Trying to run up-to-date ZimaOS on my HP EliteDesk 800 G5 Mini made some trouble: The installer exits fine, but after reboot it gets stuck on a blinking cursor in the top left corner.
To fix this we need change the GRUB bootloader config:
- During boot you will briefly see a flashing GRUB bootloader screen with "Slot A (OK=0 Try=0)", "Slot B (OK=0 Try=0)", "Slot A (rescue shell)", "Slot B (rescue shell)”. Press any arrow key here to stop it from auto-booting.
- Make sure "Slot A (OK=0 Try=0)" in the list is active and press “e” to edit the boot config
- In the third line you should see a “linux …” command. At the end of that line add “debug intel_iommu=off”. The “debug” is optional here but it gives us some more detailled boot output if something happens.
- Press F10 to boot with the updated config.
This should now boot ZimaOS and you can connect to it in your web browser.
If it still doesn’t boot, now at least you should have some more debug output that you can use to find the issue.
However, our GRUB config change will reset if we just reboot normally now! We’ll need to update the actual bootloader config:
- In the ZimaOS Web Interface, go to the settings (Top Left Cog), Scroll down to “Developer Mode” and click “View”, enable SSH access and open the web-based terminal, logging in with your normal ZimaOS credentials
- Run “sudo -i” to change to root
- Run "mount -o remount,rw /mnt/boot” to allow changing the boot info
- Run “nano /mnt/boot/EFI/BOOT/grub.cfg” to edit the config. At the bottom of the file you can find the actual menu entries with our desired Option A:
menuentry "Slot A (OK=$A_OK TRY=$A_TRY)" { linux (${boothd},gpt2)/bzImage root=PARTUUID=... $default_cmdline $cmdline rauc.slot=A }
Edit this to also add “debug intel_iommu=off” at the end:
menuentry "Slot A (OK=$A_OK TRY=$A_TRY)" { linux (${boothd},gpt2)/bzImage root=PARTUUID=... $default_cmdline $cmdline rauc.slot=A debug intel_iommu=off }
- Save and reboot your device with “reboot”