[syslinux] Memory upgrade breaks net boot (PXE + NFS Root)

[Alex Still]

Hi list !

A memory upgrade (from 2 to 4Gb) on a bunch of IBM LS21 blades has triggered
a very weird behavior.
I really can't say if this could be PXE related or not - apologies if it
isn't.

These machines start via PXE and then NFS-mount their root.

Following the upgrade, none of them would boot. I've played with the "mem="
kernel option, and the result is :
- if mem < 3250m : everything's fine
- for some values of mem : Machine auto-reboots while loading the initrd
"Loading initrd...*bam*"
- some others : Initrd loads, but turns out it's corrupted ("can't find a
valid initrd", then panic)
- some others : Kernel starts booting, bnx2 driver errors all over the
place, machine hangs during the boot process

Unfortunately I have no other hardware to try this on. We're using a 64 bits
kernel, which should handle 4Gb fine.
Booting from a CD works fine. At this point I can't figure out if this is
related to PXE or the kernel (nfs-root setup)

If anyone else has seen this, I'd love to hear about it !

Regards,

-- 
Alex