diff --git a/sdk/common.mk b/sdk/common.mk
new file mode 100644
index 0000000..19c3548
--- /dev/null
+++ b/sdk/common.mk
@@ -0,0 +1,7 @@
+# Common declarations for Makefiles.
+#
+# Supported environments:
+#   * GNU/Linux
+#   * Windows NT (using MinGW/MSYS/Cygwin/WSL)
+
+ZXUNOSDK	:= $(patsubst %/,%,$(abspath $(dir $(lastword $(MAKEFILE_LIST)))))
diff --git a/sdk/setvars.bat b/sdk/setvars.bat
new file mode 100644
index 0000000..bfee4aa
--- /dev/null
+++ b/sdk/setvars.bat
@@ -0,0 +1,5 @@
+@echo off
+if not x%ZXUNOSDK% == x exit /b
+set ZXUNOSDK=%~dp0
+set ZXUNOSDK=%ZXUNOSDK:~0,-1%
+set PATH=%ZXUNOSDK%;%PATH%