PPC64 is not functional without [OPAL] with which Linux kernel
communicates to implement important functionality like a TPM driver.
In addition to providing runtime services via OPAL Skiboot also handles
some parts of the boot process (like extracting kernel from flash) and
adjusts device tree as needed.
coreboot does not currently implement OPAL and is not likely to do it
any time soon (if ever), so must use Skiboot as a second-stage firmware
to have a fully functional PPC64 device.
mb/raptor-cs/talos-2/Kconfig is updated because Skiboot doesn't fit into
512 KiB image.
[OPAL]: https://open-power.github.io/skiboot/doc/opal-spec.html
Change-Id: I49ad6094acaccf731ab6d6b45ac103d485a3179c
Signed-off-by: Sergii Dmytruk <sergii.dmytruk@3mdeb.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/67070
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
d4b6b55977