GRUB fails to load kernel on linux-sparc64

GRUB fails to load kernel on linux-sparc64

[John Paul Adrian Glaubitz]

Hi!

I have been doing some RC testing with GRUB 2.04~rc1 and actually
ran into a problem on sparc64 after updating from 2.02 (debian)
to 2.04~rc1.

GRUB itself starts fine, but it fails to load the kernel with the
following error:

Loading Linux 4.19.0-4-sparc64-smp ...
error: premature end of file /boot/vmlinuz-4.19.0-4-sparc64-smp.
Loading initial ramdisk ...
error: you need to load the kernel first.

Press any key to continue...

I have tried reinstalling the kernel package but that didn't help.

Does anyone have a clue?

@Eric: Does GRUB 2.04~rc1 work fine for you on sparc64?

Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz@debian.org
`. `'   Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913

Re: GRUB fails to load kernel on linux-sparc64

[Eric Snowberg]

> On Apr 16, 2019, at 9:15 AM, John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> wrote:
> 
> Hi!
> 
> I have been doing some RC testing with GRUB 2.04~rc1 and actually
> ran into a problem on sparc64 after updating from 2.02 (debian)
> to 2.04~rc1.
> 
> GRUB itself starts fine, but it fails to load the kernel with the
> following error:
> 
> Loading Linux 4.19.0-4-sparc64-smp ...
> error: premature end of file /boot/vmlinuz-4.19.0-4-sparc64-smp.
> Loading initial ramdisk ...
> error: you need to load the kernel first.
> 
> Press any key to continue...
> 
> I have tried reinstalling the kernel package but that didn't help.
> 
> Does anyone have a clue?

Is your kernel compressed?

> 
> @Eric: Does GRUB 2.04~rc1 work fine for you on sparc64?

I boot with an uncompressed kernel and do not see a problem. If I try with a compressed kernel I do see the error you have above.  But this is a known platform limitation: https://www.gnu.org/software/grub/manual/grub/grub.html#Platform-limitations

Re: GRUB fails to load kernel on linux-sparc64

[John Paul Adrian Glaubitz]

Hi Eric!

On 4/16/19 9:27 PM, Eric Snowberg wrote:
>> @Eric: Does GRUB 2.04~rc1 work fine for you on sparc64?
> 
> I boot with an uncompressed kernel and do not see a problem. If I try with a compressed kernel I do see the error you have above.  But this is a known platform limitation: https://www.gnu.org/software/grub/manual/grub/grub.html#Platform-limitations

That would indeed explain the problem. However, Debian's GRUB version
does support compressed kernels on sparc64. I wonder whether we have
a local modification that makes this possible.

Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz@debian.org
`. `'   Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913

Re: GRUB fails to load kernel on linux-sparc64

[Didier Spaier]

On 16/04/2019 21:38, John Paul Adrian Glaubitz wrote:
> That would indeed explain the problem. However, Debian's GRUB version
> does support compressed kernels on sparc64. I wonder whether we have
> a local modification that makes this possible.

Which makes me ask this OT question:
with the release of GRUB 2.04, will Debian be able to get rid of the 136 patches currently applied in SID?

More generally will distributors be able get rid of the patches they apply?

Best,

Diider

Re: GRUB fails to load kernel on linux-sparc64

[Colin Watson]

On Tue, Apr 16, 2019 at 09:51:07PM +0200, Didier Spaier wrote:
> On 16/04/2019 21:38, John Paul Adrian Glaubitz wrote:
> > That would indeed explain the problem. However, Debian's GRUB version
> > does support compressed kernels on sparc64. I wonder whether we have
> > a local modification that makes this possible.
> 
> Which makes me ask this OT question:
> with the release of GRUB 2.04, will Debian be able to get rid of the 136 patches currently applied in SID?

As is usual with new upstream releases, we'll be able to get rid of many
of them but not all.

> More generally will distributors be able get rid of the patches they apply?

Same answer.

-- 
Colin Watson                                       [cjwatson@ubuntu.com]

Re: GRUB fails to load kernel on linux-sparc64

[Colin Watson]

On Tue, Apr 16, 2019 at 09:38:34PM +0200, John Paul Adrian Glaubitz wrote:
> On 4/16/19 9:27 PM, Eric Snowberg wrote:
> >> @Eric: Does GRUB 2.04~rc1 work fine for you on sparc64?
> > 
> > I boot with an uncompressed kernel and do not see a problem. If I try with a compressed kernel I do see the error you have above.  But this is a known platform limitation: https://www.gnu.org/software/grub/manual/grub/grub.html#Platform-limitations
> 
> That would indeed explain the problem. However, Debian's GRUB version
> does support compressed kernels on sparc64. I wonder whether we have
> a local modification that makes this possible.

I'm not aware of anything specific; I think if it works it'll be a
matter of divergence between patch sets rather than an explicit patch to
make it work, if you see what I mean.

