diff --git a/scripts/abi_check.py b/scripts/abi_check.py
index c2288432ce..ac1d60ffd0 100755
--- a/scripts/abi_check.py
+++ b/scripts/abi_check.py
@@ -113,6 +113,8 @@ from types import SimpleNamespace
 
 import xml.etree.ElementTree as ET
 
+from mbedtls_dev import build_tree
+
 
 class AbiChecker:
     """API and ABI checker."""
@@ -150,11 +152,6 @@ class AbiChecker:
         self.git_command = "git"
         self.make_command = "make"
 
-    @staticmethod
-    def check_repo_path():
-        if not all(os.path.isdir(d) for d in ["include", "library", "tests"]):
-            raise Exception("Must be run from Mbed TLS root")
-
     def _setup_logger(self):
         self.log = logging.getLogger()
         if self.verbose:
@@ -540,7 +537,7 @@ class AbiChecker:
     def check_for_abi_changes(self):
         """Generate a report of ABI differences
         between self.old_rev and self.new_rev."""
-        self.check_repo_path()
+        build_tree.check_repo_path()
         if self.check_api or self.check_abi:
             self.check_abi_tools_are_installed()
         self._get_abi_dump_for_ref(self.old_version)
diff --git a/scripts/mbedtls_dev/__init__.py b/scripts/mbedtls_dev/__init__.py
new file mode 100644
index 0000000000..15b0d60dd3
--- /dev/null
+++ b/scripts/mbedtls_dev/__init__.py
@@ -0,0 +1,3 @@
+# This file needs to exist to make mbedtls_dev a package.
+# Among other things, this allows modules in this directory to make
+# relative imports.
diff --git a/scripts/mbedtls_dev/build_tree.py b/scripts/mbedtls_dev/build_tree.py
new file mode 100644
index 0000000000..f52b785d95
--- /dev/null
+++ b/scripts/mbedtls_dev/build_tree.py
@@ -0,0 +1,67 @@
+"""Mbed TLS build tree information and manipulation.
+"""
+
+# 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 os
+import inspect
+
+
+def looks_like_mbedtls_root(path: str) -> bool:
+    """Whether the given directory looks like the root of the Mbed TLS source tree."""
+    return all(os.path.isdir(os.path.join(path, subdir))
+               for subdir in ['include', 'library', 'programs', 'tests'])
+
+def check_repo_path():
+    """
+    Check that the current working directory is the project root, and throw
+    an exception if not.
+    """
+    if not all(os.path.isdir(d) for d in ["include", "library", "tests"]):
+        raise Exception("This script must be run from Mbed TLS root")
+
+def chdir_to_root() -> None:
+    """Detect the root of the Mbed TLS source tree and change to it.
+
+    The current directory must be up to two levels deep inside an Mbed TLS
+    source tree.
+    """
+    for d in [os.path.curdir,
+              os.path.pardir,
+              os.path.join(os.path.pardir, os.path.pardir)]:
+        if looks_like_mbedtls_root(d):
+            os.chdir(d)
+            return
+    raise Exception('Mbed TLS source tree not found')
+
+
+def guess_mbedtls_root():
+    """Guess mbedTLS source code directory.
+
+    Return the first possible mbedTLS root directory
+    """
+    dirs = set({})
+    for frame in inspect.stack():
+        path = os.path.dirname(frame.filename)
+        for d in ['.', os.path.pardir] \
+                 + [os.path.join(*([os.path.pardir]*i)) for i in range(2, 10)]:
+            d = os.path.abspath(os.path.join(path, d))
+            if d in dirs:
+                continue
+            dirs.add(d)
+            if looks_like_mbedtls_root(d):
+                return d
+    raise Exception('Mbed TLS source tree not found')
diff --git a/scripts/mbedtls_dev/crypto_knowledge.py b/scripts/mbedtls_dev/crypto_knowledge.py
index 2173d10fdd..f227a411b0 100644
--- a/scripts/mbedtls_dev/crypto_knowledge.py
+++ b/scripts/mbedtls_dev/crypto_knowledge.py
@@ -22,7 +22,7 @@ import enum
 import re
 from typing import FrozenSet, Iterable, List, Optional, Tuple
 
