config root man

/*-
 * Copyright (c) 2009 Neelkanth Natu
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD: release/9.1.0/sys/mips/sibyte/sb_asm.S 205675 2010-03-26 07:15:27Z neel $
 */

#include <machine/asm.h>
#include <machine/cpuregs.h>

.set	mips64
.set	noat
.set	noreorder

#ifdef SMP
/*
 * This function must be implemented in assembly because it is called early
 * in AP boot without a valid stack.
 *
 * This cpu number is available in bits 25 to 27 of the coprocessor 0 PRID
 * register. This is not documented in the BCM1250 user manual but can be
 * gleaned from the CFE source code - see sb1250_altcpu.S
 */
LEAF(platform_processor_id)
	mfc0	v0, MIPS_COP_0_PRID
	srl	v0, v0, 25
	jr	ra
	and	v0, v0, 7
END(platform_processor_id)
#endif	/* SMP */