Not able to write data to serial console via cu with UART adapters that support flow control

[selmf]

In order to write to the serial console on the router, both hardware and software flow need to be disabled. For some UART adapters, this seems to be the case out-of-the box, while others come with flow control enabled on Linux.

As cu does not disable the flow control by default, this leads to a problem where everything works but no data can be written and it is impossible to select the correct boot entry in the recovery menu.

This is especially devious as people might come to the wrong conclusion that their hardware (either the adapter or the router) is defect.

I ran into this issue using a CP2102 adapter and was able to solve it by using putty and disabling the flow control.

It would be good if the tutorial would warn about this possible stumbling block so people can avoid the issue and are not mislead into thinking their hardware is broken.