Example of FPU_SRC and NONFPU_SRC added

README.md

@@ -11,10 +11,20 @@ required for ESA projects. The Makefiles and the example sources demonstrate
 Application sources
 -------------------
 The sources of your project must be set inside the Makefile, in the FPU_SRC and
-NONFPU_SRC variables. As their names suggest, you add a file in the FPU_SRC list
+NONFPU_SRC variables. The VPATH can be used to automatically locate them in 
+your source tree:
+
+    NONFPU_SRC=          \
+    	init.c           \
+    	${EDISOFT_SRC}
+    
+    FPU_SRC=              \
+    	gnc.c
+    
+As their names suggest, you add a file in the FPU_SRC list
 if you want it to be compiled for native FPU use (i.e. without `-msoft-float`).
-Whether native FPU compilation is performed on it or not, is selected during 
-build time, by the FPU=1 Makefile parameter (see below)
+Whether native or emulated FPU compilation is performed on it, is selected during 
+build time ; by the FPU=1 Makefile parameter (see below)
 
 Compilation options
 -------------------