QoRTOS

Quite Ok RTOS for microcontrollers.

tickless
minimal (500 lines of code)
No mutexes and semaphores
only static memory mailboxes
MIT liberal license

Project goal

The aim of this project is to provide a very simple and basic RTOS that is easy to port and understand, especially for educational purpose. It was created to test software design of tickless RTOS and avoid typicall problems with mutexes and mis-understanding of semaphores.

A second goal is to be minimal, in the future maybe only one file to drop in your project.

Project status / limitations

First working version on Raspberry Pico
No documentation
Not heavily tested
Feedback are welcome!
Only GCC

Compatible platforms

Only GCC is supported for now.

CPU	Status
RP2040 (Raspberry Pico)	working

TODO before 1.0 stable release

Move stacks out of qor.c
API documentation with examples
Documentation (only on this README.txt)
Design documentation (in a separated Markdown file in docs)
Examples in examples directory
Port on a RISC-V microcontroller
Mailbox wait in IRQ context (return immediately instead of sleep which is non sense)

Documentation

Typical usage

qor_tcb_t BlinkyTcb;
qor_tcb_t IdleTcb;

void BlinkyTask(void *args)
{
    while (1)
    {
        ost_hal_gpio_set(OST_GPIO_DEBUG_LED, 0);
        qor_sleep(500);
        ost_hal_gpio_set(OST_GPIO_DEBUG_LED, 1);
        qor_sleep(500);
    }
}

void IdleTaskFunction(void *args)
{
    while (1)
    {
        // Use the idle thread for instrumentation or power saving
	// Beware, OS functions won't work here
        // __asm volatile("wfi");
    }
}

int main()
{
    qor_init(THREADFREQ);
    qor_create_thread(&BlinkyTcb, BlinkyTask, 3, "BlinkyTask");
    qor_start(&IdleTcb, IdleTaskFunction);

    return 0;
}

How to use it in your project

Add qor.c and qor_armv6m.s files in your project build system
Initialize the RTOS, create threads and then start it

Porting guide

For the moment, the RTOS is limited to the RP2040 MCU (Raspberry Pico), especially for the OS Timer used to wakeup the processor for task switching. It requires a 64-bit timer at us unit as a base time. Porting to a 32-bit timer should be quite easy. Some macros should be used to make things agnostic.

License

MIT License

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

arabine / qortos