diff --git a/tests/scripts/generate_test_code.py b/tests/scripts/generate_test_code.py
index 33da990..b2d4912 100755
--- a/tests/scripts/generate_test_code.py
+++ b/tests/scripts/generate_test_code.py
@@ -23,14 +23,18 @@
 
 Generates a test source file using following input files:
 
-test_suite_xyz.function - Read test functions from test suite functions file.
-test_suite_xyz.data - Read test functions and their dependencies to generate
-                      dispatch and dependency check code.
-main template - Substitute generated test function dispatch code, dependency
-                checking code.
-platform .function - Read host or target platform implementation for
-                     dispatching test cases from .data file.
-helper .function - Read common reusable functions.
+test_suite_xyz.function     -   Read test functions from test suite
+                                functions file.
+test_suite_xyz.data         -   Read test functions and their
+                                dependencies to generate dispatch and
+                                dependency check code.
+main_test.function          -   Template to substitute generated test
+                                function dispatch code, dependency
+                                checking code.
+platform .function          -   Read host or target platform
+                                implementation for dispatching test
+                                cases from .data file.
+helpers.function -              Read common reusable functions.
 """
 
 
@@ -83,8 +87,8 @@
         super(FileWrapper, self).__init__(file_name, 'r')
         self.line_no = 0
 
-    # Override the generator function in a way that works in both Python 2
-    # and Python 3.
+    # Override the generator function in a way that works in both
+    # Python 2 and Python 3.
     def __next__(self):
         """
         Iterator return impl.
@@ -109,7 +113,8 @@
     Split NOT character '!' from dependency. Used by gen_deps()
 
     :param dep: Dependency list
-    :return: list of tuples where index 0 has '!' if there was a '!' before the dependency string
+    :return: list of tuples where index 0 has '!' if there was a '!'
+             before the dependency string
     """
     return ('!', dep[1:]) if dep[0] == '!' else ('', dep)
 
@@ -119,7 +124,8 @@
     Generates dependency i.e. if def and endif code
 
     :param deps: List of dependencies.
-    :return: if defined and endif code with macro annotations for readability.
+    :return: if defined and endif code with macro annotations for
+             readability.
     """
     dep_start = ''.join(['#if %sdefined(%s)\n' % split_dep(x) for x in deps])
     dep_end = ''.join(['#endif /* %s */\n' % x for x in reversed(deps)])
@@ -129,22 +135,26 @@
 
 def gen_deps_one_line(deps):
     """
-    Generates dependency checks in one line. Useful for writing code in #else case.
+    Generates dependency checks in one line. Useful for writing code
+    in #else case.
 
     :param deps: List of dependencies.
     :return: ifdef code
     """
-    defines = ('#if ' if len(deps) else '') + ' && '.join(['%sdefined(%s)' % split_dep(x) for x in deps])
+    defines = '#if ' if len(deps) else ''
+    defines += ' && '.join(['%sdefined(%s)' % split_dep(x) for x in deps])
     return defines
 
 
 def gen_function_wrapper(name, locals, args_dispatch):
     """
-    Creates test function wrapper code. A wrapper has the code to unpack parameters from parameters[] array.
+    Creates test function wrapper code. A wrapper has the code to
+    unpack parameters from parameters[] array.
 
     :param name: Test function name
     :param locals: Local variables declaration code
-    :param args_dispatch: List of dispatch arguments. Ex: ['(char *)params[0]', '*((int *)params[1])']
+    :param args_dispatch: List of dispatch arguments.
+           Ex: ['(char *)params[0]', '*((int *)params[1])']
     :return: Test function wrapper.
     """
     # Then create the wrapper
@@ -200,7 +210,8 @@
             break
         headers += line
     else:
-        raise InvalidFileFormat("file: %s - end pattern [%s] not found!" % (funcs_f.name, end_regex))
+        raise InvalidFileFormat("file: %s - end pattern [%s] not found!" %
+                                (funcs_f.name, end_regex))
 
     return headers
 
@@ -220,7 +231,8 @@
         if re.search(END_DEP_REGEX, line):
             break
     else:
-        raise InvalidFileFormat("file: %s - end dependency pattern [%s] not found!" % (funcs_f.name, END_DEP_REGEX))
+        raise InvalidFileFormat("file: %s - end dependency pattern [%s]"
+                                " not found!" % (funcs_f.name, END_DEP_REGEX))
 
