Mender

IMAGE GALLERY (1)

How to reset bootloader configurations

Remove the jumper from CMOS clock or the entire battery, press and hold power button for sometime 20 sec to discharge.

Linux images

Note: the difference between ‘zImage’ files and ‘bzImage’ files is that ‘bzImage’ uses a different layout and a different loading algorithm, and thus has a larger capacity. Both files use gzip compression. The ‘bz’ in ‘bzImage’ stands for ‘big zImage’, not for ‘bzip’!

Boot and root partition

• System partition and boot partition

• Is a /boot partition always necessary?

  scp -v skysails-mastercontrol-image-genericx86-64.mender root@192.168.122.36:/data
  /etc/fstab
  /etc/mender/artifact_ingo
  /sbin/init.sh
  fw_printenv
  
  mender -rootfs /data/skysails-mastercontrol-image-genericx86-64.mender
  
  ................................  96% 139264 KiB
  ................................  97% 140288 KiB
  ................................  97% 141312 KiB
  ................................  98% 142336 KiB
  ................................  99% 143360 KiB
  ..........................INFO[0051] wrote 1072693248/1072693248 bytes of update to device /dev/sda3  module=device
  .      100% 144224 KiB
  INFO[0053] Enabling partition with new image installed to be a boot candidate: 3  module=device
  

After reboot

root@genericx86-64:~# lsblk --fs
NAME   FSTYPE LABEL    UUID                                 MOUNTPOINT
sda
|-sda1 vfat   efi      A5F1-6F37                            /boot/efi
|-sda2 ext4   rootfs_0 909242fd-11b5-4f29-a94f-44a3b8790faa
|-sda3 ext4            e5a42c52-6bef-43c4-824a-5ea3ef4d817a /
|-sda4
|-sda5 ext4   config   93831baf-6c60-4883-96e0-3d6e78a55c8d
`-sda6 ext4   data     6c4ce979-e364-4315-a346-9b9662f87c6f /data

Reboot again and / will change to sda2

root@genericx86-64:~# fw_printenv
bootcount=1
mender_boot_part=3
upgrade_available=1
mender_boot_part_hex=3

#REBOOT

root@genericx86-64:~# fw_printenv
bootcount=0
mender_boot_part=2
upgrade_available=0
mender_boot_part_hex=3

After upgrade, .mender file is lost

Footnotes

[1]: What is the difference between the following kernel Makefile terms: vmLinux, vmlinuz, vmlinux.bin, zimage & bzimage? [2]: Roderick W. Smith -linux expert