meta: add sources from prototype meadow build system

prototype/env.py

@@ -0,0 +1,28 @@
+import os
+
+
+source_root = None
+
+
+class Environment:
+    def set_source_root(path):
+        global source_root
+        source_root = path
+
+
+    def source_root():
+        global source_root
+        return source_root
+
+
+    def build_root():
+        global source_root
+        return os.path.join(source_root, 'build')
+
+
+    def system_root():
+        return os.path.join(Environment.build_root(), 'target-root')
+
+
+    def native_root():
+        return os.path.join(Environment.build_root(), 'host-root')