diff --git a/depend-trace-tool/README.rst b/depend-trace-tool/README.rst
new file mode 100644
index 0000000..3c332ad
--- /dev/null
+++ b/depend-trace-tool/README.rst
@@ -0,0 +1,230 @@
+#############################
+Library dependency trace tool
+#############################
+
+.. contents:: Table of Contents
+
+This is a script to search a specific library's dependencies, including linked
+libraries, source files, include paths and some other information about it.
+
+****************
+Install graphviz
+****************
+
+Linux
+=====
+Install graphviz to generate diagram of dependencies.
+
+.. code-block:: bash
+
+    sudo apt install graphviz # via Ubuntu package management
+    pip install graphviz # via Python package installer
+
+Windows
+=======
+
+In windows, graphviz is also needed and moreover, it is required to install the
+software with same name. It can be downloaded from
+`graphviz <https://graphviz.org/download/>`__. Note that it shall be added
+into system path of Windows.
+
+*****
+Usage
+*****
+
+The command is:
+
+.. code-block:: bash
+
+    python3 lib_trace.py -l <library_name>
+                         -p <repo_path_1,repo_path_2,...>
+                         -d <max depth>
+                         -i # only draw input dependent libraries
+                         -o # only draw output dependent libraries
+                         -h # help
+
+It is required to input library name and repo paths, and at least one of ``-o``
+or ``-i``. The default max depth of graph is 1. The output files are
+``<library>.png``, ``<library>.log`` and ``<library>.txt``. The
+``<library>.png`` shows the relationship of the specific library. The
+``<library>.log`` gives the information of the library with JSON format. The
+``<library>.txt`` gives plain text format of the information.
+
+Dependency trace output diagram
+===============================
+
+.. code-block:: bash
+
+    python3 lib_trace.py -p '<tf-m-path>,<tf-m-tests-path>' \
+    -l secure_fw -d 2 -i
+
+.. figure:: secure_fw.png
+   :scale: 50 %
+   :align: center
+
+   Library secure_fw's dependent libraries
+
+From the piture we can see the input dependent libraries of ``secure_fw``. The
+edges in the diagram show like:
+
+.. code-block:: bash
+
+     ------          condition           ------
+    |source|  ---------------------->   |target|
+     ------                              ------
+
+In CMAKE, it means:
+
+.. code-block:: CMAKE
+
+    target_link_libraries(target
+        PUBLIC|PRIVATE|INTERFACE
+            <condition> : source
+    )
+
+Different CMAKE link key word shows different edge color:
+
++----------------------+-------------+
+| CMAKE link key words | Edge Colors |
++======================+=============+
+| PUBLIC               | Green       |
++----------------------+-------------+
+| PRIVATE              | Red         |
++----------------------+-------------+
+| INTERFACE            | Blue        |
++----------------------+-------------+
+
+Different node of library or target has different color:
+
++-----------------------+-------------+
+| Node meaning          | Node Colors |
++=======================+=============+
+| Static library        | Green       |
++-----------------------+-------------+
+| Interface library     | Light blue  |
++-----------------------+-------------+
+| Unkown from workspace | Pink        |
++-----------------------+-------------+
+
+.. Note::
+    The pink node is an exception, it can be a static, interface library. It can
+    be an executable target in CMAKE as well. This tool cannot locate where it
+    is created if the workspace isn't added into the list of imput paths.
+
+Another diagram of ``tfm_sprt`` shows:
+
+.. code-block:: bash
+
+    python3 lib_trace.py -p '<tf-m-path>,<tf-m-tests-path>' \
+    -l tfm_sprt -d 1 -i -o
+
+.. figure:: tfm_sprt.png
+   :scale: 50 %
+   :align: center
+
+   Library tfm_sprt's dependency trace
+
+This picture shows the specific library's input and output dependencies.
+
+Dependency trace output log
+===========================
+
+The log shows in two ways, a plain text or JSON file. The plain text is more
+readable. The text behind ``<----`` is the condition if the source has.
+
+.. code-block:: bash
+
+    library name: library name
+
+    source libraries:
+        INTERFACE
+            tfm_partitions
+            tfm_spm
+
+    destination libraries:
+        PRIVATE
+            tfm_app_rot_partition_ps
+            tfm_psa_rot_partition_attestation
+            tfm_psa_rot_partition_psa_proxy
+            tfm_s
+
+    include directories:
+        INTERFACE
+            /home/sjl/work/tf-m/secure_fw/include	<----	BUILD_INTERFACE
+            /home/sjl/work/tf-m/secure_fw/partitions	<----	BUILD_INTERFACE
+
+    source files:
+
+    compiler definitions:
+
+The JSON file is supplied for users to get formatted input.
