git clone --recursive https://github.com/ndless-nspire/Ndless.git
cd ndless-sdk/toolchain/
./build_toolchain.sh
export PATH="[path_to_ndless]/ndless-sdk/toolchain/install/bin:[path_to_ndless]/ndless-sdk/bin:${PATH}
make
nspire-gcc -Wall -W -marm -Os -c hello-sdl.c
mkdir -p .
nspire-ld hello-sdl.o -o ./helloworld-sdl.elf
genzehn --input ./helloworld-sdl.elf --output ./helloworld-sdl.tns --name "helloworld-sdl"
make-prg ./helloworld-sdl.tns ./helloworld-sdl.prg.tns