2 * cramfs_common - cramfs common code
4 * Copyright (c) 2008 Roy Peled, the.roy.peled -at- gmail.com
5 * Copyright (c) 2004-2006 by Michael Holzt, kju -at- fqdn.org
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
20 #include "cramfs_common.h"
21 #include "../include/bitops.h"
23 u32 u32_toggle_endianness(int big_endian, u32 what)
25 return big_endian == HOST_IS_BIG_ENDIAN ? what : swab32(what);
28 void super_toggle_endianness(int big_endian, struct cramfs_super *super)
30 if (big_endian != HOST_IS_BIG_ENDIAN) {
31 super->magic = swab32(super->magic);
32 super->size = swab32(super->size);
33 super->flags = swab32(super->flags);
34 super->future = swab32(super->future);
35 super->fsid.crc = swab32(super->fsid.crc);
36 super->fsid.edition = swab32(super->fsid.edition);
37 super->fsid.blocks = swab32(super->fsid.blocks);
38 super->fsid.files = swab32(super->fsid.files);
42 void inode_toggle_endianness(int input_big_endian, int output_big_endian, struct cramfs_inode *inode_in, struct cramfs_inode *inode_out)
44 if (input_big_endian == output_big_endian) {
45 memmove(inode_out, inode_in, sizeof(*inode_out));
48 unsigned char inode_out_buf[sizeof(*inode_in)];
49 unsigned char *inode_in_buf = (unsigned char*)inode_in;
51 inode_out_buf[0] = inode_in_buf[1]; /* 16 bit: mode */
52 inode_out_buf[1] = inode_in_buf[0];
54 inode_out_buf[2] = inode_in_buf[3]; /* 16 bit: uid */
55 inode_out_buf[3] = inode_in_buf[2];
57 inode_out_buf[4] = inode_in_buf[6]; /* 24 bit: size */
58 inode_out_buf[5] = inode_in_buf[5];
59 inode_out_buf[6] = inode_in_buf[4];
61 inode_out_buf[7] = inode_in_buf[7]; /* 8 bit: gid width */
63 /* Stop the madness! Outlaw C bitfields! They are unportable and nasty!
64 See for yourself what a mess this is: */
66 if (output_big_endian) {
67 inode_out_buf[ 8] = ( (inode_in_buf[ 8]&0x3F) << 2 ) |
68 ( (inode_in_buf[11]&0xC0) >> 6 );
70 inode_out_buf[ 9] = ( (inode_in_buf[11]&0x3F) << 2 ) |
71 ( (inode_in_buf[10]&0xC0) >> 6 );
73 inode_out_buf[10] = ( (inode_in_buf[10]&0x3F) << 2 ) |
74 ( (inode_in_buf[ 9]&0xC0) >> 6 );
76 inode_out_buf[11] = ( (inode_in_buf[ 9]&0x3F) << 2 ) |
77 ( (inode_in_buf[ 8]&0xC0) >> 6 );
80 inode_out_buf[ 8] = ( (inode_in_buf[ 8]&0xFD) >> 2 ) |
81 ( (inode_in_buf[11]&0x03) << 6 );
83 inode_out_buf[ 9] = ( (inode_in_buf[11]&0xFD) >> 2 ) |
84 ( (inode_in_buf[10]&0x03) << 6 );
86 inode_out_buf[10] = ( (inode_in_buf[10]&0xFD) >> 2 ) |
87 ( (inode_in_buf[ 9]&0x03) << 6 );
89 inode_out_buf[11] = ( (inode_in_buf[ 9]&0xFD) >> 2 ) |
90 ( (inode_in_buf[ 8]&0x03) << 6 );
93 memmove(inode_out, inode_out_buf, sizeof(*inode_out));
97 void inode_to_host(int from_big_endian, struct cramfs_inode *inode_in, struct cramfs_inode *inode_out)
99 inode_toggle_endianness(from_big_endian, HOST_IS_BIG_ENDIAN, inode_in, inode_out);
102 void inode_from_host(int to_big_endian, struct cramfs_inode *inode_in, struct cramfs_inode *inode_out)
104 inode_toggle_endianness(HOST_IS_BIG_ENDIAN, to_big_endian, inode_in, inode_out);