byte swapping

git-svn-id: svn://svn.coreboot.org/coreboot/trunk@1406 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
This commit is contained in:
Greg Watson 2004-03-13 03:37:11 +00:00
parent 1624782bbe
commit 4f566ca1c0
1 changed files with 33 additions and 0 deletions

33
src/include/swab.h Normal file
View File

@ -0,0 +1,33 @@
#ifndef _SWAB_H
#define _SWAB_H
/*
* linux/byteorder/swab.h
* Byte-swapping, independently from CPU endianness
* swabXX[ps]?(foo)
*
* Francois-Rene Rideau <fare@tunes.org> 19971205
* separated swab functions from cpu_to_XX,
* to clean up support for bizarre-endian architectures.
*
* See asm-i386/byteorder.h and suches for examples of how to provide
* architecture-dependent optimized versions
*
*/
/* casts are necessary for constants, because we never know how for sure
* how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way.
*/
#define swab16(x) \
((unsigned short)( \
(((unsigned short)(x) & (unsigned short)0x00ffU) << 8) | \
(((unsigned short)(x) & (unsigned short)0xff00U) >> 8) ))
#define swab32(x) \
((unsigned int)( \
(((unsigned int)(x) & (unsigned int)0x000000ffUL) << 24) | \
(((unsigned int)(x) & (unsigned int)0x0000ff00UL) << 8) | \
(((unsigned int)(x) & (unsigned int)0x00ff0000UL) >> 8) | \
(((unsigned int)(x) & (unsigned int)0xff000000UL) >> 24) ))
#endif /* _SWAB_H */