external toolchain: slightly optimize the copy of the toolchain sysroot

The sysroot of an ARM CodeSourcery toolchain takes about 1.4 GB of
space, but 1.1+ GB of this space consists in locale-related
information which Buildroot doesn't use. By skipping the copy of those
unused files, we save quite a bit of time while importing the
toolchain sysroot.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

toolchain/helpers.mk

@@ -79,6 +79,9 @@ copy_toolchain_lib_root = \
 #    non-default architecture variant is used. Without this, the
 #    compiler fails to find libraries and headers.
 #
+# Note that the 'locale' directories are not copied. They are huge
+# (400+MB) in CodeSourcery toolchains, and they are not really useful.
+#
 # $1: main sysroot directory of the toolchain
 # $2: arch specific sysroot directory of the toolchain
 # $3: arch specific subdirectory in the sysroot
@@ -89,7 +92,7 @@ copy_toolchain_sysroot = \
 	ARCH_SUBDIR="$(strip $3)"; \
 	for i in etc lib sbin usr ; do \
 		if [ -d $${ARCH_SYSROOT_DIR}/$$i ] ; then \
-			cp -a $${ARCH_SYSROOT_DIR}/$$i $(STAGING_DIR)/ ; \
+			rsync -au --exclude 'usr/lib/locale' $${ARCH_SYSROOT_DIR}/$$i $(STAGING_DIR)/ ; \
 		fi ; \
 	done ; \
 	if [ `readlink -f $${SYSROOT_DIR}` != `readlink -f $${ARCH_SYSROOT_DIR}` ] ; then \