software: dependencies the Werner way

software/include.mak

@@ -43,3 +43,15 @@ CFLAGS = -O9 -Wall -Wstrict-prototypes -Wold-style-definition -Wshadow \
 	 -msign-extend-enabled -fno-builtin -fsigned-char \
 	 -fsingle-precision-constant $(INCLUDES)
 LDFLAGS = -nostdlib -nodefaultlibs
+
+# compile and generate dependencies, based on
+# http://scottmcpeak.com/autodepend/autodepend.html
+
+%.o: %.c
+	$(CC) -c $(CFLAGS) $*.c -o $*.o
+	@$(CC_normal) -MM $(CFLAGS) $*.c > $*.d
+	@mv -f $*.d $*.d.tmp
+	@sed -e 's|.*:|$*.o:|' < $*.d.tmp > $*.d
+	@sed -e 's/.*://' -e 's/\\$$//' < $*.d.tmp | fmt -1 | \
+	  sed -e 's/^ *//' -e 's/$$/:/' >> $*.d
+	@rm -f $*.d.tmp

software/libbase/Makefile

@@ -3,6 +3,9 @@ include $(MMDIR)/software/include.mak
 
 OBJECTS=divsi3.o libc.o console.o system.o board.o uart.o softfloat.o softfloat-glue.o vsnprintf.o atof.o
 
+# pull in dependency info for *existing* .o files
+-include $(OBJECTS:.o=.d)
+
 all: libbase.a
 
 libbase.a: $(OBJECTS)
@@ -12,4 +15,4 @@ libbase.a: $(OBJECTS)
 .PHONY: clean
 
 clean:
-	rm -f *.o libbase.a .*~ *~ Makefile.bak
+	rm -f $(OBJECTS) $(OBJECTS:.o=.d) libbase.a .*~ *~ Makefile.bak