KeltOS is very simple ARM realtime operating system.
You need make, bare-metal gcc compiler (arm-none-eabi-gcc in Arch Linux) and maybe gdb.
Run:
make
And KeltOS will be built.
Currently, KeltOS supports only Cortex-M4 processor and STM32F407 board and was not tested on real hardware. We use awesome QEMU fork called GNU ARM Eclipse QEMU to run it:
/opt/gnuarmeclipse/qemu/bin/qemu-system-gnuarmeclipse -M STM32-E407 -cpu cortex-m4 -kernel kelt.bin --semihosting-config enable=on,target=native -d unimp,guest_errors
Or simply:
./run.sh
Also, if you want to debug it, run with -s -S flags. QEMU will listen at :1234 for gdb and will start the kernel after successful connection.