[S] Change in coreboot[master]: libpayload/Makefile.inc: Initialize vboot depending on UPDATED_SUBMOD...

[Nico Huber (Code Review)]

Attention is currently required from: Bora Guvendik, Wonkyu Kim, Selma Bensaid, Jérémy Compostella, Nicholas Chin.

Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/67118 )

Change subject: libpayload/Makefile.inc: Initialize vboot depending on UPDATED_SUBMODULES
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Patch Set 3:

(2 comments)

Patchset:

PS3:
> @Nicholas, thanks for all the details. […]

UPDATED_SUBMODULES is not meant to be used as a user interface. I assume
this change would only work if the payload's Makefile isn't updated yet to
unexport COREBOOT_EXPORTS. So things would be very fragile and might break
again soon.

To avoid a checkout of the wrong commit in a submodule, you can always add
the change to the index. Would that solve your problem?

File payloads/libpayload/Makefile.inc:

https://review.coreboot.org/c/coreboot/+/67118/comment/f130a2c6_a3d6121f 
PS2, Line 91: ifneq ($(UPDATED_SUBMODULES),1)
> Apparently one purpose of UPDATED_SUBMODULES in coreboot's top level Makefile.inc is to avoid calling the git command again if make is called recursively.

AIUI, that is its only purpose. And repurposing it makes things complicated.
> That said, even if I set the variable, similar to the top level Makefile.inc, it still seems to run the update twice when building manually, so I guess something else is the source of that issue.

This seems odd, did you also export the variable?