Re: RPI4 usb, external ssd

[email protected] (Greg Troxel) writes:

>On the RPI4, I see in dmesg

>  dwctwo0 at simplebus1: USB controller
>  usb0 at dwctwo0: USB revision 2.0
>  uhub0 at usb0: NetBSD (0x0000) DWC2 root hub (0x0000), class 9/0, rev 2.00/1.00, addr 1
>  uhub0: 1 port with 1 removable, self powered

>Does umass work for people in general?  Am I missing something?


dwctwo0 is the USB2 controller in the SoC which is only connected
to the USB-C "power" connector. You should also see xhci, which
is the extra USB3 controller chip that is connected via a PCI lane.

The xhci controller requires firmware. Early RPI4 boards use
an EEPROM for that, newer RPI4 (including all 8GB models) need
to tell the "GPU" to upload the xhci firmware. That is done
by UEFI, maybe your UEFI code is too old?