I have ran into this problem numerous times now, the problem of Linux going completely silent half way through the boot sequence for no apparent reason. The machine has not crashed because I can still SSH in from across the network. But the serial console is completely dead. This has happened to me a number of times both when connected to a real device running embedded Linux through a physical serial cable and when connecting to a paravirtualised Linux guest running inside Xen through Xen’s virtual serial console.
The solution is to make sure that the getty deamon is spawning correctly and with suitable parameters set in
/etc/inittab; specifically baud rate and the serial device name.
Below is an example for Xen where
9600 is the baud rate and
hvc0 is the name of the virtual serial port i.e.
Chances are that if your login screen is not appearing at all then this line is either missing from
/etc/inittab or the baud rate or serial port name are missing.
If you are interested in learning what the rest of the line means consult the relevant man pages: