lvgl / lv_port_linux

LVGL configured to work with a standard Linux framebuffer

LVGL on top of Linux graphics stack

Example project to use LVGL on top of Linux graphics stack. Currently supported backends are either legacy framebuffer (fbdev), modern DRM/KMS, or SDL2.

By default, legacy framebuffer backend uses /dev/fb0 device node, DRM/KMS backend uses '/dev/dri/card0' card node, SDL2 uses window resolution of 800x480.

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

Clone the project

Clone the LVGL Framebuffer Demo project and its related sub modules.

git clone https://github.com/lvgl/lv_port_linux.git
cd lv_port_linux/
git submodule update --init --recursive

Select graphics backend (optional)

To use legacy framebuffer (fbdev) support, adjust lv_conf.h as follows:

#define LV_USE_LINUX_FBDEV	1
#define LV_USE_LINUX_DRM	0
#define LV_USE_SDL		0

To use modern DRM/KMS support, adjust lv_conf.h as follows:

#define LV_USE_LINUX_FBDEV	0
#define LV_USE_LINUX_DRM	1
#define LV_USE_SDL		0

To use SDL2 support, adjust lv_conf.h as follows:

#define LV_USE_LINUX_FBDEV	0
#define LV_USE_LINUX_DRM	0
#define LV_USE_SDL		1

Build the project (cmake or Makefile)

cmake

mkdir build
cd build 
cmake ..
make -j

Makefile

make -j

Environment variables

Environment variables can be set to modify behavior of the demo. The following variables are supported.

Legacy framebuffer (fbdev)

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

DRM/KMS

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

SDL2

• LV_SDL_VIDEO_WIDTH - width of SDL2 surface (default 800).
• LV_SDL_VIDEO_HEIGHT - height of SDL2 surface (default 480).

Run the demo application

As root

Normal users don't have access to /dev/fb0 so use sudo (or see below) :

cmake:

cd ../bin
sudo main

Makefile:

cd build/bin/
sudo main

Userland

You can give a normal user access to the framebuffer by adding them to the video group :

cmake:

sudo adduser $USER video
newgrp video
cd ../bin
./main

Makefile:

sudo adduser $USER video
newgrp video
cd build/bin/
./main