u-boot/common/env_eeprom.c

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2002-09-18 11:09:59 +00:00
/*
* (C) Copyright 2000-2002
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
* Andreas Heppel <aheppel@sysgo.de>
* 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
*/
#include <common.h>
#if defined(CFG_ENV_IS_IN_EEPROM) /* Environment is in EEPROM */
#include <command.h>
#include <environment.h>
#include <linux/stddef.h>
DECLARE_GLOBAL_DATA_PTR;
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env_t *env_ptr = NULL;
char * env_name_spec = "EEPROM";
extern uchar env_get_char_memory (int index);
uchar env_get_char_spec (int index)
{
uchar c;
eeprom_read (CFG_DEF_EEPROM_ADDR,
CFG_ENV_OFFSET+index+offsetof(env_t,data),
&c, 1);
return (c);
}
void env_relocate_spec (void)
{
eeprom_read (CFG_DEF_EEPROM_ADDR,
CFG_ENV_OFFSET,
(uchar*)env_ptr,
CFG_ENV_SIZE);
}
int saveenv(void)
{
return eeprom_write (CFG_DEF_EEPROM_ADDR,
CFG_ENV_OFFSET,
(uchar *)env_ptr,
CFG_ENV_SIZE);
}
/************************************************************************
* Initialize Environment use
*
* We are still running from ROM, so data use is limited
* Use a (moderately small) buffer on the stack
*/
int env_init(void)
{
ulong crc, len, new;
unsigned off;
uchar buf[64];
eeprom_init (); /* prepare for EEPROM read/write */
/* read old CRC */
eeprom_read (CFG_DEF_EEPROM_ADDR,
CFG_ENV_OFFSET+offsetof(env_t,crc),
(uchar *)&crc, sizeof(ulong));
new = 0;
len = ENV_SIZE;
off = offsetof(env_t,data);
while (len > 0) {
int n = (len > sizeof(buf)) ? sizeof(buf) : len;
eeprom_read (CFG_DEF_EEPROM_ADDR, CFG_ENV_OFFSET+off, buf, n);
new = crc32 (new, buf, n);
len -= n;
off += n;
}
if (crc == new) {
gd->env_addr = offsetof(env_t,data);
gd->env_valid = 1;
} else {
gd->env_addr = 0;
gd->env_valid = 0;
}
return (0);
}
#endif /* CFG_ENV_IS_IN_EEPROM */