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 <ext_common.h>
  42
  43 static block_dev_desc_t *ext4fs_block_dev_desc;
  44 static disk_partition_t part_info;
  45
  46 int ext4fs_set_blk_dev(block_dev_desc_t *rbdd, int part)
  47 {
  48         ext4fs_block_dev_desc = rbdd;
  49
  50         if (part == 0) {
  51                 /* disk doesn't use partition table */
  52                 part_info.start = 0;
  53                 part_info.size = rbdd->lba;
  54                 part_info.blksz = rbdd->blksz;
  55         } else {
  56                 if (get_partition_info(ext4fs_block_dev_desc,
  57                                         part, &part_info))
  58                         return 0;
  59         }
  60         return part_info.size;
  61 }
  62
  63 int ext4fs_devread(int sector, int byte_offset, int byte_len, char *buf)
  64 {
  65         ALLOC_CACHE_ALIGN_BUFFER(char, sec_buf, SECTOR_SIZE);
  66         unsigned block_len;
  67
  68         /* Check partition boundaries */
  69         if ((sector < 0)
  70             || ((sector + ((byte_offset + byte_len - 1) >> SECTOR_BITS)) >=
  71                 part_info.size)) {
  72                 printf("%s read outside partition %d\n", __func__, sector);
  73                 return 0;
  74         }
  75
  76         /* Get the read to the beginning of a partition */
  77         sector += byte_offset >> SECTOR_BITS;
  78         byte_offset &= SECTOR_SIZE - 1;
  79
  80         debug(" <%d, %d, %d>\n", sector, byte_offset, byte_len);
  81
  82         if (ext4fs_block_dev_desc == NULL) {
  83                 printf("** Invalid Block Device Descriptor (NULL)\n");
  84                 return 0;
  85         }
  86
  87         if (byte_offset != 0) {
  88                 /* read first part which isn't aligned with start of sector */
  89                 if (ext4fs_block_dev_desc->
  90                     block_read(ext4fs_block_dev_desc->dev,
  91                                 part_info.start + sector, 1,
  92                                 (unsigned long *) sec_buf) != 1) {
  93                         printf(" ** ext2fs_devread() read error **\n");
  94                         return 0;
  95                 }
  96                 memcpy(buf, sec_buf + byte_offset,
  97                         min(SECTOR_SIZE - byte_offset, byte_len));
  98                 buf += min(SECTOR_SIZE - byte_offset, byte_len);
  99                 byte_len -= min(SECTOR_SIZE - byte_offset, byte_len);
 100                 sector++;
 101         }
 102
 103         if (byte_len == 0)
 104                 return 1;
 105
 106         /* read sector aligned part */
 107         block_len = byte_len & ~(SECTOR_SIZE - 1);
 108
 109         if (block_len == 0) {
 110                 ALLOC_CACHE_ALIGN_BUFFER(u8, p, SECTOR_SIZE);
 111
 112                 block_len = SECTOR_SIZE;
 113                 ext4fs_block_dev_desc->block_read(ext4fs_block_dev_desc->dev,
 114                                                   part_info.start + sector,
 115                                                   1, (unsigned long *)p);
 116                 memcpy(buf, p, byte_len);
 117                 return 1;
 118         }
 119
 120         if (ext4fs_block_dev_desc->block_read(ext4fs_block_dev_desc->dev,
 121                                                part_info.start + sector,
 122                                                block_len / SECTOR_SIZE,
 123                                                (unsigned long *) buf) !=
 124                                                block_len / SECTOR_SIZE) {
 125                 printf(" ** %s read error - block\n", __func__);
 126                 return 0;
 127         }
 128         block_len = byte_len & ~(SECTOR_SIZE - 1);
 129         buf += block_len;
 130         byte_len -= block_len;
 131         sector += block_len / SECTOR_SIZE;
 132
 133         if (byte_len != 0) {
 134                 /* read rest of data which are not in whole sector */
 135                 if (ext4fs_block_dev_desc->
 136                     block_read(ext4fs_block_dev_desc->dev,
 137                                 part_info.start + sector, 1,
 138                                 (unsigned long *) sec_buf) != 1) {
 139                         printf("* %s read error - last part\n", __func__);
 140                         return 0;
 141                 }
 142                 memcpy(buf, sec_buf, byte_len);
 143         }
 144         return 1;
 145 }