Re: Deprecate the ppc405 boards in QEMU? (was: [PATCH v3 4/7] MAINTAINERS: Orphan obscure ppc platforms)

From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Thomas Huth <thuth@redhat.com>,
	David Gibson <david@gibson.dropbear.id.au>,
	qemu-devel@nongnu.org, qemu-ppc@nongnu.org
Cc: Christophe Leroy <christophe.leroy@c-s.fr>,
	peter.maydell@linaro.org, dbarboza@redhat.com, aik@ozlabs.ru,
	mark.cave-ayland@ilande.co.uk, groug@kaod.org,
	wainersm@redhat.com, Alexander Graf <agraf@csgraf.de>,
	hpoussin@reactos.org, clg@kaod.org, crosa@redhat.com,
	"Edgar E. Iglesias" <edgar.iglesias@gmail.com>,
	philmd@redhat.com
Subject: Re: Deprecate the ppc405 boards in QEMU? (was: [PATCH v3 4/7] MAINTAINERS: Orphan obscure ppc platforms)
Date: Fri, 1 Oct 2021 11:14:37 +0200	[thread overview]
Message-ID: <df767942-be5f-c920-2924-a5221e9db2b3@csgroup.eu> (raw)
In-Reply-To: <18fa56ee-956e-ee2f-9270-82aa96dfde09@redhat.com>

Le 01/10/2021 à 10:35, Thomas Huth a écrit :
> On 27/09/2021 06.48, David Gibson wrote:
>> There are a nunber of old embedded ppc machine types which have been 
>> little
>> changed and in "Odd Fixes" state for a long time.  With both myself and
>> Greg Kurz moving toward other areas, we no longer have the capacity to
>> keep reviewing and maintaining even the rare patches that come in for 
>> those
>> platforms.
>>
>> Therefore, remove our names as reviewers and mark these platforms as
>> orphaned.
>>
>> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
>> Reviewed-by: Greg Kurz <groug@kaod.org>
>> Reviewed-by: Cédric Le Goater <clg@kaod.org>
>> ---
>>   MAINTAINERS | 19 +++++--------------
>>   1 file changed, 5 insertions(+), 14 deletions(-)
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index f2060b46f9..1ecb5716c8 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -1236,24 +1236,18 @@ F: hw/openrisc/openrisc_sim.c
>>   PowerPC Machines
>>   ----------------
>>   405
>> -M: David Gibson <david@gibson.dropbear.id.au>
>> -M: Greg Kurz <groug@kaod.org>
>>   L: qemu-ppc@nongnu.org
>> -S: Odd Fixes
>> +S: Orphan
>>   F: hw/ppc/ppc405_boards.c
> 
> Related question: Does *anybody* know how to still use the ref405ep or 
> taihu board in QEMU? We just got another ticket asking for the related 
> firmware image:
> 
>   https://gitlab.com/qemu-project/qemu/-/issues/651
> 
> And if you google for 'ppc405_rom.bin', I only find pages where people 
> are asking basically the same question, e.g.:
> 
>   https://lists.nongnu.org/archive/html/qemu-devel/2007-08/msg00252.html 
> (in 2007 already! And no answer)
> 
>   https://github.com/Xilinx/qemu/issues/36 (in 2019, no answer)
> 
>   https://lists.libreplanet.org/archive/html/qemu-ppc/2019-12/msg00263.html (in 2019, no answer about bios location)
> 
>   https://lkml.org/lkml/2020/4/25/61 (in 2020, no answer)
> 
> 
> Seems like the Linux kernel removed support for the 405ep board here:
> 
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=548f5244f1064c9facb19c5e9 
> 

The EP405 board was removed because it was apparently based on the buggy 
405GP processor (It was selecting option CONFIG_405GP).

AFAIU the EP405 board is different from the ref405ep. The ref405ep has a 
405EP processor which is still supported, see 
https://elixir.bootlin.com/linux/v5.15-rc3/source/arch/powerpc/kernel/cputable.c#L1300

Christophe

> 
> ... to me this all sounds like these 405 boards are pretty dead code in 
> QEMU right now, so if nobody has a clue how to use them, I'd suggest to 
> mark them as deprecated and remove them in a couple of releases?
> 