+
+.. code-block:: json
+
+    {
+        "library name": "secure_fw",
+        "source library": {
+            "PUBLIC": [],
+            "PRIVATE": [],
+            "INTERFACE": [
+                {
+                    "name": "tfm_partitions",
+                    "condition": ""
+                },
+                {
+                    "name": "tfm_spm",
+                    "condition": ""
+                }
+            ]
+        },
+        "dst library": {
+            "PUBLIC": [],
+            "PRIVATE": [
+                {
+                    "name": "tfm_app_rot_partition_ps",
+                    "condition": ""
+                },
+                {
+                    "name": "tfm_psa_rot_partition_attestation",
+                    "condition": ""
+                },
+                {
+                    "name": "tfm_psa_rot_partition_psa_proxy",
+                    "condition": ""
+                },
+                {
+                    "name": "tfm_s",
+                    "condition": ""
+                }
+            ],
+            "INTERFACE": []
+        },
+        "include": {
+            "PUBLIC": [],
+            "PRIVATE": [],
+            "INTERFACE": [
+                {
+                    "name": "/home/sjl/work/tf-m/secure_fw/include",
+                    "condition": "BUILD_INTERFACE"
+                },
+                {
+                    "name": "/home/sjl/work/tf-m/secure_fw/partitions",
+                    "condition": "BUILD_INTERFACE"
+                }
+            ]
+        },
+        "source": {
+            "PUBLIC": [],
+            "PRIVATE": [],
+            "INTERFACE": []
+        },
+        "compile definition": {
+            "PUBLIC": [],
+            "PRIVATE": [],
+            "INTERFACE": []
+        }
+    }
+
+--------------
+
+*Copyright (c) 2021, Arm Limited. All rights reserved.*
diff --git a/depend-trace-tool/lib_trace.py b/depend-trace-tool/lib_trace.py
new file mode 100644
index 0000000..bdbf785
--- /dev/null
+++ b/depend-trace-tool/lib_trace.py
@@ -0,0 +1,473 @@
+# -----------------------------------------------------------------------------
+# Copyright (c) 2021, Arm Limited. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+# -----------------------------------------------------------------------------
+
+import os
+import glob
+import sys
+import getopt
+import json
+from graphviz import Digraph
+
+# Const variables
+Public, Interface, Private = 0, 1, 2
+Static_lib, Interface_lib, Unknown_lib = 'lightgreen', 'lightblue2', 'pink'
+input_flag, output_flag = 0, 1
+library_flag, include_flag, source_flag, compile_definition_flag = 0, 1, 2, 3
+help_msg = 'This is a tool to draw a library\'s link relationship.\
+The usage is:\n\
+python3 lib_trace.py -l <library_name>\n\
+                     -p <repo_path_1,repo_path_2,...>\n\
+                     -d <max depth>\n\
+                     -i # draw src libraries\n\
+                     -o # draw dst libraries\n\
+                     -h # help message'
+edge_color = {
+    'PUBLIC': 'green',
+    'PRIVATE': 'red',
+    'INTERFACE': 'blue',
+    '': 'black'
+}
+gz_library = Digraph(
+    name="CMake Library Relationship",
+    comment='comment',
+    filename=None,
+    directory=None,
+    format='png',
+    engine=None,
+    encoding="UTF-8",
+    graph_attr={'rankdir': 'LR'},
+    node_attr={
+        'color': 'lightblue2',
+            'fontcolor': 'black',
+            'fontname': 'TimesNewRoman',
+            'fontsize': '24',
+            'shape': 'Mrecord',
+            'style': 'filled',
+    },
+    edge_attr={
+        'color': '#999999',
+        'fontcolor': 'black',
+        'fontsize': '16',
+        'fontname': 'TimesNewRoman'
+    },
+    body=None,
+    strict=True
+)
+
+def find_file_in_path(path, name_list):
+    """
+    Search file in a list of 'path' which name is in 'name_list' and the content
+    in the file includes certain cmake function key words.
+    """
+    file_list, content = [], ''
+    path_list = path.split(',')
+    for sub_path in path_list:
+        for name in name_list:
+            for root, dirs, files in os.walk(sub_path):
+                pattern = os.path.join(root, name)
+                for sub_file in glob.glob(pattern):
+                    content = open(sub_file,
+                                   encoding="utf8",
+                                   errors='ignore').read()
+                    if 'add_library' in content \
+                            or 'target_link_libraries' in content \
+                            or 'target_include_directories' in content \
+                            or 'target_sources' in content\
+                            or 'target_compile_definitions' in content:
+                        file_list.append(sub_file)
+    return file_list
+
+def get_library_name_and_property(file_list):
+    """
+    Get library name and property, including static, interface and unknown.
