gazelle

BYO RTOS targeting the Arduino Nano's ATmega328 processor

Implement List

• tasks & basic scheduler
• better scheduler - Priority-Based Round Robin
• idle task
• UART output
• IPC - shared nmemory
• timing
• semaphore (for preemptive scheduling)
• memory management?
• enum of error types

Pre-Requisites

sudo apt install gcc-avr avr-libc avrdude simavr libsimavr-dev

How To

make → compiles everything

make upload → flashes the code to the Arduino

make simulate → simulates RTOS via simavr

make clean → removes all build files

Project Outline

gazelle/
├── main.c                         # Entry point: initializes RTOS and starts tasks
├── rtos.[ch]                      # Core RTOS kernel (task management, scheduling, semaphores)
├── timer.[ch]                     # Millisecond tick using Timer1
├── uart.[ch]                      # UART driver with optional ring buffer
├── uart_buffer.[ch]               # Ring buffer implementation for UART receive
├── ipc.[ch]                       # Shared memory IPC implementation
├── types.h                        # Minimal custom type definitions
├── tasks/
│   ├── idle_task.c                # Idle task implementation
│   ├── task1.c                    # Demo task 1
│   ├── task2.c                    # Demo task 2
│   └── test_priority_tasks.c      # Various tasks to test scheduling functionality (different priorities, sleep timings, semaphore hold/wait, IPC, etc.)
├── tasks.h                        # Task function declarations
├── tinylibc/                      # Minimal libc subset
│   ├── io.[ch]                    # printf-style UART output
│   ├── conv.[ch]                  # itoa/atoi
│   ├── debug.[ch]                 # panic/assert
│   ├── string.[ch]                # strlen, strcmp, strcpy, memset
│   └── tinylibc.h                 # Unified include
├── Makefile                       # Build system
└── README.md                      # This file