[Linux-ia64] Question about .opd section

["Wichmann, Mats D" <mats.d.wichmann@intel.com>]

The gnu toolchain (well, binutils) emits a .opd section
for  architectures which use function descriptors -
it's not unique to Itanium.

But I can't find much information about it.  Google
has been unhelpful (to me, anyway) on this one. It's
described as holding function descriptors, but I'm not 
clear who uses this information - is this used at
runtime?

Is this section considered normal/required for
Linux/ia64?  I'm asking because it wasn't in the
Itanium psABI, and thus didn't make it into the
current version of the Itanium LSB spec; our
application checker tool is flagging this as an
unknown section.

Thanks,

Mats