[S] Change in coreboot[main]: treewide: Assume FMAP_SECTION_FLASH_START = 0

[Shuo Liu (Code Review)]

Attention is currently required from: Ana Carolina Cabral, Erik van den Bogaert, Felix Held, Frans Hendriks, Fred Reitberger, Intel coreboot Reviewers, Jakub "Kuba" Czapiga, Jason Glenesk, Julius Werner, Jérémy Compostella, Martin L Roth, Matt DeVillier, Maximilian Brune, Nick Kochlowski.

Shuo Liu has posted comments on this change by Maximilian Brune. ( https://review.coreboot.org/c/coreboot/+/86771?usp=email )

Change subject: treewide: Assume FMAP_SECTION_FLASH_START = 0
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Patch Set 4:

(1 comment)

File src/arch/x86/walkcbfs.S:

https://review.coreboot.org/c/coreboot/+/86771/comment/80cfc06e_67713cd0?usp... :
PS4, Line 20: #define COREBOOT_CBFS_START (0xffffffff - CONFIG_ROM_SIZE + 1 + FMAP_SECTION_COREBOOT_START)
Not sure if this could be put into a header file as a macro util, since it is a common assumption for x86 arch