u-boot/board/gdsys/p1022/sdhc_boot.c

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/*
* Copyright 2011 Freescale Semiconductor, Inc.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <mmc.h>
#include <malloc.h>
/*
* The environment variables are written to just after the u-boot image
* on SDCard, so we must read the MBR to get the start address and code
* length of the u-boot image, then calculate the address of the env.
*/
#define ESDHC_BOOT_IMAGE_SIZE 0x48
#define ESDHC_BOOT_IMAGE_ADDR 0x50
int mmc_get_env_addr(struct mmc *mmc, int copy, u32 *env_addr)
{
u8 *tmp_buf;
u32 blklen, code_offset, code_len, n;
blklen = mmc->read_bl_len;
tmp_buf = malloc(blklen);
if (!tmp_buf)
return 1;
/* read out the first block, get the config data information */
n = mmc->block_dev.block_read(mmc->block_dev.dev, 0, 1, tmp_buf);
if (!n) {
free(tmp_buf);
return 1;
}
/* Get the Source Address, from offset 0x50 */
code_offset = *(u32 *)(tmp_buf + ESDHC_BOOT_IMAGE_ADDR);
/* Get the code size from offset 0x48 */
code_len = *(u32 *)(tmp_buf + ESDHC_BOOT_IMAGE_SIZE);
*env_addr = code_offset + code_len;
free(tmp_buf);
return 0;
}