This application note describes the use of VS Code debugging RT-THREAD QEMU-VEXPRESS-A9 BSP project in the Windows platform.
The purpose and structure of this article
The purpose and background of this article
VS C ++ ODE (full name Visual Studio Code is a lightweight code editor, supporting Windows, OS X, and Linux. Support for built-in JavaScript, TypeScript, and Node.js, and has a wealth of plug-in ecosystems that support C ++, C #, Python, PHP, etc. other languages by installing plugins.
This article mainly introduces the use of VS Code debug qemu-vexpress-a9 BSP projects in the Windows platform.
This article
This article mainly introduces VS Code debugging preparations and how to debug projects.
Ready to work
Download the RT-THREAD source code, recommend download 3.1.0 and above.
Download the RT-THREAD ENV tool, recommend version 1.0.0 and above.
Https://www.rt-thread.org/document/site/rtthread-development-guide/rtthread-tool-manual/env/env-user-manual/
Download VS Code
Https://code.visualstudio.com/downloadload
Please copy it to your browser before
Run and debug RT-THREAD
Step one installation and debug plugin
Download and install debugging plugins supporting C / C ++ in vs code extensions:
After installing, confirm that the plugin is the following state, if not, click to reload:
Step Second to open the VS Code project project
Enter the QEMU-VEXPRESS-A9 BSP root directory in the ENV console, then enter the command code. Open the VS CODE.
The QEMU-VEXPRESS-A9 BSP folder is automatically opened after the VS Code is turned on, as shown below.
Step three compilation RT-THREAD
Click VS Code "View -> Term" to open the VS Code internal terminal, enter the command SCONS in the terminal to compile the project, and the terminal prints the compilation information.
After the compilation is completed, you can run the project. The terminal will output the RT-Thread launch LOGO information, and the QEMU has run.
Precautions:
1. Need to compile the project to generate the RTTHREAD.ELF file before debugging the BSP project.
2, you can use the Scons - Target = vsc -s command to update the C / C ++ header file search path information for VS CODE. It is not necessary to update every time, only RT-THREAD is reconfigured by menusfig or change the RTConfig.h header file.
Step 4 Modify QEMU-DBG.BAT files
Before start debugging, you need to edit the QEMU-DBG.bat file under the directory of QEMU-VEXPRESS-A9, add Start before QEMU-System-ARM:
@echo offif exist sd.bin goto run qemu-img create -f raw sd.bin 64m: Run Start QEMU-SYSTEM-ARM -M VEXPRESS-A9-Kenergy RTTHREAD.ELF -SERIAL STDIO -SD SD.BIN -S -S
Step five debugging projects
As shown in the figure below, click the Trial Menu (Parquel icon) in VS Code, the debug platform selects Windows, then press F5 to turn on the QEMU debug mode, and the breakpoint stays in the main function. The VS Code debug options are shown below:
Qemu has also running, as shown in the following figure.
You can use the GDB command in VS Code, you need to add -EXEC in front. For example, the -exec info registers command can view the contents of the register:
Some of the other major orders are as follows:
View memory address content: X /, each parameter description as follows:
n is a positive integer that represents the number of memory cells that need to be displayed, that is, the content of a memory cell is displayed from the current address, and the size of the memory unit is defined by the following U
f represents the format shown, see below. If the address refers to a string, the format can be s. Other formats are shown in the following table:
u Represents the number of bytes requested from the current address, if not specified, the GDB defaults to 4 Bytes. u Parameters can be replaced by the following characters, b represents the single-byte, h represents the double byte, w represents the four-byte, g represents eight bytes. When we specify the length of the byte length, the GDB will start from the memory address, read and write the specified byte, and take it as a value.
Addr represents a memory address.
Note: Strictly distinguish between N and u, n represents the number of units, u represents the size of each unit.
Example: X / 3uh 0x54320 represents reading content from the memory address 0x54320, H represents a double-byte as a unit, 3 indicates the output three units, u means that pressing hexadecimal display.
View the contents of the current program: X / 10X $ SP -. 1882. Print the top 10 elements of the Stack View the current quarter information: Info frame ---- List general Info About the frame View the parameters of the current program: Info Args --- Lists Arguments to the function View the local variable of the current program: Info locals --- List variables Stored in The Frame View the value of the current register: Info Registers Info All-Registers (including Floating point register) View an exception processor in the current stack frame: Info Catch (Exception Handlers)
Tips: You can only enter the first letter of each command when you enter a command. For example: Info Registers can only enter I R.
Precautions
If you add an additional folder in the VS Code directory, it will cause debugging that cannot be started.
Every time you start debugging, you need to use the ENV tool to use the code in the BSP root directory. Command Open VS CODE to debug the project.
refer to
ENV Tool User Manual
common problem
For questions related to the ENV tool, please refer to the Common Data Link Section of the ENV Tool User Manual.
Can't find 'QEMU-System-Arm'.
Workaround: Direct Open the VS Code debugging project will have this error. Use the ENV tool to use the code in the BSP root directory. Command Open vs code.
The VS Code debug option does not appear the debug @ windows option.
Workaround: Please update the RT-THREAD source code to 3.1.0 and above. , Read full text, original text title: [RTOS column] Using VS Code + QEMU debug rt-thread
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