[syslinux] extlinux 6.03 serial console not responding to input

[Andrew J. Schorr]

Hi,

I just upgraded some systems from Fedora 19 (extlinux 4.05)
to Fedora 21 (extlinux 6.03).  I am using IPMI 2.0 serial-over-lan
console redirection.  Under the old version, this worked without
any problem:

   serial 0 57600 0x003
   ui menu.c32
   menu title ExtLinux Boot Menu
   timeout 100

   label Linux1
   ...

Using the new version of extlinux in Fedora 21, I can no longer communicate
with the extlinux boot menu.  It does not see anything that I type.
I tried grub2, and that works fine.

I tried removing the flowcontrol flag bits, and I also tried 0x00b,
but nothing works.

I scanned the syslinux changelogs, but I did not find any mention of changes
in this area.

Does anybody have any idea of what's going wrong and/or a suggestion for how
to get this working again?  I'd prefer to use extlinux rather than grub2.

Thanks,
Andy