+    """
+    ret = {}
+    for sub_file in file_list:
+        file_content = open(sub_file).read()
+        position_start = 0
+        while position_start >= 0:
+            position_start = file_content.find(
+                'add_library', position_start + len('add_library'))
+            if position_start > 0:
+                position_end = file_content.find(')', position_start) + 1
+                add_library = file_content[position_start:position_end]
+                lib_name = add_library[add_library.find(
+                    '(')+1: add_library.find(' ')]
+                if add_library.find('STATIC') > 0:
+                    ret[lib_name] = Static_lib
+                elif add_library.find('INTERFACE') > 0:
+                    ret[lib_name] = Interface_lib
+                else:
+                    ret[lib_name] = Unknown_lib
+    return ret
+
+def check_input_library():
+    """
+    Check the input library whether exists.
+    """
+    flag = False
+    for s in all_libs.keys():
+        if s == library:
+            flag = True
+    if not flag:
+        print("Error: library %s doesn't exist!"% library)
+        exit(2)
+
+def get_relationship(key_word, relationship_flag):
+    """
+    Get relationship in cmake files between target and source.
+
+    The target is usaually a library name and it will be added into the key_word
+    to search suitable dependencies, including source_libraries, include paths,
+    source files and compiler definitions. These different classes are
+    determined by relationship_flag.
+
+    It will return a list of [source, target, cmake_key_word, condition]
+    """
+    def rename_file(initial_file, current_path, relationship_flag):
+        """
+        Format the source name into ablsolute path if it is a include path or
+        source file.
+        TODO: Add more checks about CMAKE variables
+        """
+        ret = ""
+        if relationship_flag == library_flag or \
+                relationship_flag == compile_definition_flag:
+            ret = initial_file
+        elif relationship_flag == include_flag:
+            if 'CMAKE_CURRENT_SOURCE_DIR' in initial_file:
+                ret = current_path[:-len('CMakeLists.txt')] + \
+                    initial_file[len('$\{CMAKE_CURRENT_SOURCE_DIR\}') - 1:]
+            elif '$' in initial_file:
+                ret = initial_file
+            else:
+                if len(initial_file) == 1 and initial_file[0] == '.':
+                    ret = current_path[:-
+                                       len('CMakeLists.txt')] + initial_file[1:]
+                else:
+                    ret = current_path[:- len('CMakeLists.txt')] + initial_file
+        elif relationship_flag == source_flag:
+            if 'CMAKE_CURRENT_SOURCE_DIR' in initial_file:
+                ret = current_path[:-len('CMakeLists.txt')] + \
+                    initial_file[len('$\{CMAKE_CURRENT_SOURCE_DIR\}') - 1:]
+            elif '$' in initial_file:
+                ret = initial_file
+            else:
+                ret = current_path[:- len('CMakeLists.txt')] + initial_file
+        return ret
+
+    def delete_comment(input):
+        """
+        Sometimes there are comments in cmake key content which will affect the
+        source deal.
+        """
+        left_idx = 0
+        right_idx = 0
+        while left_idx >= 0:
+            left_idx = input.find('#', left_idx + 1)
+            right_idx = input.find('\n', left_idx)
+            input = input.replace(input[left_idx:right_idx], "")
+        return input
+
+    ret, cmake_key_word = [], ""
+    for sub_file in file_list:
+        left_idx = 0
+        file_content = open(sub_file,
+                            encoding="utf8",
+                            errors='ignore').read()
+        while left_idx >= 0:
+            left_idx = file_content.find(key_word, left_idx + len(key_word))
+            if left_idx > 0:
+                right_idx = file_content.find(')', left_idx) + 1
+
+                # Get the key content without any cmake comment
+                key_content = delete_comment(file_content[left_idx:right_idx])
+
+                # Get source list
+                src_list = key_content.split()
+
+                # Get the target library name
+                target = src_list[0][key_content.find('(') + 1:]
+
+                for src in src_list[1:-1]:
+                    if src in ['PUBLIC', 'INTERFACE', 'PRIVATE']:
+                        cmake_key_word = src
+                        continue
+                    else:
+                        condition = ""
+                        if src.find(':') > 0:
+
+                            # Get link condition
+                            condition = src[2:-(len(src.split(':')[-1]) + 1)]
+                            src = src.split(':')[-1][:-1]
+
+                        ret.append([rename_file(src,
+                                                sub_file,
+                                                relationship_flag),
+                                    target,
+                                    cmake_key_word,
+                                    condition])
+    return ret
+
+def append_lib():
+    """
+    Append more libraries into all_libs from link_library
+    """
+    tmp = []
+    for s in all_libs:
+        tmp.append(s)
+
+    for s in link_library:
+        if s[0] not in tmp:
+            tmp.append(s[0])
+            all_libs[s[0]] = Unknown_lib
+        if s[1] not in tmp:
+            tmp.append(s[1])
+            all_libs[s[1]] = Unknown_lib
+
+def restruct_relationship(flag, target_library, input_relationship):
+    """
+    The input_relationship is a list of [source, target, cmake_key_word,
+    condition], and it shows like:
+                   condition
+    source   -----cmake_key_word--->     target
+
+    This function will traverse the input_relationship and restruct the
+    relationship into a dictionary.
