Add platform-independent coreboot support library
This patch adds the foundation for a platform-independent coreboot
support library that can be shared by all platforms that boot BL31 from
coreboot (acting as BL2). It adds code to parse the "coreboot table", a
data structure that coreboot uses to communicate different kinds of
information to later-stage firmware and certain OS drivers.
As a first small use case for this information, allow platforms to
access the serial console configuration used by coreboot, removing the
need to hardcode base address and divisors and allowing Trusted Firmware
to benefit from coreboot's user configuration (e.g. which UART to pick
and which baud rate to use).
Change-Id: I2bfb39cd2609ce6640b844ab68df6c9ae3f28e9e
Signed-off-by: Julius Werner <jwerner@chromium.org>
diff --git a/make_helpers/defaults.mk b/make_helpers/defaults.mk
index 2eb922f..eb1bb0a 100644
--- a/make_helpers/defaults.mk
+++ b/make_helpers/defaults.mk
@@ -31,6 +31,10 @@
# The platform Makefile is free to override this value.
COLD_BOOT_SINGLE_CPU := 0
+# Flag to compile in coreboot support code. Exclude by default. The coreboot
+# Makefile system will set this when compiling TF as part of a coreboot image.
+COREBOOT := 0
+
# For Chain of Trust
CREATE_KEYS := 1