     return deps
 
@@ -246,8 +258,10 @@
     """
     Parsing function signature
 
-    :param line: Line from .functions file that has a function signature.
-    :return: function name, argument list, local variables for wrapper function and argument dispatch code.
+    :param line: Line from .functions file that has a function
+                 signature.
+    :return: function name, argument list, local variables for
+             wrapper function and argument dispatch code.
     """
     args = []
     locals = ''
@@ -271,13 +285,16 @@
         elif re.search('HexParam_t\s*\*\s*.*', arg.strip()):
             args.append('hex')
             # create a structure
+            pointer_initializer = '(uint8_t *) params[%d]' % arg_idx
+            len_initializer = '*( (uint32_t *) params[%d] )' % (arg_idx+1)
             locals += """    HexParam_t hex%d = {%s, %s};
-""" % (arg_idx, '(uint8_t *) params[%d]' % arg_idx, '*( (uint32_t *) params[%d] )' % (arg_idx + 1))
+""" % (arg_idx, pointer_initializer, len_initializer)
 
             args_dispatch.append('&hex%d' % arg_idx)
             arg_idx += 1
         else:
-            raise ValueError("Test function arguments can only be 'int', 'char *' or 'HexParam_t'\n%s" % line)
+            raise ValueError("Test function arguments can only be 'int', "
+                             "'char *' or 'HexParam_t'\n%s" % line)
         arg_idx += 1
 
     return name, args, locals, args_dispatch
@@ -285,7 +302,8 @@
 
 def parse_function_code(funcs_f, deps, suite_deps):
     """
-    Parses out a function from function file object and generates function and dispatch code.
+    Parses out a function from function file object and generates
+    function and dispatch code.
 
     :param funcs_f: file object of the functions file.
     :param deps: List of dependencies
@@ -308,14 +326,16 @@
             name = 'test_' + name
             break
     else:
-        raise InvalidFileFormat("file: %s - Test functions not found!" % funcs_f.name)
+        raise InvalidFileFormat("file: %s - Test functions not found!" %
+                                funcs_f.name)
 
     for line in funcs_f:
         if re.search(END_CASE_REGEX, line):
             break
         code += line
     else:
-        raise InvalidFileFormat("file: %s - end case pattern [%s] not found!" % (funcs_f.name, END_CASE_REGEX))
+        raise InvalidFileFormat("file: %s - end case pattern [%s] not "
+                                "found!" % (funcs_f.name, END_CASE_REGEX))
 
     # Add exit label if not present
     if code.find('exit:') == -1:
@@ -336,8 +356,9 @@
     Returns functions code pieces
 
     :param funcs_f: file object of the functions file.
-    :return: List of test suite dependencies, test function dispatch code, function code and
-             a dict with function identifiers and arguments info.
+    :return: List of test suite dependencies, test function dispatch
+             code, function code and a dict with function identifiers
+             and arguments info.
     """
     suite_headers = ''
     suite_helpers = ''
@@ -358,7 +379,8 @@
             suite_deps += deps
         elif re.search(BEGIN_CASE_REGEX, line):
             deps = parse_function_deps(line)
-            func_name, args, func_code, func_dispatch = parse_function_code(funcs_f, deps, suite_deps)
+            func_name, args, func_code, func_dispatch =\
+                parse_function_code(funcs_f, deps, suite_deps)
             suite_functions += func_code
             # Generate dispatch code and enumeration info
             if func_name in func_info:
@@ -378,8 +400,9 @@
 def escaped_split(str, ch):
     """
     Split str on character ch but ignore escaped \{ch}
-    Since return value is used to write back to the intermediate data file.
-    Any escape characters in the input are retained in the output.
+    Since, return value is used to write back to the intermediate
+    data file, any escape characters in the input are retained in the
+    output.
 
     :param str: String to split
     :param ch: split character
@@ -407,7 +430,8 @@
     Parses .data file
 
     :param data_f: file object of the data file.
-    :return: Generator that yields test name, function name, dependency list and function argument list.
+    :return: Generator that yields test name, function name,
+             dependency list and function argument list.
     """
     STATE_READ_NAME = 0
     STATE_READ_ARGS = 1
@@ -422,9 +446,10 @@
         # Blank line indicates end of test
         if len(line) == 0:
             if state == STATE_READ_ARGS:
-                raise GeneratorInputError("[%s:%d] Newline before arguments. " \
-                        "Test function and arguments missing for %s" % \
-                        (data_f.name, data_f.line_no, name))
+                raise GeneratorInputError("[%s:%d] Newline before arguments. "
+                                          "Test function and arguments "
+                                          "missing for %s" %
+                                          (data_f.name, data_f.line_no, name))
             continue
 
         if state == STATE_READ_NAME:
@@ -435,7 +460,8 @@
             # Check dependencies
             m = re.search('depends_on\:(.*)', line)
             if m:
-                deps = [x.strip() for x in m.group(1).split(':') if len(x.strip())]
+                deps = [x.strip() for x in m.group(1).split(':') if len(
+                    x.strip())]
             else:
                 # Read test vectors
                 parts = escaped_split(line, ':')
@@ -445,9 +471,9 @@
                 deps = []
                 state = STATE_READ_NAME
     if state == STATE_READ_ARGS:
-        raise GeneratorInputError("[%s:%d] Newline before arguments. " \
-                "Test function and arguments missing for %s" % \
-                (data_f.name, data_f.line_no, name))
+        raise GeneratorInputError("[%s:%d] Newline before arguments. "
+                                  "Test function and arguments missing for "
+                                  "%s" % (data_f.name, data_f.line_no, name))
 
 
 def gen_dep_check(dep_id, dep):
@@ -459,7 +485,8 @@
     :return: Dependency check code
     """
     if dep_id < 0:
-        raise GeneratorInputError("Dependency Id should be a positive integer.")
+        raise GeneratorInputError("Dependency Id should be a positive "
+                                  "integer.")
     noT, dep = ('!', dep[1:]) if dep[0] == '!' else ('', dep)
     if len(dep) == 0:
         raise GeneratorInputError("Dependency should not be an empty string.")
@@ -485,7 +512,8 @@
     :return: Expression check code
     """
     if exp_id < 0:
-        raise GeneratorInputError("Expression Id should be a positive integer.")
+        raise GeneratorInputError("Expression Id should be a positive "
+                                  "integer.")
     if len(exp) == 0:
         raise GeneratorInputError("Expression should not be an empty string.")
     exp_code = '''
@@ -504,7 +532,8 @@
 
     :param out_data_f: Output intermediate data file
     :param test_deps: Dependencies
-    :param unique_deps: Mutable list to track unique dependencies that are global to this re-entrant function.
+    :param unique_deps: Mutable list to track unique dependencies
+           that are global to this re-entrant function.
     :return: returns dependency check code.
     """
     dep_check_code = ''
@@ -530,7 +559,8 @@
     :param out_data_f: Output intermediate data file
     :param test_args: Test parameters
     :param func_args: Function arguments
-    :param unique_expressions: Mutable list to track unique expressions that are global to this re-entrant function.
+    :param unique_expressions: Mutable list to track unique
+           expressions that are global to this re-entrant function.
     :return: Returns expression check code.
     """
     expression_code = ''
@@ -538,13 +568,14 @@
         typ = func_args[i]
         val = test_args[i]
 
-        # check if val is a non literal int val
-        if typ == 'int' and not re.match('(\d+$)|((0x)?[0-9a-fA-F]+$)', val):  # its an expression
+        # check if val is a non literal int val (i.e. an expression)
+        if typ == 'int' and not re.match('(\d+$)|((0x)?[0-9a-fA-F]+$)', val):
             typ = 'exp'
             if val not in unique_expressions:
                 unique_expressions.append(val)
-                # exp_id can be derived from len(). But for readability and consistency with case of existing let's
-                # use index().
+                # exp_id can be derived from len(). But for
+                # readability and consistency with case of existing
+                # let's use index().
                 exp_id = unique_expressions.index(val)
                 expression_code += gen_expression_check(exp_id, val)
                 val = exp_id
@@ -559,10 +590,12 @@
     """
     Adds preprocessor checks for test suite dependencies.
 
-    :param suite_deps: Test suite dependencies read from the .functions file.
+    :param suite_deps: Test suite dependencies read from the
+            .functions file.
     :param dep_check_code: Dependency check code
     :param expression_code: Expression check code
-    :return: Dependency and expression code guarded by test suite dependencies.
+    :return: Dependency and expression code guarded by test suite
+             dependencies.
     """
     if len(suite_deps):
         ifdef = gen_deps_one_line(suite_deps)
@@ -581,11 +614,13 @@
 
 def gen_from_test_data(data_f, out_data_f, func_info, suite_deps):
     """
-    Generates dependency checks, expression code and intermediate data file from test data file.
+    Generates dependency checks, expression code and intermediate
+    data file from test data file.
 
