FreeRTOS

FreeRTOS is an open source real-time operating system for embedded systems. It is based on a microkernel architecture and has been ported to a variety of microcontrollers. The current version is 7.6.0.

Features

To ensure good maintainability, FreeRTOS is largely developed in C, only a few functions are implemented in assembly language. The scheduler can be configured so that preemptive and cooperative operation is possible. The operating system since version 4 supports two different task classes. "Real" tasks and coroutines, where little space is available. " Event flags " are sold under the name " binary semaphore ". Mutexes are available in newer versions.

The package will be ready for download configurations for various architectures and various compiler environments. Furthermore, various demos are (for example, an IP stack ) at. On FreeRTOS.org there is extensive documentation on FreeRTOS, instructions ( " tutorials ") and documentation on an RTOS and a comparison of implementations on different microcontrollers.

Supported Architectures

Supported architectures:

  • Microcontroller with ARM7 architecture
  • Microcontroller from the " ARM Cortex- M" Family
  • Altera Nios II soft-core processor
  • Atmel AVR and AVR32 Atmel
  • Freescale Semiconductor HCS12 family and ColdFire V2
  • Xilinx MicroBlaze and PowerPC PPC405
  • Texas Instruments MSP430, and TMS570 RM48
  • Microchip Technology PIC18, PIC24, dsPIC, PIC32
  • Renesas H8 / S SuperH
  • Fujitsu MB91460 MB96340 32 bit and 16 bit
  • NEC V850ES 32 bit and 16 bit 78K0R
  • OpenRISC

More contributed ports

  • Microprocessors x86
  • Intel 8052/8051
  • Microcontroller with Infineon TriCore architecture
  • Jennic JN5139 microcontroller
  • Cyan ECOG microcontroller
  • Analog Devices Blackfin BF533
  • Zilog eZ80
  • Lattice Mico32

License

FreeRTOS is under a slightly modified GPL. By modifying the GPL running under FreeRTOS application software does not need to be made, which the operating system is also suitable for commercial projects under the GPL.

Related Projects

SafeRTOS was developed as a complementary product to FreeRTOS: with the same functionality, but with a uniquely designed, safety-critical implementations. The FreeRTOS function model was exposed to the full HAZOP study and both weaknesses in the functional model as well as in the API have been identified and eliminated. The resulting requirements were the " IEC 61508 SIL3 " subjected development cycle - the highest possible for a software component cycle. It is certified by TÜV Süd to safety integrity level SIL 3

Another project is OpenRTOS, which has an identical code base as FreeRTOS, but with different licensing. The OpenRTOS license removes all references to the GPL and its implications. Example: One of the FreeRTOS usage condition in a commercial product is that the end user is informed by the FreeRTOS use and that the source code must be released upon request. OpenRTOS does not meet these requirements as a commercial product and it offers the OpenRTOS users additional access to technical support.

Alternatives

A ( also free ) alternative to FreeRTOS is the TNKernel, which features a full synchronization API, but has been ported to less microcontroller as FreeRTOS.

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