Merge git://git.denx.de/u-boot-fdt

common/fdt_support.c

@@ -194,6 +194,31 @@ static inline int fdt_setprop_uxx(void *fdt, int nodeoffset, const char *name,
 		return fdt_setprop_u32(fdt, nodeoffset, name, (uint32_t)val);
 }
 
+int fdt_root(void *fdt)
+{
+	char *serial;
+	int err;
+
+	err = fdt_check_header(fdt);
+	if (err < 0) {
+		printf("fdt_root: %s\n", fdt_strerror(err));
+		return err;
+	}
+
+	serial = getenv("serial#");
+	if (serial) {
+		err = fdt_setprop(fdt, 0, "serial-number", serial,
+				  strlen(serial) + 1);
+
+		if (err < 0) {
+			printf("WARNING: could not set serial-number %s.\n",
+			       fdt_strerror(err));
+			return err;
+		}
+	}
+
+	return 0;
+}
 
 int fdt_initrd(void *fdt, ulong initrd_start, ulong initrd_end)
 {

common/image-fdt.c

@@ -471,6 +471,10 @@ int image_setup_libfdt(bootm_headers_t *images, void *blob,
 	int ret = -EPERM;
 	int fdt_ret;
 
+	if (fdt_root(blob) < 0) {
+		printf("ERROR: root node setup failed\n");
+		goto err;
+	}
 	if (fdt_chosen(blob) < 0) {
 		printf("ERROR: /chosen node create failed\n");
 		goto err;

doc/device-tree-bindings/root.txt

@@ -0,0 +1,4 @@
+The root node
+
+Optional properties:
+  - serial-number : a string representing the device's serial number

include/fdt_support.h

@@ -16,8 +16,35 @@ u32 fdt_getprop_u32_default_node(const void *fdt, int off, int cell,
 				const char *prop, const u32 dflt);
 u32 fdt_getprop_u32_default(const void *fdt, const char *path,
 				const char *prop, const u32 dflt);
+
+/**
+ * Add data to the root of the FDT before booting the OS.
+ *
+ * See doc/device-tree-bindings/root.txt
+ *
+ * @param fdt		FDT address in memory
+ * @return 0 if ok, or -FDT_ERR_... on error
+ */
+int fdt_root(void *fdt);
+
+/**
+ * Add chosen data the FDT before booting the OS.
+ *
+ * In particular, this adds the kernel command line (bootargs) to the FDT.
+ *
+ * @param fdt		FDT address in memory
+ * @return 0 if ok, or -FDT_ERR_... on error
+ */
 int fdt_chosen(void *fdt);
+
+/**
+ * Add initrd information to the FDT before booting the OS.
+ *
+ * @param fdt		FDT address in memory
+ * @return 0 if ok, or -FDT_ERR_... on error
+ */
 int fdt_initrd(void *fdt, ulong initrd_start, ulong initrd_end);
+
 void do_fixup_by_path(void *fdt, const char *path, const char *prop,
 		      const void *val, int len, int create);
 void do_fixup_by_path_u32(void *fdt, const char *path, const char *prop,