jomonjohnn / kmsxx

KMS++: C++11 library, utilities and python bindings for Linux kernel mode setting

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++.

Utilities

• 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

Dependencies:

• 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):

[binaries]
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'

[host_machine]
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 name	Values	Default	Notes
pykms	true, false	true	Python bindings
kmscube	true, false	false	GLES kmscube
omap	enabled, disabled, auto	auto	libdrm-omap support

Env variables

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

Variable	Description
KMSXX_DISABLE_UNIVERSAL_PLANES	Set to disable the use of universal planes
KMSXX_DISABLE_ATOMIC	Set to disable the use of atomic modesetting
KMSXX_DEVICE	Path to the card device node to use
KMSXX_DRIVER	Name 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