[U-Boot] [PATCH 2/2] mx6sabre: Use PARTUUID to specify the rootfs location

[Fabio Estevam <festevam@gmail.com>]

From: Fabio Estevam <fabio.estevam@nxp.com>

mx6sabre boards can run different kernel versions, such as NXP 4.1 or
mainline.

Currently the rootfs location is passed via mmcblk number and the
problem with this approach is that the mmcblk number for the eMMC
changes depending on the kernel version.

In order to avoid such issue, use UUID method to specify the rootfs
location.

Succesfully tested booting a NXP 4.1 and also a mainline kernel on a
mx6qsabresd and mx6dlsabreauto.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
---
 configs/mx6sabreauto_defconfig    | 1 +
 configs/mx6sabresd_defconfig      | 1 +
 include/configs/mx6sabre_common.h | 5 +++--
 include/configs/mx6sabreauto.h    | 1 -
 include/configs/mx6sabresd.h      | 1 -
 5 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/configs/mx6sabreauto_defconfig b/configs/mx6sabreauto_defconfig
index f8b2f7d..73b81ea 100644
--- a/configs/mx6sabreauto_defconfig
+++ b/configs/mx6sabreauto_defconfig
@@ -22,6 +22,7 @@ CONFIG_CMD_BOOTZ=y
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set
 CONFIG_CMD_MMC=y
+CONFIG_CMD_PART=y
 CONFIG_CMD_SF=y
 CONFIG_CMD_I2C=y
 CONFIG_CMD_USB=y
diff --git a/configs/mx6sabresd_defconfig b/configs/mx6sabresd_defconfig
index a1d0c84..7adc7da 100644
--- a/configs/mx6sabresd_defconfig
+++ b/configs/mx6sabresd_defconfig
@@ -23,6 +23,7 @@ CONFIG_CMD_BOOTZ=y
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set
 CONFIG_CMD_MMC=y
+CONFIG_CMD_PART=y
 CONFIG_CMD_SF=y
 CONFIG_CMD_I2C=y
 CONFIG_CMD_USB=y
diff --git a/include/configs/mx6sabre_common.h b/include/configs/mx6sabre_common.h
index 9b0fe5a..d4e4628 100644
--- a/include/configs/mx6sabre_common.h
+++ b/include/configs/mx6sabre_common.h
@@ -77,7 +77,7 @@
 	"initrd_high=0xffffffff\0" \
 	"mmcdev=" __stringify(CONFIG_SYS_MMC_ENV_DEV) "\0" \
 	"mmcpart=1\0" \
-	"mmcroot=" CONFIG_MMCROOT " rootwait rw\0" \
+	"finduuid=part uuid mmc ${mmcdev}:2 uuid\0" \
 	"update_sd_firmware=" \
 		"if test ${ip_dyn} = yes; then " \
 			"setenv get_cmd dhcp; " \
@@ -93,7 +93,7 @@
 		"fi\0" \
 	EMMC_ENV	  \
 	"mmcargs=setenv bootargs console=${console},${baudrate} " \
-		"root=${mmcroot}\0" \
+		"root=PARTUUID=${uuid} rootwait rw\0" \
 	"loadbootscript=" \
 		"fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${script};\0" \
 	"bootscript=echo Running bootscript from mmc ...; " \
@@ -101,6 +101,7 @@
 	"loadimage=fatload mmc ${mmcdev}:${mmcpart} ${loadaddr} ${image}\0" \
 	"loadfdt=fatload mmc ${mmcdev}:${mmcpart} ${fdt_addr} ${fdt_file}\0" \
 	"mmcboot=echo Booting from mmc ...; " \
+		"run finduuid; " \
 		"run mmcargs; " \
 		"if test ${boot_fdt} = yes || test ${boot_fdt} = try; then " \
 			"if run loadfdt; then " \
diff --git a/include/configs/mx6sabreauto.h b/include/configs/mx6sabreauto.h
index 2c08fd1..1883eb0 100644
--- a/include/configs/mx6sabreauto.h
+++ b/include/configs/mx6sabreauto.h
@@ -16,7 +16,6 @@
 #define CONFIG_MACH_TYPE	3529
 #define CONFIG_MXC_UART_BASE	UART4_BASE
 #define CONSOLE_DEV		"ttymxc3"
-#define CONFIG_MMCROOT			"/dev/mmcblk0p2"
 
 /* USB Configs */
 #define CONFIG_USB_HOST_ETHER
diff --git a/include/configs/mx6sabresd.h b/include/configs/mx6sabresd.h
index 3eba70a..27e7672 100644
--- a/include/configs/mx6sabresd.h
+++ b/include/configs/mx6sabresd.h
@@ -16,7 +16,6 @@
 #define CONFIG_MACH_TYPE	3980
 #define CONFIG_MXC_UART_BASE	UART1_BASE
 #define CONSOLE_DEV		"ttymxc0"
-#define CONFIG_MMCROOT			"/dev/mmcblk1p2"
 
 #define CONFIG_SUPPORT_EMMC_BOOT /* eMMC specific */
 
-- 
2.7.4