Subject: [bug#47615] [PATCH 0/9] Add 32-bit powerpc support

From: Efraim Flashner <[email-masked]>
Date: Sat, 17 Apr 2021 22:42:31 +0300

On Sat, Apr 17, 2021 at 06:04:02PM +0200, Ludovic Courtès wrote:
> Hi!
> 
> I haven’t looked into details so I’ll just share thoughts from a
> maintenance viewpoint:
> 
>   1. Those fdisk patch file names will make ‘guix lint’ unhappy.  :-)

I'll make sure to touch them up. I was also not happy about the
supported-architectures field of the package, I took that from Debain
(or was it Gentoo?) but I'm not sure of a technical reason why it can't
be built from other architectures.

>   2. Apart from mac-fdisk-p18.patch, which looks relatively big, the
>      changes seem to be rather non-intrusive, so it’s tempting to merge
>      them (on ‘core-updates’ I guess?).

Before I found some of the patches I played around with fixing the
package. Without looking at the patches too closely some of them fix
warnings and some of them actually make it compile correctly.

>   3. OTOH, what will be the status of this architecture?  I don’t think
>      new 32-bit PPC hardware is being made (right?), so I guess we
>      probably won’t have substitutes for that architecture.  That means
>      it won’t be supported at the same level as other architectures and
>      may quickly suffer from bitrot.

I don't know about new 32-bit powerpc hardware, I think it's only being
newly created for the embedded and networking space. As far as operating
systems with support¹ Adélie Linux is the only one I know that's
actually targeting the machines.

I found that emulation on my desktop (Ryzen 3900XT, 24 threads) is
faster than building on native hardware (1 core, 1.5GB of RAM, original
4200 RPM disk), edging it out on single threaded compiling and doing
great when it comes to using multiple cores and parallel builds.
Ignoring how to create an OS image if we just targeted, say, mesa and
maybe one or two other packages, we could have a core set which doesn't
change regularly and won't take up too much emulated build time but will
save days of compile time.

> I’m torn between #2 and #3.
> 
> What do people think?

The fear of bit-rot is real and I think we should mention in the manual
(when I actually write the section) that support is best-effort with
minimal substitutes.

> Thanks,
> Ludo’.

¹ https://en.wikipedia.org/wiki/PowerPC#Operating_systems_with_native_support

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