mb/lenovo/t400: Implement hybrid graphic in romstage
The hybrid driver select by DRIVERS_LENOVO_HYBRID_GRAPHICS doesn't work
for t400/t500.
Replace it with a custom romstage implementation.
Tested on Lenovo T500 with dual graphics:
* Intel Native GFX init
* AMD VBios
* GNU Linux 4.8.13
* SeaBios as payload
* Discrete is working (44 W)
* Integrated is working (24 W)
* Switchable is working (34 W)
** Both GPUs are enabled, with Intel being connected to the panel
** DRI_PRIME allows to use AMD GPU
** ACPI doesn't seem to work (no vgaswitcheroo)
Depends on Change-Id: I4dc00005270240c048272b2e4f52ae46ba1c9422
Depends on Change-Id: If389016f3bb0c4c2fd0b826914997a87a9137201
Change-Id: I7496876e9b434d4a2388e1ede27ac604670339b7
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/18010
Tested-by: build bot (Jenkins)
Reviewed-by: Alexander Couzens <lynxis@fe80.eu>
diff --git a/src/mainboard/lenovo/t400/Makefile.inc b/src/mainboard/lenovo/t400/Makefile.inc
index b382efb..c02a70b 100644
--- a/src/mainboard/lenovo/t400/Makefile.inc
+++ b/src/mainboard/lenovo/t400/Makefile.inc
@@ -15,3 +15,4 @@
ramstage-y += dock.c
ramstage-y += cstates.c
+romstage-y += hybrid_graphics.c