u-boot/common/env_dataflash.c

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/* LowLevel function for DataFlash environment support
* Author : Gilles Gastaldi (Atmel)
*
* 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>
#include <command.h>
#include <environment.h>
#include <linux/stddef.h>
#include <dataflash.h>
DECLARE_GLOBAL_DATA_PTR;
env_t *env_ptr = NULL;
char * env_name_spec = "dataflash";
extern int read_dataflash (unsigned long addr, unsigned long size, char
*result);
extern int write_dataflash (unsigned long addr_dest, unsigned long addr_src,
unsigned long size);
extern int AT91F_DataflashInit (void);
extern uchar default_environment[];
uchar env_get_char_spec (int index)
{
uchar c;
read_dataflash(CONFIG_ENV_ADDR + index + offsetof(env_t,data),
1, (char *)&c);
return (c);
}
void env_relocate_spec (void)
{
read_dataflash(CONFIG_ENV_ADDR, CONFIG_ENV_SIZE, (char *)env_ptr);
}
int saveenv(void)
{
/* env must be copied to do not alter env structure in memory*/
unsigned char temp[CONFIG_ENV_SIZE];
memcpy(temp, env_ptr, CONFIG_ENV_SIZE);
return write_dataflash(CONFIG_ENV_ADDR, (unsigned long)temp, CONFIG_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];
if (gd->env_valid == 0){
AT91F_DataflashInit(); /* prepare for DATAFLASH read/write */
/* read old CRC */
read_dataflash(CONFIG_ENV_ADDR + offsetof(env_t, crc),
sizeof(ulong), (char *)&crc);
new = 0;
len = ENV_SIZE;
off = offsetof(env_t,data);
while (len > 0) {
int n = (len > sizeof(buf)) ? sizeof(buf) : len;
read_dataflash(CONFIG_ENV_ADDR + off, n, (char *)buf);
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 = (ulong)&default_environment[0];
gd->env_valid = 0;
}
}
return (0);
}