport.c
+++ b/pico/videoport.c
@@ -8,6 +8,7 @@
  */
 
 #include "pico_int.h"
+#include "memory.h"
 
 int line_base_cycles;
 extern const unsigned char  hcounts_32[];
@@ -134,10 +135,10 @@ static void DmaSlow(int len)
     // if we have DmaHook, let it handle ROM because of possible DMA delay
     if (PicoDmaHook && PicoDmaHook(source, len, &pd, &pdend));
     else if (source<Pico.romsize) { // Rom
-      pd=(u16 *)(Pico.rom+(source&~1));
+      pd=m68k_dma_source(source);
       pdend=(u16 *)(Pico.rom+Pico.romsize);
     }
-    else {
+    if (!pd) {
       elprintf(EL_VDPDMA|EL_ANOMALY, "DmaSlow[%i] %06x->%04x: invalid src", Pico.video.type, source, a);
       return;
     }
-- 
2.39.2