+    """
+    ret = {'PUBLIC': [], 'PRIVATE': [], 'INTERFACE': []}
+    lib_public, lib_interface, lib_private = [], [], []
+    if flag == input_flag:
+        target_idx, source_idx = 1, 0
+    elif flag == output_flag:
+        """
+        An exception situation is when searching the target's destination
+        library which links the target. So the index will be reversed.
+        """
+        target_idx, source_idx = 0, 1
+
+    for lib in input_relationship:
+
+        # Avoid repeat
+        for s in ret['PUBLIC']:
+            lib_public.append(s['name'])
+        for s in ret['PRIVATE']:
+            lib_interface.append(s['name'])
+        for s in ret['INTERFACE']:
+            lib_private.append(s['name'])
+
+        if target_library == lib[target_idx]:
+            if lib[2] in ['PUBLIC', 'public', 'Public'] and \
+                    lib[source_idx] not in lib_public:
+                ret['PUBLIC'].append({'name': lib[source_idx],
+                                      'condition': lib[3]})
+            if lib[2] in ['INTERFACE', 'interface', 'Interface'] and \
+                    lib[source_idx] not in lib_interface:
+                ret['INTERFACE'].append({'name': lib[source_idx],
+                                         'condition': lib[3]})
+            if lib[2] in ['PRIVATE', 'private', 'Private'] and \
+                    lib[source_idx] not in lib_private:
+                ret['PRIVATE'].append({'name': lib[source_idx],
+                                       'condition': lib[3]})
+    for s in ret.keys():
+
+        # Sort the ret with key 'name'
+        ret[s] = sorted(ret[s], key=lambda i: i['name'])
+    return ret
+
+def draw_graph(flag, target_library, drawed_libs, drawed_edges, deep_size):
+    """
+    Draw the library graph.
+    Parameters:
+        flag:           To get whether source or destination libraries
+        target_library: The target library
+        drawed_libs:    A list of libraries which already be added as a node
+        drawed_edges:   A list of drawed edges in the graph
+        deep_size:      Current iteration count
+    """
+    if flag == input_flag:
+        libs = restruct_relationship(flag, target_library, link_library)
+    elif flag == output_flag:
+        libs = restruct_relationship(flag, target_library, link_library)
+    lib_count = 0
+
+    # Get source's count which is the condition of iteration.
+    for s in libs.keys():
+        lib_count += len(libs[s])
+    if lib_count != 0 and deep_size < max_dept:
+        for s in libs.keys():
+            for lib in libs[s]:
+
+                # Draw source node
+                if lib['name'] not in drawed_libs:
+                    deep_size += 1
+
+                    # Draw iteration
+                    draw_graph(flag, lib['name'], drawed_libs, drawed_edges,
+                               deep_size)
+                    deep_size -= 1
+                    gz_library.node(name=lib['name'],
+                                    color=all_libs[lib['name']])
+                    drawed_libs.append(lib['name'])
+
+                # Draw taget node
+                if target_library not in drawed_libs:
+                    gz_library.node(name=target_library,
+                                    color=all_libs[target_library])
+                    drawed_libs.append(target_library)
+
+                # Draw edage
+                if [lib['name'], target_library] not in drawed_edges:
+                    if flag == input_flag:
+                        gz_library.edge(lib['name'],
+                                        target_library,
+                                        color=edge_color[s],
+                                        label=lib['condition'])
+                        drawed_edges.append([lib['name'], target_library])
+                    elif flag == output_flag:
+                        gz_library.edge(target_library,
+                                        lib['name'],
+                                        color=edge_color[s],
+                                        label=lib['condition'])
+                        drawed_edges.append([target_library, lib['name']])
+
+def get_library_relationship():
+    """
+    Get a list of all library relationship.
