[PATCH v2] Makefile: Fake external blob with BINMAN_ALLOW_MISSING=1

[Yannic Moog]

On Fri, 2024-11-15 at 07:20 -0700, Simon Glass wrote:
> Hi Yannic,
> 
> On Thu, 14 Nov 2024 at 00:51, Yannic Moog <Y.Moog at phytec.de> wrote:
> > 
> > Hi Simon,
> > 
> > On Wed, 2024-11-06 at 08:35 -0700, Simon Glass wrote:
> > > This flag was lost by a previous change and has never been
> > > restored.
> > > Without it, binman cannot fully handle missing blobs which are
> > > themselves inputs to mkimage.
> > > 
> > > Discussion on this at [1] indicated that this was necessary but
> > > the
> > > patch was not updated.
> > > 
> > > Restore the flag so that all missing blobs are reported.
> > > 
> > > Link:
> > > https://patchwork.ozlabs.org/project/uboot/patch/20221206020336.315465-1-trini@konsulko.com/
> > 
> > sorry I'm picking this up so late;
> > As I am working on OP-TEE addition to imx8m boards [1], this patch
> > got my interest.
> > I applied the patch on top of my patchstack and tried to build
> > (phycore-imx8mp) with missing tee.bin
> > binary and got unexpected results:
> > 
> > 
> > Image 'image' has faked external blobs and is non-functional:
> > tee.bin
> > 
> > Image 'image' is missing optional external blobs but is still
> > functional: tee-os
> > 
> > /binman/section/fit/images/tee/tee-os (tee.bin):
> >    See the documentation for your board. You may need to build Open
> > Portable
> >    Trusted Execution Environment (OP-TEE) and build with
> > TEE=/path/to/tee.bin
> > 
> > Some images are invalid
> > 
> > 
> > So build fails even though tee.bin is marked as optional.
> > Did I miss another patch that must be used in conjunction with this
> > one?
> > 
> > Before this patch, I see the following output.
> > 
> > 
> > Image 'image' is missing optional external blobs but is still
> > functional: tee-os
> > 
> > /binman/section/fit/images/tee/tee-os (tee.bin):
> >    See the documentation for your board. You may need to build Open
> > Portable
> >    Trusted Execution Environment (OP-TEE) and build with
> > TEE=/path/to/tee.bin
> > 
> > 
> > With successful build.
> 
> The previous behaviour was a bug, at least that's what I concluded.
> It
> was ignored sections within sections, in some cases.
> 
> Do you have tee in there twice? It seems strange to get this case.

No, not as far as I am aware.

> 
> If you can't figure it out, can you send patches or share a tree?

Yes, I did supply patches in my previous comment, see [1] (Based on imx
tree).

Anyway, I did some digging in binman and so far this is what I found:

Since in this patch you add --fake-ext-blobs the default False will be
overridden in the call to binman. 
This Truth value is propagated until the following happens:

Entry_tee_os.ObtainContents() -> Entry_blob.ObtainContents() 
(this calls get_input_filename() which return None since tee is
missing) 
-> Entry.check_fake_fname().
check_fake_fname sets faked to True and this causes tee-os to be added
to the list of faked entries when control.CheckForProblems() calls
Entry_blob.CheckFakedBlobs() leading to the output in my previous
message.

Yannic

[1]
https://patchwork.ozlabs.org/project/uboot/list/?series=431695&state=*


> 
> > 
> > Yannic
> > 
> > [1]
> > https://lore.kernel.org/u-boot/20241107-phytec_imx8m_optee-v2-0-bbc3747a60e8@phytec.de
> > 
> > > 
> > > Signed-off-by: Simon Glass <sjg at chromium.org>
> > > Fixes: 93685d0dcb9 ("Makefile: With BINMAN_ALLOW_MISSING=1 don't
> > > error")
> > > ---
> > > 
> > > Changes in v2:
> > > - Use Link: and avoid a line break
> > > 
> > >  Makefile | 3 ++-
> > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/Makefile b/Makefile
> > > index 7275a02f24c..f92f46b3ab7 100644
> > > --- a/Makefile
> > > +++ b/Makefile
> > > @@ -1398,7 +1398,8 @@ cmd_binman = $(srctree)/tools/binman/binman
> > > $(if $(BINMAN_DEBUG),-D) \
> > >                  --toolpath $(objtree)/tools \
> > >               $(if $(BINMAN_VERBOSE),-v$(BINMAN_VERBOSE)) \
> > >               build -u -d u-boot.dtb -O . -m \
> > > -             --allow-missing $(if $(BINMAN_ALLOW_MISSING),--
> > > ignore-missing) \
> > > +             --allow-missing --fake-ext-blobs \
> > > +             $(if $(BINMAN_ALLOW_MISSING),--ignore-missing) \
> > >               -I . -I $(srctree) -I $(srctree)/board/$(BOARDDIR)
> > > \
> > >               $(foreach f,$(of_list_dirs),-I $(f)) -a of-
> > > list=$(of_list) \
> > >               $(foreach f,$(BINMAN_INDIRS),-I $(f)) \
> > 
> 
> Regards,
> Simon