extlinux/misc.h

   1 /*
   2  * Copyright (c) 2012 Paulo Alcantara <pcacjr@zytor.com>
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it would be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program; if not, write the Free Software Foundation,
  15  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  16  */
  17
  18 #ifndef MISC_H_
  19 #define MISC_H_
  20
  21 /* Return a 64-bit litte-endian value from a given 64-bit big-endian one */
  22 static inline uint64_t be64_to_cpu(uint64_t val)
  23 {
  24     return (uint64_t)((((uint64_t)val & (uint64_t)0x00000000000000ffULL) << 56) |
  25                       (((uint64_t)val & (uint64_t)0x000000000000ff00ULL) << 40) |
  26                       (((uint64_t)val & (uint64_t)0x0000000000ff0000ULL) << 24) |
  27                       (((uint64_t)val & (uint64_t)0x00000000ff000000ULL) <<  8) |
  28                       (((uint64_t)val & (uint64_t)0x000000ff00000000ULL) >>  8) |
  29                       (((uint64_t)val & (uint64_t)0x0000ff0000000000ULL) >> 24) |
  30                       (((uint64_t)val & (uint64_t)0x00ff000000000000ULL) >> 40) |
  31                       (((uint64_t)val & (uint64_t)0xff00000000000000ULL) >> 56));
  32 }
  33
  34 /* Return a 32-bit litte-endian value from a given 32-bit big-endian one */
  35 static inline uint32_t be32_to_cpu(uint32_t val)
  36 {
  37     return (uint32_t)((((uint32_t)val & (uint32_t)0x000000ffUL) << 24) |
  38                       (((uint32_t)val & (uint32_t)0x0000ff00UL) <<  8) |
  39                       (((uint32_t)val & (uint32_t)0x00ff0000UL) >>  8) |
  40                       (((uint32_t)val & (uint32_t)0xff000000UL) >> 24));
  41 }
  42
  43 /* Return a 16-bit litte-endian value from a given 16-bit big-endian one */
  44 static inline uint16_t be16_to_cpu(uint16_t val)
  45 {
  46     return (uint16_t)((((uint16_t)val & (uint16_t)0x00ffU) << 8) |
  47                       (((uint16_t)val & (uint16_t)0xff00U) >> 8));
  48 }
  49
  50 #endif /* MISC_H_ */