stmos

stmos is an operating system for STM microprocessors. It aims to support (or be able to support) all STM Cortex-M processors.

Features:

• Unprivileged code execution
• ELF loading and execution (loads an init from the initrd)
• Near-full C standard library support for loaded ELFs
• libgpio: GPIO access for loaded ELFs

Currently supported processors:

• STM32L476RG (board: NUCLEO-L476RG)

building

To build stmos, you'll need the following programs:

• The arm-stmos toolchain (see the arm-stmos folder)
• openocd
• gdb (with multiarch support)

To compile stmos simply run make (-j option supported). To upload, use run.sh to start openocd/gdb; do lo to load stmos, and c to run it.

notes

Only the initrd works right now in regards to filesystem access. Files in the folder src/initrd/files are put into the initrd. C source files in src/initrd are compiled with libgpio, placing the program in src/initrd/files.

What's next for stmos?

• SD card support
• Display support (ILI....)
• Script program support (a shell like sash, maybe lua)
• More ELF work (better execve, signals?, etc.)