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 2496f9bd4..2eec0ce23 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 79d41d6a7..bc3dbc609 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 96a0f055a..f64e59573 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 aaa324062..1fd852979 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 d9b3a7953..9d20ba02e 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 79ec45fd9..e43326e4a 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 4caf1e416..7aa2521e4 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 92a5a2b98..234aeb611 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 9f3849fea..7fbd20d00 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 f9b26e5d3..ae4739697 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))
 
 #########################################################################