[PATCH 1/2] boot: android: Always use 8-byte aligned DT with libfdt

[Simon Glass]

Hi,

On Fri, 14 Nov 2025 at 07:24, Tom Rini <trini at konsulko.com> wrote:
>
> On Fri, Nov 14, 2025 at 05:45:32AM -0700, Simon Glass wrote:
> > Hi Marek,
> >
> > On Thu, 13 Nov 2025 at 14:57, Marek Vasut <marek.vasut at mailbox.org> wrote:
> > >
> > > On 11/13/25 9:36 PM, Tom Rini wrote:
> > >
> > > Hello everyone,
> > >
> > > >>> Which is different from disagreeing with your specific feedback about
> > > >>> how we get there, to be clear.
> > > >
> > > > And again, since your feedback to this patch was "Don't?", I'm saying we
> > > > need to. But the rest of your feedback was structural on moving towards
> > > > resolving it and so I assume Marek will respond.
> > >
> > > The "blast radius" are these patches, that's all that tripped the tests:
> > >
> > >   - boot: android: Always use 8-byte aligned DT with libfdt
> > >   - test/py: android: Point fdt command to aligned addresses
> > >   - test/py: Use aligned address for overlays in 'extension' test
> > >   - sandbox: Fix DT compiler address warnings in sandbox DTs
> > >   - sandbox: Fix DT compiler pin warnings in sandbox DTs
> > >   - boot: Assure FDT is always at 8-byte aligned address
> > >   - arm: qemu: Eliminate fdt_high and initrd_high misuse
> > >   - efi_loader: Assure fitImage from capsule is used from 8-byte aligned
> > > address
> > >   - MIPS: Assure end of U-Boot is at 8-byte aligned offset
> > >
> > > Regarding last minute alignment, the problem with this android image
> > > seems to be in the android image itself, which packs in badly aligned
> > > FDT. We therefore have to copy it out and realign.
> >
> > My request is to implement these checks as part of the boot flow
> > (bootm, etc.) rather than adding memory allocations in leaf function.
> > We already support copying the FDT to a different address so we can
> > expand it and add things. Can we make use of that code?
>
> There are likely some cases where we should do the check-and-move
> elsewhere, but others such as MIPS where we shouldn't get it wrong to
> start with. I believe we've had a few other patches that also fix the
> other cases where we don't ensure correct alignment to start with, and
> really must.

I'm going to leave this to you and Marek.

Regards,
Simon