recovery: init script mount fixes

- Added a 5 seconds delay before mounting external disks so they have
  time to be recognized in the system.
- Check if UBI volume is mounted before formatting it.
- Check if eMMC block device exists before formatting it.

Signed-off-by: David Escalona <david.escalona@digi.com>

meta-digi-dey/recipes-core/recovery/recovery-initramfs/recovery-initramfs-init

@@ -248,6 +248,12 @@ format_ubi_volume() {
 	if [ -z "${mtd_num}" ]; then
 		quit_with_error "Could not find MTD partition for volume '${1}'"
 	else
+		# Umount in case partition is mounted, ignore errors.
+		if grep -qs "${1}" /proc/mounts; then
+			local path="$(sed -ne "s/.*:${1} \(.*\) ubifs.*/\1/g;T;p" /proc/mounts 2>/dev/null)"
+			umount "${path}" >/dev/null 2>&1
+			ubidetach -p "/dev/mtd${mtd_num}" >/dev/null 2>&1
+		fi
 		# Format MTD partition.
 		ubiformat "/dev/mtd${mtd_num}" >/dev/null 2>&1
 		if [ "$?" != "0" ]; then
@@ -277,6 +283,7 @@ format_ubi_volume() {
 format_emmc_block() {
 	# Find partition block number.
 	local partition_block="/dev/mmcblk0p$(parted -s /dev/mmcblk0 print | sed -ne "s,^[^0-9]*\([0-9]\+\).*\<${1}\>.*,\1,g;T;p")"
+	if [ -b "${partition_block}" ]; then
 		# Umount in case partition is mounted, ignore errors.
 		if grep -qs "${partition_block}" /proc/mounts; then
 			umount "${partition_block}" >/dev/null 2>&1
@@ -288,6 +295,9 @@ format_emmc_block() {
 		else
 			quit_with_error "Error erasing '${1}' partition"
 		fi
+	else
+		quit_with_error "Could not find partition block for '${1}'"
+	fi
 }
 
 # Main
@@ -376,6 +386,7 @@ if [ -n "${update_package_bool}" ]; then
 	else
 		log "Update package location: ${update_package}"
 		# Mount external disks.
+		sleep 5
 		mount_external_disks
 		# Mount update partition.
 		mount_partition update "${UPDATE_MOUNT_DIR}"