The firmware is cross-compiled, but the build system ends up using 'objcopy' instead of 'xtensa-elf-objcopy' by default. Force it to use the right one. --- source/target_firmware/configure 2014-10-28 20:57:26.834436561 +0100 +++ source/target_firmware/configure 2014-10-28 20:57:29.666436530 +0100 @@ -11,6 +11,7 @@ mkdir -p build cat > "$TOOLCHAIN_FILE" <<EOF INCLUDE(CMakeForceCompiler) +SET(CMAKE_OBJCOPY xtensa-elf-objcopy) SET(CMAKE_SYSTEM_PROCESSOR xtensa) SET(CMAKE_FIND_ROOT_PATH ${TOOLCHAIN}/$TARGET) SET(CMAKE_STRIP :)