On Jan 22, 2024, at 10:59?AM, Dave, N1AI <n1ai@...> wrote:

?On Mon, Jan 22, 2024 at 10:16 AM, Ken N2VIP wrote:

Also, Dave mentioned it, but I want to highlight the need to remove the microSD card from the RPi 4 - I suspect (but do not know for certain) that the RPi 4 boot order will have the RPi 4 boot from the microSD no mater what is attached to the USB ports.

All good points, and more on the topic of booting:

There is a boot order variable the Pi firmware supports.? Its documentation is?.? You can google BOOT_ORDER to learn more about it.?

I don't know what the resulting boot order will be by following the Tom's Hardware procedure I linked earlier, maybe someone will report it.

You can see it via the command 'rpi-eeprom-config'.

Some of my non-sbitx Pi devices have a NVMe board that is buried under the Pi and I don't want to open the box and disconnect it so I let the other things have priority in the boot order:

<dummyfile.0.part>

Note the hex digits are read low-order first so '1' is the first thing it tries not 'f'.

For the factory sbitx box the sdcard is buried inside the box by default and it's a pain to get to, so you probably want any external devices to have priority.

That makes booting slower since it takes it time to look for USB devices but IMO it's worth the tradeoff of not having to pry open the box.

Someone here posted??for a sdcard extension and ran the ribbon cable to the outside of the box and taped down the card holder.

I haven't tried that, but I plan to.

I have been USB-booting my Pi 5 with a USB hub then a USB-to-NVMe adapter.? I often see timeouts during reboot.? One 'fix' is to power-cycle the Pi and the hub together which is easy for me since they are on the same power strip.? ?The same document above describes some bootloader USB settings that can be used to make the timeouts longer, but I haven't messed with these since I intend to replace that USB-to-NVMe adapter with PCIe direct.? Yet the odd thing to me is that the same USB-to-NVMe adapter and the same NVMe device worked without timeouts on the Pi 4 so I suspect they have changed something on the Pi 5 with regard to USB timeouts.? It'd be interesting to know if others notice something similar.
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Regards,
Dave, N1AI