[U-Boot] [PATCH v3 09/20] fdt: Build the new python libfdt module

[Simon Glass]

Build the upstream python libfdt module. At present the legacy module is
still built and is the one that it used. Future work will switch this
over.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

Changes in v3:
- More machinations to avoid touching the source directory

Changes in v2:
- Fix building when srcpath is ".."

 tools/Makefile | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/tools/Makefile b/tools/Makefile
index cd08d3b33b..bc411e4ae4 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -63,6 +63,16 @@ FIT_SIG_OBJS-$(CONFIG_FIT_SIGNATURE) := common/image-sig.o
 LIBFDT_CSRCS := fdt.c fdt_ro.c fdt_wip.c fdt_sw.c fdt_rw.c fdt_strerror.c  \
 			fdt_empty_tree.c fdt_addresses.c fdt_overlay.c \
 			fdt_region.c
+
+# Unfortunately setup.py below cannot handle srctree being ".." which it often
+# is. It fails with an error like:
+# Fatal error: can't create build/temp.linux-x86_64-2.7/../lib/libfdt/fdt.o:
+#    No such file or directory
+# To fix this, use an absolute path.
+libfdt_tree := $(shell readlink -f $(srctree)/lib/libfdt)
+
+LIBFDT_SRCS := $(addprefix $(libfdt_tree)/, $(LIBFDT_CSRCS))
+LIBFDT_SWIG := $(addprefix $(libfdt_tree)/, pylibfdt/libfdt.i)
 LIBFDT_OBJS := $(addprefix lib/libfdt/, $(patsubst %.c, %.o, $(LIBFDT_CSRCS)))
 
 RSA_OBJS-$(CONFIG_FIT_SIGNATURE) := $(addprefix lib/rsa/, \
@@ -114,6 +124,23 @@ mkimage-objs   := $(dumpimage-mkimage-objs) mkimage.o
 fit_info-objs   := $(dumpimage-mkimage-objs) fit_info.o
 fit_check_sign-objs   := $(dumpimage-mkimage-objs) fit_check_sign.o
 
+# Unfortunately setup.py (or actually the Python distutil implementation)
+# puts files into the same directory as the .i file. We cannot touch the source
+# directory, so we copy the .i file into the tools/ build subdirectory before
+# calling setup. This directory is safe to write to. This ensures that we get
+# all three files in $(obj)/tools: _libfdt.so, libfdt.py and libfdt_wrap.c
+# The latter is a temporary file which we could actually remove.
+tools/_libfdt.so: $(LIBFDT_SRCS) $(LIBFDT_SWIG)
+	cp $(LIBFDT_SWIG) tools/.
+	unset CC; \
+	unset CROSS_COMPILE; \
+	LDFLAGS="$(HOSTLDFLAGS)" CFLAGS= VERSION="u-boot-$(UBOOTVERSION)" \
+		CPPFLAGS="$(_hostc_flags)" OBJDIR=tools \
+		SOURCES="$(LIBFDT_SRCS) tools/libfdt.i" \
+		SWIG_OPTS="-I$(srctree)/lib/libfdt -I$(srctree)/lib" \
+		$(libfdt_tree)/pylibfdt/setup.py --quiet build_ext \
+			--build-lib tools
+
 # Build a libfdt Python module if swig is available
 # Use 'sudo apt-get install swig libpython-dev' to enable this
 hostprogs-y += \
@@ -219,6 +246,10 @@ clean-dirs := lib common
 
 always := $(hostprogs-y)
 
+# Build a libfdt Python module if swig is available
+# Use 'sudo apt-get install swig libpython-dev' to enable this
+always += $(if $(shell which swig 2> /dev/null),_libfdt.so)
+
 # Generated LCD/video logo
 LOGO_H = $(objtree)/include/bmp_logo.h
 LOGO_DATA_H = $(objtree)/include/bmp_logo_data.h
-- 
2.13.0.219.gdb65acc882-goog