[Buildroot] [PATCH] arch/mips: Allow building for MIPS IV

[Florian Fainelli]

On 8/8/23 14:54, Thomas Petazzoni wrote:
> Hello Florian,
> 
> On Tue,  8 Aug 2023 14:41:53 -0700
> Florian Fainelli <f.fainelli at gmail.com> wrote:
> 
>> MIPS IV is an older ISA than R1 but is still useful to support older
>> MIPS-based systems (e.g.: Cobalt Qube).
>>
>> Signed-off-by: Florian Fainelli <f.fainelli at gmail.com>
> 
> Thanks for this patch. Support for MIPS IV was initially in Buildroot,
> and got removed in 2014, as part of:
> 
> commit dd45fe0efb678a8a674330ad46b7641a3284dff9
> Author: Gustavo Zacarias <gustavo at zacarias.com.ar>
> Date:   Mon Dec 1 11:16:59 2014 -0300
> 
>      arch/mips: remove deprecated mips1/2/3/4 support
>      
>      Remove the support for generating mips1/2/3/4 code since it has been
>      deprecated for more than a year now.
>      Also remove the unnecessary kludges in packages for it.
>      
>      Signed-off-by: Gustavo Zacarias <gustavo at zacarias.com.ar>
>      Acked-by: Vicente Olivert Riera <Vincent.Riera at imgtec.com>
>      Signed-off-by: Peter Korsgaard <peter at korsgaard.com>
> 
>> -	  64bit capable: 64, 64r2, 64r3, 64r5, 64r6
>> -	  non-64bit capable: 32, 32r2, 32r3, 32r5, 32r6
>> +	  64bit capable: mips4, 64, 64r2, 64r3, 64r5, 64r6
>> +	  non-64bit capable: mips4, 32, 32r2, 32r3, 32r5, 32r6
> 
> This list is quite odd, because it's not even an exhaustive list of the
> MIPS cores that we support.

Good point, I suppose that should be addressed in a separate patch.

> 
> Is mips4 supported by glibc, uclibc-ng and musl?

Yes, all 3 C libraries still support mips4.

> 
> Since IMG kind of gave up on MIPS, we have difficulties in getting some
> help in Buildroot to maintain MIPS support and address issues, so I'm a
> bit cautious about adding more MIPS stuff.

If there are not too many issues, I suppose you can CC me when you 
encounter them and I could try to take a look.
-- 
Florian