Re: [PATCH v1 15/25] Deprecate 32 bit big-endian MIPS

[Philippe Mathieu-Daudé]

Hi Alex,

(+Aleksandar/Huacai)

On 26/8/22 19:21, Alex Bennée wrote:
> It's becoming harder to maintain a cross-compiler to test this host
> architecture as the old stable Debian 10 ("Buster") moved into LTS
> which supports fewer architectures. For now:
>
>    - mark it's deprecation in the docs
>    - downgrade the containers to build TCG tests only
>    - drop the cross builds from our CI
>
> Users with an appropriate toolchain and user-space can still take
> their chances building it.
>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> ---
>   docs/about/build-platforms.rst                |  2 +-
>   docs/about/deprecated.rst                     | 13 ++++++
>   .gitlab-ci.d/container-cross.yml              |  1 -
>   .gitlab-ci.d/crossbuilds.yml                  | 14 -------
>   tests/docker/Makefile.include                 |  5 +--
>   .../dockerfiles/debian-mips-cross.docker      | 40 +++++--------------
>   6 files changed, 27 insertions(+), 48 deletions(-)
>
> diff --git a/docs/about/build-platforms.rst b/docs/about/build-platforms.rst
> index 26028756d0..1ca9144a7d 100644
> --- a/docs/about/build-platforms.rst
> +++ b/docs/about/build-platforms.rst
> @@ -41,7 +41,7 @@ Those hosts are officially supported, with various 
> accelerators:
>        - Accelerators
>      * - Arm
>        - kvm (64 bit only), tcg, xen
> -   * - MIPS
> +   * - MIPS (LE only)
>        - kvm, tcg
>      * - PPC
>        - kvm, tcg
> diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
> index 91b03115ee..22c2f4f4de 100644
> --- a/docs/about/deprecated.rst
> +++ b/docs/about/deprecated.rst
> @@ -213,6 +213,19 @@ MIPS ``Trap-and-Emul`` KVM support (since 6.0)
>   The MIPS ``Trap-and-Emul`` KVM host and guest support has been removed
>   from Linux upstream kernel, declare it deprecated.
>   
> +Host Architectures
> +------------------
> +
> +BE MIPS (since 7.2)
> +'''''''''''''''''''
> +
> +A Debian 10 ("Buster") moved into LTS the big endian 32 bit version of
> +MIPS moved out of support making it hard to maintain our
> +cross-compilation CI tests of the architecture. As we no longer have
> +CI coverage support may bitrot away before the deprecation process
> +completes. The little endian variants of MIPS (both 32 and 64 bit) are
> +still a supported host architecture.

For completeness we should update meson.build to consider 
host_machine.endian() and adapt this section:


  if not supported_cpus.contains(cpu)
    message()
    warning('SUPPORT FOR THIS HOST CPU WILL GO AWAY IN FUTURE RELEASES!')
    message()
    message('CPU host architecture ' + cpu + ' support is not currently 
maintained.')
  ...

This can be done later, and I might be able to do so in few weeks,
so meanwhile (with Thomas comment addressed):
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>