[syslinux] memdisk hangs

[Jim Wright]

I use memdisk very successfully for a large number of tasks.  Thanks
for the great tool!  However, there are a couple instances where
memdisk-loaded applications hang.  These are all BIOS upgrade floppy
images.  Some BIOS upgrade floppies do work.  This has been a problem for
quite a while, but unfortunately I have not been good at keeping records.
Here is a sample of what I've found

FAILS:
    Tyan S2462 with Phoenix BIOS
    SuperMicro 370DLR with AMI BIOS
    Tyan S2720 with AMI BIOS

WORKS:
    Tyan S2468 with Phoenix BIOS
    Intel CA810E with ?? BIOS

As I mentioned, I have many, many more sample points.  I just haven't
kept good track of what works at what doesn't.  I find it a bit odd
that the S2462 fails but the follow-on board S2468 works.  Same flash
utility.

The failure mode is that the BIOS flash utility starts up, does whatever
setup and hardware detection it may need, then starts to read the new
image from (emulated) floppy into memory prior to starting the flash.
During the read, the system hangs.  The keyboard LEDs still react to
the various lock keys, but otherwise it is hung.

What further information can I provide in helping to debug this?

Jim