Integrating SystemView in Bare-Metal Systems

Overview

SystemView is a visualization and analysis tool for embedded systems that provides full insight into an application, including a timeline, CPU load, runtime information, and context runtime details. It helps developers gain a deep understanding of runtime behavior. In addition to μC/OS-II, μC/OS-III, FreeRTOS, and embOS, SystemView also supports analysis of bare-metal systems without an operating system.

This article explains how to integrate SystemView into a bare-metal system.

Integration Steps

1. Create a new project for the target device in Embedded Studio.
2. Add all files from the /SEGGER and /Config folders in the SystemView installation directory and add the Sample/NoOS/Config/Cortex-M/SEGGER_SYSVIEW_Config_NoOS.c source file to the project.



3. In the SystemViewDescription directory create a file named SYSVIEW_NoOS.txt and add the functions to record. Use ID numbers starting at 33. Example entries:

33 _TestFunc0 34 _TestFunc1

4. Include SEGGER_SYSVIEW_Conf.h and SEGGER_SYSVIEW.h in main.c.

#include "SEGGER_SYSVIEW_Conf.h" #include "SEGGER_SYSVIEW.h"

5. In SEGGER_SYSVIEW_Conf.h set SEGGER_SYSVIEW_ID_BASE to the RAM address of the target device.

#define SEGGER_SYSVIEW_ID_BASE 0x20000000

6. In SEGGER_SYSVIEW_Config_NoOS.c modify the function _cbSendSystemDesc() as follows:

static void _cbSendSystemDesc(void) { SEGGER_SYSVIEW_SendSysDesc("N="SYSVIEW_APP_NAME",O=NoOS,D="SYSVIEW_DEVICE_NAME); }

Set SYSVIEW_RAM_BASE to the base RAM address of the target device.

// The lowest RAM address used for IDs (pointers) #define SYSVIEW_RAM_BASE (0x20000000)

7. Call SEGGER_SYSVIEW_Conf() in main(). For a no-OS application treat the entire system as an idle task and call SEGGER_SYSVIEW_OnIdle().

int main(void) { U32 v; int Cnt; Cnt = 0; SEGGER_SYSVIEW_Conf(); /* Configure and initialize SystemView */ SEGGER_SYSVIEW_Start(); /* Starts SystemView recording*/ SEGGER_SYSVIEW_OnIdle(); /* Tells SystemView that System is currently in "Idle"*/ ......

8. Optionally initialize the system tick in main. In the tick handler call SEGGER_SYSVIEW_RecordEnterISR() at the start and SEGGER_SYSVIEW_RecordExitISR() at the end.

void SysTick_Handler(void) { volatile U32 Cnt; SEGGER_SYSVIEW_RecordEnterISR(); Cnt++; SEGGER_SYSVIEW_RecordExitISR(); }

9. Invoke the functions you want to record from the application, for example _TestFunc0().
10. For each function listed in the description file call SEGGER_SYSVIEW_RecordVoid(ID) and SEGGER_SYSVIEW_RecordEndCall(ID), where ID is the ID number from the description file.

static void _TestFunc0(void) { SEGGER_SYSVIEW_RecordVoid(33); _TestFunc0Cnt = 100; while(50 < --_TestFunc0Cnt); _TestFunc1(); while(--_TestFunc0Cnt); SEGGER_SYSVIEW_RecordEndCall(33); }

11. Build and run the application, then start SystemView recording.

Expected Result

If the build succeeds, SystemView recording should show the recorded events and timeline as in the example screenshot below.

Example Project

A "NoOS" SystemView integration example project based on STM32F407 and Embedded Studio is available as the file SysView_NoOS_GenericCortexM4_Example.zip. Modify the target device name to adapt the project for other Cortex-M4 devices.