Hello, once I developed my appliance based on Armbian with Kernel 3.4. And the goal of the appliance was to work as custom USB gadget. The appliance was based on sunxi_usb_udc. Now, after big delay I returned to the need of bulding a new appliance with similar functionality. As far as I understand, there is a problem with UDC module in kernel 5.x. Am I right? Can I build my custom system based on legacy (v.4.x) kernel to workaround the problem or there is a better suggestion with available information for fast startup? Please advise.

Thanks in advance.

You can always try to fetch the armbian/build repository selecting an older tag but chances are high that compiling will not work since those tags obviously cannot revert  changes from upstream or other dependencies Armbian relies on. Fixing if necessary is up to you.

 

I think 5.10 is legacy at the moment for sunxi. Older kernels are no longer available in master branch.

 

I don't know about sunxi_usb_udc. Is that one of those vendor developed and never maintained or even upstreamed hardware-specific drivers?

I think i created the problem by attempt to customize the kernel configuration. Using the custom image I was not able to load module g_ether, got error about UDC problem. But if I load the module in standard Armbian desktop system, there is no problem. I will try now the standard console system and check, if the problem appears there. Will update later.   

The g_ether works correctly also in standard console image.

 

Hi, please review and let me know, if there is a better way to create custom USB gadget.. The libusbgx library (https://github.com/linux-usb-gadgets/libusbgx) and examples were used. After compilation, there was a problem to run example. First of all, there was no usb_gadget in /sys/kernel/config folder. It appeared after calling this sequence

 

# to create usb_gadget folder

modprobe g_ether

# not required
rmmod g_ether

 

The next commands prepare libusbgx environment, as per its README file.

 

umount /sys/kernel/config

#this removed error in the next comand

mount -t configfs non /sys/kernel/config

 

After that it was possible to run libusbgx examples. In order to run more than one example, their name should be different.