-JVM := $(JAVA_HOME)/bin/java
-JAVADOC := $(JAVA_HOME)/bin/javadoc
-ECJ_JAR := $(A2_BASE)/org.argeo.tp.sdk/org.eclipse.jdt.core.compiler.batch.3.29.jar
-BND_TOOL := /usr/bin/bnd
-
-BUILD_BASE = $(SDK_BUILD_BASE)/$(A2_CATEGORY)
-
-WORKSPACE_BNDS := $(shell cd $(SDK_SRC_BASE) && find cnf -name '*.bnd') sdk/argeo-build/argeo.bnd
-BUILD_WORKSPACE_BNDS := $(WORKSPACE_BNDS:%=$(BUILD_BASE)/%)
-
-A2_JARS = $(foreach category, $(DEP_CATEGORIES), $(shell find $(A2_BASE)/$(category) -name '*.jar'))
-A2_CLASSPATH = $(subst $(space),$(pathsep),$(strip $(A2_JARS)))
-
-A2_BUNDLES = $(foreach bundle, $(BUNDLES),$(A2_OUTPUT)/$(A2_CATEGORY)/$(shell basename $(bundle)).$(MAJOR).$(MINOR).jar)
+# The following variables are found in the sdk.mk file which is generated by the configure script:
+# SDK_SRC_BASE the base of the source code, typically the root of the cloned git repository
+# SDK_BUILD_BASE the base of the output
+# JAVA_HOME the base of the JDK used to build
+A2_OUTPUT := $(SDK_BUILD_BASE)/a2
+JVM ?= $(JAVA_HOME)/bin/java
+JAVADOC ?= $(JAVA_HOME)/bin/javadoc
+
+# The following variables should be declared in the Makefile:
+# BUNDLES the space-separated list of bundles to be built
+# A2_CATEGORY the a2 category the bundles will belong to
+#
+# The following variables have default values which can be overriden in the Makefile
+# DEP_CATEGORIES the a2 categories the compilation depends on
+# JAVADOC_PACKAGES the space-separated list of packages for which javadoc will be generated
+# A2_BASE the space-separated directories where already built a2 categories can be found
+DEP_CATEGORIES ?=
+JAVADOC_PACKAGES ?=
+A2_BASE ?= $(A2_OUTPUT)