Add a few comments and use known register values.
Based on the "2nd Generation Intel® Core™ Processor Family Mobile"
datasheet and the existing serialice trace.
Tested on Lenovo T520 (Intel Sandy Bridge).
Still boots to GNU/Linux.
Change-Id: I404515b77a22324f55581f117d79630be4ba64dd
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32071
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
bf7435087e