Re: Cross compiling user applications for armv7

From: Michał_Kruszewski <mkru_at_protonmail.com>
Date: Mon, 22 Sep 2025 09:34:07 UTC
> Linux, of course, has many distributions. Some have
> dropped armv7 support already --but others have not.
> Having 4 more years of armv7 support via 15.* looks
> like armv7 will be supported longer than a number
> of Linux distributions, but not all of them.

When you build for embedded Linux you usually don't use distros.
You just build the kernel and root file system.
The Linux _kernel_ is not planning to drop support for armv7.


Regards,
Michał


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On Monday, September 22nd, 2025 at 11:07 AM, Mark Millard <marklmi@yahoo.com> wrote:

> On Sep 21, 2025, at 23:40, Michał Kruszewski mkru@protonmail.com wrote:
> 
> > > So your context replicated the qemu hangup that I reported to
> > > Warner from my attempt at doing a tiny build [poudriere(-devel)
> > > itself, with pkg also building]. What version of FreeBSD was
> > > involved in the replication. (Mine was a main 16 boot
> > > kernel and world and poudriere jail world.)
> > 
> > 14.3 for host and target.
> > 
> > > Additional question: over what timescale might the need
> > > for armv7 support to last?
> > > 
> > > While lib32 support for armv7 may last indefinitely,
> > > including whatever in the kernel is required for that,
> > > I'm unclear on the long term status of either of:
> > > 
> > > ) chroot into an armv7 world
> > > ) jails based on an armv7 world
> > > 
> > > after freebsd 16.* (FreeBSD 17+).
> > > 
> > > poudiere(-devel) based port package builds depends on:
> > > jails.
> > > 
> > > f jails were not to be supported indefinitely, could you
> > > get by with targeting FreeBSD 16.*-RELEASE's indefinitely
> > > but not FreeBSD 17 or later? Something to think about.
> > > 
> > > While FreeBSD 16.* will have armv7 kernels, after that
> > > has no such guarantee --and seems unlikely for the kernel
> > > to support booting atively, given that even for FreeBSD
> > > 16.-RELEASE armv7 is the last and only 32-bit boot
> > > context supported by a FreeBSD 16. kernel.
> > > 
> > > If the support time frame is spanned by FreeBSD 16.* then
> > > this might not be a problem. But it you need the support
> > > after that, ???Regards,
> 
> 
> Note: I typed a bunch of references to 16.* that should
> have been to 15.* for the armv7 boot kernel support.
> Sorry.
> 
> Stable/15 for 15.* is supported for 4 years after its
> 15.0-RELEASE .
> 
> I've checked and, as things are, 15.0-ALPHA3 amd64 does
> support chroot and poudriere jail world use of
> stable/14 i386, despite that 15.0 and later will not
> provide booting kernels. It appears to not be just
> lib32 that is supported --unless something more is
> disabled before 15.0-RELEASE .
> 
> > Basically, the message is "don't use FreeBSD for armv7 embedded development".
> 
> 
> Linux, of course, has many distributions. Some have
> dropped armv7 support already --but others have not.
> Having 4 more years of armv7 support via 15.* looks
> like armv7 will be supported longer than a number
> of Linux distributions, but not all of them.
> 
> > Maybe you are right.
> > I just wanted to try.
> > However, based on the number of problems I have encountered even for such a primary build, it looks like FreeBSD is not a good alternative for Linux in embedded domain.
> 
> 
> 
> ===
> Mark Millard
> marklmi at yahoo.com