Re: multiboot2 and module2 boot issues via GRUB2

[Elliott Mitchell <ehem+xen@xxxxxxx>]

On Tue, Mar 30, 2021 at 11:28:49AM -0700, Roman Shaposhnik wrote:
> seems like I've run into an issue with multiboot2 and module2
> commands that I can't quite explain. Since it may be something
> super simply and silly -- I wanted to reach out here before I do
> a GRUB/Xen/LK source deepdive.
> 
> So here's the deal: whenever I boot straight up Linux kernel
> I can do the following sequence of commands:
>    linux /kernel
>    initrd foo.cpio.gz bar.cpio.gz
> and have linux kernel effectively stack content of bar.cpio.gz
> on top of foo.cpio.gz and present a unified initramfs that way.
> 
> I'm trying to replicate it with Xen, but:
>      multiboot2 /boot/xen.gz
>      module2 /kernel
>      module2 foo.cpio.gz
>      module2 bar.cpio.gz
> only seems to be picking up foo.cpio.gz
> 
> Has anyone run into this issue before?

Not I, but I asked questions elsewhere before I fought this battle.  You
should get a more recent version of GRUB.

More recent versions of GRUB (2.04) on ARM have the "xen_hypervisor" boot
mode.  With this boot mode the kernel and initrd get passed via
xen_module command.

Apparently newer GRUB versions have better boot methods for Xen, so
updating would be a Good Idea, if that is viable for you.


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