Openwrt/target/linux/adm5120-2.6/files/arch/mips/adm5120/prom/cfe.c

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/*
* $Id$
*
* Broadcom's CFE specific prom routines
*
* Copyright (C) 2007 OpenWrt.org
* Copyright (C) 2007 Gabor Juhos <juhosg at openwrt.org>
*
* 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., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#include <linux/types.h>
#include <linux/init.h>
#include <asm/bootinfo.h>
#include <asm/addrspace.h>
#include <prom/cfe.h>
#include "prom_read.h"
/*
* CFE based boards
*/
#define CFE_EPTSEAL 0x43464531 /* CFE1 is the magic number to recognize CFE
from other bootloaders */
static int cfe_found = 0;
static u32 cfe_handle;
static u32 cfe_entry;
static u32 cfe_seal;
int __init cfe_present(void)
{
/*
* This method only works, when we are booted directly from the CFE.
*/
u32 a1 = (u32) fw_arg1;
if (cfe_found)
return 1;
cfe_handle = (u32) fw_arg0;
cfe_entry = (u32) fw_arg2;
cfe_seal = (u32) fw_arg3;
/* Check for CFE by finding the CFE magic number */
if (cfe_seal != CFE_EPTSEAL) {
/* We are not booted from CFE */
return 0;
}
/* cfe_a1_val must be 0, because only one CPU present in the ADM5120 */
if (a1 != 0) {
return 0;
}
/* The cfe_handle, and the cfe_entry must be kernel mode addresses */
if ((cfe_handle < KSEG0) || (cfe_entry < KSEG0)) {
return 0;
}
cfe_found = 1;
return 1;
}
char *cfe_getenv(char *envname)
{
if (cfe_found == 0)
return NULL;
return NULL;
}