Trouble accessing ttyS0 from qemu w/Windows

Yalla-One · 12-16-2009, 07:38 AM

All,

I'm trying to run an APC SmartUPS application troubleshooter from a WindowsXP-install running within qemu on a Slackware server.
Windows complains it's unable to communicate with ttyS0, although no Linux service is hogging the port (ie apcupsd is shut down for this exercise) and /dev/ttyS0 is mode 666. The communication over the serial port works just fine from within apcupsd, and qemu is started with "-serial /dev/ttyS0".

qemu is compiled and installed from the SBo slackbuild with no tweaks or changes.

Does anyone have experience with running programs needing access to /dev/ttyS0 from a Windows running from within qemu?

Chuck56 · 12-16-2009, 08:27 AM

I've not used serial port access from a Windows guest in QEMU but maybe you should be using the COMn option instead of the /dev/XXX option?

From the QEMU documentation in the Debug/expert options:

Quote:

‘-serial dev’

Redirect the virtual serial port to host character device dev. The default device is vc in graphical mode and stdio in non graphical mode.

This option can be used several times to simulate up to 4 serial ports.

Use -serial none to disable all serial ports.

Available character devices are:

Quote:

/dev/XXX

[Linux only] Use host tty, e.g. ‘/dev/ttyS0’. The host serial port parameters are set according to the emulated ones.

Quote:

COMn

[Windows only] Use host serial port n

I'll be interested in the final solution.