Enabling HIDDEV on Orin AGX

[tony.reina]

I’ve got a USB device that requires the HIDDEV interface, but the Orin AGX Ubuntu doesn’t load the module.

Could someone help me with instructions on how to add HIDDEV?

Thanks.
-Tony

[DaneLLL]

Hi,
If you use Jetpack 6, the default configs are aligned with upstream kernel and you have to manually enable certain configs. Please check what configs have to enabled and follow developer guide to rebuild kernel:

Kernel Customization — NVIDIA Jetson Linux Developer Guide

This post may be helpful:
How to use HIDdev device on Jetson Nano 4GB - #4 by linuxdev

[linuxdev]

I will add that building a kernel module is not usually difficult, but there are details you need to get right. Some of this depends on what kernel you are currently used. Your L4T release is just what the flashed content is called after adding NVIDIA content, and you can see this with “head -n 1 /etc/nv_tegra_release”. What release do you have? You would then find kernel source and documentation and such from here for that particular release:
https://developer.nvidia.com/linux-tegra

Depending on whether you are using L4T R35.x or R36.x some information may change. Which release do you have? Regardless of release, you might want to copy this file to your host PC (you can build directly on the Jetson or cross compile, but you want that file as a reference; it isn’t a real file, it is the kernel telling you about most of its current configuration):
/proc/config.gz

Along with that file, you’ll want to save the output of “uname -r” to pair with that file. The suffix of that command will tell you about one of the configuration items for building the kernel (CONFIG_LOCALVERSION).

Note that L4T R35.x uses NVIDIA’s modified kernel (it has some out-of-tree content), while L4T R36.x uses the mainline kernel (and thus NVIDIA isn’t the one who configures this). Once you have that it becomes possible to build just a module which can be copied in and it should “just work”. Other methods which rebuild everything are much more involved (not difficult, but far less convenient).