build-gem5: factor dtb copy with copy_dir_if_update_non_recursive

Less code, less boring + cp prints, only copy if modified.

build-gem5

@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import glob
 import os
 import pathlib
 import subprocess
@@ -55,9 +54,11 @@ class Gem5Component(common.Component):
             dt_src_dir = os.path.join(gem5_system_src_dir, 'arm', 'dt')
             dt_build_dir = os.path.join(common.gem5_system_dir, 'arm', 'dt')
             common.run_cmd(['make', '-C', dt_src_dir])
-            os.makedirs(dt_build_dir, exist_ok=True)
-            for dt in glob.glob(os.path.join(dt_src_dir, '*.dtb')):
-                common.cp(dt, dt_build_dir)
+            common.copy_dir_if_update_non_recursive(
+                srcdir=dt_src_dir,
+                destdir=dt_build_dir,
+                filter_ext='.dtb',
+            )
 
             # Bootloader 32.
             bootloader32_dir = os.path.join(gem5_system_src_dir, 'arm', 'simple_bootloader')

common.py

@@ -170,6 +170,7 @@ def write_string_to_file(path, string, mode='w'):
             f.write(string)
 
 def copy_dir_if_update_non_recursive(srcdir, destdir, filter_ext=None):
+    # TODO print rsync equivalent.
     os.makedirs(destdir, exist_ok=True)
     for basename in os.listdir(srcdir):
         src = os.path.join(srcdir, basename)

run-gdbserver

@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 
-import glob
 import os
 import subprocess
 import sys