[adm5120] prepare trxsplit to support sysupgrade

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@9085 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 227 insertions, 0 deletions

diff --git a/target/linux/adm5120/files/drivers/mtd/trxsplit.c b/target/linux/adm5120/files/drivers/mtd/trxsplit.c
new file mode 100644
index 000000000..ad0e25a11
--- /dev/null
+++ b/target/linux/adm5120/files/drivers/mtd/trxsplit.c
@@ -0,0 +1,227 @@
+/*
+ *  $Id$
+ *
+ *  Copyright (C) 2007 OpenWrt.org
+ *  Copyright (C) Gabor Juhos <juhosg at openwrt.org>
+ *
+ *  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 = NULL;
+static unsigned long trx_offset = 0;
+static int trx_nr_parts = 0;
+static struct mtd_partition trx_parts[TRX_MAX_OFFSET];
+static struct trx_header trx_hdr;
+
+static int trxsplit_refresh_partitions(struct mtd_info *mtd);
+
+static int 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) {
+		printk(KERN_ALERT PFX "unable to read from '%s'\n", mtd->name);
+		goto err_out;
+	}
+
+	if (retlen != sizeof(trx_hdr)) {
+		printk(KERN_ALERT PFX "reading failed on '%s'\n", mtd->name);
+		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 0;
+
+err_out:
+	return -1;
+}
+
+static void trxsplit_findtrx(struct mtd_info *mtd)
+{
+	unsigned long offset;
+	unsigned long blocklen;
+	int err;
+
+	blocklen = mtd->erasesize;
+	if (blocklen < BLOCK_LEN_MIN)
+		blocklen = BLOCK_LEN_MIN;
+
+	printk(KERN_INFO PFX "searching TRX header in '%s'\n", mtd->name);
+
+	err = 0;
+	for (offset=0; offset < mtd->size; offset+=blocklen) {
+		err = trxsplit_checktrx(mtd, offset);
+		if (err == 0)
+			break;
+	}
+
+	if (err)
+		return;
+
+	printk(KERN_INFO PFX "TRX header found at 0x%lX\n", offset);
+
+	trx_mtd = mtd;
+	trx_offset = offset;
+}
+
+static void trxsplit_create_partitions(struct mtd_info *mtd)
+{
+	struct mtd_partition *part = trx_parts;
+	int err;
+	int i;
+
+	for (i=0; i<TRX_MAX_OFFSET;i++) {
+		part = &trx_parts[i];
+		if (trx_hdr.offsets[i] == 0)
+			continue;
+		part->offset = trx_offset + trx_hdr.offsets[i];
+		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 = "loader";
+		i++;
+	}
+
+	part = &trx_parts[i];
+	part->name = "kernel";
+	i++;
+
+	part = &trx_parts[i];
+	part->name = "rootfs";
+
+	err = add_mtd_partitions(mtd, trx_parts, trx_nr_parts);
+	if (err) {
+		printk(KERN_ALERT PFX "adding TRX partitions failed\n");
+		return;
+	}
+
+	mtd->refresh_device = trxsplit_refresh_partitions;
+}
+
+static int trxsplit_refresh_partitions(struct mtd_info *mtd)
+{
+	printk(KERN_INFO PFX "refreshing TRX partitions in '%s' (%d,%d)\n",
+		mtd->name, MTD_BLOCK_MAJOR, mtd->index);
+
+	/* remove old partitions */
+	del_mtd_partitions(mtd);
+
+	trxsplit_findtrx(mtd);
+	if (!trx_mtd)
+		goto err;
+
+	trxsplit_create_partitions(trx_mtd);
+	return 1;
+
+err:
+	return 0;
+}
+
+static void __init trxsplit_add_mtd(struct mtd_info *mtd)
+{
+	if (!trx_mtd)
+		trxsplit_findtrx(mtd);
+}
+
+static void __init trxsplit_remove_mtd(struct mtd_info *mtd)
+{
+	/* nothing to do */
+}
+
+static struct mtd_notifier trxsplit_notifier __initdata = {
+	.add	= trxsplit_add_mtd,
+	.remove	= trxsplit_remove_mtd,
+};
+
+static void __init trxsplit_scan(void)
+{
+	register_mtd_user(&trxsplit_notifier);
+	unregister_mtd_user(&trxsplit_notifier);
+}
+
+static int __init trxsplit_init(void)
+{
+	trxsplit_scan();
+
+	if (trx_mtd) {
+		printk(KERN_INFO PFX "creating TRX partitions in '%s' (%d,%d)\n",
+			trx_mtd->name, MTD_BLOCK_MAJOR, trx_mtd->index);
+		trxsplit_create_partitions(trx_mtd);
+	}
+
+	return 0;
+}
+
+late_initcall(trxsplit_init);