powerpc/85xx: Enable eSDHC boot support on P2020 DS

We implement our own mmc_get_env_addr since 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.

Signed-off-by: Jerry Huang <Chang-Ming.Huang@freescale.com>
Signed-off-by: Zhao Chenhui <b35336@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 64 insertions, 0 deletions

diff --git a/board/freescale/common/sdhc_boot.c b/board/freescale/common/sdhc_boot.c
new file mode 100644
index 0000000..964c6b8
--- /dev/null
+++ b/board/freescale/common/sdhc_boot.c
@@ -0,0 +1,64 @@
+/*
+ * 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, 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;
+}
+