[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: What to do with d-i on armel?



On Wed, 2024-01-10 at 08:34 +0100, Arnd Bergmann wrote:
> On Sun, Jan 7, 2024, at 23:07, Bastian Blank wrote:
> > Hi
> > 
> > With Linux 6.6 we dropped the Marvell specific kernel image, as it
> > was not known to work on any of the available devices.  We still have
> > another armel kernel left, the one of the Raspberry Pi 0 and 1, which
> > uses an ARMv6 CPU.
> > 
> > This also removed all the udebs from armel, which makes many d-i
> > components not longer have fullfiled dependencies and the release stuff
> > of course acting up.
> > 
> > Do we have any armel subarch that can be installed via d-i?
> 
> A few ideas from the kernel's point of view:
> 
> The most important ARMv5 platform is now probably at91, as
> Microchip still releases new sam9 chips[1] and is going to
> keep supporting it for a while.
> I would guess that the latest ones are not even that far off
> the performance of the kirkwood/mv78xx0 or bcm2835 parts,
> but I don't have numbers.
> 
> Qemu versatilepb is probably the most accessible arm926
> platform, though there are a couple of other armv5/v6 (ast2400,
> ast2500, pxa27x, raspi1ap) in qemu that one should be able
> to get to work as well if anyone found the time.

We used to have a configuration for Versatile, but it got broken
accidentally; when I found out I removed it because no-one had
complained in 9 months.  (Maybe that was a bit quick!)

We do have a configuration for RPi 0/1, which is supported with images
at <https://raspi.debian.net/> rather than through d-i.

I don't think anyone has proposed configurations to support the other
platforms.

> Since armel userland should work fine with any armhf or
> arm64 kernel, it might still be useful to repackage
> one or both of those for the armel archive and use this
> to have an installation method for armel on modern
> hardware. [Side note: I would also like to see an arm64
> kernel image added to armhf, it's probably more useful
> than the armmp-lpae kernel in terms of enabling users.]

We used to do this for amd64 kernels on i386.  Then Debian implemented
multiarch and it became an unnecessary waste of build resources. 
Still, we are lacking support for adding a "foreign" architecture and
kernel package at installation time.

(This specific combination would also be hard to support in the current
linux packaging because arm64 and armhf have different kernel
architectures and toolchains, unlike amd64 and i386.)

> At the moment, it is possible to enable support for
> arm1176 (as in bcm2835) in a normal armhf kernel and
> have that boot on armv6k, armv7 and armv8 hardware.
> I actually want to change that in the kernel though:
> Now that we dropped SMP support in armv6, as it now
> makes more sense to have armv6k grouped with armv5
> and instead have a generic kernel for armel that
> works on bcm2835, versatilepb, at91, kirkwood and
> all the others that one might use.

If someone wants to make this work in Debian that would be great, but
without a specific maintainer it's not going to happen.

Ben.

-- 
Ben Hutchings
Never put off till tomorrow what you can avoid all together.

Attachment: signature.asc
Description: This is a digitally signed message part


Reply to: