diff --git a/scripts/code_size_compare.py b/scripts/code_size_compare.py
index 0ed2899..53d859e 100755
--- a/scripts/code_size_compare.py
+++ b/scripts/code_size_compare.py
@@ -24,15 +24,18 @@
 # limitations under the License.
 
 import argparse
+import logging
 import os
 import re
+import shutil
 import subprocess
 import sys
 import typing
 from enum import Enum
 
-from mbedtls_dev import typing_util
 from mbedtls_dev import build_tree
+from mbedtls_dev import logging_util
+from mbedtls_dev import typing_util
 
 class SupportedArch(Enum):
     """Supported architecture for code size measurement."""
@@ -42,13 +45,13 @@
     X86_64 = 'x86_64'
     X86 = 'x86'
 
-CONFIG_TFM_MEDIUM_MBEDCRYPTO_H = "../configs/tfm_mbedcrypto_config_profile_medium.h"
-CONFIG_TFM_MEDIUM_PSA_CRYPTO_H = "../configs/crypto_config_profile_medium.h"
+
 class SupportedConfig(Enum):
     """Supported configuration for code size measurement."""
     DEFAULT = 'default'
     TFM_MEDIUM = 'tfm-medium'
 
+
 # Static library
 MBEDTLS_STATIC_LIB = {
     'CRYPTO': 'library/libmbedcrypto.a',
@@ -56,23 +59,111 @@
     'TLS': 'library/libmbedtls.a',
 }
 
+class CodeSizeDistinctInfo: # pylint: disable=too-few-public-methods
+    """Data structure to store possibly distinct information for code size
+    comparison."""
+    def __init__( #pylint: disable=too-many-arguments
+            self,
+            version: str,
+            git_rev: str,
+            arch: str,
+            config: str,
+            compiler: str,
+            opt_level: str,
+    ) -> None:
+        """
+        :param: version: which version to compare with for code size.
+        :param: git_rev: Git revision to calculate code size.
+        :param: arch: architecture to measure code size on.
+        :param: config: Configuration type to calculate code size.
+                        (See SupportedConfig)
+        :param: compiler: compiler used to build library/*.o.
+        :param: opt_level: Options that control optimization. (E.g. -Os)
+        """
+        self.version = version
+        self.git_rev = git_rev
+        self.arch = arch
+        self.config = config
+        self.compiler = compiler
+        self.opt_level = opt_level
+        # Note: Variables below are not initialized by class instantiation.
+        self.pre_make_cmd = [] #type: typing.List[str]
+        self.make_cmd = ''
+
+    def get_info_indication(self):
+        """Return a unique string to indicate Code Size Distinct Information."""
+        return '{git_rev}-{arch}-{config}-{compiler}'.format(**self.__dict__)
+
+
+class CodeSizeCommonInfo: # pylint: disable=too-few-public-methods
+    """Data structure to store common information for code size comparison."""
+    def __init__(
+            self,
+            host_arch: str,
+            measure_cmd: str,
+    ) -> None:
+        """
+        :param host_arch: host architecture.
+        :param measure_cmd: command to measure code size for library/*.o.
+        """
+        self.host_arch = host_arch
+        self.measure_cmd = measure_cmd
+
+    def get_info_indication(self):
+        """Return a unique string to indicate Code Size Common Information."""
+        return '{measure_tool}'\
+               .format(measure_tool=self.measure_cmd.strip().split(' ')[0])
+
+class CodeSizeResultInfo: # pylint: disable=too-few-public-methods
+    """Data structure to store result options for code size comparison."""
+    def __init__( #pylint: disable=too-many-arguments
+            self,
+            record_dir: str,
+            comp_dir: str,
+            with_markdown=False,
+            stdout=False,
+            show_all=False,
+    ) -> None:
+        """
+        :param record_dir: directory to store code size record.
+        :param comp_dir: directory to store results of code size comparision.
+        :param with_markdown: write comparision result into a markdown table.
+                              (Default: False)
+        :param stdout: direct comparison result into sys.stdout.
+                       (Default False)
+        :param show_all: show all objects in comparison result. (Default False)
+        """
+        self.record_dir = record_dir
+        self.comp_dir = comp_dir
+        self.with_markdown = with_markdown
+        self.stdout = stdout
+        self.show_all = show_all
+
+
 DETECT_ARCH_CMD = "cc -dM -E - < /dev/null"
 def detect_arch() -> str:
     """Auto-detect host architecture."""
     cc_output = subprocess.check_output(DETECT_ARCH_CMD, shell=True).decode()
-    if "__aarch64__" in cc_output:
+    if '__aarch64__' in cc_output:
         return SupportedArch.AARCH64.value
-    if "__arm__" in cc_output:
+    if '__arm__' in cc_output:
         return SupportedArch.AARCH32.value
-    if "__x86_64__" in cc_output:
+    if '__x86_64__' in cc_output:
         return SupportedArch.X86_64.value
-    if "__x86__" in cc_output:
+    if '__i386__' in cc_output:
         return SupportedArch.X86.value
     else:
         print("Unknown host architecture, cannot auto-detect arch.")
         sys.exit(1)
 
-class CodeSizeInfo: # pylint: disable=too-few-public-methods
+TFM_MEDIUM_CONFIG_H = 'configs/tfm_mbedcrypto_config_profile_medium.h'
+TFM_MEDIUM_CRYPTO_CONFIG_H = 'configs/crypto_config_profile_medium.h'
+
+CONFIG_H = 'include/mbedtls/mbedtls_config.h'
+CRYPTO_CONFIG_H = 'include/psa/crypto_config.h'
+BACKUP_SUFFIX = '.code_size.bak'
+
+class CodeSizeBuildInfo: # pylint: disable=too-few-public-methods
     """Gather information used to measure code size.
 
     It collects information about architecture, configuration in order to
@@ -80,90 +171,367 @@
     """
 
     SupportedArchConfig = [
-        "-a " + SupportedArch.AARCH64.value + " -c " + SupportedConfig.DEFAULT.value,
-        "-a " + SupportedArch.AARCH32.value + " -c " + SupportedConfig.DEFAULT.value,
-        "-a " + SupportedArch.X86_64.value  + " -c " + SupportedConfig.DEFAULT.value,
-        "-a " + SupportedArch.X86.value     + " -c " + SupportedConfig.DEFAULT.value,
-        "-a " + SupportedArch.ARMV8_M.value + " -c " + SupportedConfig.TFM_MEDIUM.value,
+        '-a ' + SupportedArch.AARCH64.value + ' -c ' + SupportedConfig.DEFAULT.value,
+        '-a ' + SupportedArch.AARCH32.value + ' -c ' + SupportedConfig.DEFAULT.value,
+        '-a ' + SupportedArch.X86_64.value  + ' -c ' + SupportedConfig.DEFAULT.value,
+        '-a ' + SupportedArch.X86.value     + ' -c ' + SupportedConfig.DEFAULT.value,
+        '-a ' + SupportedArch.ARMV8_M.value + ' -c ' + SupportedConfig.TFM_MEDIUM.value,
     ]
 
