minix/fs/mfs/utility.c

   1 #include "fs.h"
   2 #include "buf.h"
   3 #include "inode.h"
   4 #include "super.h"
   5
   6
   7 /*===========================================================================*
   8  *                              conv2                                        *
   9  *===========================================================================*/
  10 unsigned conv2(norm, w)
  11 int norm;                       /* TRUE if no swap, FALSE for byte swap */
  12 int w;                          /* promotion of 16-bit word to be swapped */
  13 {
  14 /* Possibly swap a 16-bit word between 8086 and 68000 byte order. */
  15   if (norm) return( (unsigned) w & 0xFFFF);
  16   return( ((w&BYTE) << 8) | ( (w>>8) & BYTE));
  17 }
  18
  19
  20 /*===========================================================================*
  21  *                              conv4                                        *
  22  *===========================================================================*/
  23 long conv4(norm, x)
  24 int norm;                       /* TRUE if no swap, FALSE for byte swap */
  25 long x;                         /* 32-bit long to be byte swapped */
  26 {
  27 /* Possibly swap a 32-bit long between 8086 and 68000 byte order. */
  28   unsigned lo, hi;
  29   long l;
  30
  31   if (norm) return(x);                  /* byte order was already ok */
  32   lo = conv2(FALSE, (int) x & 0xFFFF);  /* low-order half, byte swapped */
  33   hi = conv2(FALSE, (int) (x>>16) & 0xFFFF);    /* high-order half, swapped */
  34   l = ( (long) lo <<16) | hi;
  35   return(l);
  36 }