ea9c26f524
ARMv7-M allows overlapping MPU regions. When 2 MPU regions overlap, the MPU configuration of the higher numbered MPU region is applied. For example, if a memory area is covered by 2 MPU regions 0 and 1, the memory permissions for MPU region 1 are applied. We use 5 MPU regions for kernel code and kernel data protections and leave the remaining for the application writer. We were using lowest numbered MPU regions (0-4) for kernel protections and leaving the remaining for the application writer. The application writer could configure those higher numbered MPU regions to override kernel protections. This commit changes the code to use highest numbered MPU regions for kernel protections and leave the remaining for the application writer. This ensures that the application writer cannot override kernel protections. We thank the SecLab team at Northeastern University for reporting this issue. Signed-off-by: Gaurav Aggarwal <aggarg@amazon.com> |
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|---|---|---|
| .github | ||
| include | ||
| portable | ||
| .gitmodules | ||
| CMakeLists.txt | ||
| croutine.c | ||
| event_groups.c | ||
| GitHub-FreeRTOS-Kernel-Home.url | ||
| History.txt | ||
| LICENSE.md | ||
| list.c | ||
| manifest.yml | ||
| queue.c | ||
| Quick_Start_Guide.url | ||
| README.md | ||
| stream_buffer.c | ||
| tasks.c | ||
| timers.c | ||
Getting started
This repository contains FreeRTOS kernel source/header files and kernel ports only. This repository is referenced as a submodule in FreeRTOS/FreeRTOS repository, which contains pre-configured demo application projects under FreeRTOS/Demo directory.
The easiest way to use FreeRTOS is to start with one of the pre-configured demo application projects. That way you will have the correct FreeRTOS source files included, and the correct include paths configured. Once a demo application is building and executing you can remove the demo application files, and start to add in your own application source files. See the FreeRTOS Kernel Quick Start Guide for detailed instructions and other useful links.
Additionally, for FreeRTOS kernel feature information refer to the Developer Documentation, and API Reference.
Getting help
If you have any questions or need assistance troubleshooting your FreeRTOS project, we have an active community that can help on the FreeRTOS Community Support Forum.
Cloning this repository
To clone using HTTPS:
git clone https://github.com/FreeRTOS/FreeRTOS-Kernel.git
Using SSH:
git clone git@github.com:FreeRTOS/FreeRTOS-Kernel.git
Repository structure
-
The root of this repository contains the three files that are common to every port - list.c, queue.c and tasks.c. The kernel is contained within these three files. croutine.c implements the optional co-routine functionality - which is normally only used on very memory limited systems.
-
The
./portabledirectory contains the files that are specific to a particular microcontroller and/or compiler. See the readme file in the./portabledirectory for more information. -
The
./includedirectory contains the real time kernel header files.
Code Formatting
FreeRTOS files are formatted using the "uncrustify" tool. The configuration file used by uncrustify can be found in the FreeRTOS/FreeRTOS repository.
Spelling
lexicon.txt contains words that are not traditionally found in an English dictionary. It is used by the spellchecker to verify the various jargon, variable names, and other odd words used in the FreeRTOS code base. If your pull request fails to pass the spelling and you believe this is a mistake, then add the word to lexicon.txt. Note that only the FreeRTOS Kernel source files are checked for proper spelling, the portable section is ignored.