-    def __init__(self, arch: str, config: str, sys_arch: str) -> None:
+    def __init__(
+            self,
+            size_dist_info: CodeSizeDistinctInfo,
+            host_arch: str,
+            logger: logging.Logger,
+    ) -> None:
         """
-        arch: architecture to measure code size on.
-        config: configuration type to measure code size with.
-        sys_arch: host architecture.
-        make_command: command to build library (Inferred from arch and config).
+        :param size_dist_info:
+            CodeSizeDistinctInfo containing info for code size measurement.
+                - size_dist_info.arch: architecture to measure code size on.
+                - size_dist_info.config: configuration type to measure
+                                         code size with.
+                - size_dist_info.compiler: compiler used to build library/*.o.
+                - size_dist_info.opt_level: Options that control optimization.
+                                            (E.g. -Os)
+        :param host_arch: host architecture.
+        :param logger: logging module
         """
-        self.arch = arch
-        self.config = config
-        self.sys_arch = sys_arch
-        self.make_command = self.set_make_command()
+        self.arch = size_dist_info.arch
+        self.config = size_dist_info.config
+        self.compiler = size_dist_info.compiler
+        self.opt_level = size_dist_info.opt_level
 
-    def set_make_command(self) -> str:
-        """Infer build command based on architecture and configuration."""
+        self.make_cmd = ['make', '-j', 'lib']
 
+        self.host_arch = host_arch
+        self.logger = logger
+
+    def check_correctness(self) -> bool:
+        """Check whether we are using proper / supported combination
+        of information to build library/*.o."""
+
+        # default config
         if self.config == SupportedConfig.DEFAULT.value and \
-            self.arch == self.sys_arch:
-            return 'make -j lib CFLAGS=\'-Os \' '
+            self.arch == self.host_arch:
+            return True
+        # TF-M
         elif self.arch == SupportedArch.ARMV8_M.value and \
              self.config == SupportedConfig.TFM_MEDIUM.value:
-            return \
-                 'make -j lib CC=armclang \
-                  CFLAGS=\'--target=arm-arm-none-eabi -mcpu=cortex-m33 -Os \
-                 -DMBEDTLS_CONFIG_FILE=\\\"' + CONFIG_TFM_MEDIUM_MBEDCRYPTO_H + '\\\" \
-                 -DMBEDTLS_PSA_CRYPTO_CONFIG_FILE=\\\"' + CONFIG_TFM_MEDIUM_PSA_CRYPTO_H + '\\\" \''
+            return True
+
+        return False
+
+    def infer_pre_make_command(self) -> typing.List[str]:
+        """Infer command to set up proper configuration before running make."""
+        pre_make_cmd = [] #type: typing.List[str]
+        if self.config == SupportedConfig.TFM_MEDIUM.value:
+            pre_make_cmd.append('cp {src} {dest}'
+                                .format(src=TFM_MEDIUM_CONFIG_H, dest=CONFIG_H))
+            pre_make_cmd.append('cp {src} {dest}'
+                                .format(src=TFM_MEDIUM_CRYPTO_CONFIG_H,
+                                        dest=CRYPTO_CONFIG_H))
+
+        return pre_make_cmd
+
+    def infer_make_cflags(self) -> str:
+        """Infer CFLAGS by instance attributes in CodeSizeDistinctInfo."""
+        cflags = [] #type: typing.List[str]
+
+        # set optimization level
+        cflags.append(self.opt_level)
+        # set compiler by config
+        if self.config == SupportedConfig.TFM_MEDIUM.value:
+            self.compiler = 'armclang'
+            cflags.append('-mcpu=cortex-m33')
+        # set target
+        if self.compiler == 'armclang':
+            cflags.append('--target=arm-arm-none-eabi')
+
+        return ' '.join(cflags)
+
+    def infer_make_command(self) -> str:
+        """Infer make command by CFLAGS and CC."""
+
+        if self.check_correctness():
+            # set CFLAGS=
+            self.make_cmd.append('CFLAGS=\'{}\''.format(self.infer_make_cflags()))
+            # set CC=
+            self.make_cmd.append('CC={}'.format(self.compiler))
+            return ' '.join(self.make_cmd)
         else:
-            print("Unsupported combination of architecture: {} and configuration: {}"
-                  .format(self.arch, self.config))
-            print("\nPlease use supported combination of architecture and configuration:")
-            for comb in CodeSizeInfo.SupportedArchConfig:
-                print(comb)
-            print("\nFor your system, please use:")
-            for comb in CodeSizeInfo.SupportedArchConfig:
-                if "default" in comb and self.sys_arch not in comb:
+            self.logger.error("Unsupported combination of architecture: {} " \
+                              "and configuration: {}.\n"
+                              .format(self.arch,
+                                      self.config))
+            self.logger.error("Please use supported combination of " \
+                             "architecture and configuration:")
+            for comb in CodeSizeBuildInfo.SupportedArchConfig:
+                self.logger.error(comb)
+            self.logger.error("")
+            self.logger.error("For your system, please use:")
+            for comb in CodeSizeBuildInfo.SupportedArchConfig:
+                if "default" in comb and self.host_arch not in comb:
                     continue
-                print(comb)
+                self.logger.error(comb)
             sys.exit(1)
 
-class SizeEntry: # pylint: disable=too-few-public-methods
-    """Data Structure to only store information of code size."""
-    def __init__(self, text, data, bss, dec):
-        self.text = text
-        self.data = data
-        self.bss = bss
-        self.total = dec # total <=> dec
 
-class CodeSizeBase:
+class CodeSizeCalculator:
+    """ A calculator to calculate code size of library/*.o based on
+    Git revision and code size measurement tool.
+    """
+
+    def __init__( #pylint: disable=too-many-arguments
+            self,
+            git_rev: str,
+            pre_make_cmd: typing.List[str],
+            make_cmd: str,
+            measure_cmd: str,
+            logger: logging.Logger,
+    ) -> None:
+        """
+        :param git_rev: Git revision. (E.g: commit)
+        :param pre_make_cmd: command to set up proper config before running make.
+        :param make_cmd: command to build library/*.o.
+        :param measure_cmd: command to measure code size for library/*.o.
+        :param logger: logging module
+        """
+        self.repo_path = "."
+        self.git_command = "git"
+        self.make_clean = 'make clean'
+
+        self.git_rev = git_rev
+        self.pre_make_cmd = pre_make_cmd
+        self.make_cmd = make_cmd
+        self.measure_cmd = measure_cmd
+        self.logger = logger
+
+    @staticmethod
+    def validate_git_revision(git_rev: str) -> str:
+        result = subprocess.check_output(["git", "rev-parse", "--verify",
+                                          git_rev + "^{commit}"],
+                                         shell=False, universal_newlines=True)
+        return result[:7]
+
+    def _create_git_worktree(self) -> str:
+        """Create a separate worktree for Git revision.
+        If Git revision is current, use current worktree instead."""
+
+        if self.git_rev == 'current':
+            self.logger.debug("Using current work directory.")
+            git_worktree_path = self.repo_path
+        else:
+            self.logger.debug("Creating git worktree for {}."
+                              .format(self.git_rev))
+            git_worktree_path = os.path.join(self.repo_path,
+                                             "temp-" + self.git_rev)
+            subprocess.check_output(
+                [self.git_command, "worktree", "add", "--detach",
+                 git_worktree_path, self.git_rev], cwd=self.repo_path,
+                stderr=subprocess.STDOUT
+            )
+
+        return git_worktree_path
+
+    @staticmethod
+    def backup_config_files(restore: bool) -> None:
+        """Backup / Restore config files."""
+        if restore:
+            shutil.move(CONFIG_H + BACKUP_SUFFIX, CONFIG_H)
+            shutil.move(CRYPTO_CONFIG_H + BACKUP_SUFFIX, CRYPTO_CONFIG_H)
+        else:
+            shutil.copy(CONFIG_H, CONFIG_H + BACKUP_SUFFIX)
+            shutil.copy(CRYPTO_CONFIG_H, CRYPTO_CONFIG_H + BACKUP_SUFFIX)
+
+    def _build_libraries(self, git_worktree_path: str) -> None:
+        """Build library/*.o in the specified worktree."""
+
+        self.logger.debug("Building library/*.o for {}."
+                          .format(self.git_rev))
+        my_environment = os.environ.copy()
+        try:
+            if self.git_rev == 'current':
+                self.backup_config_files(restore=False)
+            for pre_cmd in self.pre_make_cmd:
+                subprocess.check_output(
+                    pre_cmd, env=my_environment, shell=True,
+                    cwd=git_worktree_path, stderr=subprocess.STDOUT,
+                    universal_newlines=True
+                )
+            subprocess.check_output(
+                self.make_clean, env=my_environment, shell=True,
+                cwd=git_worktree_path, stderr=subprocess.STDOUT,
+                universal_newlines=True
+            )
+            subprocess.check_output(
+                self.make_cmd, env=my_environment, shell=True,
+                cwd=git_worktree_path, stderr=subprocess.STDOUT,
+                universal_newlines=True
+            )
+            if self.git_rev == 'current':
+                self.backup_config_files(restore=True)
+        except subprocess.CalledProcessError as e:
+            self._handle_called_process_error(e, git_worktree_path)
+
+    def _gen_raw_code_size(self, git_worktree_path: str) -> typing.Dict[str, str]:
+        """Measure code size by a tool and return in UTF-8 encoding."""
+
+        self.logger.debug("Measuring code size for {} by `{}`."
+                          .format(self.git_rev,
+                                  self.measure_cmd.strip().split(' ')[0]))
+
+        res = {}
+        for mod, st_lib in MBEDTLS_STATIC_LIB.items():
+            try:
+                result = subprocess.check_output(
+                    [self.measure_cmd + ' ' + st_lib], cwd=git_worktree_path,
+                    shell=True, universal_newlines=True
+                )
+                res[mod] = result
+            except subprocess.CalledProcessError as e:
+                self._handle_called_process_error(e, git_worktree_path)
+
+        return res
+
+    def _remove_worktree(self, git_worktree_path: str) -> None:
+        """Remove temporary worktree."""
+        if git_worktree_path != self.repo_path:
+            self.logger.debug("Removing temporary worktree {}."
+                              .format(git_worktree_path))
+            subprocess.check_output(
+                [self.git_command, "worktree", "remove", "--force",
+                 git_worktree_path], cwd=self.repo_path,
+                stderr=subprocess.STDOUT
+            )
+
+    def _handle_called_process_error(self, e: subprocess.CalledProcessError,
+                                     git_worktree_path: str) -> None:
+        """Handle a CalledProcessError and quit the program gracefully.
+        Remove any extra worktrees so that the script may be called again."""
+
+        # Tell the user what went wrong
+        self.logger.error(e, exc_info=True)
+        self.logger.error("Process output:\n {}".format(e.output))
+
+        # Quit gracefully by removing the existing worktree
+        self._remove_worktree(git_worktree_path)
+        sys.exit(-1)
+
+    def cal_libraries_code_size(self) -> typing.Dict[str, str]:
+        """Do a complete round to calculate code size of library/*.o
+        by measurement tool.
+
+        :return A dictionary of measured code size
+            - typing.Dict[mod: str]
+        """
+
+        git_worktree_path = self._create_git_worktree()
+        try:
+            self._build_libraries(git_worktree_path)
+            res = self._gen_raw_code_size(git_worktree_path)
+        finally:
+            self._remove_worktree(git_worktree_path)
+
+        return res
+
+
+class CodeSizeGenerator:
+    """ A generator based on size measurement tool for library/*.o.
+
+    This is an abstract class. To use it, derive a class that implements
+    write_record and write_comparison methods, then call both of them with
+    proper arguments.
+    """
+    def __init__(self, logger: logging.Logger) -> None:
+        """
+        :param logger: logging module
+        """
+        self.logger = logger
+
+    def write_record(
+            self,
+            git_rev: str,
+            code_size_text: typing.Dict[str, str],
+            output: typing_util.Writable
+    ) -> None:
+        """Write size record into a file.
+
+        :param git_rev: Git revision. (E.g: commit)
+        :param code_size_text:
+            string output (utf-8) from measurement tool of code size.
+                - typing.Dict[mod: str]
+        :param output: output stream which the code size record is written to.
+                       (Note: Normally write code size record into File)
+        """
+        raise NotImplementedError
+
+    def write_comparison( #pylint: disable=too-many-arguments
+            self,
+            old_rev: str,
+            new_rev: str,
+            output: typing_util.Writable,
+            with_markdown=False,
+            show_all=False
+    ) -> None:
+        """Write a comparision result into a stream between two Git revisions.
+
+        :param old_rev: old Git revision to compared with.
+        :param new_rev: new Git revision to compared with.
+        :param output: output stream which the code size record is written to.
+                       (File / sys.stdout)
+        :param with_markdown:  write comparision result in a markdown table.
+                               (Default: False)
+        :param show_all: show all objects in comparison result. (Default False)
+        """
+        raise NotImplementedError
+
+
+class CodeSizeGeneratorWithSize(CodeSizeGenerator):
     """Code Size Base Class for size record saving and writing."""
 
-    def __init__(self) -> None:
-        """ Variable code_size is used to store size info for any revisions.
-        code_size: (data format)
-        {revision: {module: {file_name: SizeEntry,
-                             etc ...
-                            },
-                    etc ...
-                   },
-         etc ...
-        }
-        """
-        self.code_size = {} #type: typing.Dict[str, typing.Dict]
+    class SizeEntry: # pylint: disable=too-few-public-methods
+        """Data Structure to only store information of code size."""
+        def __init__(self, text: int, data: int, bss: int, dec: int):
+            self.text = text
+            self.data = data
+            self.bss = bss
+            self.total = dec # total <=> dec
 
-    def set_size_record(self, revision: str, mod: str, size_text: str) -> None:
-        """Store size information for target revision and high-level module.
+    def __init__(self, logger: logging.Logger) -> None:
+        """ Variable code_size is used to store size info for any Git revisions.
+        :param code_size:
+            Data Format as following:
+            code_size = {
+                git_rev: {
+                    module: {
+                        file_name: SizeEntry,
+                        ...
+                    },
+                    ...
+                },
+                ...
+            }
+        """
+        super().__init__(logger)
+        self.code_size = {} #type: typing.Dict[str, typing.Dict]
+        self.mod_total_suffix = '-' + 'TOTALS'
+
+    def _set_size_record(self, git_rev: str, mod: str, size_text: str) -> None:
+        """Store size information for target Git revision and high-level module.
 
         size_text Format: text data bss dec hex filename
         """
         size_record = {}
         for line in size_text.splitlines()[1:]:
             data = line.split()
-            size_record[data[5]] = SizeEntry(data[0], data[1], data[2], data[3])
-        if revision in self.code_size:
-            self.code_size[revision].update({mod: size_record})
-        else:
-            self.code_size[revision] = {mod: size_record}
+            if re.match(r'\s*\(TOTALS\)', data[5]):
+                data[5] = mod + self.mod_total_suffix
+            # file_name: SizeEntry(text, data, bss, dec)
+            size_record[data[5]] = CodeSizeGeneratorWithSize.SizeEntry(
+                int(data[0]), int(data[1]), int(data[2]), int(data[3]))
+        self.code_size.setdefault(git_rev, {}).update({mod: size_record})
 
-    def read_size_record(self, revision: str, fname: str) -> None:
+    def read_size_record(self, git_rev: str, fname: str) -> None:
         """Read size information from csv file and write it into code_size.
 
         fname Format: filename text data bss dec
@@ -179,232 +547,325 @@
                     continue
 
                 if mod:
-                    size_record[data[0]] = \
-                        SizeEntry(data[1], data[2], data[3], data[4])
+                    # file_name: SizeEntry(text, data, bss, dec)
+                    size_record[data[0]] = CodeSizeGeneratorWithSize.SizeEntry(
+                        int(data[1]), int(data[2]), int(data[3]), int(data[4]))
 
                 # check if we hit record for the end of a module
-                m = re.match(r'.?TOTALS', line)
+                m = re.match(r'\w+' + self.mod_total_suffix, line)
                 if m:
-                    if revision in self.code_size:
-                        self.code_size[revision].update({mod: size_record})
+                    if git_rev in self.code_size:
+                        self.code_size[git_rev].update({mod: size_record})
                     else:
-                        self.code_size[revision] = {mod: size_record}
+                        self.code_size[git_rev] = {mod: size_record}
                     mod = ""
                     size_record = {}
 
-    def _size_reader_helper(
+    def write_record(
             self,
-            revision: str,
-            output: typing_util.Writable
-    ) -> typing.Iterator[tuple]:
-        """A helper function to peel code_size based on revision."""
-        for mod, file_size in self.code_size[revision].items():
-            output.write("\n" + mod + "\n")
-            for fname, size_entry in file_size.items():
-                yield mod, fname, size_entry
-
-    def write_size_record(
-            self,
-            revision: str,
+            git_rev: str,
+            code_size_text: typing.Dict[str, str],
             output: typing_util.Writable
     ) -> None:
         """Write size information to a file.
 
-        Writing Format: file_name text data bss total(dec)
+        Writing Format: filename text data bss total(dec)
         """
-        output.write("{:<30} {:>7} {:>7} {:>7} {:>7}\n"
-                     .format("filename", "text", "data", "bss", "total"))
-        for _, fname, size_entry in self._size_reader_helper(revision, output):
-            output.write("{:<30} {:>7} {:>7} {:>7} {:>7}\n"
-                         .format(fname, size_entry.text, size_entry.data,\
-                                 size_entry.bss, size_entry.total))
+        for mod, size_text in code_size_text.items():
+            self._set_size_record(git_rev, mod, size_text)
 
-    def write_comparison(
+        format_string = "{:<30} {:>7} {:>7} {:>7} {:>7}\n"
+        output.write(format_string.format("filename",
+                                          "text", "data", "bss", "total"))
+
+        for mod, f_size in self.code_size[git_rev].items():
+            output.write("\n" + mod + "\n")
+            for fname, size_entry in f_size.items():
+                output.write(format_string
+                             .format(fname,
+                                     size_entry.text, size_entry.data,
+                                     size_entry.bss, size_entry.total))
+
+    def write_comparison( #pylint: disable=too-many-arguments
             self,
             old_rev: str,
             new_rev: str,
-            output: typing_util.Writable
+            output: typing_util.Writable,
+            with_markdown=False,
+            show_all=False
     ) -> None:
+        # pylint: disable=too-many-locals
         """Write comparison result into a file.
 
-        Writing Format: file_name current(total) old(total) change(Byte) change_pct(%)
+        Writing Format:
+            Markdown Output:
+                filename new(text) new(data) change(text) change(data)
+            CSV Output:
+                filename new(text) new(data) old(text) old(data) change(text) change(data)
         """
-        output.write("{:<30} {:>7} {:>7} {:>7} {:>7}\n"
-                     .format("filename", "current", "old", "change", "change%"))
-        for mod, fname, size_entry in self._size_reader_helper(new_rev, output):
-            new_size = int(size_entry.total)
-            # check if we have the file in old revision
-            if fname in self.code_size[old_rev][mod]:
-                old_size = int(self.code_size[old_rev][mod][fname].total)
-                change = new_size - old_size
-                if old_size != 0:
-                    change_pct = change / old_size
-                else:
-                    change_pct = 0
-                output.write("{:<30} {:>7} {:>7} {:>7} {:>7.2%}\n"
-                             .format(fname, new_size, old_size, change, change_pct))
+        header_line = ["filename", "new(text)", "old(text)", "change(text)",
+                       "new(data)", "old(data)", "change(data)"]
+        if with_markdown:
+            dash_line = [":----", "----:", "----:", "----:",
+                         "----:", "----:", "----:"]
+            # | filename | new(text) | new(data) | change(text) | change(data) |
+            line_format = "| {0:<30} | {1:>9} | {4:>9} | {3:>12} | {6:>12} |\n"
+            bold_text = lambda x: '**' + str(x) + '**'
+        else:
+            # filename new(text) new(data) old(text) old(data) change(text) change(data)
+            line_format = "{0:<30} {1:>9} {4:>9} {2:>10} {5:>10} {3:>12} {6:>12}\n"
+
+        def cal_sect_change(
+                old_size: typing.Optional[CodeSizeGeneratorWithSize.SizeEntry],
+                new_size: typing.Optional[CodeSizeGeneratorWithSize.SizeEntry],
+                sect: str
+        ) -> typing.List:
+            """Inner helper function to calculate size change for a section.
+
+            Convention for special cases:
+                - If the object has been removed in new Git revision,
+                  the size is minus code size of old Git revision;
+                  the size change is marked as `Removed`,
+                - If the object only exists in new Git revision,
+                  the size is code size of new Git revision;
+                  the size change is marked as `None`,
+
+            :param: old_size: code size for objects in old Git revision.
+            :param: new_size: code size for objects in new Git revision.
+            :param: sect: section to calculate from `size` tool. This could be
+                          any instance variable in SizeEntry.
+            :return: List of [section size of objects for new Git revision,
+                     section size of objects for old Git revision,
+                     section size change of objects between two Git revisions]
+            """
+            if old_size and new_size:
+                new_attr = new_size.__dict__[sect]
+                old_attr = old_size.__dict__[sect]
+                delta = new_attr - old_attr
+                change_attr = '{0:{1}}'.format(delta, '+' if delta else '')
+            elif old_size:
+                new_attr = 'Removed'
+                old_attr = old_size.__dict__[sect]
+                delta = - old_attr
+                change_attr = '{0:{1}}'.format(delta, '+' if delta else '')
+            elif new_size:
+                new_attr = new_size.__dict__[sect]
+                old_attr = 'NotCreated'
+                delta = new_attr
+                change_attr = '{0:{1}}'.format(delta, '+' if delta else '')
             else:
-                output.write("{} {}\n".format(fname, new_size))
+                # Should never happen
+                new_attr = 'Error'
+                old_attr = 'Error'
+                change_attr = 'Error'
+            return [new_attr, old_attr, change_attr]
+
+        # sort dictionary by key
+        sort_by_k = lambda item: item[0].lower()
+        def get_results(
+                f_rev_size:
+                typing.Dict[str,
+                            typing.Dict[str,
+                                        CodeSizeGeneratorWithSize.SizeEntry]]
+            ) -> typing.List:
+            """Return List of results in the format of:
+            [filename, new(text), old(text), change(text),
+             new(data), old(data), change(data)]
+            """
+            res = []
+            for fname, revs_size in sorted(f_rev_size.items(), key=sort_by_k):
+                old_size = revs_size.get(old_rev)
+                new_size = revs_size.get(new_rev)
+
+                text_sect = cal_sect_change(old_size, new_size, 'text')
+                data_sect = cal_sect_change(old_size, new_size, 'data')
+                # skip the files that haven't changed in code size
+                if not show_all and text_sect[-1] == '0' and data_sect[-1] == '0':
+                    continue
+
+                res.append([fname, *text_sect, *data_sect])
+            return res
+
+        # write header
+        output.write(line_format.format(*header_line))
+        if with_markdown:
+            output.write(line_format.format(*dash_line))
+        for mod in MBEDTLS_STATIC_LIB:
+        # convert self.code_size to:
+        # {
+        #   file_name: {
+        #       old_rev: SizeEntry,
+        #       new_rev: SizeEntry
+        #   },
+        #   ...
+        # }
+            f_rev_size = {} #type: typing.Dict[str, typing.Dict]
+            for fname, size_entry in self.code_size[old_rev][mod].items():
+                f_rev_size.setdefault(fname, {}).update({old_rev: size_entry})
+            for fname, size_entry in self.code_size[new_rev][mod].items():
+                f_rev_size.setdefault(fname, {}).update({new_rev: size_entry})
+
+            mod_total_sz = f_rev_size.pop(mod + self.mod_total_suffix)
+            res = get_results(f_rev_size)
+            total_clm = get_results({mod + self.mod_total_suffix: mod_total_sz})
+            if with_markdown:
+                # bold row of mod-TOTALS in markdown table
+                total_clm = [[bold_text(j) for j in i] for i in total_clm]
+            res += total_clm
+
+            # write comparison result
+            for line in res:
+                output.write(line_format.format(*line))
 
 
-class CodeSizeComparison(CodeSizeBase):
+class CodeSizeComparison:
     """Compare code size between two Git revisions."""
 
-    def __init__(
+    def __init__( #pylint: disable=too-many-arguments
             self,
-            old_revision: str,
-            new_revision: str,
-            result_dir: str,
-            code_size_info: CodeSizeInfo
+            old_size_dist_info: CodeSizeDistinctInfo,
+            new_size_dist_info: CodeSizeDistinctInfo,
+            size_common_info: CodeSizeCommonInfo,
+            result_options: CodeSizeResultInfo,
+            logger: logging.Logger,
     ) -> None:
         """
-        old_revision: revision to compare against.
-        new_revision:
-        result_dir: directory for comparison result.
-        code_size_info: an object containing information to build library.
+        :param old_size_dist_info: CodeSizeDistinctInfo containing old distinct
+                                   info to compare code size with.
+        :param new_size_dist_info: CodeSizeDistinctInfo containing new distinct
+                                   info to take as comparision base.
+        :param size_common_info: CodeSizeCommonInfo containing common info for
+                                 both old and new size distinct info and
+                                 measurement tool.
+        :param result_options: CodeSizeResultInfo containing results options for
+                               code size record and comparision.
+        :param logger: logging module
         """
-        super().__init__()
-        self.repo_path = "."
-        self.result_dir = os.path.abspath(result_dir)
-        os.makedirs(self.result_dir, exist_ok=True)
 
