Custom carrier board with NX module

Hi,

We designed our own carrier board take the NX devkit as a reference. We do some changes to the GPIO usage. Such as GPIO06, it is used as input instead of an output. Will we need to change the device tree and recompile the kernel? Can we do some minor changes to the devkit image, such as simply changing the pinmux to run it on our board?

Thanks.

hello diverger,

you may control the GPIO via sysnode to test the behavior,
please also refer to Pinmux Changes session, If your board schematic differs from that for Jetson Xavier NX Developer Kit board, you must change the pinmux configuration applied by the software.
thanks

Changing pinmux means must I recompile the kernel and flash the image, right?

Thanks.

hello diverger,

correct, you’ll need to download pinmux spreadsheets to have customization, after that, please include the generated *.dtsi files and re-compile the device tree. you may also need to execute the python script, pinmux-dts2cfg.py to create the *.cfg file,
please do full flash to update those file correctly.
thanks

Thanks for the answer.

BTW, will I need to download the kernel source separately or it’s already there in the JetPack, such Linux_for_Tegra foler?

Thanks.

hello diverger,

Linux_for_Tegra foler it only contain the release binary, tool, scripts for image flashing.
please access Jetson Linux | NVIDIA Developer to download L4T Driver Package (BSP) Sources to get the public sources.

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HI, Chang

Do I need recompile the Linux kernel? Or just throw the .cfg to ‘BCT’ folder and re-flash the board?

hello diverger,

it’s cfg file for pin initialization in the bootloader stage, later when it boot into linux, it’s device tree to handle pin configuration.

So, the .dtsi files generate by pinmux tool are used only for bootloader. They are not used for Linux, and I need to download the sources of the kernel to do some changes to the .dtsi files in there, right?

Thanks.

hello diverger,

you should integrate the generated dtsi file into the device tree sources to compile the device tree binary also.

That means, the .dtsi files generated by pinmux should also be integrated into the Linux device tree ?

yes