mb/emulation/qemu-q35: Enable CHROMEOS as an option

Allow Chrome OS to be enabled for this QEMU target.  By default
this does not change anything unless it is selected in the build
configuration, but it makes it possible.

Native VGA init is not forced when Chrome OS is enabled because the
drm-bochs driver does not work with chrome (even the latest upstream
kernel driver with drm atomic support) but it does work with virtio.
The coreboot graphics init needs to match what is selected with qemu
(with -vga std or -vga virtio) which in turn will determine which
kernel driver is used.

A second FMAP is added with both RW-A and RW-B regions which is
required by chromeos.

Recovery mode can be entered by supplying a custom fw_cfg option
when launching qemu: -fw_cfg name=opt/cros/recovery,string=1

Change-Id: I24b4532ea961e68558663292c99d121f0a30ce3b
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39837
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
diff --git a/src/mainboard/emulation/qemu-q35/Kconfig b/src/mainboard/emulation/qemu-q35/Kconfig
index ee64060..31aa3d8 100644
--- a/src/mainboard/emulation/qemu-q35/Kconfig
+++ b/src/mainboard/emulation/qemu-q35/Kconfig
@@ -11,15 +11,16 @@
 	select BOARD_ROMSIZE_KB_2048 if !VBOOT
 	select BOARD_ROMSIZE_KB_16384 if VBOOT
 	select MAINBOARD_HAS_NATIVE_VGA_INIT
-	select MAINBOARD_FORCE_NATIVE_VGA_INIT
+	select MAINBOARD_FORCE_NATIVE_VGA_INIT if !CHROMEOS
 	select MAINBOARD_HAS_LPC_TPM
+	select MAINBOARD_HAS_CHROMEOS
 
 config VBOOT
 	select VBOOT_MUST_REQUEST_DISPLAY
 	select VBOOT_STARTS_IN_BOOTBLOCK
 	select VBOOT_SEPARATE_VERSTAGE
 	select VBOOT_VBNV_CMOS
-	select VBOOT_NO_BOARD_SUPPORT
+	select VBOOT_NO_BOARD_SUPPORT if !CHROMEOS
 	select GBB_FLAG_DISABLE_LID_SHUTDOWN
 	select GBB_FLAG_DISABLE_PD_SOFTWARE_SYNC
 	select GBB_FLAG_DISABLE_EC_SOFTWARE_SYNC
@@ -27,7 +28,8 @@
 
 config FMDFILE
 	string
-	default "src/mainboard/$(CONFIG_MAINBOARD_DIR)/vboot-rwa-16M.fmd" if VBOOT_SLOTS_RW_A
+	default "src/mainboard/$(CONFIG_MAINBOARD_DIR)/vboot-rwa-16M.fmd" if VBOOT_SLOTS_RW_A && !VBOOT_SLOTS_RW_AB
+	default "src/mainboard/$(CONFIG_MAINBOARD_DIR)/vboot-rwab-16M.fmd" if VBOOT_SLOTS_RW_AB
 
 if VBOOT