-        self.csv_dir = os.path.abspath("code_size_records/")
+        self.logger = logger
+
+        self.old_size_dist_info = old_size_dist_info
+        self.new_size_dist_info = new_size_dist_info
+        self.size_common_info = size_common_info
+        # infer pre make command
+        self.old_size_dist_info.pre_make_cmd = CodeSizeBuildInfo(
+            self.old_size_dist_info, self.size_common_info.host_arch,
+            self.logger).infer_pre_make_command()
+        self.new_size_dist_info.pre_make_cmd = CodeSizeBuildInfo(
+            self.new_size_dist_info, self.size_common_info.host_arch,
+            self.logger).infer_pre_make_command()
+        # infer make command
+        self.old_size_dist_info.make_cmd = CodeSizeBuildInfo(
+            self.old_size_dist_info, self.size_common_info.host_arch,
+            self.logger).infer_make_command()
+        self.new_size_dist_info.make_cmd = CodeSizeBuildInfo(
+            self.new_size_dist_info, self.size_common_info.host_arch,
+            self.logger).infer_make_command()
+        # initialize size parser with corresponding measurement tool
+        self.code_size_generator = self.__generate_size_parser()
+
+        self.result_options = result_options
+        self.csv_dir = os.path.abspath(self.result_options.record_dir)
         os.makedirs(self.csv_dir, exist_ok=True)
+        self.comp_dir = os.path.abspath(self.result_options.comp_dir)
+        os.makedirs(self.comp_dir, exist_ok=True)
 
-        self.old_rev = old_revision
-        self.new_rev = new_revision
-        self.git_command = "git"
-        self.make_clean = 'make clean'
-        self.make_command = code_size_info.make_command
-        self.fname_suffix = "-" + code_size_info.arch + "-" +\
-                            code_size_info.config
-
-    @staticmethod
-    def validate_revision(revision: str) -> bytes:
-        result = subprocess.check_output(["git", "rev-parse", "--verify",
-                                          revision + "^{commit}"], shell=False)
-        return result
-
-    def _create_git_worktree(self, revision: str) -> str:
-        """Make a separate worktree for revision.
-        Do not modify the current worktree."""
-
-        if revision == "current":
-            print("Using current work directory")
-            git_worktree_path = self.repo_path
+    def __generate_size_parser(self):
+        """Generate a parser for the corresponding measurement tool."""
+        if re.match(r'size', self.size_common_info.measure_cmd.strip()):
+            return CodeSizeGeneratorWithSize(self.logger)
         else:
-            print("Creating git worktree for", revision)
-            git_worktree_path = os.path.join(self.repo_path, "temp-" + revision)
-            subprocess.check_output(
-                [self.git_command, "worktree", "add", "--detach",
-                 git_worktree_path, revision], cwd=self.repo_path,
-                stderr=subprocess.STDOUT
-            )
+            self.logger.error("Unsupported measurement tool: `{}`."
+                              .format(self.size_common_info.measure_cmd
+                                      .strip().split(' ')[0]))
+            sys.exit(1)
 
-        return git_worktree_path
+    def cal_code_size(
+            self,
+            size_dist_info: CodeSizeDistinctInfo
+        ) -> typing.Dict[str, str]:
+        """Calculate code size of library/*.o in a UTF-8 encoding"""
 
-    def _build_libraries(self, git_worktree_path: str) -> None:
-        """Build libraries in the specified worktree."""
+        return CodeSizeCalculator(size_dist_info.git_rev,
+                                  size_dist_info.pre_make_cmd,
+                                  size_dist_info.make_cmd,
+                                  self.size_common_info.measure_cmd,
+                                  self.logger).cal_libraries_code_size()
 
-        my_environment = os.environ.copy()
-        try:
-            subprocess.check_output(
-                self.make_clean, env=my_environment, shell=True,
-                cwd=git_worktree_path, stderr=subprocess.STDOUT,
-            )
-            subprocess.check_output(
-                self.make_command, env=my_environment, shell=True,
-                cwd=git_worktree_path, stderr=subprocess.STDOUT,
-            )
-        except subprocess.CalledProcessError as e:
-            self._handle_called_process_error(e, git_worktree_path)
+    def gen_code_size_report(self, size_dist_info: CodeSizeDistinctInfo) -> None:
+        """Generate code size record and write it into a file."""
 
-    def _gen_code_size_csv(self, revision: str, git_worktree_path: str) -> None:
-        """Generate code size csv file."""
-
-        if revision == "current":
-            print("Measuring code size in current work directory")
-        else:
-            print("Measuring code size for", revision)
-
-        for mod, st_lib in MBEDTLS_STATIC_LIB.items():
-            try:
-                result = subprocess.check_output(
-                    ["size", st_lib, "-t"], cwd=git_worktree_path
-                )
-            except subprocess.CalledProcessError as e:
-                self._handle_called_process_error(e, git_worktree_path)
-            size_text = result.decode("utf-8")
-
-            self.set_size_record(revision, mod, size_text)
-
-        print("Generating code size csv for", revision)
-        csv_file = open(os.path.join(self.csv_dir, revision +
-                                     self.fname_suffix + ".csv"), "w")
-        self.write_size_record(revision, csv_file)
-
-    def _remove_worktree(self, git_worktree_path: str) -> None:
-        """Remove temporary worktree."""
-        if git_worktree_path != self.repo_path:
-            print("Removing temporary worktree", git_worktree_path)
-            subprocess.check_output(
-                [self.git_command, "worktree", "remove", "--force",
-                 git_worktree_path], cwd=self.repo_path,
-                stderr=subprocess.STDOUT
-            )
-
-    def _get_code_size_for_rev(self, revision: str) -> None:
-        """Generate code size csv file for the specified git revision."""
-
+        self.logger.info("Start to generate code size record for {}."
+                         .format(size_dist_info.git_rev))
+        output_file = os.path.join(
+            self.csv_dir,
+            '{}-{}.csv'
+            .format(size_dist_info.get_info_indication(),
+                    self.size_common_info.get_info_indication()))
         # Check if the corresponding record exists
-        csv_fname = revision + self.fname_suffix +  ".csv"
-        if (revision != "current") and \
-           os.path.exists(os.path.join(self.csv_dir, csv_fname)):
-            print("Code size csv file for", revision, "already exists.")
-            self.read_size_record(revision, os.path.join(self.csv_dir, csv_fname))
+        if size_dist_info.git_rev != "current" and \
+           os.path.exists(output_file):
+            self.logger.debug("Code size csv file for {} already exists."
+                              .format(size_dist_info.git_rev))
+            self.code_size_generator.read_size_record(
+                size_dist_info.git_rev, output_file)
         else:
-            git_worktree_path = self._create_git_worktree(revision)
-            self._build_libraries(git_worktree_path)
-            self._gen_code_size_csv(revision, git_worktree_path)
-            self._remove_worktree(git_worktree_path)
+            # measure code size
+            code_size_text = self.cal_code_size(size_dist_info)
 
-    def _gen_code_size_comparison(self) -> int:
-        """Generate results of the size changes between two revisions,
-        old and new. Measured code size results of these two revisions
-        must be available."""
+            self.logger.debug("Generating code size csv for {}."
+                              .format(size_dist_info.git_rev))
+            output = open(output_file, "w")
+            self.code_size_generator.write_record(
+                size_dist_info.git_rev, code_size_text, output)
 
-        res_file = open(os.path.join(self.result_dir, "compare-" +
-                                     self.old_rev + "-" + self.new_rev +
-                                     self.fname_suffix +
-                                     ".csv"), "w")
+    def gen_code_size_comparison(self) -> None:
+        """Generate results of code size changes between two Git revisions,
+        old and new.
 
