util/vgabios/include/swab.h

   1 /* This file is part of the coreboot project. */
   2 /* SPDX-License-Identifier: GPL-2.0-only */
   3
   4 #ifndef _SWAB_H
   5 #define _SWAB_H
   6
   7 /*
   8  * linux/byteorder/swab.h
   9  * Byte-swapping, independently from CPU endianness
  10  *      swabXX[ps]?(foo)
  11  *
  12  * Francois-Rene Rideau <fare@tunes.org> 19971205
  13  *    separated swab functions from cpu_to_XX,
  14  *    to clean up support for bizarre-endian architectures.
  15  *
  16  * See asm-i386/byteorder.h and such for examples of how to provide
  17  * architecture-dependent optimized versions
  18  *
  19  */
  20
  21 /* casts are necessary for constants, because we never know how for sure
  22  * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way.
  23  */
  24 #define swab16(x) \
  25         ((unsigned short)( \
  26                 (((unsigned short)(x) & (unsigned short)0x00ffU) << 8) | \
  27                 (((unsigned short)(x) & (unsigned short)0xff00U) >> 8) ))
  28
  29 #define swab32(x) \
  30         ((unsigned int)( \
  31                 (((unsigned int)(x) & (unsigned int)0x000000ffUL) << 24) | \
  32                 (((unsigned int)(x) & (unsigned int)0x0000ff00UL) <<  8) | \
  33                 (((unsigned int)(x) & (unsigned int)0x00ff0000UL) >>  8) | \
  34                 (((unsigned int)(x) & (unsigned int)0xff000000UL) >> 24) ))
  35
  36 #define swab64(x) \
  37         ((uint64_t)( \
  38                 (((uint64_t)(x) & (uint64_t)0x00000000000000ffULL) << 56) | \
  39                 (((uint64_t)(x) & (uint64_t)0x000000000000ff00ULL) << 40) | \
  40                 (((uint64_t)(x) & (uint64_t)0x0000000000ff0000ULL) << 24) | \
  41                 (((uint64_t)(x) & (uint64_t)0x00000000ff000000ULL) <<  8) | \
  42                 (((uint64_t)(x) & (uint64_t)0x000000ff00000000ULL) >>  8) | \
  43                 (((uint64_t)(x) & (uint64_t)0x0000ff0000000000ULL) >> 24) | \
  44                 (((uint64_t)(x) & (uint64_t)0x00ff000000000000ULL) >> 40) | \
  45                 (((uint64_t)(x) & (uint64_t)0xff00000000000000ULL) >> 56) ))
  46
  47 #endif /* _SWAB_H */