-- 
Colin Watson                                       [cjwatson@ubuntu.com]

Re: GRUB fails to load kernel on linux-sparc64

[Vladimir 'phcoder' Serbinenko]

[-- Attachment #1: Type: text/plain, Size: 1100 bytes --]

Try
insmod xzio
insmod gzio
insmod lzopio

On Wed, 17 Apr 2019, 07:39 John Paul Adrian Glaubitz, <
glaubitz@physik.fu-berlin.de> wrote:

> Hi Eric!
>
> On 4/16/19 9:27 PM, Eric Snowberg wrote:
> >> @Eric: Does GRUB 2.04~rc1 work fine for you on sparc64?
> >
> > I boot with an uncompressed kernel and do not see a problem. If I try
> with a compressed kernel I do see the error you have above.  But this is a
> known platform limitation:
> https://www.gnu.org/software/grub/manual/grub/grub.html#Platform-limitations
>
> That would indeed explain the problem. However, Debian's GRUB version
> does support compressed kernels on sparc64. I wonder whether we have
> a local modification that makes this possible.
>
> Adrian
>
> --
>  .''`.  John Paul Adrian Glaubitz
> : :' :  Debian Developer - glaubitz@debian.org
> `. `'   Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
>   `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> https://lists.gnu.org/mailman/listinfo/grub-devel
>

[-- Attachment #2: Type: text/html, Size: 2015 bytes --]

Re: GRUB fails to load kernel on linux-sparc64

[John Paul Adrian Glaubitz]

On 4/17/19 11:02 AM, Vladimir 'phcoder' Serbinenko wrote:
> Try
> insmod xzio
> insmod gzio
> insmod lzopio
That doesn't help unfortunately:

                           GNU GRUB  version 2.04~rc1

   Minimal BASH-like line editing is supported. For the first word, TAB   
   lists possible command completions. Anywhere else TAB lists possible   
   device or file completions. ESC at any time exits.                     


grub> insmod gzio
grub> linux /boot/vmlinuz-4.19.0-4-sparc64-smp ro root=/dev/vdiska2
error: premature end of file /boot/vmlinuz-4.19.0-4-sparc64-smp.
grub> insmod xzio
grub> 
grub> linux /boot/vmlinuz-4.19.0-4-sparc64-smp ro root=/dev/vdiska2
error: premature end of file /boot/vmlinuz-4.19.0-4-sparc64-smp.
grub> insmod lzopio
grub> linux /boot/vmlinuz-4.19.0-4-sparc64-smp ro root=/dev/vdiska2
error: premature end of file /boot/vmlinuz-4.19.0-4-sparc64-smp.
grub>

Going to decompress the kernel now and see if that helps. I'm just surprised
that GRUB supposedly doesn't support compressed kernels on sparc64 when
we have used that before with 2.02.

Not that I have a problem with an uncompressed kernel, I am just surprised.

Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz@debian.org
`. `'   Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913

Re: GRUB fails to load kernel on linux-sparc64

[John Paul Adrian Glaubitz]

On 4/17/19 11:34 AM, John Paul Adrian Glaubitz wrote:
> Going to decompress the kernel now and see if that helps. I'm just surprised
> that GRUB supposedly doesn't support compressed kernels on sparc64 when
> we have used that before with 2.02.

Okay, the uncompressed kernel works. Guess it was just pure luck that it
worked with the compressed one in the past.

I'll just change debian-installer, the kernel package and debian-cd to use an
uncompressed kernel in the future.

Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz@debian.org
`. `'   Freie Universitaet Berlin - glaubitz@physik.fu-berlin.de
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913

Re: GRUB fails to load kernel on linux-sparc64

[Eric Snowberg]

> On Apr 17, 2019, at 3:40 AM, John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> wrote:
> 
> On 4/17/19 11:34 AM, John Paul Adrian Glaubitz wrote:
>> Going to decompress the kernel now and see if that helps. I'm just surprised
>> that GRUB supposedly doesn't support compressed kernels on sparc64 when
>> we have used that before with 2.02.
> 
> Okay, the uncompressed kernel works. Guess it was just pure luck that it
> worked with the compressed one in the past.

I don’t know the history behind the compression limitation, it was documented as a platform limitation before I started using GRUB on SPARC64.  It may be related to the hardcoded 2M heap.  In the past I’ve bumped it up and had better results with other things. You could try increasing it in: grub-core/kern/ieee1275/init.c (line 156) and see if it resolves your problem. I don’t know the impact a change like this would cause to older platforms or if the maintainers would accept such a change.

Re: GRUB fails to load kernel on linux-sparc64

[Daniel Kiper]

On Wed, Apr 17, 2019 at 11:43:01AM -0600, Eric Snowberg wrote:
> > On Apr 17, 2019, at 3:40 AM, John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> wrote:
> > On 4/17/19 11:34 AM, John Paul Adrian Glaubitz wrote:
> >> Going to decompress the kernel now and see if that helps. I'm just surprised
> >> that GRUB supposedly doesn't support compressed kernels on sparc64 when
> >> we have used that before with 2.02.
> >
> > Okay, the uncompressed kernel works. Guess it was just pure luck that it
> > worked with the compressed one in the past.
>
> I don’t know the history behind the compression limitation, it was
> documented as a platform limitation before I started using GRUB on
> SPARC64.  It may be related to the hardcoded 2M heap.  In the past
> I’ve bumped it up and had better results with other things. You could
> try increasing it in: grub-core/kern/ieee1275/init.c (line 156) and
> see if it resolves your problem. I don’t know the impact a change like
> this would cause to older platforms or if the maintainers would accept
> such a change.

I will be happy if somebody fixes this decompression issue and makes
GRUB working with compressed kernels on SPARC platforms. However,
relevant fix has to be tested on various SPARC machines. Though even
then I am not convinced to treat this as a release material. Until you
convince me that I should...

Daniel