Problem with COM1 port from with GDB 5.3 under Cygwin 1.5.3-1

[Creighton MacDonnell <creighton at macdonnell dot ca>]

I upgraded my Cygwin installation a few days ago (Thursday, September 4) 
to the new 1.5.3-1 version, from the previous 1.3.22-1 version.

This broke a self-compiled (under the previous 1.3.22-1 version of 
Cygwin) version of GDB 5.3 compiled for "arm-elf" that I use.

It seems to me that GDB simply hangs after opening the COM1 serial port 
when trying to make an "RDI" (Angel Debug) connection.

I have recompiled my GNU tools with the new version of Cygwin but I have 
the same problem.

I still have my old installation of Cygwin, which still works. From this 
I know that the problem is not  with the target board or the serial port 
on my PC.

So something has changed in the Cygwin support for serial devices.

I have posted to the Cygwin mailing list, but I thought I would try this 
list too.

I had noticed previously that GDB would not use a serial port if it was 
refered to as /dev/com1 or /dev/ttyS0 (it would say and still says that 
it could not open it), although Cygwin claims to support these names. 
But it did work if "com1" was used as the device name.

I have looked at the code for serial device access in the GDB source, 
and it does not seem to make any special allowance for Cygwin. I see in 
the GDB code (after only a very quick look) some sort of  "serial 
interface discovery" process. This suggests that GDB does not just go 
ahead and attempt to open the device name. So understanding this code 
would probably not be trivial.

Does anyone else on this list use GDB in this way? Do you also have 
problems with Cygwin 1.5.1-1?

Is there anyone on this list with insight into the GDB code for 
accessing serial ports who might be able to suggest a hack that I might 
attempt to the code?

Thanks.