From 4153c0adff074167f1eb934235129471d2c04199 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Fri, 2 Jan 2015 21:52:35 +0000 Subject: kernel: move mtdsplit files to drivers/mtd/mtdsplit/ to simplify maintenance, unify patches across kernel versions Signed-off-by: Felix Fietkau SVN-Revision: 43805 --- .../generic/files/drivers/mtd/mtdsplit/mtdsplit.c | 116 +++++++++++++++++++++ 1 file changed, 116 insertions(+) create mode 100644 target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit.c (limited to 'target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit.c') diff --git a/target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit.c b/target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit.c new file mode 100644 index 0000000000..162739f472 --- /dev/null +++ b/target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit.c @@ -0,0 +1,116 @@ +/* + * Copyright (C) 2009-2013 Felix Fietkau + * Copyright (C) 2009-2013 Gabor Juhos + * Copyright (C) 2012 Jonas Gorski + * Copyright (C) 2013 Hauke Mehrtens + * + * 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. + * + */ + +#define pr_fmt(fmt) "mtdsplit: " fmt + +#include +#include +#include +#include +#include +#include +#include + +#include "mtdsplit.h" + +struct squashfs_super_block { + __le32 s_magic; + __le32 pad0[9]; + __le64 bytes_used; +}; + +int mtd_get_squashfs_len(struct mtd_info *master, + size_t offset, + size_t *squashfs_len) +{ + struct squashfs_super_block sb; + size_t retlen; + int err; + + err = mtd_read(master, offset, sizeof(sb), &retlen, (void *)&sb); + if (err || (retlen != sizeof(sb))) { + pr_alert("error occured while reading from \"%s\"\n", + master->name); + return -EIO; + } + + if (le32_to_cpu(sb.s_magic) != SQUASHFS_MAGIC) { + pr_alert("no squashfs found in \"%s\"\n", master->name); + return -EINVAL; + } + + retlen = le64_to_cpu(sb.bytes_used); + if (retlen <= 0) { + pr_alert("squashfs is empty in \"%s\"\n", master->name); + return -ENODEV; + } + + if (offset + retlen > master->size) { + pr_alert("squashfs has invalid size in \"%s\"\n", + master->name); + return -EINVAL; + } + + *squashfs_len = retlen; + return 0; +} +EXPORT_SYMBOL_GPL(mtd_get_squashfs_len); + +static ssize_t mtd_next_eb(struct mtd_info *mtd, size_t offset) +{ + return mtd_rounddown_to_eb(offset, mtd) + mtd->erasesize; +} + +int mtd_check_rootfs_magic(struct mtd_info *mtd, size_t offset) +{ + u32 magic; + size_t retlen; + int ret; + + ret = mtd_read(mtd, offset, sizeof(magic), &retlen, + (unsigned char *) &magic); + if (ret) + return ret; + + if (retlen != sizeof(magic)) + return -EIO; + + if (le32_to_cpu(magic) != SQUASHFS_MAGIC && + magic != 0x19852003) + return -EINVAL; + + return 0; +} +EXPORT_SYMBOL_GPL(mtd_check_rootfs_magic); + +int mtd_find_rootfs_from(struct mtd_info *mtd, + size_t from, + size_t limit, + size_t *ret_offset) +{ + size_t offset; + int err; + + for (offset = from; offset < limit; + offset = mtd_next_eb(mtd, offset)) { + err = mtd_check_rootfs_magic(mtd, offset); + if (err) + continue; + + *ret_offset = offset; + return 0; + } + + return -ENODEV; +} +EXPORT_SYMBOL_GPL(mtd_find_rootfs_from); + -- cgit v1.2.3