Switch from archive libraries to partial linking

Before this commit, weak symbols were not overridden by non-weak symbols
found in archive libraries when linking with recent versions of
binutils.  As stated in the System V ABI, "the link editor does not
extract archive members to resolve undefined weak symbols".

This commit changes all Makefiles to use partial linking (ld -r) instead
of creating library archives, which forces all symbols to participate in
linking, allowing non-weak symbols to override weak symbols as intended.
This approach is also used by Linux, from which the gmake function
cmd_link_o_target (defined in config.mk and used in all Makefiles) is
inspired.

The name of each former library archive is preserved except for
extensions which change from ".a" to ".o".  This commit updates
references accordingly where needed, in particular in some linker
scripts.

This commit reveals board configurations that exclude some features but
include source files that depend these disabled features in the build,
resulting in undefined symbols.  Known such cases include:
- disabling CMD_NET but not CMD_NFS;
- enabling CONFIG_OF_LIBFDT but not CONFIG_QE.

Signed-off-by: Sebastien Carlier <sebastien.carlier@gmail.com>

10 files changed, 20 insertions, 20 deletions

diff --git a/board/atmel/at91cap9adk/Makefile b/board/atmel/at91cap9adk/Makefile
index 2496f9b..2eec0ce 100644
--- a/board/atmel/at91cap9adk/Makefile
+++ b/board/atmel/at91cap9adk/Makefile
@@ -27,7 +27,7 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	= $(obj)lib$(BOARD).a
+LIB	= $(obj)lib$(BOARD).o
 
 COBJS-y	+= at91cap9adk.o
 COBJS-y	+= led.o
@@ -38,7 +38,7 @@ OBJS    := $(addprefix $(obj),$(COBJS-y))
 SOBJS	:= $(addprefix $(obj),$(SOBJS))
 
 $(LIB):	$(obj).depend $(OBJS) $(SOBJS)
-	$(AR) $(ARFLAGS) $@ $(OBJS) $(SOBJS)
+	$(call cmd_link_o_target, $(OBJS) $(SOBJS))
 
 clean:
 	rm -f $(SOBJS) $(OBJS)
diff --git a/board/atmel/at91rm9200dk/Makefile b/board/atmel/at91rm9200dk/Makefile
index 79d41d6..bc3dbc6 100644
--- a/board/atmel/at91rm9200dk/Makefile
+++ b/board/atmel/at91rm9200dk/Makefile
@@ -23,7 +23,7 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	= $(obj)lib$(BOARD).a
+LIB	= $(obj)lib$(BOARD).o
 
 COBJS-y += $(BOARD).o
 COBJS-y += flash.o
@@ -38,7 +38,7 @@ OBJS	:= $(addprefix $(obj),$(COBJS-y))
 SOBJS	:= $(addprefix $(obj),$(SOBJS))
 
 $(LIB):	$(obj).depend $(OBJS) $(SOBJS)
-	$(AR) $(ARFLAGS) $@ $(OBJS) $(SOBJS)
+	$(call cmd_link_o_target, $(OBJS) $(SOBJS))
 
 clean:
 	rm -f $(SOBJS) $(OBJS)
diff --git a/board/atmel/at91rm9200ek/Makefile b/board/atmel/at91rm9200ek/Makefile
index 96a0f05..f64e595 100644
--- a/board/atmel/at91rm9200ek/Makefile
+++ b/board/atmel/at91rm9200ek/Makefile
@@ -23,7 +23,7 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	= $(obj)lib$(BOARD).a
+LIB	= $(obj)lib$(BOARD).o
 
 COBJS-y += $(BOARD).o
 COBJS-y += led.o
@@ -33,7 +33,7 @@ OBJS	:= $(addprefix $(obj),$(COBJS-y))
 SOBJS	:= $(addprefix $(obj),$(SOBJS))
 
 $(LIB):	$(obj).depend $(OBJS) $(SOBJS)
-	$(AR) $(ARFLAGS) $@ $(OBJS) $(SOBJS)
+	$(call cmd_link_o_target, $(OBJS) $(SOBJS))
 
 clean:
 	rm -f $(SOBJS) $(OBJS)
diff --git a/board/atmel/at91sam9260ek/Makefile b/board/atmel/at91sam9260ek/Makefile
index aaa3240..1fd8529 100644
--- a/board/atmel/at91sam9260ek/Makefile
+++ b/board/atmel/at91sam9260ek/Makefile
@@ -27,7 +27,7 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	= $(obj)lib$(BOARD).a
+LIB	= $(obj)lib$(BOARD).o
 
 COBJS-y	+= at91sam9260ek.o
 COBJS-y	+= led.o
@@ -38,7 +38,7 @@ OBJS	:= $(addprefix $(obj),$(COBJS-y))
 SOBJS	:= $(addprefix $(obj),$(SOBJS))
 
 $(LIB):	$(obj).depend $(OBJS) $(SOBJS)
-	$(AR) $(ARFLAGS) $@ $(OBJS) $(SOBJS)
+	$(call cmd_link_o_target, $(OBJS) $(SOBJS))
 
 clean:
 	rm -f $(SOBJS) $(OBJS)
diff --git a/board/atmel/at91sam9261ek/Makefile b/board/atmel/at91sam9261ek/Makefile
index d9b3a79..9d20ba0 100644
--- a/board/atmel/at91sam9261ek/Makefile
+++ b/board/atmel/at91sam9261ek/Makefile
@@ -27,7 +27,7 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	= $(obj)lib$(BOARD).a
+LIB	= $(obj)lib$(BOARD).o
 
