[coreboot-gerrit] Change in coreboot[master]: arch/x86: Set RTC century byte offset in FADT x86-wide

[Werner Zeh (Code Review)]

Attention is currently required from: Arthur Heymans, Raul Rangel, Mariusz Szafrański, Jonathan Zhang, Angel Pons, Patrick Rudolph, Jason Glenesk, Anjaneya "Reddy" Chagam, Marshall Dawson, Johnny Lin, Suresh Bellampalli, Vanessa Eusebio, Michal Motyl, Morgan Jang, Felix Held.
Werner Zeh has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/55012 )

Change subject: arch/x86: Set RTC century byte offset in FADT x86-wide
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Patch Set 2:

(1 comment)

File src/southbridge/intel/i82371eb/fadt.c:

https://review.coreboot.org/c/coreboot/+/55012/comment/7ecdb179_31a7452f 
PS2, Line 45: /* not supported */
> The PIIX4 datasheet doesn't mention anything about centuries nor centenary (I looked for "cent"). […]

This is not a special feature of the chipset. It is more a random byte inside the CMOS RAM which is used to store the century. Our MC146818 RTC driver just uses this location to store this information and the OS (at least Linux) can be mada aware of this by reporting this location via FADT.