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>

8 files changed, 16 insertions, 16 deletions

diff --git a/arch/arm/cpu/arm920t/Makefile b/arch/arm/cpu/arm920t/Makefile
index cbb13b2..dcc7782 100644
--- a/arch/arm/cpu/arm920t/Makefile
+++ b/arch/arm/cpu/arm920t/Makefile
@@ -23,7 +23,7 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	= $(obj)lib$(CPU).a
+LIB	= $(obj)lib$(CPU).o
 
 START	= start.o
 
@@ -37,7 +37,7 @@ START	:= $(addprefix $(obj),$(START))
 all:	$(obj).depend $(START) $(LIB)
 
 $(LIB):	$(OBJS)
-	$(AR) $(ARFLAGS) $@ $(OBJS)
+	$(call cmd_link_o_target, $(OBJS))
 
 #########################################################################
 
diff --git a/arch/arm/cpu/arm920t/a320/Makefile b/arch/arm/cpu/arm920t/a320/Makefile
index f030c53..31da706 100644
--- a/arch/arm/cpu/arm920t/a320/Makefile
+++ b/arch/arm/cpu/arm920t/a320/Makefile
@@ -23,7 +23,7 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	= $(obj)lib$(SOC).a
+LIB	= $(obj)lib$(SOC).o
 
 SOBJS	+= reset.o
 COBJS	+= timer.o
@@ -35,7 +35,7 @@ OBJS	:= $(addprefix $(obj),$(SOBJS) $(COBJS))
 all:	$(obj).depend $(LIB)
 
 $(LIB):	$(OBJS)
-	$(AR) $(ARFLAGS) $@ $(OBJS)
+	$(call cmd_link_o_target, $(OBJS))
 
 #########################################################################
 
diff --git a/arch/arm/cpu/arm920t/at91/Makefile b/arch/arm/cpu/arm920t/at91/Makefile
index d8a4383..5c71b77 100644
--- a/arch/arm/cpu/arm920t/at91/Makefile
+++ b/arch/arm/cpu/arm920t/at91/Makefile
@@ -23,7 +23,7 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	= $(obj)lib$(SOC).a
+LIB	= $(obj)lib$(SOC).o
 
 SOBJS	+= lowlevel_init.o
 COBJS	+= reset.o
@@ -35,7 +35,7 @@ OBJS	:= $(addprefix $(obj),$(SOBJS) $(COBJS))
 all:	$(obj).depend $(LIB)
 
 $(LIB):	$(OBJS)
-	$(AR) $(ARFLAGS) $@ $(OBJS)
+	$(call cmd_link_o_target, $(OBJS))
 
 #########################################################################
 
diff --git a/arch/arm/cpu/arm920t/at91rm9200/Makefile b/arch/arm/cpu/arm920t/at91rm9200/Makefile
index 114d8ad..7530e6a 100644
--- a/arch/arm/cpu/arm920t/at91rm9200/Makefile
+++ b/arch/arm/cpu/arm920t/at91rm9200/Makefile
@@ -23,7 +23,7 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	= $(obj)lib$(SOC).a
+LIB	= $(obj)lib$(SOC).o
 
 SOBJS	+= lowlevel_init.o
 
@@ -44,7 +44,7 @@ OBJS	:= $(addprefix $(obj),$(SOBJS) $(COBJS) $(COBJS-y))
 all:	$(obj).depend $(LIB)
 
 $(LIB):	$(OBJS)
-	$(AR) $(ARFLAGS) $@ $(OBJS)
+	$(call cmd_link_o_target, $(OBJS))
 
 #########################################################################
 
diff --git a/arch/arm/cpu/arm920t/ep93xx/Makefile b/arch/arm/cpu/arm920t/ep93xx/Makefile
index 01a2f55..1d6a538 100644
--- a/arch/arm/cpu/arm920t/ep93xx/Makefile
+++ b/arch/arm/cpu/arm920t/ep93xx/Makefile
@@ -32,7 +32,7 @@
 #
 include $(TOPDIR)/config.mk
 
-LIB = $(obj)lib$(SOC).a
+LIB = $(obj)lib$(SOC).o
 
 COBJS   = cpu.o led.o speed.o timer.o
 SOBJS   = lowlevel_init.o
@@ -43,7 +43,7 @@ OBJS    := $(addprefix $(obj),$(SOBJS) $(COBJS))
 all:    $(obj).depend $(LIB)
 
 $(LIB): $(OBJS)
-	$(AR) $(ARFLAGS) $@ $(OBJS)
+	$(call cmd_link_o_target, $(OBJS))
 
 #########################################################################
 
diff --git a/arch/arm/cpu/arm920t/imx/Makefile b/arch/arm/cpu/arm920t/imx/Makefile
index 28945e2..32b41b3 100644
--- a/arch/arm/cpu/arm920t/imx/Makefile
+++ b/arch/arm/cpu/arm920t/imx/Makefile
@@ -23,7 +23,7 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	= $(obj)lib$(SOC).a
+LIB	= $(obj)lib$(SOC).o
 
 COBJS	+= generic.o
 COBJS	+= speed.o
@@ -35,7 +35,7 @@ OBJS	:= $(addprefix $(obj),$(SOBJS) $(COBJS))
 all:	$(obj).depend $(LIB)
 
 $(LIB):	$(OBJS)
-	$(AR) $(ARFLAGS) $@ $(OBJS)
+	$(call cmd_link_o_target, $(OBJS))
 
 #########################################################################
 
diff --git a/arch/arm/cpu/arm920t/ks8695/Makefile b/arch/arm/cpu/arm920t/ks8695/Makefile
index f53fdc2..00ce62b 100644
--- a/arch/arm/cpu/arm920t/ks8695/Makefile
+++ b/arch/arm/cpu/arm920t/ks8695/Makefile
@@ -23,7 +23,7 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	= $(obj)lib$(SOC).a
+LIB	= $(obj)lib$(SOC).o
 
 SOBJS	= lowlevel_init.o
 
@@ -35,7 +35,7 @@ OBJS	:= $(addprefix $(obj),$(SOBJS) $(COBJS))
 all:	$(obj).depend $(LIB)
 
 $(LIB):	$(OBJS)
-	$(AR) $(ARFLAGS) $@ $(OBJS)
+	$(call cmd_link_o_target, $(OBJS))
 
 #########################################################################
 
diff --git a/arch/arm/cpu/arm920t/s3c24x0/Makefile b/arch/arm/cpu/arm920t/s3c24x0/Makefile
index 7e8d6ed..bd53724 100644
--- a/arch/arm/cpu/arm920t/s3c24x0/Makefile
+++ b/arch/arm/cpu/arm920t/s3c24x0/Makefile
@@ -23,7 +23,7 @@
 
 include $(TOPDIR)/config.mk
 
-LIB	= $(obj)lib$(SOC).a
+LIB	= $(obj)lib$(SOC).o
 
 COBJS-$(CONFIG_USE_IRQ) += interrupts.o
 COBJS-y	+= speed.o
@@ -38,7 +38,7 @@ OBJS	:= $(addprefix $(obj),$(SOBJS) $(COBJS-y))
 all:	$(obj).depend $(LIB)
 
 $(LIB):	$(OBJS)
-	$(AR) $(ARFLAGS) $@ $(OBJS)
+	$(call cmd_link_o_target, $(OBJS))
 
 #########################################################################