 COBJS-y += at91sam9261ek.o
 COBJS-y += led.o
@@ -38,7 +38,7 @@ OBJS	:= $(addprefix $(obj),$(COBJS-y))
 SOBJS	:= $(addprefix $(obj),$(SOBJS))
 
 $(LIB):	$(obj).depend $(OBJS) $(SOBJS)
-	$(AR) $(ARFLAGS) $@ $(OBJS) $(SOBJS)
+	$(call cmd_link_o_target, $(OBJS) $(SOBJS))
 
 clean:
 	rm -f $(SOBJS) $(OBJS)
diff --git a/board/atmel/at91sam9263ek/Makefile b/board/atmel/at91sam9263ek/Makefile
index 79ec45f..e43326e 100644
--- a/board/atmel/at91sam9263ek/Makefile
+++ b/board/atmel/at91sam9263ek/Makefile
@@ -27,7 +27,7 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	= $(obj)lib$(BOARD).a
+LIB	= $(obj)lib$(BOARD).o
 
 COBJS-y += at91sam9263ek.o
 COBJS-y += led.o
@@ -38,7 +38,7 @@ OBJS	:= $(addprefix $(obj),$(COBJS-y))
 SOBJS	:= $(addprefix $(obj),$(SOBJS-y))
 
 $(LIB):	$(obj).depend $(OBJS) $(SOBJS)
-	$(AR) $(ARFLAGS) $@ $(OBJS) $(SOBJS)
+	$(call cmd_link_o_target, $(OBJS) $(SOBJS))
 
 clean:
 	rm -f $(SOBJS) $(OBJS)
diff --git a/board/atmel/at91sam9m10g45ek/Makefile b/board/atmel/at91sam9m10g45ek/Makefile
index 4caf1e4..7aa2521 100644
--- a/board/atmel/at91sam9m10g45ek/Makefile
+++ b/board/atmel/at91sam9m10g45ek/Makefile
@@ -27,7 +27,7 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	= $(obj)lib$(BOARD).a
+LIB	= $(obj)lib$(BOARD).o
 
 COBJS-y += at91sam9m10g45ek.o
 COBJS-y += led.o
@@ -37,7 +37,7 @@ OBJS	:= $(addprefix $(obj),$(COBJS-y))
 SOBJS	:= $(addprefix $(obj),$(SOBJS))
 
 $(LIB):	$(obj).depend $(OBJS) $(SOBJS)
-	$(AR) $(ARFLAGS) $@ $(OBJS) $(SOBJS)
+	$(call cmd_link_o_target, $(OBJS) $(SOBJS))
 
 clean:
 	rm -f $(SOBJS) $(OBJS)
diff --git a/board/atmel/at91sam9rlek/Makefile b/board/atmel/at91sam9rlek/Makefile
index 92a5a2b..234aeb6 100644
--- a/board/atmel/at91sam9rlek/Makefile
+++ b/board/atmel/at91sam9rlek/Makefile
@@ -27,7 +27,7 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	= $(obj)lib$(BOARD).a
+LIB	= $(obj)lib$(BOARD).o
 
 COBJS-y += at91sam9rlek.o
 COBJS-y += led.o
@@ -38,7 +38,7 @@ OBJS	:= $(addprefix $(obj),$(COBJS-y))
 SOBJS	:= $(addprefix $(obj),$(SOBJS))
 
 $(LIB):	$(obj).depend $(OBJS) $(SOBJS)
-	$(AR) $(ARFLAGS) $@ $(OBJS) $(SOBJS)
+	$(call cmd_link_o_target, $(OBJS) $(SOBJS))
 
 clean:
 	rm -f $(SOBJS) $(OBJS)
diff --git a/board/atmel/atngw100/Makefile b/board/atmel/atngw100/Makefile
index 9f3849f..7fbd20d 100644
--- a/board/atmel/atngw100/Makefile
+++ b/board/atmel/atngw100/Makefile
@@ -20,7 +20,7 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	:= $(obj)lib$(BOARD).a
+LIB	:= $(obj)lib$(BOARD).o
 
 COBJS	:= $(BOARD).o
 
@@ -28,7 +28,7 @@ SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(SOBJS) $(COBJS))
 
 $(LIB): $(obj).depend $(OBJS)
-	$(AR) $(ARFLAGS) $@ $(OBJS)
+	$(call cmd_link_o_target, $(OBJS))
 
 #########################################################################
 
diff --git a/board/atmel/atstk1000/Makefile b/board/atmel/atstk1000/Makefile
index f9b26e5..ae47396 100644
--- a/board/atmel/atstk1000/Makefile
+++ b/board/atmel/atstk1000/Makefile
@@ -24,7 +24,7 @@
 
 include $(TOPDIR)/config.mk
 
-LIB			:= $(obj)lib$(BOARD).a
+LIB			:= $(obj)lib$(BOARD).o
 
 COBJS-y			+= $(BOARD).o
 COBJS-y			+= flash.o
@@ -33,7 +33,7 @@ SRCS			:= $(SOBJS-y:.o=.S) $(COBJS-y:.o=.c)
 OBJS			:= $(addprefix $(obj),$(SOBJS-y) $(COBJS-y))
 
 $(LIB): $(obj).depend $(OBJS)
-	$(AR) $(ARFLAGS) $@ $(OBJS)
+	$(call cmd_link_o_target, $(OBJS))
 
 #########################################################################