board/freescale/common/sdhc_boot.c

   1 /*
   2  * Copyright 2011 Freescale Semiconductor, Inc.
   3  *
   4  * See file CREDITS for list of people who contributed to this
   5  * project.
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation; either version 2 of
  10  * the License, or (at your option) any later version.
  11  *
  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.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  20  * MA 02111-1307 USA
  21  */
  22
  23 #include <common.h>
  24 #include <mmc.h>
  25 #include <malloc.h>
  26
  27 /*
  28  * The environment variables are written to just after the u-boot image
  29  * on SDCard, so we must read the MBR to get the start address and code
  30  * length of the u-boot image, then calculate the address of the env.
  31  */
  32 #define ESDHC_BOOT_IMAGE_SIZE   0x48
  33 #define ESDHC_BOOT_IMAGE_ADDR   0x50
  34
  35 int mmc_get_env_addr(struct mmc *mmc, int copy, u32 *env_addr)
  36 {
  37         u8 *tmp_buf;
  38         u32 blklen, code_offset, code_len, n;
  39
  40         blklen = mmc->read_bl_len;
  41         tmp_buf = malloc(blklen);
  42         if (!tmp_buf)
  43                 return 1;
  44
  45         /* read out the first block, get the config data information */
  46         n = mmc->block_dev.block_read(mmc->block_dev.dev, 0, 1, tmp_buf);
  47         if (!n) {
  48                 free(tmp_buf);
  49                 return 1;
  50         }
  51
  52         /* Get the Source Address, from offset 0x50 */
  53         code_offset = *(u32 *)(tmp_buf + ESDHC_BOOT_IMAGE_ADDR);
  54
  55         /* Get the code size from offset 0x48 */
  56         code_len = *(u32 *)(tmp_buf + ESDHC_BOOT_IMAGE_SIZE);
  57
  58         *env_addr = code_offset + code_len;
  59
  60         free(tmp_buf);
  61
  62         return 0;
  63 }