OCTOS

About

OCTOS is a compact real-time operating system (RTOS) featuring a preemptive kernel and an O(1) scheduler.

Currently, it supports only the ARM Cortex-M4 processor, but the system is designed to be extensible (see Core/Arch).

Features

• FreeRTOS-like preemptive scheduler
  • Round-Robin within priority level
  • "Cooperative" between priority level
  • Support scheduler suspension
• Basic Task Management
  • task_create, task_create_static, task_delete
  • task_delay, task_abort_delay
  • task_suspend, task_resume, task_resume_from_isr
  • task_yield, task_yield_from_isr
• Python-like Sync Primitives
  • Sema_t: Semaphore (ISR-compatible)
  • Mutex_t: Mutex (Support Priority Inheritance)
  • Cond_t: Condition (ISR-compatible)
  • Barrier_t: Barrier
  • Event_t: Event (ISR-compatible)
• Fexlible Inter-task Communication
  • Lightweight Task Notification (ISR-compatible)
  • Message Queue (ISR-compatible)

Usage

Prerequisites

• GNU Arm Embedded Toolchain
• CMake
• OpenOCD (Optional)

Build

# Start from project root directory
mkdir build
cd build
cmake ..

# or `cmake --build . --target flash` (OpenOCD and ST-LINK required)
cmake --build . --target octos

Debugging

# Inside Build Directory
# Open a gdb server at :3333 (OpenOCD and ST-LINK required)
cmake --build . --target gdbhost

# Inside project root directory
# Try input `oinfo` and `otasks` in gdb
arm-none-eabi-gcc -x .gdbinit

Credits

• https://www.udemy.com/course/rtos-building-from-ground-up-on-arm-processors
• https://jyywiki.cn/OS/2024
• https://www.freertos.org
• https://github.com/Eplankton/mos-stm32
• https://github.com/FARLY7/embedded-cli