Add fastbuild option

builder/frameworks/mbed.py

@@ -28,6 +28,7 @@ http://mbed.org/
 import os
 
 from SCons.Script import Import, SConscript
+import os
 
 Import("env")
 
@@ -66,7 +67,27 @@ def applymbedignore():
 applymbedignore()
 
 
+oldbuild = env.BuildSources
+
+def fastbuild(variant_dir, src_dir, src_filter=None):
+    env.Append(
+        LINKOBJS=[
+            env.subst(f'$PROJECT_DIR/mbedos/{f}')
+            for f in os.listdir(env.subst('$PROJECT_DIR/mbedos'))
+            if f.endswith('.o')
+        ]
+    )
+
+if env.GetBuildType() == 'release' and os.path.exists(env.subst('$PROJECT_DIR/mbedos')):
+    env.Replace(
+        LINKCOM="${TEMPFILE('$LINK -o $TARGET $LINKFLAGS $__RPATH $LINKOBJS $SOURCES $_LIBDIRFLAGS $_LIBFLAGS','$LINKCOMSTR')}"
+    )
+    env.BuildSources = fastbuild
+
+
 # https://github.com/platformio/builder-framework-mbed.git
 SConscript(
     os.path.join(env.PioPlatform().get_package_dir("framework-mbed"), "platformio",
          "platformio-build.py"))
+
+env.BuildSources = oldbuild

builder/main.py

@@ -134,3 +134,13 @@ AlwaysBuild(env.Alias('upload', target_elf, upload_actions))
 #
 
 Default([target_buildprog, target_size])
+
+#
+# Custom targets
+#
+
+env.AddCustomTarget(
+    'Unpack Mbed OS',
+    None,
+    'cd mbedos; $AR x mbedos.lib',
+)