add command fitupd to run an update from a FIT image

Command calls update_tftp() analogous to automatic update described
in doc/README.update.

Usage:
fitupd [addr]
        - run update from FIT image at addr
          or from tftp 'updatefile'

Signed-off-by: Andreas Pretzsch <apr@cn-eng.de>

common/Makefile

@@ -92,6 +92,7 @@ COBJS-$(CONFIG_CMD_FAT) += cmd_fat.o
 COBJS-$(CONFIG_CMD_FDC)$(CONFIG_CMD_FDOS) += cmd_fdc.o
 COBJS-$(CONFIG_OF_LIBFDT) += cmd_fdt.o fdt_support.o
 COBJS-$(CONFIG_CMD_FDOS) += cmd_fdos.o
+COBJS-$(CONFIG_CMD_FITUPD) += cmd_fitupd.o
 COBJS-$(CONFIG_CMD_FLASH) += cmd_flash.o
 ifdef CONFIG_FPGA
 COBJS-$(CONFIG_CMD_FPGA) += cmd_fpga.o

common/cmd_fitupd.c

@@ -0,0 +1,36 @@
+/*
+ * (C) Copyright 2011
+ * Andreas Pretzsch, carpe noctem engineering, apr@cn-eng.de
+ *
+ * This file is released under the terms of GPL v2 and any later version.
+ * See the file COPYING in the root directory of the source tree for details.
+ */
+
+#include <common.h>
+#include <command.h>
+
+#if !defined(CONFIG_UPDATE_TFTP)
+#error "CONFIG_UPDATE_TFTP required"
+#endif
+
+extern int update_tftp(ulong addr);
+
+static int do_fitupd(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	ulong addr = 0UL;
+
+	if (argc > 2)
+		return cmd_usage(cmdtp);
+
+	if (argc == 2)
+		addr = simple_strtoul(argv[1], NULL, 16);
+
+	return update_tftp(addr);
+}
+
+U_BOOT_CMD(fitupd, 2, 0, do_fitupd,
+	"update from FIT image",
+	"[addr]\n"
+	"\t- run update from FIT image at addr\n"
+	"\t  or from tftp 'updatefile'"
+);

doc/README.update

@@ -51,6 +51,11 @@ the mkimage tool. dtc tool with support for binary includes, e.g. in version
 to be prepared. Refer to the doc/uImage.FIT/ directory for more details on FIT
 images.
 
+This mechanism can be also triggered by the commmand "fitupd".
+If an optional, non-zero address is provided as argument, the TFTP transfer
+is skipped and the image at this address is used.
+The fitupd command is enabled by CONFIG_CMD_FITUPD.
+
 
 Example .its files
 ------------------