I was going to start adding support for configuring the various logging methods and configurations in tboot. Joe, were you planning on keeping the existing command line parsing code as it is in tboot/common/lib.c? If so I will use the framework to add the various logging settings.


Also memory and vga logging are already present but just not really used. One thing I will do is unify the logging/tracing to include these methods.





From: Cihula, Joseph [mailto:joseph.cihula@intel.com]
Sent: Wednesday, November 12, 2008 4:27 AM
To: Ross Philipson; tboot-devel@lists.sourceforge.net
Subject: RE: Enhance serial support in tboot


I’ve been giving some thought to this and I think that it would be valuable to have a command line parameter that allowed specifying how logging is done:  VGA, memory, serial (and any combination of them or lack of them).  The serial parameter would also need to support specifying the various serial configs .


I’ve been holding off on this because I wanted to limit the amount of command line options since the command line is not currently part of the measurement of tboot, and thus there is a greater potential for malicious manipulation of the code via command line.  E.g. if by adding more command line options one of them introduces a buffer overflow then there would be no way to determine if a given invocation of tboot was done with such a malicious command line.


But I think that it is time to bite the bullet and add the command line to the tboot measurement.  So with that support, making the command line more complex will be less risky.  I’ll take care of the command line measurement changes, but I would welcome patches for the above logging support.



P.S.  Back from vacation now so emails should be more timely.


From: Ross Philipson [mailto:Ross.Philipson@citrix.com]
Sent: Monday, November 03, 2008 11:14 AM
To: tboot-devel@lists.sourceforge.net
Subject: [tboot-devel] Enhance serial support in tboot


I have recently been working on laptops that do not have serial ports so I have been using an ExpressCard serial adapter. I had to make modification to tboot to use a different IO port and clock frequency. I have found that having serial debug output for tboot is incredibly valuable during development.


The Xen console driver (on which the tboot early_printk is loosely based as it seems) allows serial console configuration with command line arguments (including setting the clock freq. now). I was thinking of pulling this into tboot but I wanted to see if the community thought this was something valuable to do – something that could be incorporated in tboot?





Ross Philipson

Senior Software Engineer

Citrix Systems, Inc

14 Crosby Drive

Bedford, MA 01730