Debugging with com0com and QEmu

All you must do is:

1) Get QEMU. If you have not it yet, my suggestion is to download Qemu Manager, it already includes a recent build of QEMU and it it helps you to configure virtual machines.

2) Get com0com and install it.
Next, run the com0com command shell and type

install PortName=COM4 PortName=COM5

and it will create two virtual ports connected together.
If you prefer different ports, just change the com names; however you can get a simple help by typing "help" to the shell prompt.

3) Create a virtual machine for running ReactOS under QEMU.
Be sure to select one of the newly created ports by adding this option to the command line of QEMU:

-serial COM4

WARNING: you must write "COM4" with capital letters and not "com4" otherwise QEMU won't use serial port at all!!!

4) Open a terminal programme.
You can use Teraterm or HyperTerminal.
Start a new connection and select "COM5" as communication port.

5) Finally, launch QEMU and select ReactOS debug into the boot menu.

FINAL NOTE: the properties of the serial port, like the baud rate, are not important.
Instead, be sure to select "NO FLOW CONTROL" otherwise the terminal programme doesn't seem to receive the characters.
Hardware flow control (with RTS/CTS) or software flow control (XON/XOFF) does not seem to work during my tests.

I hope this will help.
Perhaps it would be nice to write a little tutorial in the wiki since I think that QEMU and com0com combination is really useful.

Sincerely,

Carlo Bramini.

 

Use RosTE
it contain qemu and setup the debug for u.
Only u need todo is select reactos debug from freeldr if u have debug build (*_DBG.iso) of reactos