kernel/3.1x: add split code for LZMA compressed kernel based firmwares

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@39387 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 95 insertions, 0 deletions

diff --git a/target/linux/generic/files/drivers/mtd/mtdsplit_lzma.c b/target/linux/generic/files/drivers/mtd/mtdsplit_lzma.c
new file mode 100644
index 0000000000..d23060a7d5
--- /dev/null
+++ b/target/linux/generic/files/drivers/mtd/mtdsplit_lzma.c
@@ -0,0 +1,95 @@
+/*
+ *  Copyright (C) 2014 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 <asm/unaligned.h>
+
+#include "mtdsplit.h"
+
+#define LZMA_NR_PARTS		2
+#define LZMA_PROPERTIES_SIZE	5
+
+struct lzma_header {
+	u8 props[LZMA_PROPERTIES_SIZE];
+	u8 size_low[4];
+	u8 size_high[4];
+};
+
+static int mtdsplit_parse_lzma(struct mtd_info *master,
+			       struct mtd_partition **pparts,
+			       struct mtd_part_parser_data *data)
+{
+	struct lzma_header hdr;
+	size_t hdr_len, retlen;
+	size_t rootfs_offset;
+	u32 t;
+	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;
+
+	/* verify LZMA properties */
+	if (hdr.props[0] >= (9 * 5 * 5))
+		return -EINVAL;
+
+	t = get_unaligned_le32(&hdr.props[1]);
+	if (!is_power_of_2(t))
+		return -EINVAL;
+
+	t = get_unaligned_le32(&hdr.size_high);
+	if (t)
+		return -EINVAL;
+
+	err = mtd_find_rootfs_from(master, master->erasesize,
+				   master->size, &rootfs_offset);
+	if (err)
+		return err;
+
+	parts = kzalloc(LZMA_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 LZMA_NR_PARTS;
+}
+
+static struct mtd_part_parser mtdsplit_lzma_parser = {
+	.owner = THIS_MODULE,
+	.name = "lzma-fw",
+	.parse_fn = mtdsplit_parse_lzma,
+	.type = MTD_PARSER_TYPE_FIRMWARE,
+};
+
+static int
+mtdsplit_lzma_init(void)
+{
+	return register_mtd_parser(&mtdsplit_lzma_parser);
+}
+
+subsys_initcall(mtdsplit_lzma_init);