Increase supported USB port range to 0-255

[Mik3Rizzo]

This pull request enhances the flexibility of the tool by expanding the supported range for the USB port parameter. The previous limit, which was hardcoded to a maximum of 6, has been updated to accept any value from 0 to 255.

Motivation

The original limitation of 0-6 ports can be restrictive for users with more complex hardware setups, such as those utilizing large or multiple USB hubs.

This modification provides a simple yet effective improvement, making the tool more versatile for a broader range of use cases.

[timg236]

The change looks ok, although for interop testing we would only claim to support a direct connection to a Pi or known good (doesn't back-power) powered USB hub on Linux (hubs are problematic in libusb on Windows)

[nbuchwitz]

Wouldn't be the -l argument with the proper usb path a better fit for complexer setups? I use it myself quite often and ir makes it easier as from the path the topology is also clear. But just asking out of curiosity

[timg236]

Using a fully qualified path obtained via udev is probably the more robust solution instead of specifying numbers, although the restriction of 0..6 for this old method seems a bit restrictive

[burtyb]

The port number is the port number on the USB hub it's connected to so additional levels of hub will most likely only have ports 0-6 for 7 port hubs, I don't remember seeing any hubs which actually have more than 7 ports without chaining.

For example on a Raspberry Pi 3B+ port 3 could be the top right USB or bottom left USB port which is why I added the option to set a path like "1-1.3" or "1-1.1.3" which allows these to be differentiated.

[timg236]

The port number is the port number on the USB hub it's connected to so additional levels of hub will most likely only have ports 0-6 for 7 port hubs, I don't remember seeing any hubs which actually have more than 7 ports without chaining.

For example on a Raspberry Pi 3B+ port 3 could be the top right USB or bottom left USB port which is why I added the option to set a path like "1-1.3" or "1-1.1.3" which allows these to be differentiated.

Good point. Please can the author describe their hardware setup ?

[Mik3Rizzo]

Good point. Please can the author describe their hardware setup ?

I'm using the rpiboot from a full tower windows PC that has 9 physical usb ports, but for some reason one of them is seen as USB 10 in the device manager.

Wouldn't be the -l argument with the proper usb path a better fit for complexer setups? I use it myself quite often and ir makes it easier as from the path the topology is also clear. But just asking out of curiosity

Yes, it'd be a good solution.
In my case, I've just opened the device manager on windows and I've seen that my CM4 was on USB 10.

For example on a Raspberry Pi 3B+ port 3 could be the top right USB or bottom left USB port which is why I added the option to set a path like "1-1.3" or "1-1.1.3" which allows these to be differentiated.

On windows I don't know how to obtain the usb path honestly.