diff options
Diffstat (limited to 'fs/fdos/fat.c')
| -rw-r--r-- | fs/fdos/fat.c | 122 |
1 files changed, 0 insertions, 122 deletions
diff --git a/fs/fdos/fat.c b/fs/fdos/fat.c deleted file mode 100644 index 408fec7..0000000 --- a/fs/fdos/fat.c +++ /dev/null @@ -1,122 +0,0 @@ -/* - * (C) Copyright 2002 - * Stäubli Faverges - <www.staubli.com> - * Pierre AUBERT p.aubert@staubli.com - * - * SPDX-License-Identifier: GPL-2.0+ - */ - -#include <common.h> -#include <config.h> -#include <malloc.h> - -#include "dos.h" -#include "fdos.h" - - -/*----------------------------------------------------------------------------- - * fat_decode -- - *----------------------------------------------------------------------------- - */ -unsigned int fat_decode (Fs_t *fs, unsigned int num) -{ - unsigned int start = num * 3 / 2; - unsigned char *address = fs -> fat_buf + start; - - if (num < 2 || start + 1 > (fs -> fat_len * SZ_STD_SECTOR)) - return 1; - - if (num & 1) - return ((address [1] & 0xff) << 4) | ((address [0] & 0xf0 ) >> 4); - else - return ((address [1] & 0xf) << 8) | (address [0] & 0xff ); -} -/*----------------------------------------------------------------------------- - * check_fat -- - *----------------------------------------------------------------------------- - */ -static int check_fat (Fs_t *fs) -{ - int i, f; - - /* Cluster verification */ - for (i = 3 ; i < fs -> num_clus; i++){ - f = fat_decode (fs, i); - if (f < FAT12_LAST && f > fs -> num_clus){ - /* Wrong cluster number detected */ - return (-1); - } - } - return (0); -} -/*----------------------------------------------------------------------------- - * read_one_fat -- - *----------------------------------------------------------------------------- - */ -static int read_one_fat (BootSector_t *boot, Fs_t *fs, int nfat) -{ - if (dev_read (fs -> fat_buf, - (fs -> fat_start + nfat * fs -> fat_len), - fs -> fat_len) < 0) { - return (-1); - } - - if (fs -> fat_buf [0] || fs -> fat_buf [1] || fs -> fat_buf [2]) { - if ((fs -> fat_buf [0] != boot -> descr && - (fs -> fat_buf [0] != 0xf9 || boot -> descr != MEDIA_STD)) || - fs -> fat_buf [0] < MEDIA_STD){ - /* Unknown Media */ - return (-1); - } - if (fs -> fat_buf [1] != 0xff || fs -> fat_buf [2] != 0xff){ - /* FAT doesn't start with good values */ - return (-1); - } - } - - if (fs -> num_clus >= FAT12_MAX_NB) { - /* Too much clusters */ - return (-1); - } - - return check_fat (fs); -} -/*----------------------------------------------------------------------------- - * read_fat -- - *----------------------------------------------------------------------------- - */ -int read_fat (BootSector_t *boot, Fs_t *fs) -{ - unsigned int buflen; - int i; - - /* Allocate Fat Buffer */ - buflen = fs -> fat_len * SZ_STD_SECTOR; - if (fs -> fat_buf) { - free (fs -> fat_buf); - } - - if ((fs -> fat_buf = malloc (buflen)) == NULL) { - return (-1); - } - - /* Try to read each Fat */ - for (i = 0; i< fs -> nb_fat; i++){ - if (read_one_fat (boot, fs, i) == 0) { - /* Fat is OK */ - fs -> num_fat = i; - break; - } - } - - if (i == fs -> nb_fat){ - return (-1); - } - - if (fs -> fat_len > (((fs -> num_clus + 2) * - (FAT_BITS / 4) -1 ) / 2 / - SZ_STD_SECTOR + 1)) { - return (-1); - } - return (0); -} |