[syslinux] IPMI serial over lan disconnects seem to trigger extlinux reboots

[Andrew J. Schorr]

Hi,

I hope somebody can help me with this problem.  I don't know whether
it's a problem with my configuration or a bug or feature in extlinux.
I am using an IPMI 2.0 serial-over-lan console to connect to a system
with an Intel S3200SHL motherboard.  The first line of my extlinux.conf
file looks like this:
   serial 0 57600 0x003
I am using ipmitool to access the console, like so:
   ipmitool -f /etc/ipmi.passwd -U <user> -I lanplus -H <host> sol activate

I just converted this system from grub 0.97 to extlinux 4.05.  The IPMI BMC
software on this system is pretty flaky.  The IPMI serial-over-lan session
disconnects frequently, particularly during the boot process.  After converting
to extlinux, it looks to me as if the extlinux loader reboots the system
whenever the IPMI serial console disconnects.  This often happens while
extlinux is loading the kernel or the initrd.  As a result, it can reboot
itself many times before it gets lucky and makes it far enough to hand off
control to the kernel.  Once the kernel takes over, there is no problem -- it
doesn't mind the disconnects.

This problem did not occur with grub.  My question is whether there is some
serial flag configuration that would tell extlinux to ignore the disconnects,
or would it require a patch to the software to achieve that?
It is not obvious to me from reading the description of the serial flag
values whether I could somehow fix the problem that way.  I tried searching
the source code, but I was unable to find the relevant bits.

Does anybody know how to solve this problem?

Thanks,
Andy