CMake¶

Overview¶

CMake is a cross-platform build system generator. It is used to easily integrate a project/library into another project. It also offers the possibility to configure the build with different options, to enable or disable components, or to integrate custom scripts executions during the configuration/build phase.

LVGL includes CMake natively, which means that one can use it to configure and build LVGL directly or integrate it into an higher level cmake build.

This project uses CMakePresets to ensure an easy build. Find out more on Cmake Presets here: https://cmake.org/cmake/help/latest/manual/cmake-presets.7.html

Prerequisites¶

You need to install

CMake with GNU make or Ninja (for Linux builds). Be sure to add ninja/make to your PATH!
The prerequisites listed in scripts/install-prerequisites.sh/bat
A python3 interpreter if you wish to use KConfig.

How to build this project using cmake¶

Build with Command line¶

The simplest way to build LVGL using cmake is to use the command line calls:

# Method 1
cd <lvgl_repo>
mkdir build
cd build
cmake ..            # Configure phase
cmake --build .     # Build phase

# Method 2
cd <lvgl_repo>
cmake -B build      # Configure phase
cmake --build build # build phase

Build with cmake presets¶

Another way to build this project is to use the provided CMakePresets.json or passing option using the command line. The CMakePresets.json file describes some cmake configurations and build phase. It is a way to quickly use a set of predefined cmake options.

For now, these configuration presets are available:

windows-base: A Windows configuration, using VS MSVC. Uses lv_conf.h as the configuration system.
windows-kconfig: A Windows configuration, using VS MSVC. Uses Kconfig as the configuration system.
linux-base: A Linux configuration, using Ninja and GCC. Uses lv_conf.h as the configuration system.
linux-kconfig: A Linux configuration, using Ninja and GCC. Uses Kconfig as the configuration system.

And these build presets:

windows-base_dbg: Windows Debug build.
windows-base_rel: Windows Release build.
linux-base_dbg: Linux Debug build.
linux-base_rel: Linux Release build.

Here is how to build using the presets:

cmake --preset windows-base
cmake --build --preset windows-base_dbg
ctest --preset windows-base_dbg

Build with IDE¶

The recommended way for consuming CMakePresets is a CMakePresets aware IDE such as

VS 2022
VS Code
CLion

Simply load this project into your IDE and select your desired preset and you are good to go.

Build with CMake GUI¶

Open this project with CMake GUI and select your desired preset. When hitting the generate button, CMake will create solution files (for VS) or Ninja Files (for Linux Ninja Build)

The following targets are available.

lvgl (the actual library, required)
lvgl_thorvg (an vector graphics extension, optional)
lvgl_examples (example usages, optional)
lvgl_demos (some demos, optional)

All optional targets can be disabled by setting the proper cache variables. If you use cmake to install lvgl, 3 folders will be created.

include/lvgl (contains all public headers)
bin (contains all binaries (*.dll))
lib (contains all precompiled source files (*.lib))

Integrate LVGL to your project using cmake¶

The LVGL cmake system is made to be integrated into higher level projects. To do so, simply add this to your project's CMakeLists.txt.

This snippet adds LVGL and needs an lv_conf.h file present next to the lvgl folder:

add_subdirectory(lvgl)

This snippet sets up LVGL and tells it which lv_conf.h file to use:

set(LV_BUILD_CONF_PATH path/to/my_lv_conf.h)
add_subdirectory(lvgl)

This snippet sets up LVGL and points to the folder where lv_conf.h is located:

set(LV_BUILD_CONF_DIR path/to/directory)
add_subdirectory(lvgl)

This snippet adds LVGL and specifies to use Kconfig as the configuration system:

set(LV_BUILD_USE_KCONFIG ON)
add_subdirectory(lvgl)

This snippet adds LVGL and specify to use Kconfig as the configuration system and to use a specific defconfig:

set(LV_BUILD_USE_KCONFIG ON)
set(LV_BUILD_DEFCONFIG_PATH path/to/my_defconfig)
add_subdirectory(lvgl)

To enable the demos and examples set these options:

set(CONFIG_LV_BUILD_EXAMPLES ON)
set(CONFIG_LV_BUILD_DEMOS ON)
add_subdirectory(lvgl)

Below is a list of the available options/variables

Variable/Option	Type	Description
LV_BUILD_CONF_PATH	PATH	Allows to set a custom path for `lv_conf.h`
LV_BUILD_CONF_DIR	PATH	Allows to set a directory containing `lv_conf.h`
LV_BUILD_USE_KCONFIG	BOOLEAN	When set KConfig is used as the configuration source. This option is disabled by default.
LV_BUILD_DEFCONFIG_PATH	PATH	Specify to use a .defconfig file instead of the current .config in a Kconfig setup.
LV_BUILD_LVGL_H_SYSTEM_INCLUDE	BOOLEAN	Enable if LVGL will be installed to the system or your build system uses a sysroot. Turning this option on implies that the resources generated by the image generation script will include `lvgl.h` as a system include. i.e: `#include <lvgl.h>`. This option is disabled by default.
LV_BUILD_LVGL_H_SIMPLE_INCLUDE	BOOLEAN	When enabled the resources will include `lvgl.h` as a simple include, this option is enabled by default.
LV_BUILD_SET_CONFIG_OPTS	BOOLEAN	When enabled, this option runs a script that processes the `lv_conf.h`/Kconfig configuration using `pcpp` to generate corresponding `CONFIG_LV_` and `CONFIG_LV_BUILD_` CMake variables based on the contents of `lv_conf_internal.h`. This requires python3 with `venv` and `pip` or access to a working `pcpp`. If KConfig is used, this is enabled automatically.
CONFIG_LV_BUILD_DEMOS	BOOLEAN	When enabled builds the demos
CONFIG_LV_BUILD_EXAMPLES	BOOLEAN	When enabled builds the examples
CONFIG_LV_USE_THORVG_INTERNAL	BOOLEAN	When enabled the in-tree LVGL version of ThorVG is compiled
CONFIG_LV_USE_PRIVATE_API	BOOLEAN	When enabled the private headers `*_private.h` are installed on the system

Note

When LV_BUILD_SET_CONFIG_OPTS or LV_BUILD_USE_KCONFIG are enabled, the options/variables beginning with the prefix CONFIG_* are automatically set to the values found in lv_conf.h