libinstaller/syslxint.h

/* ----------------------------------------------------------------------- *
 *
 *   Copyright 2007-2008 H. Peter Anvin - All Rights Reserved
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
 *   Boston MA 02111-1307, USA; either version 2 of the License, or
 *   (at your option) any later version; incorporated herein by reference.
 *
 * ----------------------------------------------------------------------- */

#ifndef SYSLXINT_H
#define SYSLXINT_H

#include "syslinux.h"

/*
 * Access functions for littleendian numbers, possibly misaligned.
 */
static inline uint8_t get_8(const unsigned char *p)
{
    return *(const uint8_t *)p;
}

static inline uint16_t get_16(const unsigned char *p)
{
#if defined(__i386__) || defined(__x86_64__)
    /* Littleendian and unaligned-capable */
    return *(const uint16_t *)p;
#else
    return (uint16_t) p[0] + ((uint16_t) p[1] << 8);
#endif
}

static inline uint32_t get_32(const unsigned char *p)
{
#if defined(__i386__) || defined(__x86_64__)
    /* Littleendian and unaligned-capable */
    return *(const uint32_t *)p;
#else
    return (uint32_t) p[0] + ((uint32_t) p[1] << 8) +
	((uint32_t) p[2] << 16) + ((uint32_t) p[3] << 24);
#endif
}

static inline void set_16(unsigned char *p, uint16_t v)
{
#if defined(__i386__) || defined(__x86_64__)
    /* Littleendian and unaligned-capable */
    *(uint16_t *) p = v;
#else
    p[0] = (v & 0xff);
    p[1] = ((v >> 8) & 0xff);
#endif
}

static inline void set_32(unsigned char *p, uint32_t v)
{
#if defined(__i386__) || defined(__x86_64__)
    /* Littleendian and unaligned-capable */
    *(uint32_t *) p = v;
#else
    p[0] = (v & 0xff);
    p[1] = ((v >> 8) & 0xff);
    p[2] = ((v >> 16) & 0xff);
    p[3] = ((v >> 24) & 0xff);
#endif
}

#define SECTOR_SHIFT	9	/* 512-byte sectors */
#define SECTOR_SIZE	(1 << SECTOR_SHIFT)

#endif /* SYSLXINT_H */