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/*
* $Id$
*
* Copyright (C) 2007 OpenWrt.org
* Copyright (C) Gabor Juhos <juhosg@freemail.hu>
*
* 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/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/kmod.h>
#include <linux/root_dev.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/byteorder/generic.h>
#define PFX "trxsplit: "
#define TRX_MAGIC 0x30524448 /* "HDR0" */
#define TRX_VERSION 1
#define TRX_MAX_LEN 0x3A0000
#define TRX_NO_HEADER 1 /* Do not write TRX header */
#define TRX_GZ_FILES 0x2 /* Contains up to TRX_MAX_OFFSET individual gzip files */
#define TRX_MAX_OFFSET 3
#define TRX_MIN_KERNEL_SIZE 256*1024
struct trx_header {
u32 magic; /* "HDR0" */
u32 len; /* Length of file including header */
u32 crc32; /* 32-bit CRC from flag_version to end of file */
u32 flag_version; /* 0:15 flags, 16:31 version */
u32 offsets[TRX_MAX_OFFSET]; /* Offsets of partitions from start of header */
};
#define BLOCK_LEN_MIN 0x10000
static struct mtd_info *trx_mtd_master = NULL;
static struct mtd_info *trx_mtds[TRX_MAX_OFFSET];
static struct mtd_partition trx_parts[TRX_MAX_OFFSET];
static struct trx_header trx_hdr;
static int trx_nr_parts = 0;
static int trx_rootfs_part = -1;
static int __init trxsplit_checktrx(struct mtd_info *mtd, unsigned long offset)
{
size_t retlen;
int err;
err = mtd->read(mtd, offset, sizeof(trx_hdr), &retlen, (void *)&trx_hdr);
if (err)
goto err_out;
if (retlen != sizeof(trx_hdr))
goto err_out;
trx_hdr.magic = le32_to_cpu(trx_hdr.magic);
trx_hdr.len = le32_to_cpu(trx_hdr.len);
trx_hdr.crc32 = le32_to_cpu(trx_hdr.crc32);
trx_hdr.flag_version = le32_to_cpu(trx_hdr.flag_version);
trx_hdr.offsets[0] = le32_to_cpu(trx_hdr.offsets[0]);
trx_hdr.offsets[1] = le32_to_cpu(trx_hdr.offsets[1]);
trx_hdr.offsets[2] = le32_to_cpu(trx_hdr.offsets[2]);
/* sanity checks */
if (trx_hdr.magic != TRX_MAGIC)
goto err_out;
if (trx_hdr.len > mtd->size - offset)
goto err_out;
/* TODO: add crc32 checking too? */
return 1;
err_out:
return 0;
}
static void __init trxsplit_create_partitions(struct mtd_info *mtd,
unsigned long offset)
{
struct mtd_partition *part = trx_parts;
int i;
for (i=0;i<TRX_MAX_OFFSET;i++) {
part = &trx_parts[i];
if (trx_hdr.offsets[i] == 0)
continue;
part->offset = offset + trx_hdr.offsets[i];
part->mtdp = &trx_mtds[trx_nr_parts];
trx_nr_parts++;
}
for (i=0; i<trx_nr_parts-1; i++) {
trx_parts[i].size = trx_parts[i+1].offset - trx_parts[i].offset;
}
trx_parts[i].size = mtd->size - trx_parts[i].offset;
i=0;
part = &trx_parts[i];
if (part->size < TRX_MIN_KERNEL_SIZE) {
part->name = "trx_loader";
i++;
}
part = &trx_parts[i];
part->name = "trx_kernel";
i++;
part = &trx_parts[i];
part->name = "trx_rootfs";
trx_rootfs_part = i;
}
static void __init trxsplit_add_mtd(struct mtd_info *mtd)
{
unsigned long offset;
unsigned long blocklen;
int found;
if (trx_mtd_master)
return;
blocklen = mtd->erasesize;
if (blocklen < BLOCK_LEN_MIN)
blocklen = BLOCK_LEN_MIN;
printk(KERN_INFO PFX "searching TRX header in '%s'\n", mtd->name);
found = 0;
for (offset=0; offset < mtd->size; offset+=blocklen) {
found = trxsplit_checktrx(mtd, offset);
if (found)
break;
}
if (found == 0) {
printk(KERN_ALERT PFX "no TRX header found\n");
return;
}
printk(KERN_INFO PFX "TRX header found at 0x%lX\n", offset);
trxsplit_create_partitions(mtd, offset);
trx_mtd_master = mtd;
}
static void trxsplit_remove_mtd(struct mtd_info *mtd)
{
}
static struct mtd_notifier trxsplit_notifier __initdata = {
.add = trxsplit_add_mtd,
.remove = trxsplit_remove_mtd,
};
static void __init trxsplit_find_trx(void)
{
register_mtd_user(&trxsplit_notifier);
unregister_mtd_user(&trxsplit_notifier);
}
static int __init trxsplit_init(void)
{
int err;
int i;
trxsplit_find_trx();
if (trx_mtd_master == NULL)
goto err;
printk(KERN_INFO PFX "creating TRX partitions in '%s'\n",
trx_mtd_master->name);
err = add_mtd_partitions(trx_mtd_master, trx_parts, trx_nr_parts);
if (err) {
printk(KERN_ALERT PFX "creating TRX partitions failed\n");
goto err;
}
for (i=0; i<trx_nr_parts; i++) {
/* TODO: add error checking */
add_mtd_device(trx_mtds[i]);
}
if (ROOT_DEV == 0 && trx_rootfs_part >= 0) {
printk(KERN_INFO PFX "set '%s' to be root filesystem\n",
trx_mtds[trx_rootfs_part]->name);
ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, trx_mtds[trx_rootfs_part]->index);
}
return 0;
err:
return -1;
}
late_initcall(trxsplit_init);
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