[syslinux] Version 3.35 problems with Broadcom BCM5780 chipset

[Ole Holm Nielsen]

Ole H. Nielsen wrote:
> But when I use those very same SYSLINUX menus on an AMD Opteron server
> (IBM x326m), it is capable of loading up vesamenu.c32 and menu.c32
> and displaying a list of menu items.  But as soon as I select any item
> whatsoever in the menu list, the server locks up and must be power cycled.

and H. Peter Anvin replied:
> Please try out the 3.32-pre* and 3.35-pre* prepatches (or, if you're 
> familiar with git, get the git repository and do a git-bisect.)  The 
> smaller a changeset I can get this down to the more likely I am at 
> actually resolving anything.

I have tried 9 different version of SYSLINUX up to 3.35 (3.36-pre5 and
3.40-pre4 won't build with "make").  I built the code and copied these files
to /tftpboot for each test: pxelinux.0 memdisk/memdisk com32/modules/*.c32.

I have some puzzling observations with the 3.20-3.35 versions of menu.c32:
1) On one server all these versions of the menus always work correctly.
2) On a second server with *identical* hardware and firmware versions the
    SYSLINUX menus behave like this:
    3.20: OK, OK, Fail
    3.30: Fail
    3.31: Fail
    3.32-pre8: Fail
    3.35-pre1: OK
    3.35-pre4: OK
    3.35-pre5: OK
    3.35: Fail, Fail, OK
    When the menus fail, the server locks up when a menu item is pressed.
    If a menu item has a password, I can type in the password, and then
    the server locks up.

It really bugs me that two 100% identical servers (from a Linux xompute
cluster) consistently behave differently with the SYSLINUX menu system.
There seems to be an element of randomness in the second server regarding
whether the menus work or not.  I have no idea how this may come about.

FYI: The IBM x326m dual-Opteron servers have BCM5780 Gigabit Ethernet
firmware 3.24, and the latest IBM BIOS 1.32.  The keyboard is a USB
keyboard (no PS/2 connectors on this server), and another USB keyboard
gave the same result.

-- 
Ole Holm Nielsen
Department of Physics, Technical University of Denmark