Can't boot from SSD with USB camera connected

I have been running Octopi flawlessly on an SSD using a SATA to USB cable. However, I've just moved from the Pi camera to a Logitech C270 and the Pi won't boot with the SSD and camera attached. If I plug the camera in after the boot has started (activity on SSD), it boots fine and I get a webcam stream no problem. This suggests that the Pi is not sure which device to boot from when I have them both connected. Perhaps it is trying to boot from the webcam?

Does anyone know how I can specify a USB boot device or somehow delay the webcam being detected long enough for the SSD to boot?

EDIT: by the way, it's unlikely to be a power issue. My Pi is powered by a PSU that is rated for 6A.


Which Pi is it? The boot process differs from Pi to Pi. OctoPi is based on Raspberry Pi OS, so something like this: USB mass storage boot - Raspberry Pi Documentation would still be relevant. Which in turn, say that the boot order can be specified using sudo raspi-config, but not sure if that is per-device.

Raspberry Pi 4 bootloader configuration - Raspberry Pi Documentation is also linked to, which has this section:

Multiple bootable drives
When searching for a bootable partition the bootloader scans all USB mass storage devices in parallel and will select the first to respond. If the boot partition does not contain a suitable start.elf file the next available device is selected.
As with earlier Raspberry Pi models there is no method for specifying the boot device according to the USB topology because this would slow down boot and adds unecessary and hard to support configuration complexity.

So my guess is that it should work (since the camera is not USB mass storage) but you cannot specify a device explicitly.

Thanks Charlie. Its a 3B+. Raspi-config doesn't allow me to change boot device. However, I just discovered a workaround that works for the time being, although it would be good to be able to sort this without the below fix.

What I did was insert a SD to boot from, containing just the bootcode.bin file here:

This boots the Pi from the SD but then loads the Ocotpi from the SSD.

Glad that this works, but would be good to be able to fix this without having an SD in the slot.