Merge pull request #3527 from balena-os/mtoman/abroot-wait

initrdscripts: Wait for boot partition in the abroot script

meta-balena-common/recipes-core/initrdscripts/files/abroot

@@ -45,9 +45,27 @@ abroot_enabled() {
 abroot_run() {
  BOOT_PART=$(find_boot_partition)
 
- if [ "x${BOOT_PART}" = "x" ]; then
- fail "Failed to identify boot partition"
- fi
+ # Give the boot partition 5s to appear.
+ # This is necessary when the rootfs is on a device that takes
+ # a while to initialize, such as a USB disk.
+ # Similar waiting already happens in the rootfs script, because
+ # on most device types it is the first one that needs to access
+ # the root device. But in the case of balena bootloader, the abroot
+ # script is called before rootfs, so it needs to do the waiting.
+ C=0
+ delay=${bootparam_rootdelay:-1}
+ timeout=${bootparam_roottimeout:-5}
+ while [ -z "${BOOT_PART}" ]; do
+ C=$(( C + 1 ))
+
+ if [ $(( C * delay )) -gt "$timeout" ]; then
+ fail "Failed to identify boot partition"
+ fi
+
+ sleep "${delay}"
+
+ BOOT_PART=$(find_boot_partition)
+ done
 
  BOOT_DEV="/dev/$(lsblk -nlo pkname ${BOOT_PART})"