arch/x86: Configure EBDA through Kconfig

EBDA (Extended BIOS Data Area) is a memory area below 0xA0000 and
one of the default areas where OS will scan ACPI RSDP pointer from.

coreboot's default EBDA's starting address is 0xF6000, which is in
PAM (Programmable Attribute Map) F-segment's scope. For some platforms
without writeable PAM-F segment (e.g. some simics virtual platforms),
corboot's default EBDA is not writable.

Make DEFAULT_EBDA_LOWMEM, DEFAULT_EBDA_SEGMENT, DEFAULT_EBDA_SIZE
as Kconfig items so that coreboot's EBDA could be relocated to a
writable low memory place.

Change-Id: Icd7ba0c902560f7d498934392685dc2af9c5ce09
Signed-off-by: Gang Chen <gang.c.chen@intel.com>
Co-authored-by: Shuo Liu <shuo.liu@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/84321
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Jérémy Compostella <jeremy.compostella@intel.com>

0 files changed, 0 insertions, 0 deletions