A memory-protected module's queue request reaches the Module Manager's dispatch layer, which decides how much of the module's buffer the privileged queue copy may touch and hands that extent to the module port's range check. A queue's tx_queue_message_size is a count of ULONGs and the copy moves that many words, so the extent is message_size * sizeof(ULONG) bytes. Front-send passed the word count itself. Send and receive, either side of it in the same header, have always multiplied. So a source buffer ending message_size bytes into memory the module may reach was accepted, and _txe_queue_front_send then read message_size * sizeof(ULONG) bytes from it in privileged mode: 3 * message_size bytes past the end of what the module is allowed to read, which is 48 bytes at ThreadX's default message size limit and 96 at the limit this test tree builds with. The words land in the queue, and a module that can receive from that queue reads them back, so the over-read is disclosed rather than merely performed. Where the memory past the region is not mapped for the requesting module, the privileged read faults instead. The buffer cannot be aimed: it has to pass the same check to be accepted at all, so it is anchored to the end of a region the module can already read and the overrun is the fixed window immediately after it. That bounds what this reaches; it does not make it the module's business. The fix is the multiplication the other two services do, in the units the port check has always expected. It changes nothing for a module loaded without memory protection, because the check it corrects is inside the dispatcher's memory protection block, and the tests hold that. The regression test drives the three queue dispatchers directly, which nothing in the tree did before, and measures the extent each one validates rather than sampling either side of it: for a given message size it walks the room left between the buffer and the end of the module's region and finds the smallest amount the dispatcher accepts. That number is the extent. It has to be message_size * sizeof(ULONG) for all three services, in the module's data, in a shared region registered to it, and -- for the two services that read the buffer rather than write it -- in the module's read-only image, which is where a module sending a constant message sends it from. A receive destination in the read-only image is refused at every extent. Two things had to be arranged for a dispatcher to be testable on the host at all. The dispatch table is a header of static functions wrapped one per service in #ifndef TXM_<SERVICE>_CALL_NOT_USED, and at -O0 a compiler emits them all, so linking the whole table would mean standing up every kernel entry point it reaches. Defining the 93 guards the test does not exercise compiles the header down to the three queue services, which leaves four symbols to stub and exercises that conditional compilation, which nothing else in the tree does. The extent also has to reach a check that honours it, so the test takes its module port headers from a Cortex-M port, whose inline data check is the shape the memory-protected module ports share. The Cortex-A7 port's data check takes the pointer alone and translates a single address, so on that port no extent reaches anything and a test built on it would pass equally with and without this change. That is also the affected-port claim: the defect is in the portable dispatch layer and was live on every memory-protected module port that honours the size it is given, which is all of them except Cortex-A7, where the port's own check discarded the size before this one's error could matter. Assisted-by: Claude Code (Opus 5) <noreply@anthropic.com>
Eclipse ThreadX RTOS
This advanced real-time operating system (RTOS) is designed specifically for deeply embedded applications. Among the multiple benefits it provides are advanced scheduling facilities, message passing, interrupt management, and messaging services. Eclipse ThreadX RTOS has many advanced features, including picokernel architecture, preemption threshold, event chaining, and a rich set of system services.
Here are the key features and modules of ThreadX:
Getting Started
Eclipse ThreadX has been integrated to the semiconductor's SDKs and development environment. You can develop using the tools of choice from STMicroelectronics, NXP, Renesas and Microchip.
We also provide getting started guide and samples using development boards from semiconductors you can build and test with.
See Overview of Eclipse ThreadX RTOS for the high-level overview.
Repository Structure and Usage
Directory layout
.
├── cmake # CMakelist files for building the project
├── common # Core ThreadX files
├── common_modules # Core ThreadX module files
├── common_smp # Core ThreadX SMP files
├── docs # Documentation supplements
├── ports # Architecture and compiler specific files. See below for directory breakdown
│ ├── cortex_m7
│ │ ├── iar # Example IAR compiler sample project
│ │ │ ├── example build # IAR workspace and sample project files
│ │ │ ├── inc # tx_port.h for this architecture
│ │ │ └── src # Source files for this architecture
│ │ ├── ac6 # Example ac6/Keil sample project
│ │ ├── gnu # Example gnu sample project
│ │ └── ...
│ └── ...
├── ports_modules # Architecture and compiler specific files for threadX modules
├── ports_smp # Architecture and compiler specific files for threadX SMP
├── samples # demo_threadx.c
└── utility # Test cases and utilities
Branches & Releases
The master branch has the most recent code with all new features and bug fixes. It does not represent the latest General Availability (GA) release of the library. Each official release (preview or GA) will be tagged to mark the commit and push it into the Github releases tab, e.g. v6.2-rel.
When you see xx-xx-xxxx, 6.x or x.x in function header, this means the file is not officially released yet. They will be updated in the next release. See example below.
