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Diffstat (limited to '')
| -rw-r--r-- | disk-utils/cramfs_common.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/disk-utils/cramfs_common.c b/disk-utils/cramfs_common.c new file mode 100644 index 0000000..9fe3fa1 --- /dev/null +++ b/disk-utils/cramfs_common.c @@ -0,0 +1,109 @@ +/* + * cramfs_common - cramfs common code + * + * Copyright (c) 2008 Roy Peled, the.roy.peled -at- gmail.com + * Copyright (c) 2004-2006 by Juliane Holzt, kju -at- fqdn.org + * + * 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; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include <string.h> +#include "cramfs.h" +#include "../include/bitops.h" + +uint32_t u32_toggle_endianness(int big_endian, uint32_t what) +{ + return big_endian == HOST_IS_BIG_ENDIAN ? what : swab32(what); +} + +void super_toggle_endianness(int big_endian, struct cramfs_super *super) +{ + if (big_endian != HOST_IS_BIG_ENDIAN) { + super->magic = swab32(super->magic); + super->size = swab32(super->size); + super->flags = swab32(super->flags); + super->future = swab32(super->future); + super->fsid.crc = swab32(super->fsid.crc); + super->fsid.edition = swab32(super->fsid.edition); + super->fsid.blocks = swab32(super->fsid.blocks); + super->fsid.files = swab32(super->fsid.files); + } +} + +static void inode_toggle_endianness(int input_big_endian, int output_big_endian, + struct cramfs_inode *inode_in, + struct cramfs_inode *inode_out) +{ + if (input_big_endian == output_big_endian) { + memmove(inode_out, inode_in, sizeof(*inode_out)); + } else { + unsigned char inode_out_buf[sizeof(*inode_in)]; + unsigned char *inode_in_buf = (unsigned char*)inode_in; + + inode_out_buf[0] = inode_in_buf[1]; /* 16 bit: mode */ + inode_out_buf[1] = inode_in_buf[0]; + + inode_out_buf[2] = inode_in_buf[3]; /* 16 bit: uid */ + inode_out_buf[3] = inode_in_buf[2]; + + inode_out_buf[4] = inode_in_buf[6]; /* 24 bit: size */ + inode_out_buf[5] = inode_in_buf[5]; + inode_out_buf[6] = inode_in_buf[4]; + + inode_out_buf[7] = inode_in_buf[7]; /* 8 bit: gid width */ + + /* + * Stop the madness! Outlaw C bitfields! They are unportable + * and nasty! See for yourself what a mess this is: + */ + if (output_big_endian) { + inode_out_buf[ 8] = ( (inode_in_buf[ 8]&0x3F) << 2 ) | + ( (inode_in_buf[11]&0xC0) >> 6 ); + + inode_out_buf[ 9] = ( (inode_in_buf[11]&0x3F) << 2 ) | + ( (inode_in_buf[10]&0xC0) >> 6 ); + + inode_out_buf[10] = ( (inode_in_buf[10]&0x3F) << 2 ) | + ( (inode_in_buf[ 9]&0xC0) >> 6 ); + + inode_out_buf[11] = ( (inode_in_buf[ 9]&0x3F) << 2 ) | + ( (inode_in_buf[ 8]&0xC0) >> 6 ); + } else { + inode_out_buf[ 8] = ( (inode_in_buf[ 8]&0xFD) >> 2 ) | + ( (inode_in_buf[11]&0x03) << 6 ); + + inode_out_buf[ 9] = ( (inode_in_buf[11]&0xFD) >> 2 ) | + ( (inode_in_buf[10]&0x03) << 6 ); + + inode_out_buf[10] = ( (inode_in_buf[10]&0xFD) >> 2 ) | + ( (inode_in_buf[ 9]&0x03) << 6 ); + + inode_out_buf[11] = ( (inode_in_buf[ 9]&0xFD) >> 2 ) | + ( (inode_in_buf[ 8]&0x03) << 6 ); + } + memmove(inode_out, inode_out_buf, sizeof(*inode_out)); + } +} + +void inode_to_host(int from_big_endian, struct cramfs_inode *inode_in, + struct cramfs_inode *inode_out) +{ + inode_toggle_endianness(from_big_endian, HOST_IS_BIG_ENDIAN, inode_in, + inode_out); +} + +void inode_from_host(int to_big_endian, struct cramfs_inode *inode_in, + struct cramfs_inode *inode_out) +{ + inode_toggle_endianness(HOST_IS_BIG_ENDIAN, to_big_endian, inode_in, + inode_out); +} |