apps/plugins/rockboy/fastmem.c

   1
   2
   3 #include "rockmacros.h"
   4 #include "fastmem.h"
   5
   6 byte readb(int a)
   7 {
   8     byte *p = mbc.rmap[a>>12];
   9     if (p) return p[a];
  10     else return mem_read(a);
  11 }
  12
  13 void writeb(int a, byte b)
  14 {
  15     byte *p = mbc.wmap[a>>12];
  16     if (p) p[a] = b;
  17     else mem_write(a, b);
  18 }
  19
  20 int readw(int a)
  21 {
  22     if ((a+1) & 0xfff)
  23     {
  24         byte *p = mbc.rmap[a>>12];
  25         if (p)
  26         {
  27 #ifdef ROCKBOX_LITTLE_ENDIAN
  28 #ifndef ALLOW_UNALIGNED_IO
  29             if (a&1) return p[a] | (p[a+1]<<8);
  30 #endif
  31             return *(word *)(p+a);
  32 #else
  33             return p[a] | (p[a+1]<<8);
  34 #endif
  35         }
  36     }
  37     return mem_read(a) | (mem_read(a+1)<<8);
  38 }
  39
  40 void writew(int a, int w)
  41 {
  42     if ((a+1) & 0xfff)
  43     {
  44         byte *p = mbc.wmap[a>>12];
  45         if (p)
  46         {
  47 #ifdef ROCKBOX_LITTLE_ENDIAN
  48 #ifndef ALLOW_UNALIGNED_IO
  49             if (a&1)
  50             {
  51                 p[a] = w;
  52                 p[a+1] = w >> 8;
  53                 return;
  54             }
  55 #endif
  56             *(word *)(p+a) = w;
  57             return;
  58 #else
  59             p[a] = w;
  60             p[a+1] = w >> 8;
  61             return;
  62 #endif
  63         }
  64     }
  65     mem_write(a, w);
  66     mem_write(a+1, w>>8);
  67 }
  68
  69 byte readhi(int a)
  70 {
  71     return readb(a | 0xff00);
  72 }
  73
  74 void writehi(int a, byte b)
  75 {
  76     writeb(a | 0xff00, b);
  77 }