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _tx_initialize_low_level Cortex-M23/GNU */
/* 6.x */
/* AUTHOR */
/* */
/* Scott Larson, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function is responsible for any low-level processor */
/* initialization, including setting up interrupt vectors, setting */
/* up a periodic timer interrupt source, saving the system stack */
/* pointer for use in ISR processing later, and finding the first */
/* available RAM memory address for tx_application_define. */
/* */
/* INPUT */
/* */
/* None */
/* */
/* OUTPUT */
/* */
/* None */
/* */
/* CALLS */
/* */
/* None */
/* */
/* CALLED BY */
/* */
/* _tx_initialize_kernel_enter ThreadX entry function */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 09-30-2020 Scott Larson Initial Version 6.1 */
/* xx-xx-xxxx Scott Larson Include tx_user.h, */
/* resulting in version 6.x */
/* */
/**************************************************************************/
Supported Architecture Ports
ThreadX
arc_em cortex_a12 cortex_m0 cortex_r4
arc_hs cortex_a15 cortex_m23 cortex_r5
arm11 cortex_a17 cortex_m3 cortex_r7
arm9 cortex_a34 cortex_m33
c667x cortex_a35 cortex_m4
linux cortex_a5 cortex_m55
risc-v32 cortex_a53 cortex_m7
rxv1 cortex_a55 cortex_m85
rxv2 cortex_a57
rxv3 cortex_a5x
win32 cortex_a65
xtensa cortex_a65ae
cortex_a7
cortex_a72
cortex_a73
cortex_a75
cortex_a76
cortex_a76ae
cortex_a77
cortex_a8
cortex_a9
ThreadX Modules
Eclipse ThreadX Modules component provides an infrastructure for applications to dynamically load modules that are built separately from the resident portion of the application.
cortex_a35
cortex_a35_smp
cortex_a7
cortex_m0+
cortex_m23
cortex_m3
cortex_m33
cortex_m4
cortex_m7
cortex_r4
rxv2
ThreadX SMP
Eclipse ThreadX SMP is a high-performance real-time SMP kernel designed specifically for embedded applications.
arc_hs_smp
cortex_a34_smp
cortex_a35_smp
cortex_a53_smp
cortex_a55_smp
cortex_a57_smp
cortex_a5x_smp
cortex_a5_smp
cortex_a65ae_smp
cortex_a65_smp
cortex_a72_smp
cortex_a73_smp
cortex_a75_smp
cortex_a76ae_smp
cortex_a76_smp
cortex_a77_smp
cortex_a78_smp
cortex_a7_smp
cortex_a9_smp
linux
Adaptation layer for ThreadX
ThreadX is an advanced real-time operating system (RTOS) designed specifically for deeply embedded applications. To help ease application migration to ThreadX RTOS, Eclipse ThreadX provides adaption layers for various legacy RTOS APIs (FreeRTOS, POSIX, OSEK, etc.).
Component dependencies
The main components of ThreadX RTOS are each provided in their own repository, but there are dependencies between them, as shown in the following graph. This is important to understand when setting up your builds.
You will have to take the dependency graph above into account when building anything other than ThreadX itself.
Building and using the library
Instruction for building the ThreadX as static library using Arm GNU Toolchain and CMake. If you are using toolchain and IDE from semiconductor, you might follow its own instructions to use ThreadX RTOS components as explained in the Getting Started section.
-
Install the following tools:
- CMake version 3.0 or later
- Arm GNU Toolchain for arm-none-eabi
- Ninja
-
Cloning the repo
$ git clone https://github.com/eclipse-threadx/threadx.git -
Define the features and addons you need in
tx_user.hand build together with the component source code. You can refer totx_user_sample.has an example. -
Building as a static library
Each component of ThreadX RTOS comes with a composable CMake-based build system that supports many different MCUs and host systems. Integrating any of these components into your device app code is as simple as adding a git submodule and then including it in your build using the CMake
add_subdirectory().While the typical usage pattern is to include ThreadX into your device code source tree to be built & linked with your code, you can compile this project as a standalone static library to confirm your build is set up correctly.
An example of building the library for Cortex-M4:
$ cmake -Bbuild -GNinja -DCMAKE_TOOLCHAIN_FILE=cmake/cortex_m4.cmake . $ cmake --build ./build
Licensing
License terms for using Eclipse ThreadX are defined in the LICENSE.txt file of this repo. Please refer to this file for all definitive licensing information for all content, incl. the history of this repo.
Resources
The following are references to additional ThreadX RTOS resources:
- Product introduction: https://github.com/eclipse-threadx/rtos-docs
- Product issues and bugs, or feature requests: https://github.com/eclipse-threadx/threadx/issues
- TraceX Installer: https://aka.ms/azrtos-tracex-installer
You can also check previous questions or ask new ones on StackOverflow using the threadx-rtos and threadx tags.
Security
Eclipse ThreadX provides OEMs with components to secure communication and to create code and data isolation using underlying MCU/MPU hardware protection mechanisms. It is ultimately the responsibility of the device builder to ensure the device fully meets the evolving security requirements associated with its specific use case.
Contribution
Please follow the instructions provided in the CONTRIBUTING.md for the corresponding repository.

