MCUXpresso VSCode
Overview
This guide demonstrates how to develop and cross compile applications for the DART-MX8M-MINI Cortex-m4 co-processor using Microsoft Visual Studio Code.
Please visit Variscite's MCUXpresso Guide for additional information about manually building demos, integration with Yocto, running applications from U-Boot and Linux, and JTAG debugging.
Setup Host Computer Environment
Follow the steps below to prepare a fresh Ubuntu 20.04 installation for VS Code debugging:
Install Dependencies
$ sudo apt-get -y update $ sudo apt-get -y install build-essential gdb gdb-multiarch git cmake
Install VS Code
$ sudo snap install --classic code
Install VS Code Extensions
VS Code has a graphical interface for installing and managing extensions. To learn more, please see Using extensions in Visual Studio Code
For this guide, we will install the required extensions using the command line:
$ code --install-extension ms-vscode.cpptools $ code --install-extension marus25.cortex-debug $ code --install-extension dan-c-underwood.arm
Install Segger JLink
$ Download JLink_Linux_V760b_x86_64.deb from https://www.segger.com/downloads/jlink/ $ sudo dpkg -i JLink_Linux_V760b_x86_64.deb
The software will be installed in /opt/SEGGER folder
Install MCUXpresso Toolchain and SDK
Download and install GNU-ARM bare-metal toolchain:
$ mkdir ~/var-mcuxpresso $ cd ~/var-mcuxpresso $ wget https://developer.arm.com/-/media/Files/downloads/gnu-rm/10-2020q4/gcc-arm-none-eabi-10-2020-q4-major-x86_64-linux.tar.bz2 $ tar xvf gcc-arm-none-eabi-10-2020-q4-major-x86_64-linux.tar.bz2
Download MCUXpresso SDK for the SOM:
$ cd ~/var-mcuxpresso $ git clone https://github.com/varigit/freertos-variscite -b mcuxpresso_sdk_2.10.x-var01 $ cd freertos-variscite
Add Visual Studio Code support to the Variscite examples
Available Demos
All of the Variscite examples are located under the following folder.
~/var-mcuxpresso/freertos-variscite/boards/dart_mx8mm
Variscite provides a script to simplify the Project Configuration
Configure a single Project
For this example, we will configure the hello_world demo. However, the process is the same for all demos.
$ ./var_add_vscode_support.sh -b dart_mx8mm -e boards/dart_mx8mm/demo_apps/hello_world -t tcm -d /opt/SEGGER/JLink (for TCM target) $ ./var_add_vscode_support.sh -b dart_mx8mm -e boards/dart_mx8mm/demo_apps/hello_world -t ddr -d /opt/SEGGER/JLink (for DDR target)
Configure all Projects
$ ./var_add_vscode_support.sh -b dart_mx8mm -e all -t tcm -d /opt/SEGGER/JLink (for TCM target) $ ./var_add_vscode_support.sh -b dart_mx8mm -e all -t ddr -d /opt/SEGGER/JLink (for DDR target)
Disable LMEM caches to debug demos mapped in DDR
$ cd ~/var-mcuxpresso/freertos-variscite $ git apply patches/0001-iMX8M-MINI-deactivated-the-LMEM-caches-to-debug-in-e.patch
Please visit the SEGGER forum to additional information
https://forum.segger.com/index.php/Thread/2948-SOLVED-DEBUGGING-doesn-t-work-in-external-RAM-but-in-internal-RAM
Open a Demo in VS Code
For this example, we will use the hello_world demo. However, the process is the same for all demos. From a terminal, launch VS Code and open the hello_world demo directory:
$ code ~/var-mcuxpresso/freertos-variscite/boards/dart_mx8mm/demo_apps/hello_world/
VS Code should open and look similiar too:
Build Demo using VS Code
If the build task completes successfully, the following output files will be generated:
~/var-mcuxpresso/freertos-variscite/boards/dart_mx8mm/demo_apps/hello_world/armgcc/debug/hello_world.bin (for TCM target, load in U-Boot) ~/var-mcuxpresso/freertos-variscite/boards/dart_mx8mm/demo_apps/hello_world/armgcc/debug/hello_world.elf (for TCM target, load using debugger or remoteproc) ~/var-mcuxpresso/freertos-variscite/boards/dart_mx8mm/demo_apps/hello_world/armgcc/ddr_debug/hello_world.bin (for DDR target, load in U-Boot) ~/var-mcuxpresso/freertos-variscite/boards/dart_mx8mm/demo_apps/hello_world/armgcc/ddr_debug/hello_world.elf (for DDR target, load using debugger or remoteproc)
Please visit Variscite's MCUXpresso Guide for instructions to run the demo using U-Boot or the Linux Remote Processor Framework.
Debugging with VS Code
Test Enviroment
Hardware
JTAG Debbugger: J-Link PLUS: https://www.segger.com/products/debug-probes/j-link/models/j-link-plus/ ARM-JTAG-20-10 adapter: https://www.digikey.it/it/products/detail/olimex-ltd/ARM-JTAG-20-10/3471401 Variscite Board: VAR-DT8MCustomBoard
Software
You can see the Yocto release details at link:
Connect Hardware
Connect J-Link PLUS to JTAG connector of Variscite board Connect J-Link PLUS to Development PC via USB cable
Load dedicated device tree
Please visit Variscite's MCUXpresso Guide for instructions to load a dedicated device tree.
For this example we will use :
From U-Boot
u-boot> setenv fdt_file u-boot> saveenv Saving Environment to MMC... Writing to MMC(1)... OK Power off / Power on the board
From Linux
$ fw_setenv fdt_file $ reboot
Start Debugging
Open source code and add a breakpoint
Start Debugging
if everything worked well the program will stop at the configured breakpoint
Debug RPMSG demos
The RPMSG demos can be debugged only starting from U-Boot
You need even to change M4 Kernel Device Tree enabling rpmsg and disabling imx8mm-cm4
Edit arch/arm64/boot/dts/freescale/imx8mm-var-dart-dt8mcustomboard-m4.dtsi.
imx8mm-cm4 {
....
....
status = "disabled";
};
&rpmsg {
....
....
status = "okay";
};
Save the changes.
Compile the device tree and update the SD-Card/eMMC.
For this example, we will debug pingpong demo mapped in DDR.
$ cd ~/var-mcuxpresso/freertos-variscite $ git apply patches/0001-iMX8M-MINI-deactivated-the-LMEM-caches-to-debug-in-e.patch $ ./var_add_vscode_support.sh -b dart_mx8mm -e boards/dart_mx8mm/multicore_examples/rpmsg_lite_pingpong_rtos/linux_remote -t ddr -d /opt/SEGGER/JLink $ code ~/var-mcuxpresso/freertos-variscite/boards/dart_mx8mm/multicore_examples/rpmsg_lite_pingpong_rtos/linux_remote/
because it produces a long delay time.
You can use vTaskDelay() instead.
Build application following the guide at the Build Demo using VS Code section above:
Power on the Board and interrupt the boot in the U-Boot prompt<>
From Visual Studio Code start Debugging
From U-Boot prompt
$ u-boot=> boot
Waiting for completed boot kernel
From Userspace prompt
$ sysctl kernel.printk=7 $ modprobe imx_rpmsg_pingpong
if everything worked well the program will stop at the configured breakpoint
