ARM: uniphier: add emmcupdate command

The Boot ROM expects the boot image (SPL) in the Boot Partition 1.
So, updating images involves the hardware partition switch.  It might
be a bit advanced for some users.

To be user-friendly, this commit adds a useful command to update the
images; just put SPL and U-Boot proper into the public directory of
the TFTP server and execute "run emmcupdate" from the command line.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

doc/README.uniphier

@@ -78,6 +78,20 @@ directory, and then run the following command at the U-Boot command line:
   => run nandupdate
 
 
+Burn U-Boot images to eMMC
+--------------------------
+
+Write two files to the Boot partition 1 of the eMMC device as follows:
+ - spl/u-boot-spl.bin at the offset address 0x00000000
+ - u-boot.img         at the offset address 0x00010000
+
+If a TFTP server is available, the images can be easily updated.
+Just copy the u-boot-spl-dtb.bin and u-boot-dtb.img to the TFTP public
+directory, and then run the following command at the U-Boot command line:
+
+  => run emmcupdate
+
+
 UniPhier specific commands
 --------------------------
 

include/configs/uniphier.h

@@ -233,6 +233,13 @@
 	"netdev=eth0\0"						\
 	"verify=n\0"						\
 	"nor_base=0x42000000\0"					\
+	"emmcupdate=mmcsetn &&"					\
+		"mmc partconf $mmc_first_dev 0 1 1 &&"		\
+		"mmc erase 0 800 &&"				\
+		"tftpboot u-boot-spl.bin &&"			\
+		"mmc write $loadaddr 0 80 &&"			\
+		"tftpboot u-boot.img &&"			\
+		"mmc write $loadaddr 80 780\0"			\
 	"nandupdate=nand erase 0 0x00100000 &&"			\
 		"tftpboot u-boot-spl.bin &&"			\
 		"nand write $loadaddr 0 0x00010000 &&"		\