Easily use different toolchain - for example:

RTEMS=/opt/rtems-4.12-2016.06.15 \
    CROSS_PREFIX=sparc-rtems4.12 LEON=ngmp \
    make CFG=release FPU=0 V=1

OAR/Makefile

@@ -17,10 +17,10 @@ endif
 
 # Build up our settings from our inputs and our environment
 LEON ?= leon3
+CROSS_PREFIX ?= sparc-rtems4.11
 RTEMS ?= /opt/rtems-4.11-2016.04.01.${FPU_SUFFIX}
-RTEMS_MAKEFILE_PATH = ${RTEMS}/sparc-rtems4.11/${LEON}
+RTEMS_MAKEFILE_PATH = ${RTEMS}/${CROSS_PREFIX}/${LEON}
 RTEMS_LIB=${RTEMS_MAKEFILE_PATH}/lib
-CROSS_PREFIX=sparc-rtems4.11
 
 # If not selected, compile debug version of binary (no optimizations)
 #ifeq ($(CFG),)
@@ -117,8 +117,8 @@ else
 	@$(CC) -g -o $@ $^ ${LDFLAGS}
 endif
 ifeq ($(CFG),release)
-	@${CROSS_PREFIX}-objcopy --only-keep-debug $@ ${@}.debug
-	@${CROSS_PREFIX}-strip $@
+	@${RTEMS}/bin/${CROSS_PREFIX}-objcopy --only-keep-debug $@ ${@}.debug
+	@${RTEMS}/bin/${CROSS_PREFIX}-strip $@
 endif
 	@echo Built with RTEMS at ${RTEMS_LIB} for ${LEON}.