linux/drivers/mtd/afs.c
Catalin Marinas 747aead34d [PATCH] ARM: 2780/1: AFS partition length calculation fix
Patch from Catalin Marinas

This patch calculates the AFS partition length by expanding the image
length information to the nearest erase block boundary. This
eliminates the problems with JFFS2 erasing the footer.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-06-30 23:01:09 +01:00

285 lines
6.4 KiB
C

/*======================================================================
drivers/mtd/afs.c: ARM Flash Layout/Partitioning
Copyright (C) 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.
$Id: afs.c,v 1.13 2004/02/27 22:09:59 rmk Exp $
======================================================================*/
#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,
unsigned long origin)
{
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 = kmalloc(sz, GFP_KERNEL);
if (!parts)
return -ENOMEM;
memset(parts, 0, sz);
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, %5dKB, %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)
{
return register_mtd_parser(&afs_parser);
}
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");