Pre-build config for lvgl hmi lib

Clone lvgl-hmi-lib + (lvgl-lib + lvgl-drivers submodules)

git clone https://github.com/redpesk-common/lvgl-hmi-lib
cd lvgl-hmi-lib
git submodule init
git submodule update

for frame-buffer use

no special dependencies required

mkdir build
cd build
cmake ..
make -j install

for gtl emulator

install gtk dependencies

sudo dnf install -y gtk3-devel

compile with GTK_USE option

mkdir build
cd build
cmake -DUSE_GTK=1 -DX_RES=1024 Y_RES=600 ..
make -j install

Warning

GTK seems to break json-c dynamic loading order. You should enforce the lib at binding level to enforce json-c original API.

fn main() {
    println!("cargo:rustc-link-search=/usr/local/lib64");
    println!("cargo:rustc-link-arg=-ljson-c");
    println!("cargo:rustc-link-arg=-llvgl");
    println!("cargo:rustc-link-arg=-llv_drivers");
}

I had to manually change in lvgl to get a dynamic lib

//Build shared as library (as opposed to static)
BUILD_SHARED_LIBS:BOOL=ON