-        print("\nGenerating comparison results between",\
-                self.old_rev, "and", self.new_rev)
-        self.write_comparison(self.old_rev, self.new_rev, res_file)
+        - Measured code size result of these two Git revisions must be available.
+        - The result is directed into either file / stdout depending on
+          the option, size_common_info.result_options.stdout. (Default: file)
+        """
 
-        return 0
+        self.logger.info("Start to generate comparision result between "\
+                         "{} and {}."
+                         .format(self.old_size_dist_info.git_rev,
+                                 self.new_size_dist_info.git_rev))
+        if self.result_options.stdout:
+            output = sys.stdout
+        else:
+            output_file = os.path.join(
+                self.comp_dir,
+                '{}-{}-{}.{}'
+                .format(self.old_size_dist_info.get_info_indication(),
+                        self.new_size_dist_info.get_info_indication(),
+                        self.size_common_info.get_info_indication(),
+                        'md' if self.result_options.with_markdown else 'csv'))
+            output = open(output_file, "w")
 
-    def get_comparision_results(self) -> int:
-        """Compare size of library/*.o between self.old_rev and self.new_rev,
-        and generate the result file."""
+        self.logger.debug("Generating comparison results between {} and {}."
+                          .format(self.old_size_dist_info.git_rev,
+                                  self.new_size_dist_info.git_rev))
+        if self.result_options.with_markdown or self.result_options.stdout:
+            print("Measure code size between {} and {} by `{}`."
+                  .format(self.old_size_dist_info.get_info_indication(),
+                          self.new_size_dist_info.get_info_indication(),
+                          self.size_common_info.get_info_indication()),
+                  file=output)
+        self.code_size_generator.write_comparison(
+            self.old_size_dist_info.git_rev,
+            self.new_size_dist_info.git_rev,
+            output, self.result_options.with_markdown,
+            self.result_options.show_all)
+
+    def get_comparision_results(self) -> None:
+        """Compare size of library/*.o between self.old_size_dist_info and
+        self.old_size_dist_info and generate the result file."""
         build_tree.check_repo_path()
-        self._get_code_size_for_rev(self.old_rev)
-        self._get_code_size_for_rev(self.new_rev)
-        return self._gen_code_size_comparison()
-
-    def _handle_called_process_error(self, e: subprocess.CalledProcessError,
-                                     git_worktree_path: str) -> None:
-        """Handle a CalledProcessError and quit the program gracefully.
-        Remove any extra worktrees so that the script may be called again."""
-
-        # Tell the user what went wrong
-        print("The following command: {} failed and exited with code {}"
-              .format(e.cmd, e.returncode))
-        print("Process output:\n {}".format(str(e.output, "utf-8")))
-
-        # Quit gracefully by removing the existing worktree
-        self._remove_worktree(git_worktree_path)
-        sys.exit(-1)
+        self.gen_code_size_report(self.old_size_dist_info)
+        self.gen_code_size_report(self.new_size_dist_info)
+        self.gen_code_size_comparison()
 
 def main():
     parser = argparse.ArgumentParser(description=(__doc__))
@@ -412,55 +873,92 @@
         'required arguments',
         'required arguments to parse for running ' + os.path.basename(__file__))
     group_required.add_argument(
-        "-o", "--old-rev", type=str, required=True,
-        help="old revision for comparison.")
+        '-o', '--old-rev', type=str, required=True,
+        help='old Git revision for comparison.')
 
     group_optional = parser.add_argument_group(
         'optional arguments',
         'optional arguments to parse for running ' + os.path.basename(__file__))
     group_optional.add_argument(
-        "-r", "--result-dir", type=str, default="comparison",
-        help="directory where comparison result is stored, \
-              default is comparison")
+        '--record-dir', type=str, default='code_size_records',
+        help='directory where code size record is stored. '
+             '(Default: code_size_records)')
     group_optional.add_argument(
-        "-n", "--new-rev", type=str, default=None,
-        help="new revision for comparison, default is the current work \
-              directory, including uncommitted changes.")
+        '--comp-dir', type=str, default='comparison',
+        help='directory where comparison result is stored. '
+             '(Default: comparison)')
     group_optional.add_argument(
-        "-a", "--arch", type=str, default=detect_arch(),
+        '-n', '--new-rev', type=str, default='current',
+        help='new Git revision as comparison base. '
+             '(Default is the current work directory, including uncommitted '
+             'changes.)')
+    group_optional.add_argument(
+        '-a', '--arch', type=str, default=detect_arch(),
         choices=list(map(lambda s: s.value, SupportedArch)),
-        help="specify architecture for code size comparison, default is the\
-              host architecture.")
+        help='Specify architecture for code size comparison. '
+             '(Default is the host architecture.)')
     group_optional.add_argument(
-        "-c", "--config", type=str, default=SupportedConfig.DEFAULT.value,
+        '-c', '--config', type=str, default=SupportedConfig.DEFAULT.value,
         choices=list(map(lambda s: s.value, SupportedConfig)),
-        help="specify configuration type for code size comparison,\
-              default is the current MbedTLS configuration.")
+        help='Specify configuration type for code size comparison. '
+             '(Default is the current MbedTLS configuration.)')
+    group_optional.add_argument(
+        '--markdown', action='store_true', dest='markdown',
+        help='Show comparision of code size in a markdown table. '
+             '(Only show the files that have changed).')
+    group_optional.add_argument(
+        '--stdout', action='store_true', dest='stdout',
+        help='Set this option to direct comparison result into sys.stdout. '
+             '(Default: file)')
+    group_optional.add_argument(
+        '--show-all', action='store_true', dest='show_all',
+        help='Show all the objects in comparison result, including the ones '
+             'that haven\'t changed in code size. (Default: False)')
+    group_optional.add_argument(
+        '--verbose', action='store_true', dest='verbose',
+        help='Show logs in detail for code size measurement. '
+             '(Default: False)')
     comp_args = parser.parse_args()
 
-    if os.path.isfile(comp_args.result_dir):
-        print("Error: {} is not a directory".format(comp_args.result_dir))
-        parser.exit()
+    logger = logging.getLogger()
+    logging_util.configure_logger(logger, split_level=logging.NOTSET)
+    logger.setLevel(logging.DEBUG if comp_args.verbose else logging.INFO)
 
