Postmortem Debugging to serial port (#20492)

buildroot/share/PlatformIO/scripts/fix_framework_weakness.py

@@ -0,0 +1,29 @@
+from os.path import join, isfile
+import shutil
+from pprint import pprint
+
+Import("env")
+
+if env.MarlinFeatureIsEnabled("POSTMORTEM_DEBUGGING"):
+    FRAMEWORK_DIR = env.PioPlatform().get_package_dir("framework-arduinoststm32-maple")
+    patchflag_path = join(FRAMEWORK_DIR, ".exc-patching-done")
+
+    # patch file only if we didn't do it before
+    if not isfile(patchflag_path):
+        print("Patching libmaple exception handlers")
+        original_file = join(FRAMEWORK_DIR, "STM32F1", "cores", "maple", "libmaple", "exc.S")
+        backup_file = join(FRAMEWORK_DIR, "STM32F1", "cores", "maple", "libmaple", "exc.S.bak")
+        src_file = join("buildroot", "share", "PlatformIO", "scripts", "exc.S")
+
+        assert isfile(original_file) and isfile(src_file)
+        shutil.copyfile(original_file, backup_file)
+        shutil.copyfile(src_file, original_file);
+
+        def _touch(path):
+            with open(path, "w") as fp:
+                fp.write("")
+
+        env.Execute(lambda *args, **kwargs: _touch(patchflag_path))
+        print("Done patching exception handler")
+
+    print("Libmaple modified and ready for post mortem debugging")