Last site update June 02 2015
Please support the FreeRTOS project!
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The FreeRTOS project has been generated through many years of hard work - but is provided to you from this page free of charge. Please show your support by
buying a book. Thank you.
Purchasing FreeRTOS documentation will not only help you by ensuring you get up and
running as quickly as possible, and with an in-depth knowledge of how to use FreeRTOS,
it will help the FreeRTOS project to continue with its mission of providing professional
grade, cross platform, de facto standard solutions for microcontrollers - completely
free of charge!
- Buy PDF with Reference Manual -
- Buy Paperback -
RTOS Source Code Download Instructions
To download, and get the most out of FreeRTOS, follow the following steps:
Please keep up to date by joining the
announcements mailing list for
infrequent comprehensive notifications. We respect your
privacy, so do not provide email addresses to any third party.
Every email sent contains unsubscribe instructions.
The download is available as a standard zip file (.zip), and as a self extracting zip file (.exe).
Click to download the latest official release from SourceForge
A version change description is also available.
Unzip the source code into a suitable directory - taking care to ensure the directory structure within the zip file
is maintained. Please read the quick start guide
to understand the directory structure and get up and running quickly.
The monitored support forum,
known issue list, FAQ
and version change description, all provide additional resources.
You can keep up to date with very occasional announcements by adding yourself to the FreeRTOS mailing list.
Emails are infrequent and kept short. We respect your privacy, so do not provide email addresses to any third party. Every email sent contains unsubscribe instructions.
- Heap_4.c cannot be used on 8-bit devices (FreeRTOS V8.2.1)
A typo in the calculation of xHeapStructSize means heap_4.c cannot be used
to provide the heap when FreeRTOS is being built for an 8-bit microcontroller.
- Software timers and FreeRTOS-MPU
The software timer API is not yet included in the official distribution of
- Coldfire V2 CodeWarrior port
The Coldfire V2 CodeWarrior code will not run with the latest (Eclipse) based
CodeWarrior tools. A fix is posted on the support forum
(post 4), and will be incorporated into the main release in due course.
- Coldfire V1 CodeWarrior port
The Coldfire V1 CodeWarrior projects will not automatically update to later CodeWarrior
versions unless all unnecessary files are deleted from the FreeRTOS/Source directory first.
support thread for more information.
- MSP430 CrossWorks and GCC demos
The CrossWorks demo has not yet been updated to use CrossWorks V2.0 or later.
The GCC demo has not yet been updated to use the latest MSPGCC compiler version.
- AVR32 demos
The IAR Embedded Workbench demos for the AVR32 will not currently build if you are using a later version of the IAR tool chain. The issue is caused by
changes to macro names within the compiler header files.
- Silicon Labs SDCC ports
Unfortunately these will not work with the latest compiler versions. The compiler version used to generate the port is now rather old, but is stated
on the port documentation page.
Copyright (C) 2004-2010 Richard Barry. Copyright (C) 2010-2015 Real Time Engineers Ltd.
Any and all data, files, source code, html content and documentation included in the FreeRTOSTM distribution or available on this site are the exclusive property of Real Time Engineers Ltd..
See the files license.txt (included in the distribution) and this copyright notice for more information. FreeRTOSTM and FreeRTOS.orgTM are trade marks of Real Time Engineers Ltd.