Add more verbose error message for common problems on modern operating systems, like Secure Boot and CONFIG_STRICT_DEVMEM. Change-Id: Ie3361910d48271bcc2cd3b4b74937fbc5df0a176 Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com> Reviewed-on: https://review.coreboot.org/25401 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>