-from mbedtls_dev.asymmetric_key_data import ASYMMETRIC_KEY_DATA
+from .asymmetric_key_data import ASYMMETRIC_KEY_DATA
 
 
 def short_expression(original: str, level: int = 0) -> str:
diff --git a/scripts/mbedtls_dev/psa_storage.py b/scripts/mbedtls_dev/psa_storage.py
index a06dce13ba..bae99383dc 100644
--- a/scripts/mbedtls_dev/psa_storage.py
+++ b/scripts/mbedtls_dev/psa_storage.py
@@ -26,7 +26,7 @@ import struct
 from typing import Dict, List, Optional, Set, Union
 import unittest
 
-from mbedtls_dev import c_build_helper
+from . import c_build_helper
 
 
 class Expr:
diff --git a/scripts/mbedtls_dev/test_case.py b/scripts/mbedtls_dev/test_case.py
index d0afa592fd..8f08703678 100644
--- a/scripts/mbedtls_dev/test_case.py
+++ b/scripts/mbedtls_dev/test_case.py
@@ -1,4 +1,4 @@
-"""Library for generating Mbed TLS test data.
+"""Library for constructing an Mbed TLS test case.
 """
 
 # Copyright The Mbed TLS Contributors
@@ -21,7 +21,7 @@ import os
 import sys
 from typing import Iterable, List, Optional
 
-from mbedtls_dev import typing_util
+from . import typing_util
 
 def hex_string(data: bytes) -> str:
     return '"' + binascii.hexlify(data).decode('ascii') + '"'
diff --git a/scripts/mbedtls_dev/test_generation.py b/scripts/mbedtls_dev/test_data_generation.py
similarity index 93%
rename from scripts/mbedtls_dev/test_generation.py
rename to scripts/mbedtls_dev/test_data_generation.py
index 5de0b885c8..9e36af32e7 100644
--- a/scripts/mbedtls_dev/test_generation.py
+++ b/scripts/mbedtls_dev/test_data_generation.py
@@ -1,4 +1,7 @@
-"""Common test generation classes and main function.
+"""Common code for test data generation.
+
+This module defines classes that are of general use to automatically
+generate .data files for unit tests, as well as a main function.
 
 These are used both by generate_psa_tests.py and generate_bignum_tests.py.
 """
@@ -26,7 +29,8 @@ import re
 from abc import ABCMeta, abstractmethod
 from typing import Callable, Dict, Iterable, Iterator, List, Type, TypeVar
 
-from mbedtls_dev import test_case
+from . import build_tree
+from . import test_case
 
 T = TypeVar('T') #pylint: disable=invalid-name
 
@@ -136,9 +140,8 @@ class BaseTarget(metaclass=ABCMeta):
 
 class TestGenerator:
     """Generate test cases and write to data files."""
-    def __init__(self, options) -> None:
-        self.test_suite_directory = self.get_option(options, 'directory',
-                                                    'tests/suites')
+    def __init__(self, _options) -> None:
+        self.test_suite_directory = 'tests/suites'
         # Update `targets` with an entry for each child class of BaseTarget.
         # Each entry represents a file generated by the BaseTarget framework,
         # and enables generating the .data files using the CLI.
@@ -147,11 +150,6 @@ class TestGenerator:
             for subclass in BaseTarget.__subclasses__()
         })
 
