LVGL on top of Linux graphics stack

This is an example project demonstrating how to use LVGL on a GNU/Linux systems and other Unix-like operating systems

LVGL provides drivers for many graphics backends. Legacy framebuffer (fbdev), modern DRM/KMS, Wayland, X11, GLFW3 and SDL2.

Check out this blog post for a step by step tutorial for fbdev https://blog.lvgl.io/2018-01-03/linux_fb

Clone the project

Clone the project

git clone https://github.com/lvgl/lv_port_linux.git
cd lv_port_linux/

LVGL is a submodule of lv_port_linux, use the following command to fetch it, it will be downloaded to the lvgl/ directory

git submodule update --init --recursive

Configure drivers and libraries

Adjust lv_conf.h to select the drivers and libraries that will be compiled by modifying the following definitions, setting them to 1 or 0

Graphics drivers

Definition	Description
LV_USE_LINUX_FBDEV	Legacy frame buffer (/dev/fb*)
LV_USE_LINUX_DRM	DRM/KMS (/dev/dri/*)
LV_USE_SDL	SDL
LV_USE_WAYLAND	WAYLAND
LV_USE_X11	X11
LV_USE_OPENGLES	GLFW3

Device drivers

Definition	Description
LV_USE_EVDEV	libevdev input devices

Install dependencies

Be sure to install the required dependencies for the selected drivers by checking the documentation for each driver here: https://docs.lvgl.io/master/details/integration/driver/

You can also check the Dockerfiles to get the names of the packages for various distributions

Build instructions

LVGL supports GNU make and CMake

CMake

cmake -B build -S .
make -C build -j

GNU make

make -j

Cross compilation is supported with CMake, edit the user_cross_compile_setup.cmake to set the location of the compiler toolchain and build using the commands below

cmake -DCMAKE_TOOLCHAIN_FILE=./user_cross_compile_setup.cmake -B build -S .
make  -C build -j

Installing LVGL

It is possible to install LVGL to your system however, this is currently only supported with cmake.

cmake --install ./build

Run the demo application

./build/bin/lvglsim

This will start the widgets demo

If multiple backends are enabled you can run with a specific backend via the -b option

./build/bin/lvglsim -b sdl

To get a list of supported backends use the -B option

Environment variables

Environment variables can be set to modify the behavior of the driver(s) Check the documentation of the drivers for more details

Legacy framebuffer (fbdev)

• LV_LINUX_FBDEV_DEVICE - override default (/dev/fb0) framebuffer device node.

EVDEV touchscreen/mouse pointer device

• LV_LINUX_EVDEV_POINTER_DEVICE - the path of the input device, i.e. /dev/input/by-id/my-mouse-or-touchscreen. If not set, devices will be discovered and added automatically.

DRM/KMS

• LV_LINUX_DRM_CARD - override default (/dev/dri/card0) card.

Simulator

• LV_SIM_WINDOW_WIDTH - width of the window (default 800).
• LV_SIM_WINDOW_HEIGHT - height of the window (default 480).

Permissions

When using fbdev or DRM, run lvglsim with sudo or su, Usually, unpriviledged users don't have access to the framebuffer device /dev/fb0 sudo or su must be used.

Access to the framebuffer device can be granted by adding the unpriviledged user to the video group

sudo adduser $USER video
newgrp video
./build/bin/lvglsim