u-boot: enable boot from additional mmc device

Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>

config/u-boot/boot.cmd

@@ -3,8 +3,12 @@ if test ${boot_dev} = ""; then
 	setenv root_dev /dev/mmcblk0p3;
 fi;
 
+if test ${dev_num} = ""; then
+	setenv dev_num 0;
+fi;
+
 if test ${boot_part} = ""; then
-	setenv boot_part 0:1;
+	setenv boot_part ${dev_num}:1;
 fi;
 
 if test ${soc} = "kirkwood"; then

config/u-boot/uEnv.txt

@@ -1,3 +1,4 @@
 KVER=xxxKVERxxx
 DTBSUNXI=sun8i-h3-nanopi-r1.dtb
+root_dev=UUID=xxxROOT-UUIDxxx
 SERIAL-CONSOLE=ON

lfs/flash-images

@@ -215,6 +215,12 @@ endif
 	rm -f $(MNThdd)/etc/grub.d/11_linux_scon
 endif
 
+ifeq "$(BUILD_ARCH)" "armv5tel"
+	# Insert the UUID to uENV.txt
+	sed -i $(MNThdd)/boot/uENV.txt \
+		-e "s/^root_dev=.*/root_dev=UUID=$$(blkid -o value -s UUID $(PART_ROOT))/g"
+endif
+
 	# Set ramdisk mode to automatic
 	echo RAMDISK_MODE=2 > $(MNThdd)/etc/sysconfig/ramdisk