Re: [PATCH v2 1/6] ia64: Remove support

[matoro]

On 2023-05-11 18:09, Ard Biesheuvel wrote:
> On Thu, 11 May 2023 at 20:59, matoro
> <matoro_mailinglist_grub-devel@matoro.tk> wrote:
> > On 2023-05-11 10:29, Ard Biesheuvel wrote:
> > > On Thu, 11 May 2023 at 15:34, John Paul Adrian Glaubitz
> > > <glaubitz@physik.fu-berlin.de> wrote:
> > >>
> > >> On Thu, 2023-05-11 at 14:17 +0200, Ard Biesheuvel wrote:
> > >> > On Thu, 11 May 2023 at 14:14, John Paul Adrian Glaubitz
> > >> > <glaubitz@physik.fu-berlin.de> wrote:
> > >> > >
> > >> > > On Thu, 2023-05-11 at 14:06 +0200, Ard Biesheuvel wrote:
> > >> > > > Itanium IA-64 support is obsolete, and implements its own flavor of EFI
> > >> > > > boot that deviates from other architectures. Given that IA64 is unused
> > >> > > > and unmaintained, it makes no sense to pretend that the EFI changes we
> > >> > > > are making are tested or supported on IA64, so let's just get rid of 
> > it.
> > >> > >
> > >> > > But I just recently tested GRUB from git on IA64 and it worked without
> > >> > > any problems. We're using GRUB to boot Debian on IA64.
> > >> > >
> > >> >
> > >> > IA-64 is a dead platform, and a waste of electricity.
> > >>
> > >> I was just making a statement regarding the testability of the code.
> > >> That's all.
> > >>
> > >
> > > Fair enough. That is good to know actually - that way, we have a known
> > > working state right before we remove it.
> > >
> > >> > Feel free to keep using it, but please stop demanding that our people
> > >> > keep wasting their time on it. If you want to support it in Debian,
> > >> > you can carry it as a downstream patch and shoulder the maintenance
> > >> > burden.
> > >>
> > >> Who is "our people"? Do you think that you are part of the community
> > >> and
> > >> I am not? I don't think this kind of hostility is justified. Neither
> > >> you
> > >> nor I own this project.
> > >>
> > >
> > > Apologies - I had meant to type 'other people' not 'our people'. I
> > > rarely contribute to GRUB myself, so I wouldn't consider myself more a
> > > part of this community than anyone else.
> > >
> > > But my point remains: I have inferred from your response (and your
> > > involvement in similar discussions around the Linux kernel) that you
> > > would prefer Itanium support to be retained, right?
> > >
> > > So could you explain who you think should carry the maintenance
> > > burden? IA64 will be the only EFI architecture in GRUB that does not
> > > boot via an EFI stub in Linux, and this deviation means that retaining
> > > support for it is going to take actual developer and maintainer
> > > bandwidth. GRUB gets very little of that as it is, which means that
> > > keeping IA64 support alive comes at the cost of worse support for
> > > other architectures and platforms. (The series that this patch is part
> > > of breaks the ia64 build, and i i struggle to see why i should care
> > > about that)
> > >
> > > Very few of those people have access to such systems to begin with
> > > (probably none), and the companies that manufactured them stopped
> > > supporting them in the open source years ago, so testing these changes
> > > is not straight-forward, making it unreasonable to demand this from
> > > contributors. Also, it is unclear to me why the needs of the few
> > > people that do still run such a system are not served by a build based
> > > on today's GRUB tree, and why ia64 support needs to be retained going
> > > forward.
> > >
> > > I'll leave it to the maintainers whether to merge this patch or not,
> > > but if this needs to keep working on ia64 as well, someone else will
> > > have to step up.
> >
> > Hi, I also have a functioning GRUB install on ia64 EFI.  My machine is
> > fully open and available for debugging work, including on kernel and
> > bootloader (hard resets can be done via management console).
> >
> > If there is any way this support can be saved or at least delayed by
> > providing real hardware to work on, please reach out.  The environment
> > is completely remote and available for anybody who would like to give 
> > it
> > a try.
>
> Thanks, this could be helpful if we manage to find people that have
> the bandwidth to keep working on this. Would you be willing to spend
> time and development effort yourself on building and installing GRUB
> from the upstream repository on this machine (which is a bit more
> complicated than running kernels or user space programs)? Which distro
> and version are you using btw?

Yes, of course.  I am running Gentoo (rolling), so everything is already 
built from source anyway.  Updating to the latest git revision and 
adding drop-in patches are both part of the package manager and can be 
done in a single command.

> And just out of curiosity, why does this matter to you? Given that the
> ia64 firmware, the hardware and the linux boot protocol have not
> changed in a decade, wouldn't it make much more sense to stick with a
> stable, current version of GRUB, assuming that these are machines that
> need to be kept in working order? What kind of workloads are you
> running on these machines?

I am simply an enthusiast of alternative architectures.  In particular I 
think it's the only way to keep ourselves honest about portability, and 
also the only way to ensure that many ecosystems truly build from 
source, as there's no way to pull down random binary code from the 
internet on platforms like this.

I bought this hardware at great personal expense specifically for this 
purpose - testing OSS on it, and making it available to upstreams with 
an interest for developing/debugging.  I already update to and run 
official GRUB releases, as well as every kernel mainline point release 
(and have already bisected kernel regressions resulting in boot failures 
before).

> For ia64, there are no upsides to running newer GRUB code with changes
> applied to the EFI layer, as these involve protocols and other
> functionality that the ia64 firmware simply does not implement. In the
> best case, it works exactly the same as it does today. In the worst
> case, it bricks your box and someone has to go down and reinstall the
> bootloader (or more) using some kind of rescue image. Future EFI work
> will be focused on tightening memory permissions and implementing
> other robustness and hardening improvements, and these changes might
> tickle bugs in older firmware in ways we cannot anticipate at this
> point.
>
> So what exactly would we be trying to achieve by keeping ia64
> supported in upstream GRUB? Is it really important enough to justify
> asking contributors to spend time and effort on it rather than on
> something else?

Reinstalling a bootloader is definitely no problem.  The machine is 
either running builds/test suites or sitting idle.  Gentoo Releng 
produces installation CD's that I regularly test on a USB stick, so a 
live/rescue environment is trivial:  
https://gentoo.osuosl.org//releases/ia64/autobuilds/

I don't have basically any say here.  I am not a GRUB developer.  I 
cannot help rewrite the code myself.  I'm not even officially 
representing a distro like Glaubitz.  If the GRUB maintainers are of the 
opinion that it is not worth the effort to maintain the support, that is 
sad but understandable.  Just thought I'd pipe up and offer what little 
I can to help, if it's desired.