1 files changed, 43 insertions, 0 deletions
diff --git a/zephyr/zmake/zmake/version.py b/zephyr/zmake/zmake/version.py
index 404c05cb74..2d505769f2 100644
--- a/zephyr/zmake/zmake/version.py
+++ b/zephyr/zmake/zmake/version.py
@@ -2,7 +2,11 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import datetime
+import getpass
+import io
 import os
+import platform
 import subprocess
 
 import zmake.util as util
@@ -114,3 +118,42 @@ def get_version_string(project, zephyr_base, modules, static=False):
     return "{}_v{}.{}.{}-{}".format(
         project_id, major_version, minor_version, num_commits, vcs_hashes
     )
+
+
+def write_version_header(version_str, output_path, static=False):
+    """Generate a version header and write it to the specified path.
+
+    Generate a version header in the format expected by the EC build
+    system, and write it out only if the version header does not exist
+    or changes.  We don't write in the case that the version header
+    does exist and was unchanged, which allows "zmake build" commands
+    on an unchanged tree to be an effective no-op.
+
+    Args:
+        version_str: The version string to be used in the header, such
+            as one generated by get_version_string.
+        output_path: The file path to write at (a pathlib.Path
+            object).
+        static: If true, generate a header which does not include
+            information like the username, hostname, or date, allowing
+            the build to be reproducible.
+    """
+    output = io.StringIO()
+    output.write("/* This file is automatically generated by zmake */\n")
+
+    def add_def(name, value):
+        output.write("#define {} {}\n".format(name, util.c_str(value)))
+
+    add_def("VERSION", version_str)
+    add_def("CROS_EC_VERSION32", version_str[:31])
+
+    if static:
+        add_def("BUILDER", "reproducible@build")
+        add_def("DATE", "STATIC_VERSION_DATE")
+    else:
+        add_def("BUILDER", "{}@{}".format(getpass.getuser(), platform.node()))
+        add_def("DATE", datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S"))
+
+    contents = output.getvalue()
+    if not output_path.exists() or output_path.read_text() != contents:
+        output_path.write_text(contents)