libfdt: Add support for appending the values to a existing property

Some properties may contain multiple values, these values may need
to be added to the property respectively. this patch provides this
functionality. The main purpose of fdt_append_prop() is to append
the values to a existing property, or create a new property if it
dose not exist.

Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
diff --git a/tests/appendprop1.c b/tests/appendprop1.c
new file mode 100644
index 0000000..180d296
--- /dev/null
+++ b/tests/appendprop1.c
@@ -0,0 +1,70 @@
+/*
+ * libfdt - Flat Device Tree manipulation
+ *	Testcase for fdt_appendprop()
+ * Copyright (C) 2006 David Gibson, IBM Corporation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <stdint.h>
+
+#include <fdt.h>
+#include <libfdt.h>
+
+#include "tests.h"
+#include "testdata.h"
+
+#define SPACE		65536
+
+#define CHECK(code) \
+	{ \
+		err = (code); \
+		if (err) \
+			FAIL(#code ": %s", fdt_strerror(err)); \
+	}
+
+int main(int argc, char *argv[])
+{
+	void *fdt;
+	int err;
+	uint8_t bytes[] = {0x00, 0x01, 0x02, 0x03, 0x04};
+
+	test_init(argc, argv);
+
+	/* Create an empty tree first */
+	fdt = xmalloc(SPACE);
+	CHECK(fdt_create(fdt, SPACE));
+	CHECK(fdt_finish_reservemap(fdt));
+	CHECK(fdt_begin_node(fdt, ""));
+	CHECK(fdt_end_node(fdt));
+	CHECK(fdt_finish(fdt));
+
+	/* Now use appendprop to add properties */
+	CHECK(fdt_open_into(fdt, fdt, SPACE));
+
+	CHECK(fdt_appendprop(fdt, 0, "prop-bytes", bytes, sizeof(bytes)));
+	CHECK(fdt_appendprop_cell(fdt, 0, "prop-int", TEST_VALUE_1));
+	CHECK(fdt_appendprop_string(fdt, 0, "prop-str", TEST_STRING_1));
+
+	CHECK(fdt_pack(fdt));
+
+	save_blob("appendprop1.test.dtb", fdt);
+
+	PASS();
+}