Re: Grub xen_pvh platform does not seem to support uncompressed kernels

[Jürgen Groß]

On 02.11.20 10:17, Andy Smith wrote:
> Hi,
>
> On Mon, Nov 02, 2020 at 09:43:06AM +0100, Jürgen Groß wrote:
> > On 02.11.20 09:27, Andy Smith wrote:
> > > The decompressed kernel is generated like this:
> > >
> > > # extract-vmlinux /boot/vmlinuz-5.4.0-52-generic > 
> > > /boot/vmlinuz-5.4.0-52-generic-decompressed
> > >
> > > The decompressed kernel does boot when presented to the hypervisor
> > > directly, i.e. no grub, directly listed in guest config file.
> > >
> > > I don't have an HVM test setup right now so am unable to test that,
> > > but I suppose we can assume it will fail as the problem is in the
> > > standard grub loading functions.
> > >
> > > So, is this a bug? Grub should be able to boot uncompressed kernels,
> > > shouldn't it?
> >
> > As long as the boot entry code is included in this kernel, yes.
>
> I actually think now that the output of extract-vmlinux lacks
> something and I further suspect that if I would use a vmlinux file
> from within a kernel build tree it would be fine.
>
> In which case this is not an issue for grub or xen, and only for
> those of us employing hacks based around extract-vmlinux.
>
> Apologies for the distraction!

No need to apologize.

We should really think about adding lz4 decompression support to grub
for being able to use lz4 compressed kernels with pvgrub.


Juergen