[PATCH v2 7/7] smegw01: Enable EMMC boot from multiple partitions

[Fabio Estevam]

From: Eduard Strehlau <eduard at lionizers.com>

GPT Partition labels are used for determining the right
root filesystem to boot from.

The U-Boot environment is configured to reside in the eMMC hardware
boot partition we are currently booted from.

This should enable a dual copy approach for upgrading the bootloader.
One can overwrite the inactive hardware partition with new bootloader
and environment and afterwards switch the eMMC boot partition for an
atomic bootloader switch.

Signed-off-by: Eduard Strehlau <eduard at lionizers.com>
Signed-off-by: Fabio Estevam <festevam at denx.de>
---
Changes since v1:
- Remove custom mmc macro (Pali)
- Handle all the possible partition cases (Pali).

Cc: Pali Rohár <pali at kernel.org>

 board/storopack/smegw01/smegw01.c | 32 +++++++++++++++++++++++++++++++
 configs/smegw01_defconfig         |  2 ++
 include/configs/smegw01.h         | 12 ++++++++----
 3 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/board/storopack/smegw01/smegw01.c b/board/storopack/smegw01/smegw01.c
index e6bff80e5565..db6069a02722 100644
--- a/board/storopack/smegw01/smegw01.c
+++ b/board/storopack/smegw01/smegw01.c
@@ -17,6 +17,7 @@
 #include <asm/arch/crm_regs.h>
 #include <asm/setup.h>
 #include <asm/bootm.h>
+#include <mmc.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -93,3 +94,34 @@ int board_late_init(void)
 
 	return 0;
 }
+
+uint mmc_get_env_part(struct mmc *mmc)
+{
+	uint part;
+
+	if (mmc->part_config == MMCPART_NOAVAILABLE) {
+		part = 0;
+	} else {
+		switch (EXT_CSD_EXTRACT_BOOT_PART(mmc->part_config)) {
+		case 0: /* Booting from this eMMC device is disabled */
+			printf("Error - Booting from this eMMC device is disabled\n");
+			printf("Hint: Use 'mmc partconf' command to choose boot partition\n");
+			return -ENODEV;
+		case 1: /* Boot partition 1 is used for booting */
+			part = 1;
+			break;
+		case 2: /* Boot partition 2 is used for booting */
+			part = 2;
+			break;
+		case 7: /* User area is used for booting */
+			part = 0;
+			break;
+		default: /* Other values are reserved / unsupported */
+			printf("Error - This eMMC device has configured Reserved boot option\n");
+			printf("Hint: Use 'mmc partconf' command to choose boot partition\n");
+			return -ENODEV;
+		}
+	}
+
+	return part;
+}
diff --git a/configs/smegw01_defconfig b/configs/smegw01_defconfig
index b3580d5d6e54..54cf1cfc1f1b 100644
--- a/configs/smegw01_defconfig
+++ b/configs/smegw01_defconfig
@@ -30,6 +30,7 @@ CONFIG_CMD_MEMTEST=y
 CONFIG_CMD_UNZIP=y
 CONFIG_CMD_DFU=y
 CONFIG_CMD_GPIO=y
+CONFIG_CMD_GPT=y
 CONFIG_CMD_MMC=y
 CONFIG_CMD_PART=y
 CONFIG_CMD_DHCP=y
@@ -44,6 +45,7 @@ CONFIG_OF_CONTROL=y
 CONFIG_ENV_OVERWRITE=y
 CONFIG_SYS_REDUNDAND_ENVIRONMENT=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
+CONFIG_SYS_MMC_ENV_DEV=1
 CONFIG_NET_RANDOM_ETHADDR=y
 CONFIG_BOUNCE_BUFFER=y
 CONFIG_BOOTCOUNT_LIMIT=y
diff --git a/include/configs/smegw01.h b/include/configs/smegw01.h
index 277c828d0e07..71f2d9c8e85c 100644
--- a/include/configs/smegw01.h
+++ b/include/configs/smegw01.h
@@ -32,17 +32,21 @@
 	"mmcpart=1\0" \
 	"mmcpart_committed=1\0" \
 	"mmcargs=setenv bootargs console=${console},${baudrate} " \
-		"root=/dev/mmcblk0p${mmcpart_committed} rootwait rw " \
-		__stringify(EXTRA_BOOTPARAMS) "\0" \
+		"root=/dev/mmcblk${mmcdev}p${gpt_partition_entry} rootwait rw " \
+		__stringify(EXTRA_BOOTPARAMS) " SM_ROOT_DEV=${mmcdev} SM_ROOT_PART=${gpt_partition_entry} SM_BOOT_PART=${boot_part}\0" \
 	"commit_mmc=if test \"${ustate}\" = 1 -a \"${mmcpart}\" != \"${mmcpart_committed}\"; then " \
 	              "setenv mmcpart_committed ${mmcpart};" \
 								"saveenv;" \
 						  "fi;\0" \
 	"bootlimit=3\0" \
-	"loadimage=load mmc ${mmcdev}:${mmcpart_committed} ${loadaddr} boot/${image}\0" \
-	"loadfdt=load mmc ${mmcdev}:${mmcpart_committed} ${fdt_addr} boot/${fdtfile}\0" \
+	"loadimage=load mmc ${mmcdev}#rootfs-${mmcpart_committed} ${loadaddr} boot/${image}\0" \
+	"loadfdt=load mmc ${mmcdev}#rootfs-${mmcpart_committed} ${fdt_addr} boot/${fdtfile}\0" \
+	"loadpart=gpt setenv mmc ${mmcdev} rootfs-${mmcpart_committed}\0" \
+	"loadbootpart=mmc partconf 1 boot_part\0" \
 	"mmcboot=echo Booting from mmc ...; " \
 	  "run commit_mmc; " \
+		"run loadpart; " \
+		"run loadbootpart; " \
 		"run mmcargs; " \
 		"if run loadfdt; then " \
 			"if bootz ${loadaddr} - ${fdt_addr}; then " \
-- 
2.34.1