Troubleshooting • Re: Bios does not recognize raspberry Pi in g_multi mode

Only A, A+, and 3A+ can do USB device mode on their USB A ports.

For completeness, also the Zero models.

Nope. They don't have USB A ports.

Here's the complete list of device mode capable Pi as I understand it:

• On a USB A port so cannot hotswap between host and device roles:
  • A
  • A+
  • 3A+
• On a micro USB port so can hotswap roles
  • zero
  • zeroW[H]
  • zero2W
• On their USB C port. No ID pin so cannot hotswap between host and device roles:
  • 4B
  • 400
  • Pi5
• Varies depending on carrier board:
  • CM
  • CM3
  • CM3+
  • CM4
  • CM4s

All use the dwc2 overlay.

Models that use the USB A port default to host mode with the ID pin pulled internally to signal that. Device mode must be forced when loding the overlay.

Models using microB ports have the ID pin connected so can detect and hot swap between roles.

Models with USB C ports default to device mode. No ID pin present so cannot hotswap. Host mode must be forced when loading the overlay but for host more otg_mode=1 is a better choice.

Statistics: Posted by thagrol — Mon Jul 22, 2024 2:07 pm

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