     :param data_f: Data file object
     :param out_data_f:Output intermediate data file
-    :param func_info: Dict keyed by function and with function id and arguments info
+    :param func_info: Dict keyed by function and with function id
+           and arguments info
     :param suite_deps: Test suite deps
     :return: Returns dependency and expression check code
     """
@@ -593,7 +628,8 @@
     unique_expressions = []
     dep_check_code = ''
     expression_code = ''
-    for test_name, function_name, test_deps, test_args in parse_test_data(data_f):
+    for test_name, function_name, test_deps, test_args in parse_test_data(
+            data_f):
         out_data_f.write(test_name + '\n')
 
         # Write deps
@@ -602,24 +638,29 @@
         # Write test function name
         test_function_name = 'test_' + function_name
         if test_function_name not in func_info:
-            raise GeneratorInputError("Function %s not found!" % test_function_name)
+            raise GeneratorInputError("Function %s not found!" %
+                                      test_function_name)
         func_id, func_args = func_info[test_function_name]
         out_data_f.write(str(func_id))
 
         # Write parameters
         if len(test_args) != len(func_args):
-            raise GeneratorInputError("Invalid number of arguments in test %s. See function %s signature." % (test_name,
-                        function_name))
-        expression_code += write_parameters(out_data_f, test_args, func_args, unique_expressions)
+            raise GeneratorInputError("Invalid number of arguments in test "
+                                      "%s. See function %s signature." % (
+                                      test_name, function_name))
+        expression_code += write_parameters(out_data_f, test_args, func_args,
+                                            unique_expressions)
 
         # Write a newline as test case separator
         out_data_f.write('\n')
 
-    dep_check_code, expression_code = gen_suite_deps_checks(suite_deps, dep_check_code, expression_code)
+    dep_check_code, expression_code = gen_suite_deps_checks(
+        suite_deps, dep_check_code, expression_code)
     return dep_check_code, expression_code
 
 
-def generate_code(funcs_file, data_file, template_file, platform_file, help_file, suites_dir, c_file, out_data_file):
+def generate_code(funcs_file, data_file, template_file, platform_file,
+                  help_file, suites_dir, c_file, out_data_file):
     """
     Generate mbed-os test code.
 
@@ -645,19 +686,23 @@
     snippets = {'generator_script' : os.path.basename(__file__)}
 
     # Read helpers
-    with open(help_file, 'r') as help_f, open(platform_file, 'r') as platform_f:
+    with open(help_file, 'r') as help_f, open(platform_file, 'r') as \
+            platform_f:
         snippets['test_common_helper_file'] = help_file
         snippets['test_common_helpers'] = help_f.read()
         snippets['test_platform_file'] = platform_file
-        snippets['platform_code'] = platform_f.read().replace('DATA_FILE',
-                                                              out_data_file.replace('\\', '\\\\')) # escape '\'
+        snippets['platform_code'] = platform_f.read().replace(
+            'DATA_FILE', out_data_file.replace('\\', '\\\\')) # escape '\'
 
     # Function code
-    with FileWrapper(funcs_file) as funcs_f, FileWrapper(data_file) as data_f, open(out_data_file, 'w') as out_data_f:
-        suite_deps, dispatch_code, func_code, func_info = parse_functions(funcs_f)
+    with FileWrapper(funcs_file) as funcs_f, FileWrapper(data_file) as \
+            data_f, open(out_data_file, 'w') as out_data_f:
+        suite_deps, dispatch_code, func_code, func_info = parse_functions(
+            funcs_f)
         snippets['functions_code'] = func_code
         snippets['dispatch_code'] = dispatch_code
-        dep_check_code, expression_code = gen_from_test_data(data_f, out_data_f, func_info, suite_deps)
+        dep_check_code, expression_code = gen_from_test_data(
+            data_f, out_data_f, func_info, suite_deps)
         snippets['dep_check_code'] = dep_check_code
         snippets['expression_code'] = expression_code
 
@@ -671,7 +716,8 @@
     with open(template_file, 'r') as template_f, open(c_file, 'w') as c_f:
         line_no = 1
         for line in template_f.readlines():
-            snippets['line_no'] = line_no + 1 # Increment as it sets next line number
+            # Update line number. +1 as #line directive sets next line number
+            snippets['line_no'] = line_no + 1
             code = line.format(**snippets)
             c_f.write(code)
             line_no += 1
@@ -683,7 +729,8 @@
 
     :return:
     """
-    parser = argparse.ArgumentParser(description='Generate code for mbed-os tests.')
+    parser = argparse.ArgumentParser(
+        description='Generate code for mbed-os tests.')
 
     parser.add_argument("-f", "--functions-file",
                         dest="funcs_file",
@@ -741,8 +788,9 @@
         if not os.path.exists(d):
             os.makedirs(d)
 
-    generate_code(args.funcs_file, args.data_file, args.template_file, args.platform_file,
-                  args.help_file, args.suites_dir, out_c_file, out_data_file)
+    generate_code(args.funcs_file, args.data_file, args.template_file,
+                  args.platform_file, args.help_file, args.suites_dir,
+                  out_c_file, out_data_file)
 
 
 if __name__ == "__main__":