build: use .defaults as a way to configure lvgl instead of lv_conf.h

.github/workflows/build.yml

@@ -33,27 +33,27 @@ jobs:
 
       - name: FBDEV Test building the project
         run: |
-          sed -i "s/^#define LV_USE_LINUX_FBDEV.*$/#define LV_USE_LINUX_FBDEV 1/g" lv_conf.h && \
-          sed -i "s/^#define LV_USE_LINUX_DRM.*$/#define LV_USE_LINUX_DRM 0/g" lv_conf.h && \
-          sed -i "s/^#define LV_USE_SDL.*$/#define LV_USE_SDL 0/g" lv_conf.h && \
+          sed -i "s/LV_USE_LINUX_FBDEV.*$/LV_USE_LINUX_FBDEV 1/g" lv_conf.defaults && \
+          sed -i "s/LV_USE_LINUX_DRM.*$/LV_USE_LINUX_DRM 0/g" lv_conf.defaults && \
+          sed -i "s/LV_USE_SDL.*$/LV_USE_SDL 0/g" lv_conf.defaults && \
           docker run --rm -v "$(pwd)":/workdir -t test_${{ matrix.os.image }} \
           /bin/bash -ec "cmake -DCMAKE_C_FLAGS=-Werror -B build -S . && make -j -C build && ldd build/bin/lvglsim"
 
       - name: DRM Test building the project
         run: |
           sudo rm -Rf build/ bin/ && \
-          sed -i "s/^#define LV_USE_LINUX_FBDEV.*$/#define LV_USE_LINUX_FBDEV 0/g" lv_conf.h && \
-          sed -i "s/^#define LV_USE_LINUX_DRM.*$/#define LV_USE_LINUX_DRM 1/g" lv_conf.h && \
-          sed -i "s/^#define LV_USE_SDL.*$/#define LV_USE_SDL 0/g" lv_conf.h && \
+          sed -i "s/LV_USE_LINUX_FBDEV.*$/LV_USE_LINUX_FBDEV 0/g" lv_conf.defaults && \
+          sed -i "s/LV_USE_LINUX_DRM.*$/LV_USE_LINUX_DRM 1/g" lv_conf.defaults && \
+          sed -i "s/LV_USE_SDL.*$/LV_USE_SDL 0/g" lv_conf.defaults && \
           docker run --rm -v "$(pwd)":/workdir -t test_${{ matrix.os.image }} \
           /bin/bash -ec "cmake -DCMAKE_C_FLAGS=-Werror -B build -S . && make -j -C build && ldd build/bin/lvglsim"
 
       - name: SDL Test building the project
         run: |
           sudo rm -Rf build/ bin/ && \
-          sed -i "s/^#define LV_USE_LINUX_FBDEV.*$/#define LV_USE_LINUX_FBDEV 0/g" lv_conf.h && \
-          sed -i "s/^#define LV_USE_LINUX_DRM.*$/#define LV_USE_LINUX_DRM 0/g" lv_conf.h && \
-          sed -i "s/^#define LV_USE_SDL.*$/#define LV_USE_SDL 1/g" lv_conf.h && \
+          sed -i "s/LV_USE_LINUX_FBDEV.*$/LV_USE_LINUX_FBDEV 0/g" lv_conf.defaults && \
+          sed -i "s/LV_USE_LINUX_DRM.*$/LV_USE_LINUX_DRM 0/g" lv_conf.defaults && \
+          sed -i "s/LV_USE_SDL.*$/LV_USE_SDL 1/g" lv_conf.defaults && \
           docker run --rm -v "$(pwd)":/workdir -t test_${{ matrix.os.image }} \
           /bin/bash -ec "cmake -DCMAKE_C_FLAGS=-Werror -B build -S . && make -j -C build && ldd build/bin/lvglsim"
 

