Serial console problem

[jiml8]

I have Mageia 4 on a USB stick, and I am booting an embedded computer using this stick. The computer does not have a video console port; it only has ethernet, USB, and one RS-232 port.

I have the USB installation configured to use ttyS0 for the serial port, and the system displays the bootup just fine using minicom on my workstation to talk to the serial port (workstation is also Mageia 4).

Eventually, the bootup gets to the login display, and I can enter a user name with no trouble; the text is taken and displayed properly. However, when I try to enter the password, I can only enter one character, and the cursor moves to the next line as if I had entered a newline. The login then fails because the password is wrong. In short, I am unable to enter a password into Mageia from the serial console.

I do not see this behavior with passwords on any other USB distro I employ (and I have a bunch of them); it has to be something with Mageia.

I do not have a breakout box here; I cannot look directly at the serial line and see what is happening.

Does anyone here have any idea what is going on? I suppose I will have to configure this stick for a password-less login. I'm sure that can be done but it is not the way I would prefer to do it. Alternatively, I can burn a different distro onto the stick, but given how many hours it takes to burn one of these USB sticks (they are VERY slow writing) I would prefer to not have to do that.