fdt: add "fdt checksign" command

check if a fdt is correct signed
pass an optional addr value. Contains the addr of the key blob

Signed-off-by: Heiko Schocher <hs@denx.de>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/common/cmd_fdt.c b/common/cmd_fdt.c
index 3a9edd6..a6744ed 100644
--- a/common/cmd_fdt.c
+++ b/common/cmd_fdt.c
@@ -570,7 +570,7 @@
 		ft_board_setup(working_fdt, gd->bd);
 #endif
 	/* Create a chosen node */
-	else if (argv[1][0] == 'c') {
+	else if (strncmp(argv[1], "cho", 3) == 0) {
 		unsigned long initrd_start = 0, initrd_end = 0;
 
 		if ((argc != 2) && (argc != 4))
@@ -583,6 +583,41 @@
 
 		fdt_chosen(working_fdt, 1);
 		fdt_initrd(working_fdt, initrd_start, initrd_end, 1);
+
+#if defined(CONFIG_FIT_SIGNATURE)
+	} else if (strncmp(argv[1], "che", 3) == 0) {
+		int cfg_noffset;
+		int ret;
+		unsigned long addr;
+		struct fdt_header *blob;
+
+		if (!working_fdt)
+			return CMD_RET_FAILURE;
+
+		if (argc > 2) {
+			addr = simple_strtoul(argv[2], NULL, 16);
+			blob = map_sysmem(addr, 0);
+		} else {
+			blob = (struct fdt_header *)gd->fdt_blob;
+		}
+		if (!fdt_valid(&blob))
+			return 1;
+
+		gd->fdt_blob = blob;
+		cfg_noffset = fit_conf_get_node(working_fdt, NULL);
+		if (!cfg_noffset) {
+			printf("Could not find configuration node: %s\n",
+			       fdt_strerror(cfg_noffset));
+			return CMD_RET_FAILURE;
+		}
+
+		ret = fit_config_verify(working_fdt, cfg_noffset);
+		if (ret == 1)
+			return CMD_RET_SUCCESS;
+		else
+			return CMD_RET_FAILURE;
+#endif
+
 	}
 	/* resize the fdt */
 	else if (strncmp(argv[1], "re", 2) == 0) {
@@ -992,6 +1027,11 @@
 	"fdt rsvmem delete <index>           - Delete a mem reserves\n"
 	"fdt chosen [<start> <end>]          - Add/update the /chosen branch in the tree\n"
 	"                                        <start>/<end> - initrd start/end addr\n"
+#if defined(CONFIG_FIT_SIGNATURE)
+	"fdt checksign [<addr>]              - check FIT signature\n"
+	"                                        <start> - addr of key blob\n"
+	"                                                  default gd->fdt_blob\n"
+#endif
 	"NOTE: Dereference aliases by omiting the leading '/', "
 		"e.g. fdt print ethernet0.";
 #endif