device/Kconfig: Put gfx init methods into a `choice`

Provide all gfx init methods as a Kconfig `choice`. This elimates the
option to select native gfx init along with running a Video BIOS. It's
been only theoretically useful in one corner case: Hybrid graphics
where only one controller is supported by native gfx init. Though I
suppose in that case it's fair to assume that one would use SeaBIOS to
run the VBIOS.

For the case that we want the payload to initialize graphics or no
pre-boot graphics at all, the new symbol NO_GFX_INIT was added to the
choice. If multiple options are available, the default is chosen as
follows:

  * NO_GFX_INIT, if we add a Video BIOS and the payload is SeaBIOS,
  * VGA_ROM_RUN, if we add a Video BIOS and the payload is not SeaBIOS,
  * NATIVE_VGA_INIT, if we don't add a Video BIOS.

As a side effect, libgfxinit is now an independent choice.

Change-Id: I06bc65ecf3724f299f59888a97219fdbd3d2d08b
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/19814
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

1 files changed, 25 insertions, 22 deletions

diff --git a/src/device/Kconfig b/src/device/Kconfig
index 841f2249b2..0637c699f7 100644
--- a/src/device/Kconfig
+++ b/src/device/Kconfig
@@ -42,39 +42,36 @@ config MAINBOARD_HAS_NATIVE_VGA_INIT
 config MAINBOARD_FORCE_NATIVE_VGA_INIT
 	def_bool n
 	depends on MAINBOARD_HAS_NATIVE_VGA_INIT || MAINBOARD_HAS_LIBGFXINIT
-	select MAINBOARD_DO_NATIVE_VGA_INIT
 	help
 	  Selected by mainboards / chipsets whose graphics driver can't or
 	  shouldn't be disabled.
 
-config MAINBOARD_DO_NATIVE_VGA_INIT
-	bool "Use native graphics initialization"
-	depends on MAINBOARD_HAS_NATIVE_VGA_INIT
-	default n
-	help
-	  Some mainboards, such as the Google Link, allow initializing the display
-	  without the need of a binary only VGA OPROM. Enabling this option may be
-	  faster, but also lacks flexibility in setting modes.
-
-	  If unsure, say N.
-
 config MAINBOARD_HAS_LIBGFXINIT
 	def_bool n
-	select MAINBOARD_HAS_NATIVE_VGA_INIT
 	help
 	  Selected by mainboards that implement support for `libgfxinit`.
 	  Usually this requires a list of ports to be probed for displays.
 
+choice
+	prompt "Graphics initialization"
+	default NO_GFX_INIT if VGA_BIOS && PAYLOAD_SEABIOS
+	default VGA_ROM_RUN if VGA_BIOS
+
+config MAINBOARD_DO_NATIVE_VGA_INIT
+	bool "Use native graphics init"
+	depends on MAINBOARD_HAS_NATIVE_VGA_INIT
+	help
+	  Some mainboards, such as the Google Link, allow initializing the
+	  display without the need of a binary only VGA OPROM. Enabling this
+	  option may be faster, but also lacks flexibility in setting modes.
+
 config MAINBOARD_USE_LIBGFXINIT
-	bool "Use libgfxinit for native graphics initialization"
-	depends on MAINBOARD_DO_NATIVE_VGA_INIT
+	bool "Use libgfxinit"
 	depends on MAINBOARD_HAS_LIBGFXINIT
 	select HAVE_VGA_TEXT_FRAMEBUFFER
 	select HAVE_LINEAR_FRAMEBUFFER
 	select RAMSTAGE_LIBHWBASE
 	select VGA if VGA_TEXT_FRAMEBUFFER
-	select NO_EDID_FILL_FB
-	default n
 	help
 	  Use the SPARK library `libgfxinit` for the native graphics
 	  initialization. This requires an Ada toolchain.
@@ -82,12 +79,10 @@ config MAINBOARD_USE_LIBGFXINIT
 # TODO: Explain differences (if any) for onboard cards.
 config VGA_ROM_RUN
 	bool "Run VGA Option ROMs"
-	default n if PAYLOAD_SEABIOS
-	default y if !PAYLOAD_SEABIOS
-	depends on PCI && !MAINBOARD_DO_NATIVE_VGA_INIT
+	depends on PCI && !MAINBOARD_FORCE_NATIVE_VGA_INIT
 	select HAVE_VGA_TEXT_FRAMEBUFFER
 	help
-	  Execute VGA Option ROMs in coreboot if found. This is required
+	  Execute VGA Option ROMs in coreboot if found. This can be used
 	  to enable PCI/AGP/PCI-E video cards when not using a SeaBIOS
 	  payload.
 
@@ -95,7 +90,15 @@ config VGA_ROM_RUN
 	  more complete BIOS interrupt services available than coreboot,
 	  which some option ROMs require in order to function correctly.
 
-	  If unsure, say N when using SeaBIOS as payload, Y otherwise.
+config NO_GFX_INIT
+	bool "None"
+	depends on !MAINBOARD_FORCE_NATIVE_VGA_INIT
+	help
+	  Select this to not perform any graphics initialization in
+	  coreboot. This is useful if the payload (e.g. SeaBIOS) can
+	  initialize graphics or if pre-boot graphics are not required.
+
+endchoice
 
 config S3_VGA_ROM_RUN
 	bool "Re-run VGA Option ROMs on S3 resume"