FreeBSD blocks on BOCHS serial port

[Alexander Lochmann]

Hi folks!

We are doing some automatic experiments using FreeBSD running in a
virtual machine.
To control the experiment from the outside, we use serial ports to
communicate with an userspace program.
The communication via serial does work with QEMU. However, it does not
work with BOCHS which is our desired emulator.
Even simple operations like 'echo FOO | tee /dev/ttyu1' or 'cat
/dev/ttyu1' do not work. Both commands block 'forever'.
It does not matter whether we use ttyu0 (file backend) or ttyu1 (tcp
socket).
I put some debug output in sys/dev/uart/uart_dev_ns8250.c. The output
suggests that the driver more or less reads and writes to the serial
ports. At least it does something...

Do you have any hints how we can further analyze this problem?
Did anyone came across a similar problem?

Thank you!

Regards,
Alex

-- 
Technische Universität Dortmund
Alexander Lochmann                PGP key: 0xBC3EF6FD
Otto-Hahn-Str. 16                 phone:  +49.231.7556141
D-44227 Dortmund                  fax:    +49.231.7556116
http://ess.cs.tu-dortmund.de/Staff/al

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