- 根目录:
- drivers
- mtd
- afs.c
/*======================================================================
drivers/mtd/afs.c: ARM Flash Layout/Partitioning
Copyright © 2000 ARM Limited
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
This is access code for flashes using ARM's flash partitioning
standards.
======================================================================*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>
struct footer_struct {
u32 image_info_base; /* Address of first word of ImageFooter */
u32 image_start; /* Start of area reserved by this footer */
u32 signature; /* 'Magic' number proves it's a footer */
u32 type; /* Area type: ARM Image, SIB, customer */
u32 checksum; /* Just this structure */
};
struct image_info_struct {
u32 bootFlags; /* Boot flags, compression etc. */
u32 imageNumber; /* Unique number, selects for boot etc. */
u32 loadAddress; /* Address program should be loaded to */
u32 length; /* Actual size of image */
u32 address; /* Image is executed from here */
char name[16]; /* Null terminated */
u32 headerBase; /* Flash Address of any stripped header */
u32 header_length; /* Length of header in memory */
u32 headerType; /* AIF, RLF, s-record etc. */
u32 checksum; /* Image checksum (inc. this struct) */
};
static u32 word_sum(void *words, int num)
{
u32 *p = words;
u32 sum = 0;
while (num--)
sum += *p++;
return sum;
}
static int
afs_read_footer(struct mtd_info *mtd, u_int *img_start, u_int *iis_start,
u_int off, u_int mask)
{
struct footer_struct fs;
u_int ptr = off + mtd->erasesize - sizeof(fs);
size_t sz;
int ret;
ret = mtd_read(mtd, ptr, sizeof(fs), &sz, (u_char *)&fs);
if (ret >= 0 && sz != sizeof(fs))
ret = -EINVAL;
if (ret < 0) {
printk(KERN_ERR "AFS: mtd read failed at 0x%x: %d\n",
ptr, ret);
return ret;
}
ret = 1;
/*
* Does it contain the magic number?
*/
if (fs.signature != 0xa0ffff9f)
ret = 0;
/*
* Check the checksum.
*/
if (word_sum(&fs, sizeof(fs) / sizeof(u32)) != 0xffffffff)
ret = 0;
/*
* Don't touch the SIB.
*/
if (fs.type == 2)
ret = 0;
*iis_start = fs.image_info_base & mask;
*img_start = fs.image_start & mask;
/*
* Check the image info base. This can not
* be located after the footer structure.
*/
if (*iis_start >= ptr)
ret = 0;
/*
* Check the start of this image. The image
* data can not be located after this block.
*/
if (*img_start > off)
ret = 0;
return ret;
}
static int
afs_read_iis(struct mtd_info *mtd, struct image_info_struct *iis, u_int ptr)
{
size_t sz;
int ret, i;
memset(iis, 0, sizeof(*iis));
ret = mtd_read(mtd, ptr, sizeof(*iis), &sz, (u_char *)iis);
if (ret < 0)
goto failed;
if (sz != sizeof(*iis)) {
ret = -EINVAL;
goto failed;
}
ret = 0;
/*
* Validate the name - it must be NUL terminated.
*/
for (i = 0; i < sizeof(iis->name); i++)
if (iis->name[i] == '\0')
break;
if (i < sizeof(iis->name))
ret = 1;
return ret;
failed:
printk(KERN_ERR "AFS: mtd read failed at 0x%x: %d\n",
ptr, ret);
return ret;
}
static int parse_afs_partitions(struct mtd_info *mtd,
struct mtd_partition **pparts,
struct mtd_part_parser_data *data)
{
struct mtd_partition *parts;
u_int mask, off, idx, sz;
int ret = 0;
char *str;
/*
* This is the address mask; we use this to mask off out of
* range address bits.
*/
mask = mtd->size - 1;
/*
* First, calculate the size of the array we need for the
* partition information. We include in this the size of
* the strings.
*/
for (idx = off = sz = 0; off < mtd->size; off += mtd->erasesize) {
struct image_info_struct iis;
u_int iis_ptr, img_ptr;
ret = afs_read_footer(mtd, &img_ptr, &iis_ptr, off, mask);
if (ret < 0)
break;
if (ret == 0)
continue;
ret = afs_read_iis(mtd, &iis, iis_ptr);
if (ret < 0)
break;
if (ret == 0)
continue;
sz += sizeof(struct mtd_partition);
sz += strlen(iis.name) + 1;
idx += 1;
}
if (!sz)
return ret;
parts = kzalloc(sz, GFP_KERNEL);
if (!parts)
return -ENOMEM;
str = (char *)(parts + idx);
/*
* Identify the partitions
*/
for (idx = off = 0; off < mtd->size; off += mtd->erasesize) {
struct image_info_struct iis;
u_int iis_ptr, img_ptr;
/* Read the footer. */
ret = afs_read_footer(mtd, &img_ptr, &iis_ptr, off, mask);
if (ret < 0)
break;
if (ret == 0)
continue;
/* Read the image info block */
ret = afs_read_iis(mtd, &iis, iis_ptr);
if (ret < 0)
break;
if (ret == 0)
continue;
strcpy(str, iis.name);
parts[idx].name = str;
parts[idx].size = (iis.length + mtd->erasesize - 1) & ~(mtd->erasesize - 1);
parts[idx].offset = img_ptr;
parts[idx].mask_flags = 0;
printk(" mtd%d: at 0x%08x, %5lluKiB, %8u, %s\n",
idx, img_ptr, parts[idx].size / 1024,
iis.imageNumber, str);
idx += 1;
str = str + strlen(iis.name) + 1;
}
if (!idx) {
kfree(parts);
parts = NULL;
}
*pparts = parts;
return idx ? idx : ret;
}
static struct mtd_part_parser afs_parser = {
.owner = THIS_MODULE,
.parse_fn = parse_afs_partitions,
.name = "afs",
};
static int __init afs_parser_init(void)
{
register_mtd_parser(&afs_parser);
return 0;
}
static void __exit afs_parser_exit(void)
{
deregister_mtd_parser(&afs_parser);
}
module_init(afs_parser_init);
module_exit(afs_parser_exit);
MODULE_AUTHOR("ARM Ltd");
MODULE_DESCRIPTION("ARM Firmware Suite partition parser");
MODULE_LICENSE("GPL");