Re: [PATCH 1/2] boot: Fix dtbo application by ensuring overlay alignment

[<Jamie.Gibbons@microchip.com>]

Hi Tom,

On Tue, 2026-01-27 at 08:55 -0600, Tom Rini wrote:
> On Tue, Jan 27, 2026 at 10:26:33AM +0000,
> Jamie.Gibbons@microchip.com wrote:
> > Hi Tom,
> > 
> > On Fri, 2026-01-23 at 14:15 -0600, Tom Rini wrote:
> > > On Tue, Jan 20, 2026 at 03:33:12PM +0000, Jamie Gibbons wrote:
> > > 
> > > > After U-Boot's DTC/libfdt update, device tree overlay
> > > > application
> > > > could
> > > > fail with FDT_ERR_ALIGNMENT due to the overlay DTBO being
> > > > loaded at
> > > > a
> > > > misaligned address. Change the FIT image loader option in
> > > > image-
> > > > fit.c
> > > > from FIT_LOAD_IGNORED to FIT_LOAD_OPTIONAL_NON_ZERO, to ensure
> > > > overlays
> > > > are loaded at properly aligned addresses and any alignment
> > > > errors
> > > > are
> > > > resolved.
> > > > 
> > > > Tested on: PolarFire SoC Icicle Kit
> > > > 
> > > > Fixes: 0535e46d55d ("scripts/dtc: Update to upstream version
> > > > v1.7.2-35-g52f07dcca47c")
> > > > Signed-off-by: Jamie Gibbons <jamie.gibbons@microchip.com>
> > > > ---
> > > >  boot/image-fit.c | 2 +-
> > > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > > > 
> > > > diff --git a/boot/image-fit.c b/boot/image-fit.c
> > > > index 2d040e38d97..3a327d07784 100644
> > > > --- a/boot/image-fit.c
> > > > +++ b/boot/image-fit.c
> > > > @@ -2481,7 +2481,7 @@ int boot_get_fdt_fit(struct bootm_headers
> > > > *images, ulong addr,
> > > >  			addr, &uname, &uconfig,
> > > >  			arch, IH_TYPE_FLATDT,
> > > >  			BOOTSTAGE_ID_FIT_FDT_START,
> > > > -			FIT_LOAD_IGNORED, &ovload, &ovlen);
> > > > +			FIT_LOAD_OPTIONAL_NON_ZERO, &ovload,
> > > > &ovlen);
> > > >  		if (ov_noffset < 0) {
> > > >  			printf("load of %s failed\n", uname);
> > > >  			continue;
> > > 
> > > After talking with Marek about this more, we think this is the
> > > wrong
> > > approach. Can you please try dropping the load_op test from
> > > 8fbcc0e0e839
> > > and seeing if that also fixes your problem? If so, please post a
> > > patch
> > > with that and a Fixes tag, thanks!
> > > 
> > Dropping the load_op test added in commit 8fbcc0e0e839 does not
> > solve
> > the issue - failed on fdt_open_into for DTO due to misalignment of
> > ov.
> 
> Ugh, darn. Is there another load_op check that can be removed to fix
> that case? If not, then we need to pass in a new flag that means that
> we
> always relocate the data. That was Marek's other suggestion as we
> talked
> this over.
> 
Sorry for the delay in getting back to this. There is no other load_op
check that fixes this as far as I can tell. I have tested an
implementation of a new flag for this and it is working. I will send
the patch and you can let me know if you have any feedback or further
comments.
Thanks,
Jamie.