Have the Windows batch files check for make

Makefile

@@ -11,10 +11,12 @@ all clean: %:
 	$(MAKE) -C armsrc $@
 	$(MAKE) -C $(HOST_BINARY) $@
 
-.PHONY: all clean help
+.PHONY: all clean help _test
 help:
 	@echo Multi-OS Makefile, you are running on $(DETECTED_OS)
 	@echo Possible targets:
 	@echo +	all   - Make bootrom, armsrc and the OS-specific host directory 
 	@echo +	clean - Clean in bootrom, armsrc and the OS-specific host directory
-	
+
+# Dummy target to test for GNU make availability
+_test:

cockpit/1makearm.bat

@@ -1,5 +1,8 @@
 @echo off
+call _checkmake
+IF %MAKE_FAILED%==1 GOTO end
 cd ..\armsrc
 rem make clean
 make
 cd ..\cockpit
+:end

cockpit/2makeboot.bat

@@ -1,5 +1,8 @@
 @echo off
+call _checkmake
+IF %MAKE_FAILED%==1 GOTO end
 cd ..\bootrom
 rem make clean
 make
 cd ..\cockpit
+:end

cockpit/_checkmake.bat

@@ -0,0 +1,14 @@
+@echo off
+make -C .. -s _test
+IF ERRORLEVEL 1 GOTO fail
+SET MAKE_FAILED=0
+GOTO end
+:fail
+echo ************************************************
+echo * A compatible (GNU) make was not detected     *
+echo * Please get an updated version of the Windows *
+echo * compile environment, or install GNU make     *
+echo * manually                                     *
+echo ************************************************
+SET MAKE_FAILED=1
+:end