-    @staticmethod
-    def get_option(options, name: str, default: T) -> T:
-        value = getattr(options, name, None)
-        return default if value is None else value
-
     def filename_for(self, basename: str) -> str:
         """The location of the data file with the specified base name."""
         return posixpath.join(self.test_suite_directory, basename + '.data')
@@ -185,6 +183,12 @@ def main(args, description: str, generator_class: Type[TestGenerator] = TestGene
                         help='List available targets and exit')
     parser.add_argument('targets', nargs='*', metavar='TARGET',
                         help='Target file to generate (default: all; "-": none)')
+
+    # Change to the mbedtls root, to keep things simple.
+    # Note that if any command line options refer to paths, they need to
+    # be adjusted first.
+    build_tree.chdir_to_root()
+
     options = parser.parse_args(args)
     generator = generator_class(options)
     if options.list:
diff --git a/tests/scripts/check-python-files.sh b/tests/scripts/check-python-files.sh
index dbf0365325..35319d3e1d 100755
--- a/tests/scripts/check-python-files.sh
+++ b/tests/scripts/check-python-files.sh
@@ -67,7 +67,7 @@ elif [ "$1" = "--can-mypy" ]; then
 fi
 
 echo 'Running pylint ...'
-$PYTHON -m pylint -j 2 scripts/mbedtls_dev/*.py scripts/*.py tests/scripts/*.py || {
+$PYTHON -m pylint scripts/mbedtls_dev/*.py scripts/*.py tests/scripts/*.py || {
     echo >&2 "pylint reported errors"
     ret=1
 }
diff --git a/tests/scripts/check_files.py b/tests/scripts/check_files.py
index a0f5e1f538..5c18702def 100755
--- a/tests/scripts/check_files.py
+++ b/tests/scripts/check_files.py
@@ -34,6 +34,9 @@ try:
 except ImportError:
     pass
 
+import scripts_path # pylint: disable=unused-import
+from mbedtls_dev import build_tree
+
 
 class FileIssueTracker:
     """Base class for file-wide issue tracking.
@@ -338,7 +341,7 @@ class IntegrityChecker:
         """Instantiate the sanity checker.
         Check files under the current directory.
         Write a report of issues to log_file."""
-        self.check_repo_path()
+        build_tree.check_repo_path()
         self.logger = None
         self.setup_logger(log_file)
         self.issues_to_check = [
@@ -353,11 +356,6 @@ class IntegrityChecker:
             MergeArtifactIssueTracker(),
         ]
 
-    @staticmethod
-    def check_repo_path():
-        if not all(os.path.isdir(d) for d in ["include", "library", "tests"]):
-            raise Exception("Must be run from Mbed TLS root")
-
     def setup_logger(self, log_file, level=logging.INFO):
         self.logger = logging.getLogger()
         self.logger.setLevel(level)
diff --git a/tests/scripts/check_names.py b/tests/scripts/check_names.py
index 875d0b0f5b..d1e87b5c52 100755
--- a/tests/scripts/check_names.py
+++ b/tests/scripts/check_names.py
@@ -56,6 +56,10 @@ import shutil
 import subprocess
 import logging
 
+import scripts_path # pylint: disable=unused-import
+from mbedtls_dev import build_tree
+
+
 # Naming patterns to check against. These are defined outside the NameCheck
 # class for ease of modification.
 MACRO_PATTERN = r"^(MBEDTLS|PSA)_[0-9A-Z_]*[0-9A-Z]$"
@@ -218,7 +222,7 @@ class CodeParser():
     """
     def __init__(self, log):
         self.log = log
-        self.check_repo_path()
+        build_tree.check_repo_path()
 
         # Memo for storing "glob expression": set(filepaths)
         self.files = {}
@@ -227,15 +231,6 @@ class CodeParser():
         # Note that "*" can match directory separators in exclude lists.
         self.excluded_files = ["*/bn_mul", "*/compat-1.3.h"]
 
-    @staticmethod
-    def check_repo_path():
-        """
-        Check that the current working directory is the project root, and throw
-        an exception if not.
-        """
-        if not all(os.path.isdir(d) for d in ["include", "library", "tests"]):
-            raise Exception("This script must be run from Mbed TLS root")
-
     def comprehensive_parse(self):
         """
         Comprehensive ("default") function to call each parsing function and
diff --git a/tests/scripts/generate_bignum_tests.py b/tests/scripts/generate_bignum_tests.py
index ceafa4a489..091630decc 100755
--- a/tests/scripts/generate_bignum_tests.py
+++ b/tests/scripts/generate_bignum_tests.py
@@ -6,7 +6,7 @@ generate only the specified files.
 
