Add a quick master makefile to make testing faster

Makefile

@@ -0,0 +1,31 @@
+#
+# A master make file - currently just to help with build-depends and clean
+#
+
+SUBDIRS += debian/
+SUBDIRS += linux/
+
+# The boards/* subdirs should probably be controlled from a boards/Makefile
+# - maybe later
+
+SUBDIRS += boards/common-firmware-armbian/
+SUBDIRS += boards/common-firmware-raspbian/
+
+QEMUDIRS += boards/qemu_armhf/
+QEMUDIRS += boards/qemu_i386/
+SUBDIRS += $(QEMUDIRS)
+
+BOARDDIRS += boards/raspberrypi2/
+BOARDDIRS += boards/sun8i-h2-plus-orangepi-zero/
+BOARDDIRS += boards/sun8i-h3-orangepi-lite/
+BOARDDIRS += boards/sun8i-v3s-licheepi-zero/
+SUBDIRS += $(BOARDDIRS)
+
+all:
+	$(error This Makefile currently has no default build target)
+
+build-depends clean reallyclean:
+	$(foreach dir,$(SUBDIRS),$(MAKE) -C $(dir) $@ &&) true
+
+image:
+	$(foreach dir,$(BOARDDIRS),$(MAKE) -C $(dir) $@ &&) true

README.md

@@ -26,8 +26,7 @@ Building the image
 Multiple board targets are supported, but they all use the same basic
 process.  The following commands will build for the Orange Pi Zero:
 
-    make -C debian build-depends
-    make -C boards/sun8i-h2-plus-orangepi-zero build-depends
+    make build-depends
 
     make -C boards/sun8i-h2-plus-orangepi-zero image
 
@@ -49,12 +48,11 @@ One simple answer is to completely delete your repository and do a new
 clone from upstream, however that can be a little excessive.  The following
 commands will remove all the build artifacts:
 
-    make -C debian clean reallyclean
-    make -C boards/sun8i-h2-plus-orangepi-zero clean reallyclean
+    make clean reallyclean
 
-The "clean" target removes some files one-by-one from the build dir, wheras
-the "reallyclean" target just nukes the whole build dir - so this is kind of
-a belt-and-suspender approach.
+The "clean" target removes some files one-by-one from the build dir,
+wheras the "reallyclean" target just nukes each build dir - so this is
+kind of a belt-and-suspender approach.
 
 
 Using the image
@@ -121,8 +119,7 @@ Single Board Computers that are expected to be used - and it uses exactly
 the same binaries that would be used on those.  However, it is usually
 a slower emulator.
 
-    make -C debian build-depends
-    make -C boards/qemu_armhf build-depends
+    make build-depends
 
     make -C boards/qemu_armhf test
 
@@ -137,8 +134,7 @@ While this is not the expected architecture for most physical hardware,
 it is a much faster emulation.  Additionally, all the debian packages,
 configuration and customisation is the same as the armhf architecture.
 
-    make -C debian build-depends
-    make -C boards/qemu_i386 build-depends
+    make build-depends
 
     make -C boards/qemu_i386 test