[DRAFT] Enable open source GPU support

Enable open source GPU support for Mali Utgard GPUs (lima driver) and
Mali Midgard and Bifrost GPUs (panfrost driver).
The support is enabled by:
- enabling DRM kernel CONFIGs
- enabling lima, panfrost and kmsro in Mesa

TODO: allow peaceful cohabitation with mali driver.

Signed-off-by: Diego Rondini <diego.rondini@kynetics.com>

conf/machine/include/sunxi-mali.inc

@@ -1,15 +1,15 @@
-PREFERRED_PROVIDER_virtual/mesa ?= "mesa-gl"
-PREFERRED_PROVIDER_virtual/libgl ?= "mesa-gl"
-PREFERRED_PROVIDER_virtual/libgles1 ?= "sunxi-mali"
-PREFERRED_PROVIDER_virtual/libgles2 ?= "sunxi-mali"
-PREFERRED_PROVIDER_virtual/egl ?= "sunxi-mali"
-
-PACKAGECONFIG_remove_pn-xserver-xorg = "${@bb.utils.contains('DISTRO_FEATURES', 'x11', 'glamor', '', d)}"
-
-XSERVER += "sunxi-mali \
-            sunxi-mali-dev"
-
-MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS += "\
- kernel-module-mali \
- kernel-module-mali-drm \
-  "
+#PREFERRED_PROVIDER_virtual/mesa ?= "mesa-gl"
+#PREFERRED_PROVIDER_virtual/libgl ?= "mesa-gl"
+#PREFERRED_PROVIDER_virtual/libgles1 ?= "sunxi-mali"
+#PREFERRED_PROVIDER_virtual/libgles2 ?= "sunxi-mali"
+#PREFERRED_PROVIDER_virtual/egl ?= "sunxi-mali"
+#
+#PACKAGECONFIG_remove_pn-xserver-xorg = "${@bb.utils.contains('DISTRO_FEATURES', 'x11', 'glamor', '', d)}"
+#
+#XSERVER += "sunxi-mali \
+#            sunxi-mali-dev"
+#
+#MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS += "\
+# kernel-module-mali \
+# kernel-module-mali-drm \
+#  "

recipes-graphics/mesa/mesa_%.bbappend

@@ -0,0 +1,5 @@
+# Enable lima and panfrost Mesa drivers
+PACKAGECONFIG_append = " lima panfrost"
+# Enable KMS renderonly Mesa support
+# See https://cgit.freedesktop.org/mesa/mesa/commit/?id=2b780fe89300199f2334539aa1678e9b68f0434f
+GALLIUMDRIVERS_append = ",kmsro"

recipes-kernel/linux/linux-mainline/drm.cfg

@@ -0,0 +1,8 @@
+CONFIG_DRM=y
+CONFIG_DRM_SUN4I=y
+CONFIG_DRM_SUN8I_DW_HDMI=y
+CONFIG_DRM_SUN8I_MIXER=y
+CONFIG_DRM_LIMA=y
+CONFIG_DRM_PANFROST=y
+CONFIG_CMA=y
+CONFIG_DMA_CMA=y

recipes-kernel/linux/linux-mainline_5.3.8.bb

@@ -29,6 +29,8 @@ SRC_URI = "https://www.kernel.org/pub/linux/kernel/v5.x/linux-${PV}.tar.xz \
         file://defconfig \
         "
 
+SRC_URI_append = " file://drm.cfg"
+
 SRC_URI_append_orange-pi-zero += "\
 	file://0001-dts-orange-pi-zero-Add-wifi-support.patch \
 	"