Question about a comment

[coypu%SDF.ORG@localhost]

I'm curious about what is the reason for the following comment
in sys/arch/mips/mips/locore.S:

#ifdef MIPS64_OCTEON
	//
	// U-boot on the erlite starts all cpus at the kernel entry point.
	// Use EBASE to find our CPU number and if it's not 0, call
	// octeon_cpu_spinup if MP or loop using the wait instruction since
	// non-primary CPUs can't do anything useful.
	//
	mfc0	a0, MIPS_COP_0_EBASE		# EBASE
	COP0_SYNC
	ext	a1, a0, 0, 10			# get CPU number
	beqz	a1, 2f				# normal startup if 0
	 nop
#ifdef MULTIPROCESSOR
	j	_C_LABEL(octeon_cpu_spinup)
	 nop
#else
1:	wait
	b	1b
	 nop
#endif /* MIPS64_OCTEON */

What makes octeon special, why are we unable to use the other CPU?

Thanks.