5 files changed, 125 insertions, 0 deletions
diff --git a/target/linux/generic/config-4.4 b/target/linux/generic/config-4.4
index ebc54bc7bd..e76359a8ae 100644
--- a/target/linux/generic/config-4.4
+++ b/target/linux/generic/config-4.4
@@ -2367,6 +2367,7 @@ CONFIG_MTD_SPLIT=y
 CONFIG_MTD_SPLIT_FIRMWARE_NAME="firmware"
 # CONFIG_MTD_SPLIT_FIT_FW is not set
 # CONFIG_MTD_SPLIT_LZMA_FW is not set
+# CONFIG_MTD_SPLIT_MINOR_FW is not set
 # CONFIG_MTD_SPLIT_SEAMA_FW is not set
 CONFIG_MTD_SPLIT_SQUASHFS_ROOT=y
 CONFIG_MTD_SPLIT_SUPPORT=y
diff --git a/target/linux/generic/config-4.9 b/target/linux/generic/config-4.9
index 99ba19f938..e36d77c207 100644
--- a/target/linux/generic/config-4.9
+++ b/target/linux/generic/config-4.9
@@ -2578,6 +2578,7 @@ CONFIG_MTD_SPLIT=y
 CONFIG_MTD_SPLIT_FIRMWARE_NAME="firmware"
 # CONFIG_MTD_SPLIT_FIT_FW is not set
 # CONFIG_MTD_SPLIT_LZMA_FW is not set
+# CONFIG_MTD_SPLIT_MINOR_FW is not set
 # CONFIG_MTD_SPLIT_SEAMA_FW is not set
 CONFIG_MTD_SPLIT_SQUASHFS_ROOT=y
 CONFIG_MTD_SPLIT_SUPPORT=y
diff --git a/target/linux/generic/files/drivers/mtd/mtdsplit/Kconfig b/target/linux/generic/files/drivers/mtd/mtdsplit/Kconfig
index 7e653e78a1..4a15d4879b 100644
--- a/target/linux/generic/files/drivers/mtd/mtdsplit/Kconfig
+++ b/target/linux/generic/files/drivers/mtd/mtdsplit/Kconfig
@@ -64,3 +64,8 @@ config MTD_SPLIT_EVA_FW
 	bool "EVA image based firmware partition parser"
 	depends on MTD_SPLIT_SUPPORT
 	select MTD_SPLIT
+
+config MTD_SPLIT_MINOR_FW
+	bool "Mikrotik NOR image based firmware partition parser"
+	depends on MTD_SPLIT_SUPPORT
+	select MTD_SPLIT
diff --git a/target/linux/generic/files/drivers/mtd/mtdsplit/Makefile b/target/linux/generic/files/drivers/mtd/mtdsplit/Makefile
index c843025ffb..fab85caa75 100644
--- a/target/linux/generic/files/drivers/mtd/mtdsplit/Makefile
+++ b/target/linux/generic/files/drivers/mtd/mtdsplit/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_MTD_SPLIT_TRX_FW) += mtdsplit_trx.o
 obj-$(CONFIG_MTD_SPLIT_BRNIMAGE_FW) += mtdsplit_brnimage.o
 obj-$(CONFIG_MTD_SPLIT_EVA_FW) += mtdsplit_eva.o
 obj-$(CONFIG_MTD_SPLIT_WRGG_FW) += mtdsplit_wrgg.o
+obj-$(CONFIG_MTD_SPLIT_MINOR_FW) += mtdsplit_minor.o
diff --git a/target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_minor.c b/target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_minor.c
new file mode 100644
index 0000000000..f971f0a650
--- /dev/null
+++ b/target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_minor.c
@@ -0,0 +1,117 @@
+/*
+ *  MTD splitter for MikroTik NOR devices
+ *
+ *  Copyright (C) 2017 Thibaut VARENE <varenet@parisc-linux.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.
+ *
+ *  The rootfs is expected at erase-block boundary due to the use of
+ *  mtd_find_rootfs_from(). We use a trimmed down version of the yaffs header
+ *  for two main reasons:
+ *  - the original header uses weakly defined types (int, enum...) which can
+ *    vary in length depending on build host (and the struct is not packed),
+ *    and the name field can have a different total length depending on
+ *    whether or not the yaffs code was _built_ with unicode support.
+ *  - the only field that could be of real use here (file_size_low) contains
+ *    invalid data in the header generated by kernel2minor, so we cannot use
+ *    it to infer the exact position of the rootfs and do away with
+ *    mtd_find_rootfs_from() (and thus have non-EB-aligned rootfs).
+ */
+
+#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/string.h>
+
+#include "mtdsplit.h"
+
+#define YAFFS_OBJECT_TYPE_FILE	0x1
+#define YAFFS_OBJECTID_ROOT	0x1
+#define YAFFS_SUM_UNUSED	0xFFFF
+#define YAFFS_NAME		"kernel"
+
+#define MINOR_NR_PARTS		2
+
+/*
+ * This structure is based on yaffs_obj_hdr from yaffs_guts.h
+ * The weak types match upstream. The fields have cpu-endianness
+ */
+struct minor_header {
+	int yaffs_type;
+	int yaffs_obj_id;
+	u16 yaffs_sum_unused;
+	char yaffs_name[sizeof(YAFFS_NAME)];
+};
+
+static int mtdsplit_parse_minor(struct mtd_info *master,
+				const struct mtd_partition **pparts,
+				struct mtd_part_parser_data *data)
+{
+	struct minor_header hdr;
+	size_t hdr_len, retlen;
+	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;
+
+	/* match header */
+	if (hdr.yaffs_type != YAFFS_OBJECT_TYPE_FILE)
+		return -EINVAL;
+
+	if (hdr.yaffs_obj_id != YAFFS_OBJECTID_ROOT)
+		return -EINVAL;
+
+	if (hdr.yaffs_sum_unused != YAFFS_SUM_UNUSED)
+		return -EINVAL;
+
+	if (memcmp(hdr.yaffs_name, YAFFS_NAME, sizeof(YAFFS_NAME)))
+		return -EINVAL;
+
+	err = mtd_find_rootfs_from(master, master->erasesize, master->size,
+				   &rootfs_offset, NULL);
+	if (err)
+		return err;
+
+	parts = kzalloc(MINOR_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 MINOR_NR_PARTS;
+}
+
+static struct mtd_part_parser mtdsplit_minor_parser = {
+	.owner = THIS_MODULE,
+	.name = "minor-fw",
+	.parse_fn = mtdsplit_parse_minor,
+	.type = MTD_PARSER_TYPE_FIRMWARE,
+};
+
+static int __init mtdsplit_minor_init(void)
+{
+	register_mtd_parser(&mtdsplit_minor_parser);
+
+	return 0;
+}
+
+subsys_initcall(mtdsplit_minor_init);