Minimalist RTOS implementation for ARM Cortex-M written in C23 and assembly.

Source code:

• rtos.c source code
• rtos.h header file
• context_switch.s assembly implementation of context switching
• syscalls.c system call implementations
• main.c example application for stm32g474

API:

• define_task() define a new task
• create_task() create and register a task
• rtos_start() go!
• rtos_delay() delay task execution by milliseconds

Implementation details:

• multi-priority round-robin scheduler
• task premption on 1ms quantum via SysTick interrupt
• context switching via PendSV interrupt (lowest priority)
• O(1) task creation, selection, and deletion via circular double linked list