GRUB refuses to boot a 32-bit kernel when in EFI mode
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
grub2 (Ubuntu) |
Won't Fix
|
Low
|
Unassigned |
Bug Description
Also reported at https:/
This is grub version 2.02-2ubuntu8.15 as reported by "apt show grub-efi"
GRUB2 fails to boot a 32-bit kernel when started in EFI mode (64-bit EFI) on a 64-bit x86 CPU, and gives the message:
"error: kernel doesn't support 64-bit CPUs"
However, when a bios grub image made by the same version of grub is used, with the same kernel, on the same CPU, everything is normal and the kernel boots as expected.
Hence, I know this kernel will boot on a 64-bit CPU, and with a previous version of GRUB 2 (unfortunately I don't know which version), it also booted fine in 64-bit mode using GRUB-EFI.
Running with debug=all doesn't seem to provide any extra useful information, as far as I can tell - it just lists sectors being read and then freed.
Any ideas as to what's going on?
description: | updated |
tags: | added: rls-gg-incoming |
Changed in grub2 (Ubuntu): | |
assignee: | Mathieu Trudel-Lapierre (cyphermox) → nobody |
This problem is Ubuntu-specific, caused by that line: /git.launchpad. net/ubuntu/ +source/ grub2/tree/ debian/ patches/ ubuntu- linuxefi. patch#n2105
https:/
That line was added by that commit: /git.launchpad. net/ubuntu/ +source/ grub2/commit/ ?id=6a814c759e1 0feafb40c3669be 30aa51eb5ce39b
https:/
@cyphermox, this prohibits loading 32bit kernels under UEFI, would it be possible to revert it? 18.04-desktop- i386.iso under UEFI using https:/ /github. com/alkisg/ liveusb; after the patch, I can't.
For example, before this patch, I was able to boot lubuntu-
True, the use cases for booting 32bit kernels under UEFI are limited, but is there a reason to have an Ubuntu-specific patch to block it when it works fine?