/lv_port_linux

LVGL configured to work with a standard Linux framebuffer

Primary LanguageCMIT LicenseMIT

LVGL on top of Linux graphics stack

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

Build dependencies

Check the Dockerfiles for the build dependencies.

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

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
#define LV_USE_WAYLAND		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
#define LV_USE_WAYLAND		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
#define LV_USE_WAYLAND		0

To use wayland, adjust lv_conf.h as follows:

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

cmake

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

Makefile

make -j

Command line options

Command line options are used to modify behavior of the demo, they take precedence over environment variables.

Wayland

  • -f - enters fullscreen on startup
  • -m - maximizes window on startup
  • -w <window width> - set the width of the window
  • -h <window height> - set the height of the window

SDL2

  • -w <window width> - set the width of the window
  • -h <window height> - set the height of the window

Environment variables

Environment variables can be set to modify the behavior of the demo.

Legacy framebuffer (fbdev)

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

EVDEV touchscreen/mouse pointer device

  • LV_LINUX_EVDEV_POINTER_DEVICE - override default (/dev/input/by-id/my-mouse-or-touchscreen) input device

DRM/KMS

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

SDL2

  • LV_SIM_WINDOW_WIDTH - width of SDL2 surface (default 800).
  • LV_SIM_WINDOW_HEIGHT - height of SDL2 surface (default 480).

Wayland

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

Run the demo application

FBDEV

Unpriviledged users don't have access to the framebuffer device /dev/fb0 sudo or su must be used.

cmake:

sudo ./bin/lvglsim

Makefile:

cd build/bin/
sudo main

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

cmake:

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