How to Use SystemView to Analyze μC/OS-III?

01

Adding SystemView and RTT Implementation Code on the Target Device

(1) To use SEGGER SystemView, you first need to add the SystemView and RTT source files to the target application project. The source package for SystemView and RTT is provided in the installation directory of the PC-side SystemView software.

The source code includes three parts:

1) Configuration files for SystemView and RTT real-time transfer technology: modifications may be needed based on application requirements.

2) Specific implementation source code for SystemView and RTT technology: typically, no modifications are needed here.

3) Interface files corresponding to various types of OS and different OS versions: select the corresponding interface file based on the actual application situation. In this article, we choose to add the corresponding files under the uC/OS-III directory.

After adding the aforementioned configuration files, RTT implementation source code, and OS interface files to the project, the included files in the project are as follows. Note that you also need to set the include paths for these newly added C files and assembly code files in the IDE.

(2) Perform some configurations related to SystemView

• In the os_cfg.h file, set the tracking function of μC/OS-III to 1 to enable it.

#define OS_CFG_TRACE_EN 1u

• Add header file inclusion in the application code main.c file

#include “os_trace.h”

• Configure the maximum number of tasks and other kernel objects in os_cfg_trace.h

In the SEGGER_SYSVIEW_Config_uCOSIII.c file, configure the system clock frequency, timestamp counter frequency, and the base address of the chip’s RAM. If the project uses the HAL library, you can use the functions provided in the HAL library to return these parameter values.

• Set the size of the event buffer in SEGGER_SYSVIEW_Conf.h

#define SEGGER_SYSVIEW_RTT_BUFFER_SIZE 1024

The size of the buffer space here needs to be determined based on the J-Link debug interface rate and the number of events recorded. When the J-Link rate is low or the number of recorded events is large, a larger buffer space should be set. When using SystemView Single-Shot mode, memory should be increased to record for as long as possible.

(3) Call the SystemView initialization function before creating tasks

After completing the hardware initialization of the chip, call the OS_TRACE_INIT() function to initialize SystemView before creating μC/OS tasks.

02

Installation and Setup of PC-side SystemView Software

The PC-side SystemView software can be downloaded from the Segger official website, the download link is as follows:

https://www.segger.com/downloads/systemview/

(1) To utilize J-Link for continuous recording with SystemView, you need to set the target chip model, target debug interface type (JTAG/SWD), and interface speed in the Target->Recorder Configuration option of the SystemView software.

For the RTT control block address detection, choose Auto; typically, it can be successfully detected by J-Link automatically.

(2) After completing the Recorder Configuration settings, click Target->Start Recording to start the tracking. In the demonstration, J-Link was used, and the default tracking mode is continuous recording mode, where the start and stop of tracking will be controlled by the PC-side SystemView software.

After entering tracking, you can obtain a visual tracking view as shown in Figure 6, where each column represents an interrupt or Task in the application, arranged in order of priority from high to low. Figure 6 intuitively shows the situation of task preemption occurring in the RTOS application, where the low-priority DemoTask is preempted by the high-priority TestTask during execution.

By utilizing visualization analysis tools like SystemView, developers can better understand the real-time behavior of RTOS applications, thereby creating higher quality code. The official μC/OS-III port example used in this demonstration on the STM32F767ZI_Nucleo development board can be downloaded from the following link,https://www.weston-embedded.com/micrium-examples/category/230-stm32f7

If you need a commercial license for the SystemView software, please contact[email protected]