And there could be additional timing issues as well. I can't find the thread but I encountered some issues along similar lines. There's not booted at all, but also the period between booting and presenting as a USB device.another problem that comes to mind is boot time of the zero
the bios may only check for usb drives once on startup, before the zero has booted
and then it wont detect the usb drive once the zero gets done booting
I recall my Pi acting as MSD worked if it was powered up and presenting as MSD before the PC booted but not if it was powered by the PC where it took some time to appear as MSD. Bottom line is, as you say, if the Pi is not ready and accessible at the right time, if the PC doesn't wait until it is, it won't work.
Not sure if that's the issue here because it seems to work with one PC but not another. I have no idea what one might need to change on the Pi or PC to make it work on the other. It might be that the BIOS which doesn't work is looking for a pure MSD device, doesn't consider a composite device or whatever to be bootable media. It might be necessary to present as MSD to allow booting then switch to being composite later.
I have no idea really. First step IMO is to find out why it doesn't work in order to be able to resolve that. I suspect that's going to be quite a challenging venture, a matter of identifying what does and doesn't work.
I'd recommend following thagrol's advice of seeing what happens when presenting as MSD rather than as a composite device.
Statistics: Posted by hippy — Thu Jul 11, 2024 2:54 pm