 Class structure:
 
-Child classes of test_generation.BaseTarget (file targets) represent an output
+Child classes of test_data_generation.BaseTarget (file targets) represent an output
 file. These indicate where test cases will be written to, for all subclasses of
 this target. Multiple file targets should not reuse a `target_basename`.
 
@@ -36,7 +36,7 @@ following:
         call `.create_test_case()` to yield the TestCase.
 
 Additional details and other attributes/methods are given in the documentation
-of BaseTarget in test_generation.py.
+of BaseTarget in test_data_generation.py.
 """
 
 # Copyright The Mbed TLS Contributors
@@ -63,7 +63,7 @@ from typing import Iterator, List, Tuple, TypeVar
 
 import scripts_path # pylint: disable=unused-import
 from mbedtls_dev import test_case
-from mbedtls_dev import test_generation
+from mbedtls_dev import test_data_generation
 
 T = TypeVar('T') #pylint: disable=invalid-name
 
@@ -74,18 +74,16 @@ def quote_str(val) -> str:
     return "\"{}\"".format(val)
 
 def combination_pairs(values: List[T]) -> List[Tuple[T, T]]:
-    """Return all pair combinations from input values.
-
-    The return value is cast, as older versions of mypy are unable to derive
-    the specific type returned by itertools.combinations_with_replacement.
-    """
+    """Return all pair combinations from input values."""
+    # The return value is cast, as older versions of mypy are unable to derive
+    # the specific type returned by itertools.combinations_with_replacement.
     return typing.cast(
         List[Tuple[T, T]],
         list(itertools.combinations_with_replacement(values, 2))
     )
 
 
-class BignumTarget(test_generation.BaseTarget, metaclass=ABCMeta):
+class BignumTarget(test_data_generation.BaseTarget, metaclass=ABCMeta):
     #pylint: disable=abstract-method
     """Target for bignum (mpi) test case generation."""
     target_basename = 'test_suite_mpi.generated'
@@ -235,4 +233,4 @@ class BignumAdd(BignumOperation):
 
 if __name__ == '__main__':
     # Use the section of the docstring relevant to the CLI as description
-    test_generation.main(sys.argv[1:], "\n".join(__doc__.splitlines()[:4]))
+    test_data_generation.main(sys.argv[1:], "\n".join(__doc__.splitlines()[:4]))
diff --git a/tests/scripts/generate_psa_tests.py b/tests/scripts/generate_psa_tests.py
index 867a6b4594..e7d4048ad8 100755
--- a/tests/scripts/generate_psa_tests.py
+++ b/tests/scripts/generate_psa_tests.py
@@ -30,7 +30,7 @@ from mbedtls_dev import crypto_knowledge
 from mbedtls_dev import macro_collector
 from mbedtls_dev import psa_storage
 from mbedtls_dev import test_case
-from mbedtls_dev import test_generation
+from mbedtls_dev import test_data_generation
 
 
 def psa_want_symbol(name: str) -> str:
@@ -894,7 +894,7 @@ class StorageFormatV0(StorageFormat):
         yield from super().generate_all_keys()
         yield from self.all_keys_for_implicit_usage()
 
-class PSATestGenerator(test_generation.TestGenerator):
+class PSATestGenerator(test_data_generation.TestGenerator):
     """Test generator subclass including PSA targets and info."""
     # Note that targets whose names contain 'test_format' have their content
     # validated by `abi_check.py`.
@@ -919,4 +919,4 @@ class PSATestGenerator(test_generation.TestGenerator):
         super().generate_target(name, self.info)
 
 if __name__ == '__main__':
-    test_generation.main(sys.argv[1:], __doc__, PSATestGenerator)
+    test_data_generation.main(sys.argv[1:], __doc__, PSATestGenerator)