When you failed to boot with your 2GB+ memory system from ASC 29160

  I have got solved a trouble with the Itanium system.
The trouble is, when the memory is up to 2GB
(512KB sdram in 4 slots simultaneously), the
any Linux IA-64 OS boots fine.
When the physical memory is increased beyond 2GB,
for example 2.5GB or 4GB, then suddenly the
the boot partition on the SCSI HDD is not found
is happen and no way to boot from HDD by any mean.
EFI SHELL's map info tells as if the vfat partition
is not present. If the memory is reduced to 2GB or 512MB
in total, then the map information tells there is vfat
partition. I have been puzzled with this trouble for 3 weeks.
When the total memory size is upto 2GB it boots fine and
2.5GB or 4GB, it lose the vfat boot partion.
#
Finally I got the true solution. The PCI SCSI adaptor card
the Adaptec ASC 29160, the card's BIOS revision was newest
3.10.0, which had been the the source of this trouble.
  I flushed-up the card's BIOS to revision 2.57.2, then this
bad behavior completely went away. And it boots happily for ever...

PS.
Adaptec 2940UW PCI card, with my rom revision 1.32 did not
work fine with my Itanium box to cause the red screen with
the register dump before it tries to boot, fixed with the
newest rom revision 2.20.0 after flushed up and it can boot
the SCSI HDD also. It is only Ultra SCSI (40MB/S BUS) 
compared with 29160's Ultra 160 SCSI (160MB/S SCSI BUS).

H.M.