Seems that I have some clue why I could not enter recovery mode yesterday regardless of where my flashdrive was inserted.
Hope this helps to improve the recovery process for the future...
In my box are 3 storage devices:
4TB HDD inside the box - detected as /dev/sda (EXT4)
250MB USB 2.0 Flashdrive in front USB 2.0 port - detected as /dev/sdb (FAT32) with the STARTUP_RECOVERY file
64GB USB 3.0 Flashdrive in back USB 3.0 port - detected as /dev/sdc (EXT4)
From the MultiBoot kexec logfile it seems that STARTUP_RECOVERY file was only checked in device /dev/sda which is the internal HardDrive.
Seems that none of my flashdrives (in front or back ports) have been checked for the file existence (message: not a block device ...skip).
Following output is from OpenBH 5.2.003:
Code:
root@vuduo4k:/boot# cat kexec-multiboot.log
KEXEC-1ST STAGE: STARTUP_RECOVERY not present in /dev/sda
KEXEC-1ST STAGE: STARTUP_RECOVERY not present in /dev/sda1
KEXEC-1ST STAGE: /dev/sdb is not a block device... skip
KEXEC-1ST STAGE: /dev/sdb1 is not a block device... skip
KEXEC-1ST STAGE: /dev/sdc is not a block device... skip
KEXEC-1ST STAGE: /dev/sdc1 is not a block device... skip
KEXEC-1ST STAGE: /dev/scdd is not a block device... skip
KEXEC-1ST STAGE: /dev/sdd1 is not a block device... skip
KEXEC-1ST STAGE: loading STARTUP from /dev/mmcblk0p9...
KEXEC-1ST STAGE: STARTUP: kernel=/linuxrootfs1/zImage root=/dev/mmcblk0p9 rootsubdir=linuxrootfs1
KEXEC-1ST STAGE: Found kernel /linuxrootfs1/zImage
KEXEC-1ST STAGE: Found root /dev/mmcblk0p9
KEXEC-1ST STAGE: Found rootsubdir /linuxrootfs1
KEXEC-1ST STAGE: WAITING
KEXEC-1ST STAGE: ##############################################################################
KEXEC-1ST STAGE: booting kernel: /newroot//linuxrootfs1/zImage
KEXEC-1ST STAGE: booting initrd: /newroot/STARTUP.cpio.gz
KEXEC-1ST STAGE: ##############################################################################
KEXEC-2ND STAGE: loading STARTUP from /dev/mmcblk0p9...
KEXEC-2ND STAGE: STARTUP: kernel=/linuxrootfs1/zImage root=/dev/mmcblk0p9 rootsubdir=linuxrootfs1
KEXEC-2ND STAGE: Found kernel /linuxrootfs1/zImage
KEXEC-2ND STAGE: Found root /dev/mmcblk0p9
KEXEC-2ND STAGE: Found rootsubdir linuxrootfs1
KEXEC-2ND STAGE: WAITING
KEXEC-2ND STAGE: Mount bind linuxrootfs1
KEXEC-2ND STAGE: ##############################################################################
KEXEC-2ND STAGE: Hack to override vuplus static cmdline
KEXEC-2ND STAGE: ##############################################################################
KEXEC-2ND STAGE: kernel v4
KEXEC-2ND STAGE: ##############################################################################
KEXEC-2ND STAGE: Mounting /newroot to /newroot_subdir/boot to expose STARTUP_RECOVERY
KEXEC-2ND STAGE: ##############################################################################
KEXEC-2ND STAGE: mount -o move /newroot /newroot_subdir/boot/
root@vuduo4k:/boot#
root@vuduo4k:/boot# df -h
Filesystem Size Used Available Use% Mounted on
/dev/mmcblk0p9 3.5G 2.6G 691.3M 79% /boot
/dev/mmcblk0p9 3.5G 2.6G 691.3M 79% /
tmpfs 277.0M 216.0K 276.8M 0% /var/volatile
tmpfs 277.0M 216.0K 276.8M 0% /sys/firmware/devicetree/base/chosen/bootargs
tmpfs 277.0M 216.0K 276.8M 0% /proc/cmdline
devtmpfs 268.0M 8.0K 268.0M 0% /dev
tmpfs 64.0K 0 64.0K 0% /media
/dev/sda1 3.6T 3.0T 650.4G 83% /media/hdd
/dev/sdb 246.0M 2.0K 246.0M 0% /media/sdb
/dev/sdc1 58.1G 293.3M 57.8G 0% /media/usb
root@vuduo4k:/boot#