kernel/3.10: add partition parser for Seama firmwares

Signed-off-by: Gabor Juhos <juhosg@openwrt.org> SVN-Revision: 38114
2013-09-21 17:56:18 +00:00
parent 2f2ed5c5c1
commit 2e62ff9320
3 changed files with 126 additions and 0 deletions
--- a/target/linux/generic/files/drivers/mtd/mtdsplit_seama.c
+++ b/target/linux/generic/files/drivers/mtd/mtdsplit_seama.c
@@ -0,0 +1,102 @@
+/*
+ *  Copyright (C) 2013 Gabor Juhos <juhosg@openwrt.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/byteorder/generic.h>
+
+#include "mtdsplit.h"
+
+#define SEAMA_MAGIC		0x5EA3A417
+#define SEAMA_NR_PARTS		2
+#define SEAMA_MIN_ROOTFS_OFFS	0x80000	/* 512KiB */
+
+struct seama_header {
+	__be32	magic;		/* should always be SEAMA_MAGIC. */
+	__be16	reserved;	/* reserved for  */
+	__be16	metasize;	/* size of the META data */
+	__be32	size;		/* size of the image */
+};
+
+static int mtdsplit_parse_seama(struct mtd_info *master,
+				struct mtd_partition **pparts,
+				struct mtd_part_parser_data *data)
+{
+	struct seama_header hdr;
+	size_t hdr_len, retlen, kernel_size;
+	size_t rootfs_offset;
+	struct mtd_partition *parts;
+	int err;
+
+	hdr_len = sizeof(hdr);
+	err = mtd_read(master, 0, hdr_len, &retlen, (void *) &hdr);
+	if (err)
+		return err;
+
+	if (retlen != hdr_len)
+		return -EIO;
+
+	/* sanity checks */
+	if (be32_to_cpu(hdr.magic) != SEAMA_MAGIC)
+		return -EINVAL;
+
+	kernel_size = hdr_len + be32_to_cpu(hdr.size) +
+		      be16_to_cpu(hdr.metasize);
+	if (kernel_size > master->size)
+		return -EINVAL;
+
+	/* Find the rootfs after the kernel. */
+	err = mtd_check_rootfs_magic(master, kernel_size);
+	if (!err) {
+		rootfs_offset = kernel_size;
+	} else {
+		/*
+		 * The size in the header might cover the rootfs as well.
+		 * Start the search from an arbitrary offset.
+		 */
+		err = mtd_find_rootfs_from(master, SEAMA_MIN_ROOTFS_OFFS,
+					   master->size, &rootfs_offset);
+		if (err)
+			return err;
+	}
+
+	parts = kzalloc(SEAMA_NR_PARTS * sizeof(*parts), GFP_KERNEL);
+	if (!parts)
+		return -ENOMEM;
+
+	parts[0].name = KERNEL_PART_NAME;
+	parts[0].offset = 0;
+	parts[0].size = rootfs_offset;
+
+	parts[1].name = ROOTFS_PART_NAME;
+	parts[1].offset = rootfs_offset;
+	parts[1].size = master->size - rootfs_offset;
+
+	*pparts = parts;
+	return SEAMA_NR_PARTS;
+}
+
+static struct mtd_part_parser mtdsplit_seama_parser = {
+	.owner = THIS_MODULE,
+	.name = "seama-fw",
+	.parse_fn = mtdsplit_parse_seama,
+	.type = MTD_PARSER_TYPE_FIRMWARE,
+};
+
+static int
+mtdsplit_seama_init(void)
+{
+	return register_mtd_parser(&mtdsplit_seama_parser);
+}
+
+subsys_initcall(mtdsplit_seama_init);