libinstaller/syslxint.h

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 2007-2008 H. Peter Anvin - All Rights Reserved
   4  *
   5  *   This program is free software; you can redistribute it and/or modify
   6  *   it under the terms of the GNU General Public License as published by
   7  *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
   8  *   Boston MA 02111-1307, USA; either version 2 of the License, or
   9  *   (at your option) any later version; incorporated herein by reference.
  10  *
  11  * ----------------------------------------------------------------------- */
  12
  13 #ifndef SYSLXINT_H
  14 #define SYSLXINT_H
  15
  16 #include "syslinux.h"
  17
  18 /*
  19  * Access functions for littleendian numbers, possibly misaligned.
  20  */
  21 static inline uint8_t get_8(const unsigned char *p)
  22 {
  23   return *(const uint8_t *)p;
  24 }
  25
  26 static inline uint16_t get_16(const unsigned char *p)
  27 {
  28 #if defined(__i386__) || defined(__x86_64__)
  29   /* Littleendian and unaligned-capable */
  30   return *(const uint16_t *)p;
  31 #else
  32   return (uint16_t)p[0] + ((uint16_t)p[1] << 8);
  33 #endif
  34 }
  35
  36 static inline uint32_t get_32(const unsigned char *p)
  37 {
  38 #if defined(__i386__) || defined(__x86_64__)
  39   /* Littleendian and unaligned-capable */
  40   return *(const uint32_t *)p;
  41 #else
  42   return (uint32_t)p[0] + ((uint32_t)p[1] << 8) +
  43     ((uint32_t)p[2] << 16) + ((uint32_t)p[3] << 24);
  44 #endif
  45 }
  46
  47 static inline void set_16(unsigned char *p, uint16_t v)
  48 {
  49 #if defined(__i386__) || defined(__x86_64__)
  50   /* Littleendian and unaligned-capable */
  51   *(uint16_t *)p = v;
  52 #else
  53   p[0] = (v & 0xff);
  54   p[1] = ((v >> 8) & 0xff);
  55 #endif
  56 }
  57
  58 static inline void set_32(unsigned char *p, uint32_t v)
  59 {
  60 #if defined(__i386__) || defined(__x86_64__)
  61   /* Littleendian and unaligned-capable */
  62   *(uint32_t *)p = v;
  63 #else
  64   p[0] = (v & 0xff);
  65   p[1] = ((v >> 8) & 0xff);
  66   p[2] = ((v >> 16) & 0xff);
  67   p[3] = ((v >> 24) & 0xff);
  68 #endif
  69 }
  70
  71 #define SECTOR_SHIFT    9       /* 512-byte sectors */
  72 #define SECTOR_SIZE     (1 << SECTOR_SHIFT)
  73
  74 #endif /* SYSLXINT_H */