X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/8f8f3478917401f3d286dafd73902e9d80b527d2..5b6bae3445d81a00f0dddf5759aa38d011f90cef:/Bootloaders/makefile

diff --git a/Bootloaders/makefile b/Bootloaders/makefile
index 94147ead0..003069b9a 100644
--- a/Bootloaders/makefile
+++ b/Bootloaders/makefile
@@ -13,10 +13,34 @@
 # custom LUFA library build options are reflected in the compiled
 # code.
 
-PROJECT_DIRECTORIES = $(shell ls -d *)
+PROJECT_DIRECTORIES := $(shell ls -d */)
 
-all:
-	@$(foreach PROJECT, $(PROJECT_DIRECTORIES), $(MAKE) -s -C $(PROJECT) clean all;)
+# This makefile is potentially infinitely recursive if something really bad
+# happens when determining the set of project directories - hard-abort if
+# more than 10 levels deep to avoid angry emails.
+ifeq ($(MAKELEVEL), 10)
+   $(error EMERGENCY ABORT: INFINITE RECURSION DETECTED)
+endif
 
-%:
-	@$(foreach PROJECT, $(PROJECT_DIRECTORIES), $(MAKE) -s -C $(PROJECT) $@;)
+# Need to special-case building without a per-project object directory
+ifeq ($(OBJDIR),)
+   # If no target specified, force "clean all" and disallow parallel build   
+   ifeq ($(MAKECMDGOALS),)
+      MAKECMDGOALS := clean all
+      .NOTPARALLEL:
+   endif
+
+   # If one of the targets is to build, force "clean" beforehand and disallow parallel build   
+   ifneq ($(findstring all, $(MAKECMDGOALS)),)
+      MAKECMDGOALS := clean $(MAKECMDGOALS)
+      .NOTPARALLEL:
+   endif
+endif
+
+%: $(PROJECT_DIRECTORIES)
+	@echo . > /dev/null
+
+$(PROJECT_DIRECTORIES):
+	@$(MAKE) -C $@ $(MAKECMDGOALS)
+    
+.PHONY: $(PROJECT_DIRECTORIES)