kernel: mtdsplit: add support for EVA images

This allows splitting EVA images (usually found in fritz devices). The
firmware will be split into a kernel and a separate rootfs partition.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

SVN-Revision: 48262

target/linux/generic/config-3.18

@@ -2266,6 +2266,7 @@ CONFIG_MTD_ROOTFS_SPLIT=y
 # CONFIG_MTD_SPINAND_MT29F is not set
 CONFIG_MTD_SPLIT=y
 # CONFIG_MTD_SPLIT_BRNIMAGE_FW is not set
+# CONFIG_MTD_SPLIT_EVA_FW is not set
 # CONFIG_MTD_SPLIT_FIRMWARE is not set
 CONFIG_MTD_SPLIT_FIRMWARE_NAME="firmware"
 # CONFIG_MTD_SPLIT_FIT_FW is not set

target/linux/generic/config-4.1

@@ -2358,6 +2358,7 @@ CONFIG_MTD_ROOTFS_ROOT_DEV=y
 # CONFIG_MTD_SPINAND_MT29F is not set
 CONFIG_MTD_SPLIT=y
 # CONFIG_MTD_SPLIT_BRNIMAGE_FW is not set
+# CONFIG_MTD_SPLIT_EVA_FW is not set
 # CONFIG_MTD_SPLIT_FIRMWARE is not set
 CONFIG_MTD_SPLIT_FIRMWARE_NAME="firmware"
 # CONFIG_MTD_SPLIT_FIT_FW is not set

target/linux/generic/config-4.3

@@ -2416,6 +2416,7 @@ CONFIG_MTD_ROOTFS_ROOT_DEV=y
 # CONFIG_MTD_SPINAND_MT29F is not set
 CONFIG_MTD_SPLIT=y
 # CONFIG_MTD_SPLIT_BRNIMAGE_FW is not set
+# CONFIG_MTD_SPLIT_EVA_FW is not set
 # CONFIG_MTD_SPLIT_FIRMWARE is not set
 CONFIG_MTD_SPLIT_FIRMWARE_NAME="firmware"
 # CONFIG_MTD_SPLIT_FIT_FW is not set

target/linux/generic/config-4.4

@@ -2319,6 +2319,7 @@ CONFIG_MTD_ROOTFS_ROOT_DEV=y
 # CONFIG_MTD_SPI_NOR_USE_4K_SECTORS is not set
 CONFIG_MTD_SPLIT=y
 # CONFIG_MTD_SPLIT_BRNIMAGE_FW is not set
+# CONFIG_MTD_SPLIT_EVA_FW is not set
 # CONFIG_MTD_SPLIT_FIRMWARE is not set
 CONFIG_MTD_SPLIT_FIRMWARE_NAME="firmware"
 # CONFIG_MTD_SPLIT_FIT_FW is not set

target/linux/generic/files/drivers/mtd/mtdsplit/Kconfig

@@ -54,3 +54,8 @@ config MTD_SPLIT_BRNIMAGE_FW
 	bool "brnImage (brnboot image) firmware parser"
 	depends on MTD_SPLIT_SUPPORT
 	select MTD_SPLIT
+
+config MTD_SPLIT_EVA_FW
+	bool "EVA image based firmware partition parser"
+	depends on MTD_SPLIT_SUPPORT
+	select MTD_SPLIT

target/linux/generic/files/drivers/mtd/mtdsplit/Makefile

@@ -7,3 +7,4 @@ obj-$(CONFIG_MTD_SPLIT_LZMA_FW) += mtdsplit_lzma.o
 obj-$(CONFIG_MTD_SPLIT_TPLINK_FW) += mtdsplit_tplink.o
 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

target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_eva.c

@@ -0,0 +1,96 @@
+/*
+ *  Copyright (C) 2012 John Crispin <blogic@openwrt.org>
+ *  Copyright (C) 2015 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
+ *
+ *  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 EVA_NR_PARTS		2
+#define EVA_MAGIC		0xfeed1281
+#define EVA_FOOTER_SIZE		0x18
+#define EVA_DUMMY_SQUASHFS_SIZE	0x100
+
+struct eva_image_header {
+	uint32_t	magic;
+	uint32_t	size;
+};
+
+static int mtdsplit_parse_eva(struct mtd_info *master,
+				struct mtd_partition **pparts,
+				struct mtd_part_parser_data *data)
+{
+	struct mtd_partition *parts;
+	struct eva_image_header hdr;
+	size_t retlen;
+	unsigned long kernel_size, rootfs_offset;
+	int err;
+
+	err = mtd_read(master, 0, sizeof(hdr), &retlen, (void *) &hdr);
+	if (err)
+		return err;
+
+	if (retlen != sizeof(hdr))
+		return -EIO;
+
+	if (le32_to_cpu(hdr.magic) != EVA_MAGIC)
+		return -EINVAL;
+
+	kernel_size = le32_to_cpu(hdr.size) + EVA_FOOTER_SIZE;
+
+	/* rootfs starts at the next 0x10000 boundary: */
+	rootfs_offset = round_up(kernel_size, 0x10000);
+
+	/* skip the dummy EVA squashfs partition (with wrong endianness): */
+	rootfs_offset += EVA_DUMMY_SQUASHFS_SIZE;
+
+	if (rootfs_offset >= master->size)
+		return -EINVAL;
+
+	err = mtd_check_rootfs_magic(master, rootfs_offset);
+	if (err)
+		return err;
+
+	parts = kzalloc(EVA_NR_PARTS * sizeof(*parts), GFP_KERNEL);
+	if (!parts)
+		return -ENOMEM;
+
+	parts[0].name = KERNEL_PART_NAME;
+	parts[0].offset = 0;
+	parts[0].size = kernel_size;
+
+	parts[1].name = ROOTFS_PART_NAME;
+	parts[1].offset = rootfs_offset;
+	parts[1].size = master->size - rootfs_offset;
+
+	*pparts = parts;
+	return EVA_NR_PARTS;
+}
+
+static struct mtd_part_parser mtdsplit_eva_parser = {
+	.owner = THIS_MODULE,
+	.name = "eva-fw",
+	.parse_fn = mtdsplit_parse_eva,
+	.type = MTD_PARSER_TYPE_FIRMWARE,
+};
+
+static int __init mtdsplit_eva_init(void)
+{
+	register_mtd_parser(&mtdsplit_eva_parser);
+
+	return 0;
+}
+
+subsys_initcall(mtdsplit_eva_init);