X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=pico%2Fcart.c;h=26fb59bb81fafa9cfa334b150df4c7148d7f327c;hb=83ff19ec52ff47992b5d6ceda3900b914eda2123;hp=cbd4bb6323227788c82225fd376519fd7dcdf5be;hpb=5e49c3a88d1c3ece302a40d8c3a32285d3199ab6;p=picodrive.git

diff --git a/pico/cart.c b/pico/cart.c
index cbd4bb6..26fb59b 100644
--- a/pico/cart.c
+++ b/pico/cart.c
@@ -378,23 +378,21 @@ int pm_close(pm_file *fp)
   return ret;
 }
 
-
-static void Byteswap(unsigned char *data,int len)
+// byteswap, data needs to be int aligned, src can match dst
+void Byteswap(void *dst, const void *src, int len)
 {
-  int i=0;
-
-  if (len<2) return; // Too short
+  const unsigned int *ps = src;
+  unsigned int *pd = dst;
+  int i, m;
 
-  do
-  {
-    unsigned short *pd=(unsigned short *)(data+i);
-    int value=*pd; // Get 2 bytes
+  if (len < 2)
+    return;
 
-    value=(value<<8)|(value>>8); // Byteswap it
-    *pd=(unsigned short)value; // Put 2b ytes
-    i+=2;
+  m = 0x00ff00ff;
+  for (i = 0; i < len / 4; i++) {
+    unsigned int t = ps[i];
+    pd[i] = ((t & m) << 8) | ((t & ~m) >> 8);
   }
-  while (i+2<=len);
 }
 
 // Interleve a 16k block and byteswap
@@ -524,7 +522,7 @@ int PicoCartLoad(pm_file *f,unsigned char **prom,unsigned int *psize,int is_sms)
       elprintf(EL_STATUS, "SMD format detected.");
       DecodeSmd(rom,size); size-=0x200; // Decode and byteswap SMD
     }
-    else Byteswap(rom,size); // Just byteswap
+    else Byteswap(rom, rom, size); // Just byteswap
   }
   else
   {
@@ -621,9 +619,9 @@ static unsigned int rom_crc32(void)
   elprintf(EL_STATUS, "caclulating CRC32..");
 
   // have to unbyteswap for calculation..
-  Byteswap(Pico.rom, Pico.romsize);
+  Byteswap(Pico.rom, Pico.rom, Pico.romsize);
   crc = crc32(0, Pico.rom, Pico.romsize);
-  Byteswap(Pico.rom, Pico.romsize);
+  Byteswap(Pico.rom, Pico.rom, Pico.romsize);
   return crc;
 }