diff --git a/toolchain/toolchain-external/toolchain-external.mk b/toolchain/toolchain-external/toolchain-external.mk
index e2e99538ab..2351c9bc95 100644
--- a/toolchain/toolchain-external/toolchain-external.mk
+++ b/toolchain/toolchain-external/toolchain-external.mk
@@ -389,7 +389,7 @@ define TOOLCHAIN_EXTERNAL_CONFIGURE_CMDS
 	$(Q)$(call check_cross_compiler_exists,$(TOOLCHAIN_EXTERNAL_CC))
 	$(Q)$(call check_unusable_toolchain,$(TOOLCHAIN_EXTERNAL_CC))
 	$(Q)LIBC_A_LOCATION=`readlink -f $$(LANG=C $(TOOLCHAIN_EXTERNAL_CC) -print-file-name=libc.a)` ; \
-	SYSROOT_DIR=`echo $${LIBC_A_LOCATION} | sed -r -e 's:(usr/)?lib(32|64)?/(.*/)?libc\.a::'` ; \
+	SYSROOT_DIR=`echo $${LIBC_A_LOCATION} | sed -r -e 's:(usr/)?lib(32|64)?/([^/]*/)?libc\.a::'` ; \
 	if test -z "$${SYSROOT_DIR}" ; then \
 		@echo "External toolchain doesn't support --sysroot. Cannot use." ; \
 		exit 1 ; \
@@ -471,14 +471,14 @@ endif
 
 define TOOLCHAIN_EXTERNAL_INSTALL_CORE
 	$(Q)LIBC_A_LOCATION=`readlink -f $$(LANG=C $(TOOLCHAIN_EXTERNAL_CC) -print-file-name=libc.a)` ; \
-	SYSROOT_DIR=`echo $${LIBC_A_LOCATION} | sed -r -e 's:usr/lib(32|64)?/(.*/)?libc\.a::'` ; \
+	SYSROOT_DIR=`echo $${LIBC_A_LOCATION} | sed -r -e 's:(usr/)?lib(32|64)?/([^/]*/)?libc\.a::'` ; \
 	if test -z "$${SYSROOT_DIR}" ; then \
 		@echo "External toolchain doesn't support --sysroot. Cannot use." ; \
 		exit 1 ; \
 	fi ; \
 	ARCH_LIBC_A_LOCATION=`readlink -f $$(LANG=C $(TOOLCHAIN_EXTERNAL_CC) $(TOOLCHAIN_EXTERNAL_CFLAGS) -print-file-name=libc.a)` ; \
-	ARCH_SYSROOT_DIR=`echo $${ARCH_LIBC_A_LOCATION} | sed -r -e 's:usr/lib(32|64)?/(.*/)?libc\.a::'` ; \
-	ARCH_LIB_DIR=`echo $${ARCH_LIBC_A_LOCATION} | sed -r -e 's:.*/usr/(lib(32|64)?)/(.*/)?libc.a:\1:'` ; \
+	ARCH_SYSROOT_DIR=`echo $${ARCH_LIBC_A_LOCATION} | sed -r -e 's:(usr/)?lib(32|64)?/([^/]*/)?libc\.a::'` ; \
+	ARCH_LIB_DIR=`echo $${ARCH_LIBC_A_LOCATION} | sed -r -e 's:.*/(usr/)?(lib(32|64)?)/([^/]*/)?libc.a:\2:'` ; \
 	SUPPORT_LIB_DIR="" ; \
 	if test `find $${ARCH_SYSROOT_DIR} -name 'libstdc++.a' | wc -l` -eq 0 ; then \
 		LIBSTDCPP_A_LOCATION=$$(LANG=C $(TOOLCHAIN_EXTERNAL_CC) $(TOOLCHAIN_EXTERNAL_CFLAGS) -print-file-name=libstdc++.a) ; \
@@ -524,8 +524,8 @@ define TOOLCHAIN_EXTERNAL_INSTALL_BFIN_FDPIC
 	$(Q)$(call MESSAGE,"Install external toolchain FDPIC libraries to target...") ; \
 	FDPIC_EXTERNAL_CC=$(dir $(TOOLCHAIN_EXTERNAL_CC))/../../bfin-linux-uclibc/bin/bfin-linux-uclibc-gcc ; \
 	FDPIC_LIBC_A_LOCATION=`readlink -f $$(LANG=C $${FDPIC_EXTERNAL_CC} $(TOOLCHAIN_EXTERNAL_CFLAGS) -print-file-name=libc.a)` ; \
-	FDPIC_SYSROOT_DIR=`echo $${FDPIC_LIBC_A_LOCATION} | sed -r -e 's:usr/lib(32|64)?/(.*/)?libc\.a::'` ; \
-	FDPIC_LIB_DIR=`echo $${FDPIC_LIBC_A_LOCATION} | sed -r -e 's:.*/usr/(lib(32|64)?)/(.*/)?libc.a:\1:'` ; \
+	FDPIC_SYSROOT_DIR=`echo $${FDPIC_LIBC_A_LOCATION} | sed -r -e 's:(usr/)?lib(32|64)?/([^/]*/)?libc\.a::'` ; \
+	FDPIC_LIB_DIR=`echo $${FDPIC_LIBC_A_LOCATION} | sed -r -e 's:.*/(usr/)?(lib(32|64)?)/([^/]*/)?libc.a:\2:'` ; \
 	FDPIC_SUPPORT_LIB_DIR="" ; \
 	if test `find $${FDPIC_SYSROOT_DIR} -name 'libstdc++.a' | wc -l` -eq 0 ; then \
 	        FDPIC_LIBSTDCPP_A_LOCATION=$$(LANG=C $${FDPIC_EXTERNAL_CC} $(TOOLCHAIN_EXTERNAL_CFLAGS) -print-file-name=libstdc++.a) ; \