Dropping macOS and Windows host tool builds and support in U-Boot

[Mark Kettenis]

> Date: Tue, 2 Dec 2025 12:52:22 -0600
> From: Tom Rini <trini at konsulko.com>
> 
> On Tue, Dec 02, 2025 at 07:49:07PM +0100, Mark Kettenis wrote:
> > > Date: Tue, 2 Dec 2025 12:24:03 -0600
> > > From: Tom Rini <trini at konsulko.com>
> > 
> > Hi Tom,
> > 
> > > Hey all,
> > > 
> > > I am wondering if at this point in time, anyone still builds our host
> > > tools (fw_printenv / fw_getenv, a few others) to run on macOS or
> > > Windows, natively.
> > > 
> > > I ask for two reasons. The first of which is that a reason we still have
> > > to support Azure (despite its slowness) for CI is it's where we have
> > > macOS and Windows hosts. But at this point in time there's so many ways
> > > to have Linux userspace running on Windows or macOS that I don't know
> > > that there's any value to these builds.
> > > 
> > > The second reason is more macOS specific and is that with:
> > > 
> > > commit 8fbcc0e0e839a8e25f636c76e59311033d3817b5
> > > Author: Marek Vasut <marek.vasut+renesas at mailbox.org>
> > > Date:   Thu Nov 13 12:54:51 2025 +0100
> > > 
> > >     boot: Assure FDT is always at 8-byte aligned address
> > >     
> > >     The fitImage may contain FDT at 4-byte aligned address, because alignment
> > >     of DT tags is 4 bytes. However, libfdt and also Linux expects DT to be at
> > >     8-byte aligned address. Make sure that the DTs embedded in fitImages are
> > >     always used from 8-byte aligned addresses. In case the DT is decompressed,
> > >     make sure the target buffer is 8-byte aligned. In case the DT is only
> > >     loaded, make sure the target buffer is 8-byte aligned too.
> > >     
> > >     Signed-off-by: Marek Vasut <marek.vasut+renesas at mailbox.org>
> > > 
> > > Which does things we must do, we now don't build on macOS. Why? As best
> > > I can tell (and for a general purpose OS, is a good call), memalign(..)
> > > doesn't exist and you need to use posix_memalign, a not drop-in
> > > replacement. We could spend some time reworking the code here for that,
> > > but for now I've instead gone with this workaround so that CI can
> > > continue:
> > > https://lore.kernel.org/u-boot/20251202162250.2613085-1-trini@konsulko.com/
> > 
> > Are you sure about this?
> > 
> > The code in boot/image-fdt.c is part of U-Boot itself, not the host
> > tools.  As such it should be irrelevant whether the host OS provides
> > memalign() or not; U-Boot provides its own implementation.
> 
> We use parts of this code as-is (and some other less obvious files) when
> building host tools.
> 
> > OpenBSD doesn't have memalign() either.  But I can still build the
> > targets I care about on OpenBSD.
> > 
> > Or is this about sandbox?  Did sandbox ever work on macOS?
> 
> It's about "tools-only" build target, but also I suspect that if you try
> the next branch right now it'll also fail and we'll need to figure
> something out.

Ah, it is only on the next branch.  Yes

  In file included from tools/generated/boot/image-fit.c:1:
  In file included from ./tools/../boot/image-fit.c:38:
  include/malloc.h:824:20: error: conflicting types for 'sbrk'
    824 | extern Void_t*     sbrk(ptrdiff_t);
        |                    ^
  /usr/include/unistd.h:449:7: note: previous declaration is here
    449 | void    *sbrk(int);
        |          ^
  1 error generated.

Which points out another issue with sharing code between U-Boot itself
and the host tools this way.