IA64: reliable way to determine kdump_kernel?

[jlan at sgi.com (Jay Lan)]

What is a reliable way to determine whether the booting kernel
is a production kernel or a kdump kernel?

In setup_arch() routine of arch/ia64/kernel/setup.c, there is
a statement as below:

 kdump_kernel = (strstr(saved_command_line, "elfcorehdr=") != NULL);

This check is not true for an SN system. Is there a better way?
How about "maxcpus=" ? Is maxcpus=1 always true for a kdump kernel?

Thanks,
 - jay