IA64 kgdb requires a patch to gdb/remote.c. The proposed patch will eventually be in gdb but
until then, within gdb do "show remote" and look for "Support for remote protocol `p' (fetch-register) packet is auto-detected, currently unknown."  Should this line not appear, then you must
obtain the patch, apply it and build gdb.

CONFIG_KGDB_EARLY enables one with serial kgdb support to debug the kernel starting at the
end of the routine setup_arch.  A boot option of "kgdb=1" will result in a kernel breakpoint
and requires gdb to continue from the breakpoint.

For further information consult the i386 kgdb documentation.
