Change in coreboot[master]: payloads/external/GRUB2: prevent rebuild without actual changes

[Nico Huber (Code Review)]

Nico Huber has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/40955 )

Change subject: payloads/external/GRUB2: prevent rebuild without actual changes
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Patch Set 5: Code-Review-1

(1 comment)

https://review.coreboot.org/c/coreboot/+/40955/4//COMMIT_MSG 
Commit Message:

https://review.coreboot.org/c/coreboot/+/40955/4//COMMIT_MSG@10 
PS4, Line 10: caused by Make detecting a change in the dependency on the config file.
This is the intended behaviour. If the coreboot config changes,
it can mean that a different revision of GRUB is to be built, for
instance.

If that is the case (GRUB's config is affected by coreboot's) is
hard to track in `make`. One way would be to write a file with
coreboot's configuration values that affect GRUB. Then only update
that file if its contents would change and have a dependency on
that file.