-    validate_res = CodeSizeComparison.validate_revision(comp_args.old_rev)
-    old_revision = validate_res.decode().replace("\n", "")
+    if os.path.isfile(comp_args.record_dir):
+        logger.error("record directory: {} is not a directory"
+                     .format(comp_args.record_dir))
+        sys.exit(1)
+    if os.path.isfile(comp_args.comp_dir):
+        logger.error("comparison directory: {} is not a directory"
+                     .format(comp_args.comp_dir))
+        sys.exit(1)
 
-    if comp_args.new_rev is not None:
-        validate_res = CodeSizeComparison.validate_revision(comp_args.new_rev)
-        new_revision = validate_res.decode().replace("\n", "")
-    else:
-        new_revision = "current"
+    comp_args.old_rev = CodeSizeCalculator.validate_git_revision(
+        comp_args.old_rev)
+    if comp_args.new_rev != 'current':
+        comp_args.new_rev = CodeSizeCalculator.validate_git_revision(
+            comp_args.new_rev)
 
-    code_size_info = CodeSizeInfo(comp_args.arch, comp_args.config,
-                                  detect_arch())
-    print("Measure code size for architecture: {}, configuration: {}\n"
-          .format(code_size_info.arch, code_size_info.config))
-    result_dir = comp_args.result_dir
-    size_compare = CodeSizeComparison(old_revision, new_revision, result_dir,
-                                      code_size_info)
-    return_code = size_compare.get_comparision_results()
-    sys.exit(return_code)
+    # version, git_rev, arch, config, compiler, opt_level
+    old_size_dist_info = CodeSizeDistinctInfo(
+        'old', comp_args.old_rev, comp_args.arch, comp_args.config, 'cc', '-Os')
+    new_size_dist_info = CodeSizeDistinctInfo(
+        'new', comp_args.new_rev, comp_args.arch, comp_args.config, 'cc', '-Os')
+    # host_arch, measure_cmd
+    size_common_info = CodeSizeCommonInfo(
+        detect_arch(), 'size -t')
+    # record_dir, comp_dir, with_markdown, stdout, show_all
+    result_options = CodeSizeResultInfo(
+        comp_args.record_dir, comp_args.comp_dir,
+        comp_args.markdown, comp_args.stdout, comp_args.show_all)
 
+    logger.info("Measure code size between {} and {} by `{}`."
+                .format(old_size_dist_info.get_info_indication(),
+                        new_size_dist_info.get_info_indication(),
+                        size_common_info.get_info_indication()))
+    CodeSizeComparison(old_size_dist_info, new_size_dist_info,
+                       size_common_info, result_options,
+                       logger).get_comparision_results()
 
 if __name__ == "__main__":
     main()
diff --git a/scripts/mbedtls_dev/logging_util.py b/scripts/mbedtls_dev/logging_util.py
new file mode 100644
index 0000000..db1ebfe
--- /dev/null
+++ b/scripts/mbedtls_dev/logging_util.py
@@ -0,0 +1,57 @@
+"""Auxiliary functions used for logging module.
+"""
+
+# Copyright The Mbed TLS Contributors
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+import sys
+
+def configure_logger(
+        logger: logging.Logger,
+        log_format="[%(levelname)s]: %(message)s",
+        split_level=logging.WARNING
+    ) -> None:
+    """
+    Configure the logging.Logger instance so that:
+        - Format is set to any log_format.
+            Default: "[%(levelname)s]: %(message)s"
+        - loglevel >= split_level are printed to stderr.
+        - loglevel <  split_level are printed to stdout.
+            Default: logging.WARNING
+    """
+    class MaxLevelFilter(logging.Filter):
+        # pylint: disable=too-few-public-methods
+        def __init__(self, max_level, name=''):
+            super().__init__(name)
+            self.max_level = max_level
+
+        def filter(self, record: logging.LogRecord) -> bool:
+            return record.levelno <= self.max_level
+
+    log_formatter = logging.Formatter(log_format)
+
+    # set loglevel >= split_level to be printed to stderr
+    stderr_hdlr = logging.StreamHandler(sys.stderr)
+    stderr_hdlr.setLevel(split_level)
+    stderr_hdlr.setFormatter(log_formatter)
+
+    # set loglevel < split_level to be printed to stdout
+    stdout_hdlr = logging.StreamHandler(sys.stdout)
+    stdout_hdlr.addFilter(MaxLevelFilter(split_level - 1))
+    stdout_hdlr.setFormatter(log_formatter)
+
+    logger.addHandler(stderr_hdlr)
+    logger.addHandler(stdout_hdlr)
diff --git a/tests/scripts/audit-validity-dates.py b/tests/scripts/audit-validity-dates.py
index 5506e40..623fd23 100755
--- a/tests/scripts/audit-validity-dates.py
+++ b/tests/scripts/audit-validity-dates.py
@@ -24,7 +24,6 @@
 """
 
 import os
-import sys
 import re
 import typing
 import argparse
@@ -43,6 +42,7 @@
 
 import scripts_path # pylint: disable=unused-import
 from mbedtls_dev import build_tree
+from mbedtls_dev import logging_util
 
 def check_cryptography_version():
     match = re.match(r'^[0-9]+', cryptography.__version__)
@@ -393,38 +393,6 @@
             loc))
 
 
-def configure_logger(logger: logging.Logger) -> None:
-    """
-    Configure the logging.Logger instance so that:
-        - Format is set to "[%(levelname)s]: %(message)s".
-        - loglevel >= WARNING are printed to stderr.
-        - loglevel <  WARNING are printed to stdout.
-    """
-    class MaxLevelFilter(logging.Filter):
-        # pylint: disable=too-few-public-methods
-        def __init__(self, max_level, name=''):
-            super().__init__(name)
-            self.max_level = max_level
-
-        def filter(self, record: logging.LogRecord) -> bool:
-            return record.levelno <= self.max_level
-
-    log_formatter = logging.Formatter("[%(levelname)s]: %(message)s")
-
-    # set loglevel >= WARNING to be printed to stderr
-    stderr_hdlr = logging.StreamHandler(sys.stderr)
-    stderr_hdlr.setLevel(logging.WARNING)
-    stderr_hdlr.setFormatter(log_formatter)
-
-    # set loglevel <= INFO to be printed to stdout
-    stdout_hdlr = logging.StreamHandler(sys.stdout)
-    stdout_hdlr.addFilter(MaxLevelFilter(logging.INFO))
-    stdout_hdlr.setFormatter(log_formatter)
-
-    logger.addHandler(stderr_hdlr)
-    logger.addHandler(stdout_hdlr)
-
-
 def main():
     """
     Perform argument parsing.
@@ -457,7 +425,7 @@
     # start main routine
     # setup logger
     logger = logging.getLogger()
-    configure_logger(logger)
+    logging_util.configure_logger(logger)
     logger.setLevel(logging.DEBUG if args.verbose else logging.ERROR)
 
     td_auditor = TestDataAuditor(logger)