libfdt: migrate fdt_rw.c to a wrapper of scripts/dtc/libfdt/fdt_rw.c

The only difference between scripts/dtc/libfdt/fdt_rw.c and
lib/libfdt/fdt_rw.c is fdt_remove_unused_strings().

It is only used by fdtgrep, so we do not need to compile it for U-Boot
image.  Move it to tools/libfdt/fdw_rw.c so that lib/libfdt/fdt_rw.c
can be a wrapper of scripts/dtc/libfdt/fdt_rw.c.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

1 files changed, 35 insertions, 0 deletions

diff --git a/tools/libfdt/fdt_rw.c b/tools/libfdt/fdt_rw.c
new file mode 100644
index 0000000000..e475084fae
--- /dev/null
+++ b/tools/libfdt/fdt_rw.c
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier:	GPL-2.0+ BSD-2-Clause */
+#include "fdt_host.h"
+#include "../../scripts/dtc/libfdt/fdt_rw.c"
+
+int fdt_remove_unused_strings(const void *old, void *new)
+{
+	const struct fdt_property *old_prop;
+	struct fdt_property *new_prop;
+	int size = fdt_totalsize(old);
+	int next_offset, offset;
+	const char *str;
+	int ret;
+	int tag = FDT_PROP;
+
+	/* Make a copy and remove the strings */
+	memcpy(new, old, size);
+	fdt_set_size_dt_strings(new, 0);
+
+	/* Add every property name back into the new string table */
+	for (offset = 0; tag != FDT_END; offset = next_offset) {
+		tag = fdt_next_tag(old, offset, &next_offset);
+		if (tag != FDT_PROP)
+			continue;
+		old_prop = fdt_get_property_by_offset(old, offset, NULL);
+		new_prop = (struct fdt_property *)(unsigned long)
+			fdt_get_property_by_offset(new, offset, NULL);
+		str = fdt_string(old, fdt32_to_cpu(old_prop->nameoff));
+		ret = _fdt_find_add_string(new, str);
+		if (ret < 0)
+			return ret;
+		new_prop->nameoff = cpu_to_fdt32(ret);
+	}
+
+	return 0;
+}