Bug: 116741782

Clone this repo:
  1. c49c3e1 Mark ab/7061308 as merged in stage. by Xin Li · 2 weeks ago master
  2. 25415a1 [LSC] Add LOCAL_LICENSE_KINDS to external/libkmsxx am: 1c077f2a88 by Bob Badour · 3 weeks ago
  3. 1c077f2 [LSC] Add LOCAL_LICENSE_KINDS to external/libkmsxx by Bob Badour · 3 weeks ago android-s-preview-1
  4. 30e1edb Upgrade libkmsxx to b12aab5d4bb45e77934d9838576a817bc8defe4b am: a520d8d4be by Haibo Huang · 8 weeks ago
  5. a520d8d Upgrade libkmsxx to b12aab5d4bb45e77934d9838576a817bc8defe4b by Haibo Huang · 9 weeks ago

Build Status

kms++ - C++ library for kernel mode setting

kms++ is a C++17 library for kernel mode setting.

Also included are some simple utilities for KMS and python bindings for kms++.


  • kmstest - set modes and planes and show test pattern on crtcs/planes, and test page flips
  • kmsprint - print information about DRM objects
  • kmsview - view raw images
  • kmscube - rotating 3D cube on crtcs/planes
  • kmscapture - show captured frames from a camera on screen


  • libdrm
  • Python 3.x (for python bindings)

Build instructions:

To build the Python bindings you need to set up the git-submodule for pybind11:

git submodule update --init

And to compile:

meson build
ninja -C build

Cross compiling instructions:

meson build --cross-file=<path-to-meson-cross-file>
ninja -C build

Here is my cross file for arm32 (where ${BROOT} is path to my buildroot output dir):

c = ['ccache', '${BROOT}/host/bin/arm-buildroot-linux-gnueabihf-gcc']
cpp = ['ccache', '${BROOT}/host/bin/arm-buildroot-linux-gnueabihf-g++']
ar = '${BROOT}/host/bin/arm-buildroot-linux-gnueabihf-ar'
strip = '${BROOT}/host/bin/arm-buildroot-linux-gnueabihf-strip'
pkgconfig = '${BROOT}/host/bin/pkg-config'

system = 'linux'
cpu_family = 'arm'
cpu = 'arm'
endian = 'little'

Build options

You can use meson options to configure the build. E.g.

meson build -Dbuildtype=debug -Dkmscube=true

Use meson configure build to see all the configuration options and their current values.

kms++ specific build options are:

Option nameValuesDefaultNotes
pykmstrue, falsetruePython bindings
kmscubetrue, falsefalseGLES kmscube
omapenabled, disabled, autoautolibdrm-omap support

Env variables

You can use the following runtime environmental variables to control the behavior of kms++.

KMSXX_DISABLE_UNIVERSAL_PLANESSet to disable the use of universal planes
KMSXX_DISABLE_ATOMICSet to disable the use of atomic modesetting
KMSXX_DEVICEPath to the card device node to use
KMSXX_DRIVERName of the driver to use. The format is either “drvname” or “drvname:idx”

Python notes

You can run the python code directly from the build dir by defining PYTHONPATH env variable. For example:

PYTHONPATH=build/py py/tests/hpd.py