+    """
+    key_word = 'target_link_libraries'
+    ret = get_relationship(key_word, library_flag)
+    return ret
+
+def get_library_include(target_library):
+    """
+    Get a dictionary of library include pathes.
+    """
+    key_word = 'target_include_directories' + '(' + target_library
+    ret = restruct_relationship(input_flag,
+                                   target_library,
+                                   get_relationship(key_word,
+                                                    include_flag))
+    return ret
+
+def get_library_source(target_library):
+    """
+    Get a dictionary of library source files.
+    """
+    key_word = 'target_sources' + '(' + library
+    ret = restruct_relationship(input_flag,
+                                   target_library,
+                                   get_relationship(key_word,
+                                                    source_flag))
+    return ret
+
+def get_library_compile_definitions(target_library):
+    """
+    Get a dictionary of library compile definitions.
+    """
+    key_word = 'target_compile_definitions' + '(' + library
+    ret = restruct_relationship(input_flag,
+                                   target_library,
+                                   get_relationship(key_word,
+                                                    compile_definition_flag))
+    return ret
+
+def main(argv):
+    opts = []
+    global all_libs, library, link_library, PATH, max_dept, file_list
+    src_flag, dst_flag = False, False
+    drawed_edges, drawed_libs = [], []
+
+    try:
+        opts, args = getopt.getopt(
+            argv, "hiol:p:d:", ["ilib=", "ppath=", "ddept="])
+    except getopt.GetoptError:
+        print(help_msg)
+        sys.exit(2)
+    if not opts:
+        print(help_msg)
+        sys.exit(2)
+
+    # Get input options
+    for opt, arg in opts:
+        if opt == '-h':
+            print(help_msg)
+            sys.exit()
+        elif opt in ("-l", "--ilib"):
+            library = arg
+        elif opt in ("-p", "--ppath"):
+            PATH = arg
+        elif opt in ("-d", "--ddept"):
+            max_dept = int(arg)
+        elif opt == '-o':
+            dst_flag = True
+        elif opt == '-i':
+            src_flag = True
+
+    # Get all library relationship and all libraries
+    file_list = find_file_in_path(PATH, ['*.txt', '*.cmake'])
+    all_libs = get_library_name_and_property(file_list)
+    link_library = get_library_relationship()
+    append_lib()
+
+    check_input_library()
+
+    src_lib = restruct_relationship(input_flag, library, link_library)
+    dst_lib = restruct_relationship(output_flag, library, link_library)
+    include = get_library_include(library)
+    source = get_library_source(library)
+    definitions = get_library_compile_definitions(library)
+
+    # Draw graph
+    if src_flag:
+        drawed_libs = []
+        draw_graph(input_flag, library, drawed_libs, drawed_edges, 0)
+    if dst_flag:
+        drawed_libs = []
+        draw_graph(output_flag, library, drawed_libs, drawed_edges, 0)
+
+    # Redraw the target library as a bigger node
+    gz_library.node(name=library,
+                    fontsize='36',
+                    penwidth='10',
+                    shape='oval')
+
+    # Save picture
+    gz_library.render(filename=library)
+
+    # Write into a file with JSON format
+    log = {'library name': library,
+           'source libraries': src_lib,
+           'destination libraries': dst_lib,
+           'include directories': include,
+           'source files': source,
+           'compiler definitions': definitions
+           }
+    fo = open(library + ".log", "w")
+    fo.write(json.dumps(log,
+             sort_keys=False, indent=4, separators=(',', ': ')))
+    fo.close()
+
+    fo = open(library + '.txt', "w")
+    for s in log.keys():
+        if s == 'library name':
+            fo.write('library name: ' + s + '\n')
+            continue
+        fo.write('\n' + s + ':\n')
+        for t in log[s].keys():
+            if log[s][t]:
+                fo.write('\t' + t + '\n')
+                for x in log[s][t]:
+                    if x['condition']:
+                        fo.write('\t\t' + x['name'] + '\t<----\t'\
+                                  + x['condition'] + '\n')
+                    else:
+                        fo.write('\t\t' + x['name'] + '\n')
+    fo.close()
+
+if __name__ == "__main__":
+    main(sys.argv[1:])
diff --git a/depend-trace-tool/secure_fw.png b/depend-trace-tool/secure_fw.png
new file mode 100644
index 0000000..fd84603
--- /dev/null
+++ b/depend-trace-tool/secure_fw.png
Binary files differ
diff --git a/depend-trace-tool/tfm_sprt.png b/depend-trace-tool/tfm_sprt.png
new file mode 100644
index 0000000..ad6ef8e
--- /dev/null
+++ b/depend-trace-tool/tfm_sprt.png
Binary files differ