Hi everyone,
I finally managed to get USB working on the Raspberry Pi 4 in bare metal! My driver currently supports keyboards and mice only.
However, the code is still quite hardcoded, and I would really appreciate your help testing it.
If you have a Raspberry Pi 4 available, could you please try running the kernel and see how it behaves on your board? I only have one unit, so I’m curious how it performs on other devices.
There is one known bug: if you unplug the keyboard, an exception occurs. So plug-and-play isn’t fully reliable yet.

Thanks in advance!

The kernel can be downloaded here: https://www.satyria.de/arm/sources/RPI4 ... ernel8.img

I've attached a ZIP file here that contains the complete contents of the SD card. Simply format an SD card to FAT32 and copy the contents into the root directory. Then start up your Raspberry Pi 4 with a keyboard connected.

The ZIP can be downloaded here: https://www.satyria.de/arm/sources/RPI4 ... Kernel.zip

Best regards,
Satyria