x-loader/cpu/arm1136/cpu.c

/*
 * (C) Copyright 2004 Texas Insturments
 *
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

/*
 * udelay() is CPU specific code
 */

#include <common.h>

/* See also ARM Ref. Man. */
#define C1_MMU		(1<<0)		/* mmu off/on */
#define C1_ALIGN	(1<<1)		/* alignment faults off/on */
#define C1_DC		(1<<2)		/* dcache off/on */
#define C1_WB		(1<<3)		/* merging write buffer on/off */
#define C1_BIG_ENDIAN	(1<<7)	/* big endian off/on */
#define C1_SYS_PROT	(1<<8)		/* system protection */
#define C1_ROM_PROT	(1<<9)		/* ROM protection */
#define C1_IC		(1<<12)		/* icache off/on */
#define C1_HIGH_VECTORS	(1<<13)	/* location of vectors: low/high addresses */
#define RESERVED_1	(0xf << 3)	/* must be 111b for R/W */

int cpu_init (void)
{
	int i;

	/* turn off I/D-cache */
	asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));
	i &= ~(C1_DC | C1_IC);
	asm ("mcr p15, 0, %0, c1, c0, 0": :"r" (i));

	/* flush I/D-cache */
	i = 0;
	asm ("mcr p15, 0, %0, c7, c7, 0": :"r" (i));  // invalidate both caches and flush btb
	asm ("mcr p15, 0, %0, c7, c10, 4": :"r" (i)); // mem barrier to sync things

	return 0;
}