[syslinux] extlinux 6.03 IPMI SOL (serial-over-lan) console not responding to input

[Andrew J. Schorr]

Hi,

On Mon, May 18, 2015 at 01:14:01PM -0400, Andrew J. Schorr via Syslinux wrote:
> I just tested again using Fedora 21 extlinux 6.03 and the same configuration
> (but without the HALT or CONSOLE directives).  It works fine on the video
> console, and it also works correctly over a physical serial port connection.
> So the problem seems to be confined to the IPMI serial-over-lan console.  I was
> surprised that it worked correctly on a physical serial port, since I thought
> the IPMI takeover of the serial port should be transparent to extlinux.
> 
> The last step is to test with the official binaries.  I'm going to try
> to figure out how to do that now.

I removed the Fedora 21 syslinux rpms and then attempted to boot the system
using the official binaries.  The bad news is that I didn't install all
the required files, so I'm getting these error messages:

   Failed to load libutil.c32
   Failed to load COM32 file menu.c32
   boot:         

The good news is that it still has the same problem as the Fedora version.
If I attach a physical serial console, I am able to type at the boot 
prompt.  But when using the IPMI serial-over-lan console, all of my
input is ignored.  So the same problem exists in the official binaries.

I have seen this same behavior across three machines using two
different motherboards: Intel S5500WB and Intel S5520UR.  And Ferenc Wagner
says he has this problem with Fujitsu Primergy CX250 S2 servers.  So
there appears to be a bad interaction with the serial support and IPMI SOL.
This was all working fine in Fedora 19 extlinux 4.05.

Does anybody have any ideas on how to troubleshoot further?

Thanks,
Andy