From ed39f7ec1abde0d447a2dde8a8dce8042a3c5b29 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= <bjorn@mork.no>
Date: Wed, 20 Jan 2021 18:36:47 +0100
Subject: [PATCH] kernel: mtdsplit_uimage: add "openwrt, ih-magic" device-tree
 property
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Many devices use uimages with non-standard magic values. Let
device tree override the default magic.

Signed-off-by: Bjørn Mork <bjorn@mork.no>
---
 .../drivers/mtd/mtdsplit/mtdsplit_uimage.c    | 41 +++++++++++--------
 1 file changed, 23 insertions(+), 18 deletions(-)

diff --git a/target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_uimage.c b/target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_uimage.c
index f5e48c661e8..58c40e9ec70 100644
--- a/target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_uimage.c
+++ b/target/linux/generic/files/drivers/mtd/mtdsplit/mtdsplit_uimage.c
@@ -69,13 +69,17 @@ read_uimage_header(struct mtd_info *mtd, size_t offset, u_char *buf,
 	return 0;
 }
 
-static void uimage_parse_dt(struct mtd_info *master, int *extralen)
+static void uimage_parse_dt(struct mtd_info *master, int *extralen, u32 *ih_magic)
 {
 	struct device_node *np = mtd_get_of_node(master);
 
 	if (!np || !of_device_is_compatible(np, "openwrt,uimage"))
 		return;
-	of_property_read_u32(np, "openwrt,padding", extralen);
+
+	if (!of_property_read_u32(np, "openwrt,padding", extralen))
+		pr_debug("got openwrt,padding=%d from device-tree\n", *extralen);
+	if (!of_property_read_u32(np, "openwrt,ih-magic", ih_magic))
+		pr_debug("got openwrt,ih-magic=%08x from device-tree\n", *ih_magic);
 }
 
 /**
@@ -87,7 +91,7 @@ static void uimage_parse_dt(struct mtd_info *master, int *extralen)
 static int __mtdsplit_parse_uimage(struct mtd_info *master,
 		   const struct mtd_partition **pparts,
 		   struct mtd_part_parser_data *data,
-		   ssize_t (*find_header)(u_char *buf, size_t len))
+		   ssize_t (*find_header)(u_char *buf, size_t len, u32 ih_magic))
 {
 	struct mtd_partition *parts;
 	u_char *buf;
@@ -100,6 +104,7 @@ static int __mtdsplit_parse_uimage(struct mtd_info *master,
 	int uimage_part, rf_part;
 	int ret;
 	int extralen = 0;
+	u32 ih_magic = IH_MAGIC;
 	enum mtdsplit_part_type type;
 
 	nr_parts = 2;
@@ -113,7 +118,7 @@ static int __mtdsplit_parse_uimage(struct mtd_info *master,
 		goto err_free_parts;
 	}
 
-	uimage_parse_dt(master, &extralen);
+	uimage_parse_dt(master, &extralen, &ih_magic);
 
 	/* find uImage on erase block boundaries */
 	for (offset = 0; offset < master->size; offset += master->erasesize) {
@@ -125,7 +130,7 @@ static int __mtdsplit_parse_uimage(struct mtd_info *master,
 		if (ret)
 			continue;
 
-		ret = find_header(buf, MAX_HEADER_LEN);
+		ret = find_header(buf, MAX_HEADER_LEN, ih_magic);
 		if (ret < 0) {
 			pr_debug("no valid uImage found in \"%s\" at offset %llx\n",
 				 master->name, (unsigned long long) offset);
@@ -213,26 +218,26 @@ err_free_parts:
 	return ret;
 }
 
-static ssize_t uimage_verify_default(u_char *buf, size_t len)
+static ssize_t uimage_verify_default(u_char *buf, size_t len, u32 ih_magic)
 {
 	struct uimage_header *header = (struct uimage_header *)buf;
 
 	/* default sanity checks */
-	if (be32_to_cpu(header->ih_magic) != IH_MAGIC) {
-		pr_debug("invalid uImage magic: %08x\n",
-			 be32_to_cpu(header->ih_magic));
+	if (be32_to_cpu(header->ih_magic) != ih_magic) {
+		pr_debug("invalid uImage magic: %08x != %08x\n",
+			 be32_to_cpu(header->ih_magic), ih_magic);
 		return -EINVAL;
 	}
 
 	if (header->ih_os != IH_OS_LINUX) {
-		pr_debug("invalid uImage OS: %08x\n",
-			 be32_to_cpu(header->ih_os));
+		pr_debug("invalid uImage OS: %08x != %08x\n",
+			 be32_to_cpu(header->ih_os), IH_OS_LINUX);
 		return -EINVAL;
 	}
 
 	if (header->ih_type != IH_TYPE_KERNEL) {
-		pr_debug("invalid uImage type: %08x\n",
-			 be32_to_cpu(header->ih_type));
+		pr_debug("invalid uImage type: %08x != %08x\n",
+			 be32_to_cpu(header->ih_type), IH_TYPE_KERNEL);
 		return -EINVAL;
 	}
 
@@ -274,7 +279,7 @@ static struct mtd_part_parser uimage_generic_parser = {
 #define FW_MAGIC_WNDR3700V2	0x33373031
 #define FW_MAGIC_WPN824N	0x31313030
 
-static ssize_t uimage_verify_wndr3700(u_char *buf, size_t len)
+static ssize_t uimage_verify_wndr3700(u_char *buf, size_t len, u32 ih_magic)
 {
 	struct uimage_header *header = (struct uimage_header *)buf;
 	uint8_t expected_type = IH_TYPE_FILESYSTEM;
@@ -336,7 +341,7 @@ static struct mtd_part_parser uimage_netgear_parser = {
 #define FW_MAGIC_SG8208M	0x00000006
 #define FW_MAGIC_SG8310PM	0x83000006
 
-static ssize_t uimage_verify_allnet(u_char *buf, size_t len)
+static ssize_t uimage_verify_allnet(u_char *buf, size_t len, u32 ih_magic)
 {
 	struct uimage_header *header = (struct uimage_header *)buf;
 
@@ -383,7 +388,7 @@ static struct mtd_part_parser uimage_allnet_parser = {
 #define FW_EDIMAX_OFFSET	20
 #define FW_MAGIC_EDIMAX		0x43535953
 
-static ssize_t uimage_find_edimax(u_char *buf, size_t len)
+static ssize_t uimage_find_edimax(u_char *buf, size_t len, u32 ih_magic)
 {
 	u32 *magic;
 
@@ -396,7 +401,7 @@ static ssize_t uimage_find_edimax(u_char *buf, size_t len)
 	if (be32_to_cpu(*magic) != FW_MAGIC_EDIMAX)
 		return -EINVAL;
 
-	if (!uimage_verify_default(buf + FW_EDIMAX_OFFSET, len))
+	if (!uimage_verify_default(buf + FW_EDIMAX_OFFSET, len, ih_magic))
 		return FW_EDIMAX_OFFSET;
 
 	return -EINVAL;
@@ -430,7 +435,7 @@ static struct mtd_part_parser uimage_edimax_parser = {
 
 #define IH_MAGIC_OKLI	0x4f4b4c49
 
-static ssize_t uimage_verify_okli(u_char *buf, size_t len)
+static ssize_t uimage_verify_okli(u_char *buf, size_t len, u32 ih_magic)
 {
 	struct uimage_header *header = (struct uimage_header *)buf;