RT-AVR

This is a very simple RTOS written is assembly. It supports basic task scheduling without context switching. I take it from DI HALT tutorial (see link below) with some modifications, adopt it for gcc toolchain. Now it works only for ATMEGA32, probably works with others MCU, but not tested. Internally, it implemented with simple task queue, and timer list. Project also has example of usage this rtos, it linking on build with this example. Intended for use in small projects and for learning purposes and other
stuff :)

API

• RT_Init - Initializes memory and timer.

• RT_Process - Starts processing event loop

• RT_TimerInterrupt This procedure must be invoked from timer interrupt vector, it must be invoked with period of 1 ms for properly timings.

• RT_TaskProcs Pointer to table of task procedure addresses (16 bit address). Each task refers by task number, it means offset in table of procs. Task with number 0 is idle task, it invoked when no task in queue.

• RT_SendTask (macro RT_TASK) Puts task by task number into queue

• RT_SetTimer (macro RT_TIMER) Puts task into scheduler (used task number and waiting time in ms up to 65535 ms)

Links

AVR DI HALT's tutorial: http://easyelectronics.ru/avr-uchebnyj-kurs-operacionnaya-sistema-vvedenie.html

Template makefile: https://gist.github.com/bradfordbarr/9182992