1 files changed, 79 insertions, 11 deletions

diff --git a/toolchain/external-toolchain/ext-tool.mk b/toolchain/external-toolchain/ext-tool.mk
index 29a5ccab9..2c2562cde 100644
--- a/toolchain/external-toolchain/ext-tool.mk
+++ b/toolchain/external-toolchain/ext-tool.mk
@@ -2,7 +2,12 @@
 #
 # This file implements the support for external toolchains, i.e
 # toolchains that have not been produced by Buildroot itself and that
-# are already available on the system on which Buildroot runs.
+# are already available on the system on which Buildroot runs. So far,
+# we have tested this with:
+#
+#  * Toolchains generated by Crosstool-NG
+#  * Toolchains generated by Buildroot
+#  * ARM toolchains made available by Codesourcery
 #
 # The basic principle is the following
 #
@@ -35,23 +40,22 @@
 # directory to the target directory. Also optionaly strips the
 # library.
 #
-# $1: sysroot directory
+# $1: arch specific sysroot directory
 # $2: library name
 # $3: destination directory
 # $4: strip (y|n), default is to strip
 #
 copy_toolchain_lib_root = \
-	SYSROOT_DIR="$(strip $1)"; \
+	ARCH_SYSROOT_DIR="$(strip $1)"; \
 	LIB="$(strip $2)"; \
-	DST="$(strip $3)"; \
 	STRIP="$(strip $4)"; \
  \
-	LIBS=`(cd $${SYSROOT_DIR}; find . -path "./lib/$${LIB}.*" -o -path "./usr/lib/$${LIB}.*")` ; \
+	LIBS=`(cd $${ARCH_SYSROOT_DIR}; find . -path "./lib/$${LIB}.*" -o -path "./usr/lib/$${LIB}.*")` ; \
 	for FILE in $${LIBS} ; do \
 		LIB=`basename $${FILE}`; \
 		LIBDIR=`dirname $${FILE}` ; \
 		while test \! -z "$${LIB}"; do \
-			FULLPATH="$${SYSROOT_DIR}/$${LIBDIR}/$${LIB}" ; \
+			FULLPATH="$${ARCH_SYSROOT_DIR}/$${LIBDIR}/$${LIB}" ; \
 			rm -fr $(TARGET_DIR)/$${LIBDIR}/$${LIB}; \
 			mkdir -p $(TARGET_DIR)/$${LIBDIR}; \
 			if test -h $${FULLPATH} ; then \
@@ -76,13 +80,54 @@ copy_toolchain_lib_root = \
 
 #
 # Copy the full external toolchain sysroot directory to the staging
-# dir
+# dir. The operation of this function is rendered a little bit
+# complicated by the support for multilib toolchains.
 #
-# $1: sysroot directory
+# We start by copying etc, lib, sbin and usr from the sysroot of the
+# selected architecture variant (as pointed by ARCH_SYSROOT_DIR). This
+# allows to import into the staging directory the C library and
+# companion libraries for the correct architecture variant. We
+# explictly only copy etc, lib, sbin and usr since other directories
+# might exist for other architecture variants (on Codesourcery
+# toolchain, the sysroot for the default architecture variant contains
+# the armv4t and thumb2 subdirectories, which are the sysroot for the
+# corresponding architecture variants), and we don't want to import
+# them.
+#
+# Then, if the selected architecture variant is not the default one
+# (i.e, if SYSROOT_DIR != ARCH_SYSROOT_DIR), then we :
+#
+#  * Import the header files from the default architecture
+#    variant. Header files are typically shared between the sysroots
+#    for the different architecture variants. If we use the
+#    non-default one, header files were not copied by the previous
+#    step, so we copy them here from the sysroot of the default
+#    architecture variant.
+#
+#  * Create a symbolic link that matches the name of the subdirectory
+#    for the architecture variant in the original sysroot. This is
+#    required as the compiler will by default look in
+#    sysroot_dir/arch_variant/ for libraries and headers, when the
+#    non-default architecture variant is used. Without this, the
+#    compiler fails to find libraries and headers.
+#
+# $1: main sysroot directory of the toolchain
+# $2: arch specific sysroot directory of the toolchain
+# $3: arch specific subdirectory in the sysroot
 #
 copy_toolchain_sysroot = \
 	SYSROOT_DIR="$(strip $1)"; \
-	cp -a $${SYSROOT_DIR}/* $(STAGING_DIR)/ ; \
+	ARCH_SYSROOT_DIR="$(strip $2)"; \
+	ARCH_SUBDIR="$(strip $3)"; \
+	for i in etc lib sbin usr ; do \
+		cp -a $${ARCH_SYSROOT_DIR}/$$i $(STAGING_DIR)/ ; \
+	done ; \
+	if [ `readlink -f $${SYSROOT_DIR}` != `readlink -f $${ARCH_SYSROOT_DIR}` ] ; then \
+		if [ ! -d $${ARCH_SYSROOT_DIR}/usr/include ] ; then \
+			cp -a $${SYSROOT_DIR}/usr/include $(STAGING_DIR)/usr ; \
+		fi ; \
+		ln -s . $(STAGING_DIR)/$(ARCH_SUBDIR) ; \
+	fi ; \
 	find $(STAGING_DIR) -type d | xargs chmod 755
 
