kernel: mtdsplit_uimage: add support for okli image

This adds support for uImage used by OpenWrt kernel loader.
The parser searches for uImage header at flash eraseblock boundary
and it might attempt to split any firmware with loader, therefore
this entry doesn't have MTD_PARSER_TYPE_FIRMWARE so that this parser
is only used when explicitly defined in dts.

Signed-off-by: Chuanhong Guo <[email protected]>

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

@@ -423,6 +423,63 @@ static struct mtd_part_parser uimage_fonfxc_parser = {
 	.parse_fn = mtdsplit_uimage_parse_fonfxc,
 };
 
+/**************************************************
+ * OKLI (OpenWrt Kernel Loader Image)
+ **************************************************/
+
+#define IH_MAGIC_OKLI	0x4f4b4c49
+
+static ssize_t uimage_verify_okli(u_char *buf, size_t len, int *extralen)
+{
+	struct uimage_header *header = (struct uimage_header *)buf;
+
+	/* default sanity checks */
+	if (be32_to_cpu(header->ih_magic) != IH_MAGIC_OKLI) {
+		pr_debug("invalid uImage magic: %08x\n",
+			 be32_to_cpu(header->ih_magic));
+		return -EINVAL;
+	}
+
+	if (header->ih_os != IH_OS_LINUX) {
+		pr_debug("invalid uImage OS: %08x\n",
+			 be32_to_cpu(header->ih_os));
+		return -EINVAL;
+	}
+
+	if (header->ih_type != IH_TYPE_KERNEL) {
+		pr_debug("invalid uImage type: %08x\n",
+			 be32_to_cpu(header->ih_type));
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int
+mtdsplit_uimage_parse_okli(struct mtd_info *master,
+			      const struct mtd_partition **pparts,
+			      struct mtd_part_parser_data *data)
+{
+	return __mtdsplit_parse_uimage(master, pparts, data,
+				      uimage_verify_okli);
+}
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
+static const struct of_device_id mtdsplit_uimage_okli_of_match_table[] = {
+	{ .compatible = "openwrt,okli" },
+	{},
+};
+#endif
+
+static struct mtd_part_parser uimage_okli_parser = {
+	.owner = THIS_MODULE,
+	.name = "okli-fw",
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 9, 0)
+	.of_match_table = mtdsplit_uimage_okli_of_match_table,
+#endif
+	.parse_fn = mtdsplit_uimage_parse_okli,
+};
+
 /**************************************************
  * Init
  **************************************************/
@@ -433,6 +490,7 @@ static int __init mtdsplit_uimage_init(void)
 	register_mtd_parser(&uimage_netgear_parser);
 	register_mtd_parser(&uimage_edimax_parser);
 	register_mtd_parser(&uimage_fonfxc_parser);
+	register_mtd_parser(&uimage_okli_parser);
 
 	return 0;
 }