Re: Future of 32-bit platforms (including i386)

On 5/23/23 4:46 PM, John Baldwin wrote:
> On 4/27/23 10:19 AM, John Baldwin wrote:
>> For 13.0, i386 was demoted from Tier 1 to Tier 2.  In the announcement
>> of this for 13.0, the project committed to an update on i386's future
>> around the time of 14.0.  The announcement at the time suggested that
>> i386 would be supported less in 14.x than in 13.x.
>>
>> My proposal is that for 14.x we treat i386 like any other Tier 2
>> platform.  That is, release images and packages would only be provided
>> on a best-effort basis, and we would not guarantee providing them.  I
>> think we should also stop shipping binary updates for the base system
>> (freebsd-update) for 14.x for i386.
>>
>> A larger question is what to do about 32-bit platforms moving forward.
>> My proposal for powerpc, i386, and armv[67] is that we say publicly
>> that we anticipate not supporting them in 15.  That is, that we may
>> remove them outright from the tree, or we may leave them in the tree,
>> but we do not plan on building packages or release images.  Another
>> option to consider for 32-bit platforms perhaps in 15 is to remove
>> kernel support and only retain the ability to build userland.  The
>> goal of saying this now-ish (or about the time 14.0 is going to ship)
>> would be to give time for users and developers to respond in the
>> window between 14.0 and 15.0 so we can evaluate those responses as an
>> input into the final decision for 15.
> 
> We discussed this topic during the 15.0 developer summit and the consensus
> among the folks present (which is only a subset of our community), is
> that there is still interest in supporting armv7 kernels in 15.0, but not
> kernels for other platforms.  In addition, no one expressed a need for
> full 32-bit world support for i386 and powerpc, only for compat32 support
> in the kernel, and lib32 (cc -m32) support in userland.
> 
> One question for this is if we think we will have sufficient developer
> resources to maintain armv7 kernels for the life of stable/15.  We can
> largely punt on the final decision for that until close to the release of
> 15.0.  I think for what we announce for 14.0 we can still say that we
> are generally planning to remove 32-bit kernel and world support in 15.0,
> but may consider keeping armv7.

I've posted a couple of reviews to add a WARNING to dmesg during the boot
of 32-bit kernels as well as to add a note to RELNOTES to serve as the
starting point for the note in the release notes:

https://reviews.freebsd.org/D41163
https://reviews.freebsd.org/D41164

Also, Mike Karels has been working on lib32 support for aarch64 that should
be included in 14.0.

-- 
John Baldwin