-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);
-int fdt_chosen(void *fdt, int force);
-int fdt_initrd(void *fdt, ulong initrd_start, ulong initrd_end, int force);
+uint32_t fdt_getprop_u32_default_node(const void *fdt, int off, int cell,
+ const char *prop, const uint32_t dflt);
+uint32_t fdt_getprop_u32_default(const void *fdt, const char *path,
+ const char *prop, const uint32_t 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);
+