Frédéric Desbiens 146d57b235 Fixed the RISC-V64 trap frame size mismatch in the regression test BSP (#708)
The RISC-V64 port moved its interrupt frame to 528 bytes (65 slots plus 8
bytes of padding, so sp stays 16-byte aligned at a call) and published the
size as TX_RISCV_TRAP_FRAME_SIZE. The port sources were converted to use
it, but the shared regression test BSP was not: its trap_entry still
allocated a hardcoded 65 * REGBYTES, or 520 bytes.

Every interrupt therefore unwound 8 bytes more than it allocated:

    trap_entry:                   addi  sp,sp,-520
    _tx_thread_context_restore:   addi  sp,sp,528

On the RISC-V64 regression suite that left 24 of 95 tests failing in the
default configuration, typically as an illegal instruction once execution
reached a corrupted frame. The example BSP under the port directory was
converted with the port and was unaffected, which is why the functional
QEMU test kept passing.

The test BSP now takes both frame sizes from the port it is linked
against, so the two cannot drift apart again. A port that publishes no
contract keeps the historical layout, so the RISC-V32 side is unchanged
until its own port publishes one.

TX_RISCV_TRAP_CALL_FRAME_SIZE is restored to the RISC-V64 tx_port.h. It
was removed as unused when the frame sizes were introduced, but it is
part of the same contract: it is the space a trap entry reserves around a
call into C, and the psABI requires 16 bytes there rather than one
register slot.

Verified on QEMU with every linkable test built, comparing against the
commit before the port change:

    before the port change   2 failures out of 95 (both unlinkable)
    current dev              24 failures out of 95
    with this change          2 failures out of 95 (both unlinkable)

The two remaining failures predate all of this: newlib pulls _impure_ptr
out of R_RISCV_HI20 range for time(), so those two binaries do not link.
RISC-V32 is unchanged at 2 failures across all five configurations.

Assisted-by: Claude Code (Opus 5) <noreply@anthropic.com>
2026-09-09 10:56:57 -04:00
…
…

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:

ThreadX Key Features

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.

dependency graph

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.

  1. Install the following tools:

  2. Cloning the repo

    $ git clone https://github.com/eclipse-threadx/threadx.git
    
  3. Define the features and addons you need in tx_user.h and build together with the component source code. You can refer to tx_user_sample.h as an example.

  4. 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:

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.

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