This repository implements an OSEK-like, bare-metal operating system for ARM(R) Cortex(R)-M3. The goals are to achieve near-compatibility with OSEK (ECC1/BCC1) and to provide an intuitive, esay-to-understand sample application that can be extended for your own projects.

Features include:

• OSEK-like OS implementation with support of most common features.
• The sample application runs on the STM32F100-NUCLEO Board.
• Tasks and events interact to produce a blinky LED show featuring the green and blue LEDs toggling at 1Hz (green) and 1/2 Hz (blue) respectively.
• Use a simple self-written bare-metal startup.
• Power, clock and port initialization.
• 1ms timebase derived from the ARM(R) SysTick.
• Implementation in C99 with absolute minimal use of assembly.

A clear and easy-to-understand build system based on either free GNUmake/GCC or alternatively KEIL MDK completes this fun and educational project.

This repository provides keen insight on writing your own bare metal operating system from scratch on a modern microcontroller using entirely free tools and open standards.

Following low-level chip initialization, the program jumps to the main() subroutine in Application/Appli.c. Here there are two functional lines. The first line initializes the LEDs. The second line subsequently starts the operatng system via call to OS_StartOS().

An idle task and one single extended task animate the user LED, providing a simple blinky LED show featuring the gren and blue LED(s) toggling at 1Hz (green) and 1/2 Hz (blue) respectively.

Build on Win* is easy using an installed KEIL-MDK. Simply use the project file PRJ_02.uvprojx which can be found in the project's root directory.

Build on *nix* is easy using an installed gcc-arm-none-eabi

cd OSEK
./Build.sh

The build results including ELF-file, HEX-mask, MAP-file can be found in the Output directory following the GNUmake build.

Further information on open standard OSEK can be found in ISO 17356 and in the link below:

• https://en.wikipedia.org/wiki/OSEK