MAKEALL: add support for per architecture toolchains

index 5b06c54..397adef 100755
@@ -35,6 +35,9 @@ usage()
 	Environment variables:
 	  BUILD_NCPUS      number of parallel make jobs (default: auto)
 	  CROSS_COMPILE    cross-compiler toolchain prefix (default: "")
+	  CROSS_COMPILE_<ARCH> cross-compiler toolchain prefix for
+	                   architecture "ARCH".  Substitute "ARCH" for any
+	                   supported architecture (default: "")
 	  MAKEALL_LOGDIR   output all logs to here (default: ./LOG/)
 	  BUILD_DIR        output build directory (default: ./)
 	  BUILD_NBUILDS	   number of parallel targets (default: 1)

@@ -180,13 +183,6 @@ else
 	JOBS=""
 fi
 
-
-if [ "${CROSS_COMPILE}" ] ; then
-	MAKE="make CROSS_COMPILE=${CROSS_COMPILE}"
-else
-	MAKE=make
-fi
-
 if [ "${MAKEALL_LOGDIR}" ] ; then
 	LOG_DIR=${MAKEALL_LOGDIR}
 else

@@ -585,6 +581,18 @@ get_target_maintainers() {
 	echo "$mail"
 }
 
+get_target_arch() {
+	local target=$1
+
+	# Automatic mode
+	local line=`egrep -i "^[[:space:]]*${target}[[:space:]]" boards.cfg`
+
+	if [ -z "${line}" ] ; then echo "" ; return ; fi
+
+	set ${line}
+	echo "$2"
+}
+
 list_target() {
 	if [ "$PRINT_MAINTS" != 'y' ] ; then
 		echo "$1"

@@ -655,6 +663,16 @@ build_target() {
 
 	export BUILD_DIR="${output_dir}"
 
+	target_arch=$(get_target_arch ${target})
+	eval cross_toolchain=\$CROSS_COMPILE_${target_arch^^}
+	if [ "${cross_toolchain}" ] ; then
+	    MAKE="make CROSS_COMPILE=${cross_toolchain}"
+	elif [ "${CROSS_COMPILE}" ] ; then
+	    MAKE="make CROSS_COMPILE=${CROSS_COMPILE}"
+	else
+	    MAKE=make
+	fi
+
 	${MAKE} distclean >/dev/null
 	${MAKE} -s ${target}_config