[S] Change in flashrom[main]: Provide an option to use PCI_ACCESS_ECAM to access pci register

[Peter Marheine (Code Review)]

Attention is currently required from: Hsuan Ting Chen, Hsuan-ting Chen, Kane Chen, Kane Chen, Subrata Banik.

Peter Marheine has posted comments on this change by Kane Chen. ( https://review.coreboot.org/c/flashrom/+/83896?usp=email )

Change subject: Provide an option to use PCI_ACCESS_ECAM to access pci register
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Patch Set 3:

(1 comment)

File meson_options.txt:

https://review.coreboot.org/c/flashrom/+/83896/comment/7e857aad_d4091df4?usp... :
PS3, Line 9: option('use_libpci_ecam', type : 'boolean', value : false)
> My original thought is to avoid any potential impact since i only have chromebooks to verify.  […]

Yeah, I feel pretty comfortable assuming any system using a 100-series PCH should support ECAM since they're documented to not support legacy PCI and it seems likely that any system equipped with that hardware should have the appropriate firmware support for ECAM.

It might be worth adding an item to the release notes for this change, and note that it might break badly-configured systems but is not expected to actually affect any systems.