fs/ext4/dev.c

   1 /*
   2  * (C) Copyright 2011 - 2012 Samsung Electronics
   3  * EXT4 filesystem implementation in Uboot by
   4  * Uma Shankar <uma.shankar@samsung.com>
   5  * Manjunatha C Achar <a.manjunatha@samsung.com>
   6  *
   7  * made from existing ext2/dev.c file of Uboot
   8  * (C) Copyright 2004
   9  * esd gmbh <www.esd-electronics.com>
  10  * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
  11  *
  12  * based on code of fs/reiserfs/dev.c by
  13  *
  14  * (C) Copyright 2003 - 2004
  15  * Sysgo AG, <www.elinos.com>, Pavel Bartusek <pba@sysgo.com>
  16  *
  17  * This program is free software; you can redistribute it and/or modify
  18  * it under the terms of the GNU General Public License as published by
  19  * the Free Software Foundation; either version 2 of the License, or
  20  * (at your option) any later version.
  21  *
  22  * This program is distributed in the hope that it will be useful,
  23  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  25  * GNU General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU General Public License
  28  * along with this program; if not, write to the Free Software
  29  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  30  *
  31  */
  32
  33 /*
  34  * Changelog:
  35  *      0.1 - Newly created file for ext4fs support. Taken from
  36  *              fs/ext2/dev.c file in uboot.
  37  */
  38
  39 #include <common.h>
  40 #include <config.h>
  41 #include <ext4fs.h>
  42 #include <ext_common.h>
  43
  44 unsigned long part_offset;
  45
  46 static block_dev_desc_t *ext4fs_block_dev_desc;
  47 static disk_partition_t *part_info;
  48
  49 void ext4fs_set_blk_dev(block_dev_desc_t *rbdd, disk_partition_t *info)
  50 {
  51         ext4fs_block_dev_desc = rbdd;
  52         part_info = info;
  53         part_offset = info->start;
  54         get_fs()->total_sect = (info->size * info->blksz) / SECTOR_SIZE;
  55         get_fs()->dev_desc = rbdd;
  56 }
  57
  58 int ext4fs_devread(int sector, int byte_offset, int byte_len, char *buf)
  59 {
  60         ALLOC_CACHE_ALIGN_BUFFER(char, sec_buf, SECTOR_SIZE);
  61         unsigned block_len;
  62
  63         /* Check partition boundaries */
  64         if ((sector < 0)
  65             || ((sector + ((byte_offset + byte_len - 1) >> SECTOR_BITS)) >=
  66                 part_info->size)) {
  67                 printf("%s read outside partition %d\n", __func__, sector);
  68                 return 0;
  69         }
  70
  71         /* Get the read to the beginning of a partition */
  72         sector += byte_offset >> SECTOR_BITS;
  73         byte_offset &= SECTOR_SIZE - 1;
  74
  75         debug(" <%d, %d, %d>\n", sector, byte_offset, byte_len);
  76
  77         if (ext4fs_block_dev_desc == NULL) {
  78                 printf("** Invalid Block Device Descriptor (NULL)\n");
  79                 return 0;
  80         }
  81
  82         if (byte_offset != 0) {
  83                 /* read first part which isn't aligned with start of sector */
  84                 if (ext4fs_block_dev_desc->
  85                     block_read(ext4fs_block_dev_desc->dev,
  86                                 part_info->start + sector, 1,
  87                                 (unsigned long *) sec_buf) != 1) {
  88                         printf(" ** ext2fs_devread() read error **\n");
  89                         return 0;
  90                 }
  91                 memcpy(buf, sec_buf + byte_offset,
  92                         min(SECTOR_SIZE - byte_offset, byte_len));
  93                 buf += min(SECTOR_SIZE - byte_offset, byte_len);
  94                 byte_len -= min(SECTOR_SIZE - byte_offset, byte_len);
  95                 sector++;
  96         }
  97
  98         if (byte_len == 0)
  99                 return 1;
 100
 101         /* read sector aligned part */
 102         block_len = byte_len & ~(SECTOR_SIZE - 1);
 103
 104         if (block_len == 0) {
 105                 ALLOC_CACHE_ALIGN_BUFFER(u8, p, SECTOR_SIZE);
 106
 107                 block_len = SECTOR_SIZE;
 108                 ext4fs_block_dev_desc->block_read(ext4fs_block_dev_desc->dev,
 109                                                   part_info->start + sector,
 110                                                   1, (unsigned long *)p);
 111                 memcpy(buf, p, byte_len);
 112                 return 1;
 113         }
 114
 115         if (ext4fs_block_dev_desc->block_read(ext4fs_block_dev_desc->dev,
 116                                                part_info->start + sector,
 117                                                block_len / SECTOR_SIZE,
 118                                                (unsigned long *) buf) !=
 119                                                block_len / SECTOR_SIZE) {
 120                 printf(" ** %s read error - block\n", __func__);
 121                 return 0;
 122         }
 123         block_len = byte_len & ~(SECTOR_SIZE - 1);
 124         buf += block_len;
 125         byte_len -= block_len;
 126         sector += block_len / SECTOR_SIZE;
 127
 128         if (byte_len != 0) {
 129                 /* read rest of data which are not in whole sector */
 130                 if (ext4fs_block_dev_desc->
 131                     block_read(ext4fs_block_dev_desc->dev,
 132                                 part_info->start + sector, 1,
 133                                 (unsigned long *) sec_buf) != 1) {
 134                         printf("* %s read error - last part\n", __func__);
 135                         return 0;
 136                 }
 137                 memcpy(buf, sec_buf, byte_len);
 138         }
 139         return 1;
 140 }