 #
@@ -208,7 +253,30 @@ ifeq ($(BR2_INSTALL_LIBSTDCPP),y)
 EXTERNAL_LIBS+=libstdc++.so
 endif
 
+# SYSROOT_DIR selection. We first try the -print-sysroot option,
+# available in gcc 4.4.x and in some Codesourcery toolchains. If this
+# option is not available, we fallback to the value of --with-sysroot
+# as visible in CROSS-gcc -v. We don't pass the -march= option to gcc
+# as we want the "main" sysroot, which contains all variants of the C
+# library in the case of multilib toolchains.
+SYSROOT_DIR=$(shell $(TARGET_CC) -print-sysroot 2>/dev/null)
+ifeq ($(SYSROOT_DIR),)
 SYSROOT_DIR=$(shell readlink -f $$(LANG=C $(TARGET_CC) -print-file-name=libc.a |sed -r -e 's:usr/lib/libc\.a::;'))
+endif
+
+# Now, find if the toolchain specifies a sub-directory for the
+# specific architecture variant we're interested in. This is the case
+# with multilib toolchain, when the selected architecture variant is
+# not the default one. To do so, we ask the compiler by passing the
+# appropriate -march= flags. ARCH_SUBDIR will contain the
+# subdirectory, in the main SYSROOT_DIR, that corresponds to the
+# selected architecture variant. ARCH_SYSROOT_DIR will contain the
+# full path to this location.
+ifneq ($(CC_TARGET_ARCH_),)
+TARGET_CC_ARCH_CFLAGS+=-march=$(CC_TARGET_ARCH_)
+endif
+ARCH_SUBDIR=$(shell $(TARGET_CC) $(TARGET_CC_ARCH_CFLAGS) -print-multi-directory)
+ARCH_SYSROOT_DIR=$(SYSROOT_DIR)/$(ARCH_SUBDIR)
 
 $(STAMP_DIR)/ext-toolchain-installed:
 	@echo "Checking external toolchain settings"
@@ -228,8 +296,8 @@ endif
 	mkdir -p $(TARGET_DIR)/lib
 	@echo "Copy external toolchain libraries to target..."
 	$(Q)for libs in $(EXTERNAL_LIBS); do \
-		$(call copy_toolchain_lib_root,$(SYSROOT_DIR),$$libs,/lib,$(BR2_TOOLCHAIN_EXTERNAL_STRIP)); \
+		$(call copy_toolchain_lib_root,$(ARCH_SYSROOT_DIR),$$libs,$(BR2_TOOLCHAIN_EXTERNAL_STRIP)); \
 	done
 	@echo "Copy external toolchain sysroot to staging..."
-	$(Q)$(call copy_toolchain_sysroot,$(SYSROOT_DIR))
+	$(Q)$(call copy_toolchain_sysroot,$(SYSROOT_DIR),$(ARCH_SYSROOT_DIR),$(ARCH_SUBDIR))
 	@touch $@