libfdt: Introduce libfdt shared library

Build a libfdt shared library in addition to the existing .a that is
created.  Symbol versioning is used from the libfdt/version.lds script.

Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>

Makefile

@@ -16,7 +16,7 @@ LOCAL_VERSION =
 CONFIG_LOCALVERSION =
 
 CPPFLAGS = -I libfdt
-CFLAGS = -Wall -g -Os -Wpointer-arith -Wcast-qual
+CFLAGS = -Wall -g -Os -fPIC -Wpointer-arith -Wcast-qual
 
 BISON = bison
 LEX = flex
@@ -115,19 +115,23 @@ endif
 #
 LIBFDT_objdir = libfdt
 LIBFDT_srcdir = libfdt
-LIBFDT_lib = $(LIBFDT_objdir)/libfdt.a
+LIBFDT_archive = $(LIBFDT_objdir)/libfdt.a
+LIBFDT_lib = $(LIBFDT_objdir)/libfdt.so
 LIBFDT_include = $(addprefix $(LIBFDT_srcdir)/,$(LIBFDT_INCLUDES))
+LIBFDT_version = $(addprefix $(LIBFDT_srcdir)/,$(LIBFDT_VERSION))
 
 include $(LIBFDT_srcdir)/Makefile.libfdt
 
 .PHONY: libfdt
-libfdt: $(LIBFDT_lib)
+libfdt: $(LIBFDT_archive) $(LIBFDT_lib)
 
+$(LIBFDT_archive): $(addprefix $(LIBFDT_objdir)/,$(LIBFDT_OBJS))
 $(LIBFDT_lib): $(addprefix $(LIBFDT_objdir)/,$(LIBFDT_OBJS))
 
 libfdt_clean:
 	@$(VECHO) CLEAN "(libfdt)"
 	rm -f $(addprefix $(LIBFDT_objdir)/,$(STD_CLEANFILES))
+	rm -f $(LIBFDT_objdir)/*.so
 
 ifneq ($(DEPTARGETS),)
 -include $(LIBFDT_OBJS:%.o=$(LIBFDT_objdir)/%.d)
@@ -215,6 +219,11 @@ clean: libfdt_clean tests_clean
 	@$(VECHO) AR $@
 	$(AR) $(ARFLAGS) $@ $^
 
+$(LIBFDT_lib):
+	@$(VECHO) LD $@
+	$(CC) $(LDFLAGS) -fPIC -Wl,--version-script=$(LIBFDT_version) -Wl,-soname,$(notdir $@) -shared -o $(LIBFDT_objdir)/libfdt-$(DTC_VERSION).so $^
+	ln -s libfdt-$(DTC_VERSION).so $(LIBFDT_objdir)/libfdt.so
+
 %.lex.c: %.l
 	@$(VECHO) LEX $@
 	$(LEX) -o$@ $<

libfdt/Makefile.libfdt

@@ -4,5 +4,6 @@
 # be easily embeddable into other systems of Makefiles.
 #
 LIBFDT_INCLUDES = fdt.h libfdt.h
+LIBFDT_VERSION = version.lds
 LIBFDT_SRCS = fdt.c fdt_ro.c fdt_wip.c fdt_sw.c fdt_rw.c fdt_strerror.c
 LIBFDT_OBJS = $(LIBFDT_SRCS:%.c=%.o)

tests/Makefile.tests

@@ -35,9 +35,9 @@ TESTS_CLEANFILES = $(TESTS) $(TESTS_CLEANFILES_L:%=$(TESTS_PREFIX)%)
 .PHONY: tests
 tests:	$(TESTS) $(TESTS_TREES)
 
-$(LIB_TESTS): %: $(TESTS_PREFIX)testutils.o $(LIBFDT_lib)
+$(LIB_TESTS): %: $(TESTS_PREFIX)testutils.o $(LIBFDT_archive)
 
-$(LIBTREE_TESTS): %: $(TESTS_PREFIX)testutils.o $(TESTS_PREFIX)trees.o $(LIBFDT_lib)
+$(LIBTREE_TESTS): %: $(TESTS_PREFIX)testutils.o $(TESTS_PREFIX)trees.o $(LIBFDT_archive)
 
 $(TESTS_PREFIX)dumptrees: $(TESTS_PREFIX)trees.o