Re: [PATCH] - make qemu serial summagraphics settings a bitmore fluid

[Ben Thomas <bthomas@virtualiron.com>]

Hi Don,

I have this code running in another tree, so let me try to go
through these.  It's quite possible that qemu has outsmarted
me in this configuration.

Dugger, Donald D wrote:
> Ben-
> 
> I like the idea but I don't understand how this patch can work:
> 
> 1)  You never put a name into `serial_devices[]' for the summa port.
> The loop in `main' that initializes the serial devices only calls
> `qemu_chr_open' if there's a string name in `serial_devices'.  How did
> you get this to work?

I use -serial in the qemu command line.  For instance, I generally
use something like -serial pty -serial pty -serial null -serial pty,
which is asking for COM1, COM2 and COM4 assignments to a pty.  The model
is that you ask for a serial line, and also optionally indicate that you
want it to be summagraphics.

For instance, here's a command line that I just generated/used.
It requests multiple serial lines. none of which are summagraphic.

/bin/qemu-dm -d 7 -m 256 -monitor pty -serial pty -serial pty -serial pty
   -serial pty -vnc -vncconnect 10.1.2.26 -k en-us -timeoffset -1800
   -vcpus 1 -macaddr 00:0f:4b:11:01:89 -bridge nexbr1 -hda /dev/dm-4
   -domain-name "Fedora Core 4 - 32 Bit"

> 2)  Minor point, I don't see the need for the `serial_summa' array, a
> simple integer that is initialized to -1 would accomplish the same
> thing.  (I have this thing about wasting memory :-)

I use the array so that I know which of the COMn ports are actually
using the Summagraphic protocols.  A bit array would work as well,
I suppose.

I chose to allow any/all/none of the ports to be running the protocol
and not just a fixed instance or only one.

> 
> 3)  Personally, I hate counting serial ports from 1, everybody knows
> that computers count from 0.  I'd refer to it as which `ttyS' port to
> use, starting from 0, but I'm willing to live with the COM terminology.

Me, too.  I decided to follow the COM1/COM2/COM3/COM4 nomenclature as
this felt more like the PC hardware choice rather than an OS specific
choice.  I'd guess that Windows people won't be using ttyS, for instance.

How do you think we should proceed with this ?  My goal is quite
simple: allow some set (including none) of the serial lines to be
created and use the Summagraphics protocol (or not).

Does this make sense, or have I totally misunderstood something ?


Thanks,
-b

> --
> Don Dugger
> "Censeo Toto nos in Kansa esse decisse." - D. Gale
> Donald.D.Dugger@intel.com
> Ph: (303)440-1368 
> 
> 
>>-----Original Message-----
>>From: xen-devel-bounces@lists.xensource.com 
>>[mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of Ben Thomas
>>Sent: Thursday, May 18, 2006 12:50 PM
>>To: xen-devel@lists.xensource.com
>>Subject: [Xen-devel] [PATCH] - make qemu serial summagraphics 
>>settings a bitmore fluid
>>
>>Changeset 9967 made the qemu serial line Summagraphics support a little
>>more flexible with respect to the COM line chosen.  This patch
>>furthers that effort by removing the COM2 restriction.  This patch
>>allows a "-summa n" command line option to qemu to specify which, if
>>any, COM port should be using the Summagraphics protocols.
>>
>>Signed-off-by: Ben Thomas (ben@virtualiron.com)
>>
>>-- 
>>---------------------------------------------------------------
>>---------
>>Ben Thomas                                         Virtual 
>>Iron Software
>>bthomas@virtualiron.com                            Tower 1, Floor 2
>>978-849-1214                                       900 
>>Chelmsford Street
>>                                                   Lowell, MA 01851
>>


-- 
------------------------------------------------------------------------
Ben Thomas                                         Virtual Iron Software
bthomas@virtualiron.com                            Tower 1, Floor 2
978-849-1214                                       900 Chelmsford Street
                                                    Lowell, MA 01851