how many libfdts are there?

u-boot-tree/lib/libfdt/Makefile

+# SPDX-License-Identifier: GPL-2.0+
+#
+# (C) Copyright 2000-2007
+# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+
+# Use upstream code.
+obj-y += \
+	fdt.o \
+	fdt_wip.o \
+	fdt_strerror.o \
+	fdt_sw.o \
+	fdt_rw.o \
+	fdt_empty_tree.o \
+	fdt_addresses.o
+
+obj-$(CONFIG_OF_LIBFDT_OVERLAY) += fdt_overlay.o
+
+# Locally modified for U-Boot.
+# TODO: split out the local modifiction.
+obj-y += fdt_ro.o
+
+# U-Boot own file
+obj-y += fdt_region.o
+
+ccflags-y := -I$(srctree)/scripts/dtc/libfdt

u-boot-tree/lib/libfdt/README

+The libfdt functionality was written by David Gibson.  The original
+source came from the Git repository:
+
+URL:		git://ozlabs.org/home/dgibson/git/libfdt.git
+
+author		David Gibson <dgibson@sneetch.(none)>
+		Fri, 23 Mar 2007 04:16:54 +0000 (15:16 +1100)
+committer	David Gibson <dgibson@sneetch.(none)>
+		Fri, 23 Mar 2007 04:16:54 +0000 (15:16 +1100)
+commit		857f54e79f74429af20c2b5ecc00ee98af6a3b8b
+tree		2f648f0f88225a51ded452968d28b4402df8ade0
+parent		07a12a08005f3b5cd9337900a6551e450c07b515
+
+To adapt for U-Boot usage, only the applicable files were copied and
+imported into the U-Boot Git repository.
+
+Omitted:
+
+  * GPL - U-Boot comes with a copy of the GPL license
+  * test subdirectory - not directly useful for U-Boot
+
+After importing, other customizations were performed.  See the
+"git log" for details.
+
+Jerry Van Baren

u-boot-tree/lib/libfdt/fdt.c

+#include <linux/libfdt_env.h>
+#include "../../scripts/dtc/libfdt/fdt.c"

u-boot-tree/lib/libfdt/fdt_addresses.c

+#include <linux/libfdt_env.h>
+#include "../../scripts/dtc/libfdt/fdt_addresses.c"

u-boot-tree/lib/libfdt/fdt_empty_tree.c

+#include <linux/libfdt_env.h>
+#include "../../scripts/dtc/libfdt/fdt_empty_tree.c"

u-boot-tree/lib/libfdt/fdt_overlay.c

+#include <linux/libfdt_env.h>
+#include "../../scripts/dtc/libfdt/fdt_overlay.c"

u-boot-tree/lib/libfdt/fdt_rw.c

+#include <linux/libfdt_env.h>
+#include "../../scripts/dtc/libfdt/fdt_rw.c"

u-boot-tree/lib/libfdt/fdt_strerror.c

+#include <linux/libfdt_env.h>
+#include "../../scripts/dtc/libfdt/fdt_strerror.c"

u-boot-tree/lib/libfdt/fdt_sw.c

+#include <linux/libfdt_env.h>
+#include "../../scripts/dtc/libfdt/fdt_sw.c"

u-boot-tree/lib/libfdt/fdt_wip.c

+#include <linux/libfdt_env.h>
+#include "../../scripts/dtc/libfdt/fdt_wip.c"

u-boot-tree/lib/libfdt/libfdt_internal.h

+#include "../../scripts/dtc/libfdt/libfdt_internal.h"

u-boot-tree/lib/libfdt/test_libfdt.py

+#!/usr/bin/python
+
+import os
+import sys
+
+our_path = os.path.dirname(os.path.realpath(__file__))
+sys.path.append(os.path.join(our_path, '../../b/sandbox_spl/tools'))
+
+import libfdt
+
+with open('b/sandbox_spl/u-boot.dtb') as fd:
+    fdt = fd.read()
+
+print libfdt.fdt_path_offset(fdt, "/aliases")