BeRTOS Documentation


BeRTOS is a real-time operating system designed for building applications for embedded systems, like reference boards, test boards, or custom boards.

It has a modular structure: its components can be used in very different environments, from 8-bit processor to Linux and Win32 hosted application (for debug purpose), using a wide range of compilers.

Have a look at A 5 minute introduction to BeRTOS page for a quick overview of the BeRTOS system.

History and Motivation

BeRTOS was born as a extremely modular, highly optimized and fine-tuned operating system for embedded programming. As a result, each module has its own scope and can be used alone or in cooperation with other modules. It's even possible to use most of the drivers without activating the kernel module.

We have grown it following our guidelines: simplicity and beauty. These guidelines made it possible to evolve it in a full-featured real time operating system, with more modularity than many other embedded OSes, without giving up reliability and performace.

To achieve the highest possible reusability, most BeRTOS components are designed for fine-grained modularity and minimal external dependencies. Most non-essential features can be configured out for applications with small memory footprint requirements.


  • multitasking kernel with IPC, semaphores, priority levels;
  • a comprehensive set of generic drivers for a wide range of devices, which can be easily customized to the actual hardware: timer, serial, adc, ntc, pwm, stepper motors, dc motors, lcd, keyboards, buzzer, eeprom;
  • full graphic subsystem for simple displays, with font support, bitmaps, clipping, text formatting, interactive menus;
  • simple console with command parser;
  • readline-like support for command history;
  • entropy generator and random numbers generator optimized for embedded systems;
  • checksumming and hashing functions (CRC, MD2);
  • full hash-table implementation with double-hashing collision resolution;
  • XMODEM protocol implementation;
  • RLE compression algorithm;

Directory Structure

The modules are sorted in subdirectories by their category:

  • app/ : demo applications;
  • bertos/algo/ : algorithms;
  • bertos/cfg/ : configuration stuff;
  • bertos/drv/ : hardware drivers;
  • bertos/dt/ : experimental object oriented gui toolkit;
  • bertos/emul/ : Qt-based emulator framework for embedded applications;
  • bertos/fonts/ : fonts;
  • bertos/fs/ : file system related stuff;
  • bertos/gfx/ : general purpose graphics routines;
  • bertos/gui/ : widgets for simple displays;
  • bertos/hw/ : hardware-specific declarations;
  • bertos/icons/ : conversion tool from image TXT format to LCD bitmap;
  • bertos/kern/ : multitasking kernel;
  • bertos/mware/ : algorithms, other standalone code;
  • bertos/struct/ : containers and other data structures;
  • bertos/os/ : OS-abstraction layers for hosted environments;
  • doc/ : documentation;

The top-level directory contains a few support headers that are meant to be usable by any C/C++ embedded or hosted application.


BeRTOS is provided under the term of the GNU General Public License (see LICENSE.GPL) with following exception:

As a special exception, you may use this file as part of a free software
library without restriction.  Specifically, if other files instantiate
templates or use macros or inline functions from this file, or you compile
this file and link it with other files to produce an executable, this
file does not by itself cause the resulting executable to be covered by
the GNU General Public License.  This exception does not however
invalidate any other reasons why the executable file might be covered by
the GNU General Public License.