Update device-tree after changing the GPIO configuration

Robotics & Edge Computing Jetson & Embedded Systems Jetson AGX Xavier
1

Hi,

What is the exact procedure (step by step) in order to be able updating the device-tree with GPIO changes?
I know i need to use Jetson_AGX_Series_DevKit_Pinmux_Configuration_Template.xlsm in order to generate new dtsi files and then generate the cfg file using pinmux-dts2cfg.py.

Then what?
I need to replace the cfg file with the proper one and rebuild the kernel?
I think this part is not clear enough in nvidia documentation.

Thanks,
Yair

3

hello yairhav,

you’ll need to replace those cfg files and flashing the board.
you may check documentation, please refer to Jetson AGX Xavier Platform Adaptation and Bring-Up chapter.
there’s MB1 Configuration Changes session for applying pinmux configuration changes.
thanks

4

Thanks jerry, if i understand you correctly that mean i don’t need to build the device-tree?
Can i flash only the device-tree or i need to flash all the system?
The dtb binary use the cfg file?
Which case will force me to generate new dtb file?

5

hello yairhav,

device tree overwrite the settings; if you would like the settings to be applied in MB1, you’ll need to flash the cfg file to update the board configuration.

6

Thanks again,
Which command flash the cfg file?

7

hello yairhav,

you’ll need to perform a whole flash to update the cfg files.
according to Flash Script Usage, you may skip building system.img, and reuse the existing one for flashing.
for example, $ sudo ./flash.sh -r jetson-xavier mmcblk0p1

8

Thanks again,
Somthing i dont understand, if this process doesn’t change the dtb file, if i reflash the whole system, reboot my board and then dump the dtb file into dts file, should i expect to see the changes i made to gpio?

9

hello yairhav,

you should expect that GPIO behavior same as your customization,
thanks