====== HDMI ======
HDMI works with [[https://github.com/frank-w/BPI-R2-4.14/tree/4.16-hdmi|Kernel 4.16]] in some cases (1080p,1280x1024). Driver with fbdev was backported to 4.14 and ported to 4.19.in 5.0 hdmi works but fbdev does not.

Discussion in [[http://forum.banana-pi.org/t/hdmi-in-uboot-and-linux/4651|Forum]].

Resolution can be set in BPI-BOOT/bananapi/bpi-r2/linux/uEnv.txt:

  bootopts=vmalloc=496M debug=7 initcall_debug=0 video=1280x1024-32

this resolution will be used for both virtual Console and [[X-Server]].

more about this setting: [[https://nouveau.freedesktop.org/wiki/KernelModeSetting/]]

to resize only font on Console this can be done:

  setfont Uni3-TerminusBold32x16.psf.gz

available fonts are in /usr/share/consolefonts/

Thanks to ForumUser Alex R. aka "DeadMeat"

Normally hdmi will be turned off if no monitor is connected (or switched off) while bootup. You can change this with a video-option:

  video=HDMI-A-1:1280x1024-32@60D

This keeps hdmi enabled and allow hotplug,but in my case there is a resolution-issue.

http://forum.banana-pi.org/t/bpi-r2-hdmi-in-uboot-and-linux/4651/123

===== DRM Debugging =====

add "drm.debug=0x04" to bootopts in uEnv.txt (maybe 0x07 optionally with log_buf_len=1M)

===== LIMA =====

in 5.4 lima is merged to mainline-kernel and do need only some small changes for r2

but it needs mesa compiled with some small changes too {{ :en:bpi-r2:mesa.patch |}}

<code>
git clone --single-branch --branch mesa-19.3.2 https://gitlab.freedesktop.org/mesa/mesa.git mesa-source
cd mesa-source/
git checkout mesa-19.3.2
patch -p1 < mesa.patch
meson ./build --buildtype plain --libdir lib/arm-linux-gnueabihf --localstatedir /var/lib --prefix /usr --sysconfdir /etc --wrap-mode nodownload -Dplatforms=surfaceless,x11,drm -Dllvm=true -Dlmsensors=false -Dlibunwind=false -Dgallium-nine=false -Dgallium-va=false -Dgallium-vdpau=false -Dgallium-xa=false -Dgallium-xvmc=false -Dgallium-opencl=disabled -Dosmesa=none -Dbuild-tests=false -Dglx=dri -Dshared-glapi=true -Ddri3=true -Degl=true -Dgbm=true -Dgles1=false -Dgles2=true -Dglvnd=false -Dselinux=false -Dvalgrind=false -Ddri-drivers= -Dgallium-drivers=kmsro,lima
ninja -C build/
sudo ninja -C build/ install
</code>

important for debian is "--libdir lib/arm-linux-gnueabihf" with only "lib" x-server crashes while loading with segmentation fault.

maybe libdrm needs to be compiled too

<code>
git clone --single-branch --branch libdrm-2.4.100 https://gitlab.freedesktop.org/mesa/drm.git
cd drm
git checkout libdrm-2.4.100
meson build/  --prefix=/usr
#meson --reconfigure  build/ --prefix /usr --libdir lib/arm-linux-gnueabihf -Damdgpu=false -Dradeon=false -Dnouveau=false
ninja -C build/
sudo ninja -C build/ install
#or install to a folder
mkdir install
DESTDIR=$(pwd)/install ninja -C build/ install
</code>

==== usage ====

while lima initialization hdmi display needs to connected (best at boottime). You can call initialization again by unloading+loading lima module (modprobe -r lima;modprobe lima)

Xorg needs a little adjustment too,else you get this error (/var/log/Xorg.0.log):

  (EE) Cannot run in framebuffer mode. Please specify busIDs for all framebuffer devices

just create /etc/X11/xorg.conf.d/40-serverflags.conf (there is no /etc/X11/xorg.conf by default) with the following content:

  Section "ServerFlags"
        Option "AutoAddGPU" "off"
  EndSection

==== disable glamore ====

in case dri crashes on x startup with Sementation fault (because mesa is compiled for another kernel) you can disable it.

first check /var/log/Xorg.0.log for something like this:

<code>
[ 26.398] (II) Loading sub module "glamoregl"
[ 26.398] (II) LoadModule: "glamoregl"
[ 26.399] (II) Loading /usr/lib/xorg/modules/libglamoregl.so
[ 26.424] (II) Module glamoregl: vendor="X.Org Foundation"
[ 26.424] compiled for 1.20.4, module version = 1.0.1
[ 26.424] ABI class: X.Org ANSI C Emulation, version 0.4
[ 26.829] (EE)
[ 26.830] (EE) Backtrace:
[ 26.830] (EE)
[ 26.830] (EE) Segmentation fault at address 0xbc
[ 26.830] (EE)
Fatal server error:
[ 26.830] (EE) Caught signal 11 (Segmentation fault). Server aborting
[ 26.830] (EE)
[ 26.831] (EE) 
</code>

then create a file named /etc/X11/xorg.conf.d/00-noglamore.conf with following content:

<code>
Section "Device"
	Identifier "nogpu"
	Driver "modesetting"
	Option "Accelmethod" "none"
EndSection

Section "Module"
	Disable "glamoregl"
EndSection
</code>

and then restart your display-manager (e.g. service lightdm restart)

source: https://wiki.raptorcs.com/wiki/Troubleshooting/GPU