tree 111651f73da18aa17a09a1d697e7f905c0ed809e
parent 6a50e555fcc8b9de2f17c90c64196c8439bc2e8e
author Nico Huber <nico.h@gmx.de> 1689369317 +0200
committer Martin L Roth <gaumless@gmail.com> 1691085301 +0000

linux_trampoline: Handle 64-bit framebuffer addresses

To support full 64-bit addresses, there is a new field `ext_lfb_base`
since Linux 4.1. It is unclear, however, how a loader is supposed to
know if the kernel is compatible with this. Filling these previously
reserved bits doesn't hurt, but an old kernel would probably ignore
them and not know that it's handling a clipped, invalid address. So
we play safe, and only allow 64-bit addresses for kernels after the
2.15 version bump of the boot protocol.

Change-Id: Ib20184cf207f092062a91ac3e6aa819b956efd33
Signed-off-by: Nico Huber <nico.h@gmx.de>
Co-authored-by: Bill XIE <persmule@hardenedlinux.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/76479
Reviewed-by: Bill XIE <persmule@hardenedlinux.org>
Reviewed-by: Tim Wawrzynczak <inforichland@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>