2 * macros to convert each packed bitfield structure from little endian to big
3 * endian and vice versa. These are needed when creating a filesystem on a
4 * machine with different byte ordering to the target architecture.
6 * Copyright (c) 2002, 2003, 2004 Phillip Lougher <plougher@users.sourceforge.net>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version 2,
11 * or (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 * macros used to swap each structure entry, taking into account
28 * bitfields and different bitfield placing conventions on differing architectures
30 #if __BYTE_ORDER == __BIG_ENDIAN
31 /* convert from big endian to little endian */
32 #define SQUASHFS_SWAP(value, p, pos, tbits) _SQUASHFS_SWAP(value, p, pos, tbits, b_pos)
34 /* convert from little endian to big endian */
35 #define SQUASHFS_SWAP(value, p, pos, tbits) _SQUASHFS_SWAP(value, p, pos, tbits, 64 - tbits - b_pos)
38 #define _SQUASHFS_SWAP(value, p, pos, tbits, SHIFT) {\
41 unsigned long long val = (long long) value << (SHIFT);\
42 unsigned char *s = ((unsigned char *) &val) + 7;\
43 unsigned char *d = ((unsigned char *)p) + (pos / 8);\
44 for(bits = 0; bits < (tbits + b_pos); bits += 8) \
47 #define SQUASHFS_MEMSET(s, d, n) memset(d, 0, n);