fw_config: Add firmware configuration interface
This change introduces a new top-level interface for interacting with a
bitmask providing firmware configuration information.
This is motivated by Chromebook mainboards that need to support multiple
different configurations at runtime with the same BIOS. In these
devices the Embedded Controller provides a bitmask that can be broken
down into different fields and each field can then be broken down into
different options.
The firmware configuration value could also be stored in CBFS and this
interface will look in CBFS first to allow the Embedded Controller value
to be overridden.
The firmware configuration interface is intended to easily integrate
into devicetree.cb and lead to less code duplication for new mainboards
that make use of this feature.
BUG=b:147462631
TEST=this provides a new interface that is tested in subsequent commits
Change-Id: I1e889c235a81545e2ec0e3a34dfa750ac828a330
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41209
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
diff --git a/src/Kconfig b/src/Kconfig
index 2a2a144..b96d51f 100644
--- a/src/Kconfig
+++ b/src/Kconfig
@@ -323,6 +323,33 @@
The path and filename of the file to use as graphical bootsplash
screen. The file format has to be jpg.
+config FW_CONFIG
+ bool "Firmware Configuration Probing"
+ default n
+ help
+ Enable support for probing devices with fw_config. This is a simple
+ bitmask broken into fields and options for probing.
+
+config FW_CONFIG_SOURCE_CBFS
+ bool "Obtain Firmware Configuration value from CBFS"
+ depends on FW_CONFIG
+ default n
+ help
+ With this option enabled coreboot will look for the 32bit firmware
+ configuration value in CBFS at the selected prefix with the file name
+ "fw_config". This option will override other sources and allow the
+ local image to preempt the mainboard selected source.
+
+config FW_CONFIG_SOURCE_CHROMEEC_CBI
+ bool "Obtain Firmware Configuration value from Google Chrome EC CBI"
+ depends on FW_CONFIG && EC_GOOGLE_CHROMEEC
+ default n
+ help
+ This option tells coreboot to read the firmware configuration value
+ from the Google Chrome Embedded Controller CBI interface. This source
+ is not tried if FW_CONFIG_SOURCE_CBFS is enabled and the value was
+ found in CBFS.
+
config HAVE_RAMPAYLOAD
bool