Volume flashing support

[davedesro]

Today, when using smpmgr --port /dev/ttyACM0 upgrade filename.bin, if /dev/ttyACM0 is not available, smpmgr errors out. This is a common flow for many applications

The application tio does things differently. If /dev/ttyACM0 does not exist, it simply waits for it to exist.

I'm wondering if we can do something similar with smpmgr. It waits for the device to be available. Once available, it flashes the binary. After the device is removed, smpmgr goes back to 'the top' and and waits again for the device to re-appear. At that time, it again flashes the binary... and on, and on..

The value is that

• It allows for an efficient way to flash many units. No need to even touch a keyboard! Just plug in a device, wait, unplug, and plug in the next one
• Allows for the fastest possible bootloader timeout (if its set that way), minimizing negative UX impact.

thoughts?

[JPHutchins]

I think this is doable now that the connect function has a timeout: https://github.com/intercreate/smpclient/blob/9895e9822c8bc6765ac3b95f210ab75d28491e58/smpclient/__init__.py#L36-L39