CMakeLists.txt

@@ -21,6 +21,36 @@ set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -Wpedantic")
 set(LV_BUILD_SET_CONFIG_OPTS ON CACHE BOOL
     "create CMAKE variables from lv_conf_internal.h" FORCE)
 
+set(LV_BUILD_CONF_PATH
+    "${CMAKE_BINARY_DIR}/lv_conf.h"
+    CACHE PATH "path to lv_conf.h" FORCE)
+
+set(LVGL_TEMPLATE_PATH "${CMAKE_SOURCE_DIR}/lvgl/lv_conf_template.h")
+set(LV_CONF_DEFAULTS_PATH "${CMAKE_SOURCE_DIR}/lv_conf.defaults")
+set(GENERATE_SCRIPT_PATH "${CMAKE_SOURCE_DIR}/lvgl/scripts/generate_lv_conf.py")
+
+configure_file(${LVGL_TEMPLATE_PATH} ${CMAKE_BINARY_DIR}/lv_conf_template.h
+               COPYONLY)
+configure_file(${LV_CONF_DEFAULTS_PATH} ${CMAKE_BINARY_DIR}/lv_conf.defaults
+               COPYONLY)
+configure_file(${GENERATE_SCRIPT_PATH} ${CMAKE_BINARY_DIR}/generate_lv_conf.py
+               COPYONLY)
+
+execute_process(
+  COMMAND
+    ${Python3_EXECUTABLE} ${GENERATE_SCRIPT_PATH} --template
+    ${LVGL_TEMPLATE_PATH} --defaults ${LV_CONF_DEFAULTS_PATH} --config
+    ${LV_BUILD_CONF_PATH}
+  RESULT_VARIABLE config_result
+  OUTPUT_VARIABLE config_output
+  ERROR_VARIABLE config_error)
+
+if(NOT config_result EQUAL 0)
+  message(FATAL_ERROR "Failed to generate lv_conf.h: ${config_error}")
+endif()
+
+message(STATUS "${LV_BUILD_CONF_PATH} generated successfully")
+
 add_subdirectory(lvgl)
 
 if (CONFIG_LV_USE_EVDEV)

README.md

@@ -27,7 +27,7 @@ git submodule update --init --recursive
 
 ## Configure drivers and libraries
 
-Adjust `lv_conf.h` to select the drivers and libraries that will be compiled by
+Adjust `lv_conf.defaults` to select the drivers and libraries that will be compiled by
 modifying the following definitions, setting them to `1` or `0`
 
 ### Graphics drivers
@@ -46,6 +46,7 @@ modifying the following definitions, setting them to `1` or `0`
 | Definition         | Description                             |
 | ------------------ | ----------------------------------------|
 | LV_USE_EVDEV       | libevdev input devices                  |
+| LV_USE_LIBINPUT    | libinput input devices                  |
 
 ## Install dependencies
 
@@ -63,28 +64,21 @@ LVGL supports GNU make and CMake
 ### CMake
 
 ```
-cmake -B build -S .
-make -C build -j
-```
-
-### GNU make
-
-```
-make -j
+cmake -B build
+cmake --build build -j$(nproc)
 ```
 
 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
+cmake -B build -DCMAKE_TOOLCHAIN_FILE=./user_cross_compile_setup.cmake 
+cmake --build build -j$(nproc)
 ```
 
 ### Installing LVGL
 
-It is possible to install LVGL to your system however, this is currently only
-supported with cmake.
+It is possible to install LVGL to your system using cmake:
 
 ```
 cmake --install ./build
@@ -95,6 +89,7 @@ cmake --install ./build
 ```
 ./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
@@ -135,13 +130,10 @@ Check the documentation of the drivers for more details
 
 ## 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
+By default, unpriviledged users don't have access to the framebuffer device `/dev/fb0`. In such cases, you can either run the application
+with `sudo` privileges or you can grant access to the `video` group.
 
-```
+```bash
 sudo adduser $USER video
 newgrp video
 ./build/bin/lvglsim