[Question] TI's u-boot.img is built twice

[Simon Glass]

Hi Andrew,

On Fri, 22 Sept 2023 at 10:35, Andrew Davis <afd at ti.com> wrote:
>
> On 9/22/23 10:01 AM, Simon Glass wrote:
> > Hi Masahiro,
> >
> > On Thu, 21 Sept 2023 at 09:36, Masahiro Yamada <masahiroy at kernel.org> wrote:
> >>
> >> Hi.
> >>
> >> Since the TI platform migrated to binman,
> >> u-boot.img is built twice.
> >>
> >> It is created by "mkimage -E",
> >> then overwritten by binman.
> >>
> >>
> >> So, the data are embedded in the FIT structure
> >> instead of being appended.
> >>
> >> Is this intentional?
> >>
> >> To me, it looks weird.
> >>
> >>
> >>
> >>
> >> To confirm it, apply the following hack.
> >>
> >> Since u-boot.img is overwritten by binman,
> >> copy it to u-boot.img.backup.
> >>
> >>
> >>
> >>
> >> diff --git a/Makefile b/Makefile
> >> index 87f9fc786e..4cffa8a061 100644
> >> --- a/Makefile
> >> +++ b/Makefile
> >> @@ -1112,6 +1112,7 @@ endef
> >>   # Timestamp file to make sure that binman always runs
> >>   .binman_stamp: $(INPUTS-y) FORCE
> >>   ifeq ($(CONFIG_BINMAN),y)
> >> +       cp u-boot.img u-boot.img.backup
> >>          $(call if_changed,binman)
> >>   endif
> >>          @touch $@
> >>
> >>
> >>
> >> Then, build it for the main core.
> >>
> >>
> >> make -j$(nproc) CROSS_COMPILE=aarch64-linux-gnu-
> >>     am64x_evm_a53_defconfig all
> >>     TEE=~/ref/OP-TEE/optee_os/out/arm-plat-k3/core/tee-raw.bin
> >>     BL31=~/ref/trusted-firmware-a/build/k3/lite/release/bl31.bin
> >>     BINMAN_INDIRS=~/ref/ti-linux-firmware
> >>
> >>
> >>
> >>
> >> Compare the two files.
> >> Run fdtdump to see what happened to them.
> >>
> >>
> >> $ diff -u u-boot.img  u-boot.img.backup
> >> Binary files u-boot.img and u-boot.img.backup differ
> >>
> >>
> >> $ fdtdump u-boot.img
> >>      => u-boot and dt are embedded.
> >>
> >> $ fdtdump u-boot.img.backup
> >>      => u-boot and dt are appended after the
> >>         FIT structure
> >
> > That seems like a bug to me...at some point we might consider building
> > u-boot.img with Binman, but for now it is built by the Makefile.
> >
>
> This is not true for K3 as we now use Binman for u-boot.img generation
> (we need this as we have a signing step injected at this point).

No, no.

You must not mess with the outputs of Makefile - create a new file
with what you need, e.g. u-boot-ti.img

While we could use Binman to produce the .img we are quite a way from
doing that as not that many boards have been converted to binman.

>
> So as Masahiro suggested in the other branch of this thread, we need
> to disable the Makefile generation of u-boot.img for K3.
>
> Neha,
>
> Can you take this action? I assume you can add it as part of your
> work in making the data external again, which would make the u-boot.img
> identical to before and hence Makefile version could be disabled at
> the same time/series.

If you are suggesting that we slowly migrate boards away from
generating the .img using Makefile...perhaps that makes sense? I'm not
really sure. But in that case we need another Kconfig option.

Regards,
Simon