[coreboot] Coreboot for Apollolake

[Angel Pons]

Resending because I forgot to mail it to the list:

Hello Antony,

Firstly, the quoted message matches the one added by CB:28382 [1],
which makes me think you are not using 4.8.1, but master instead. This
is not the primary issue, though it is worth noting.

With regard to the message you mentioned, its purpose is to warn
unsuspecting people against flashing a *complete* coreboot.rom when it
lacks an IFD (Intel Flash Descriptor). AFAIK, most modern systems will
fail to function properly without it. That does not mean the image is
unbootable, but it is not usable on its own.

If you want to flash it to a flash chip, your flasher software must be
able to write only to the BIOS region (defined by the IFD). flashrom
[2] is capable of doing so, with the IFD or layout options. The former
uses the existing flash chip contents to determine the region to
flash.

Another option is to extract the IFD and other regions from the flash
chip, add them to coreboot (either using coreboot's Kconfig options or
manually splicing the files) and flash the resulting, complete image.
I do not recommend this unless absolutely necessary (it rewrites the
whole flash chip instead of the desired region, which is more
error-prone).

Best regards,

Angel Pons Pons

[1]: https://review.coreboot.org/c/coreboot/+/28382
[2]: https://www.flashrom.org/Flashrom (I do not know about Chromium
flashrom's capabilities)