diff --git a/cmake/cudnn.cmake b/cmake/cudnn.cmake
index 92dce20c698acb7257321bf50c569331a13b106b..69f40df51680a104c47d9335c070c570dcaff59a 100644
--- a/cmake/cudnn.cmake
+++ b/cmake/cudnn.cmake
@@ -11,23 +11,16 @@ find_path(CUDNN_INCLUDE_DIR cudnn.h
 
 get_filename_component(__libpath_hist ${CUDA_CUDART_LIBRARY} PATH)
 
-if(NOT ${CMAKE_HOST_SYSTEM_PROCESSOR})
-    execute_process(
-        COMMAND uname -m COMMAND tr -d '\n'
-        OUTPUT_VARIABLE HOST_ARCH
-        RESULT_VARIABLE UNAME_RESULT)
-    if(${UNAME_RESULT})
-        set(HOST_ARCH "x86_64")
-    endif(${UNAME_RESULT})
-else(NOT ${CMAKE_HOST_SYSTEM_PROCESSOR})
-    set(HOST_ARCH ${CMAKE_HOST_SYSTEM_PROCESSOR})
-endif(NOT ${CMAKE_HOST_SYSTEM_PROCESSOR})
+set(TARGET_ARCH "x86_64")
+if(NOT ${CMAKE_SYSTEM_PROCESSOR})
+    set(TARGET_ARCH ${CMAKE_SYSTEM_PROCESSOR})
+endif()
 
 list(APPEND CUDNN_CHECK_LIBRARY_DIRS
     ${CUDNN_ROOT}
     ${CUDNN_ROOT}/lib64
     ${CUDNN_ROOT}/lib
-    ${CUDNN_ROOT}/lib/${HOST_ARCH}-linux-gnu
+    ${CUDNN_ROOT}/lib/${TARGET_ARCH}-linux-gnu
     $ENV{CUDNN_ROOT}
     $ENV{CUDNN_ROOT}/lib64
     $ENV{CUDNN_ROOT}/lib
diff --git a/cmake/external/openblas.cmake b/cmake/external/openblas.cmake
index cb67793cf974cb8cdd0779227e8642cf7437f7fb..2341e3785bd8e951e10e3f6bbf8a32f63e4ae44d 100644
--- a/cmake/external/openblas.cmake
+++ b/cmake/external/openblas.cmake
@@ -24,20 +24,25 @@ IF(NOT ${CBLAS_FOUND})
     SET(CBLAS_LIBRARIES "${CBLAS_INSTALL_DIR}/lib/${LIBRARY_PREFIX}openblas${STATIC_LIBRARY_SUFFIX}"
         CACHE FILEPATH "openblas library." FORCE)
 
-    SET(COMMON_ARGS CC=${CMAKE_C_COMPILER} NO_SHARED=1 NO_LAPACK=1)
+    SET(COMMON_ARGS CC=${CMAKE_C_COMPILER} NO_SHARED=1 NO_LAPACK=1 libs)
 
-    IF(ANDROID)
-        # arm_soft_fp_abi branch of OpenBLAS to support softfp
-        #   https://github.com/xianyi/OpenBLAS/tree/arm_soft_fp_abi
-        SET(OPENBLAS_COMMIT "b5c96fcfcdc82945502a2303116a64d89985daf5")
-        SET(OPTIONAL_ARGS HOSTCC=${HOST_C_COMPILER} TARGET=ARMV7 ARM_SOFTFP_ABI=1 USE_THREAD=0 libs)
-    ELSEIF(RPI)
-        # use hardfp
-        SET(OPENBLAS_COMMIT "v0.2.19")
-        SET(OPTIONAL_ARGS HOSTCC=${HOST_C_COMPILER} TARGET=ARMV7 USE_THREAD=0 libs)
+    IF(CMAKE_CROSSCOMPILING)
+        IF(ANDROID)
+            # arm_soft_fp_abi branch of OpenBLAS to support softfp
+            #   https://github.com/xianyi/OpenBLAS/tree/arm_soft_fp_abi
+            SET(OPENBLAS_COMMIT "b5c96fcfcdc82945502a2303116a64d89985daf5")
+            SET(OPTIONAL_ARGS HOSTCC=${HOST_C_COMPILER} TARGET=ARMV7 ARM_SOFTFP_ABI=1 USE_THREAD=0)
+        ELSEIF(RPI)
+            # use hardfp
+            SET(OPENBLAS_COMMIT "v0.2.19")
+            SET(OPTIONAL_ARGS HOSTCC=${HOST_C_COMPILER} TARGET=ARMV7 USE_THREAD=0)
+        ENDIF()
     ELSE()
         SET(OPENBLAS_COMMIT "v0.2.19")
-        SET(OPTIONAL_ARGS DYNAMIC_ARCH=1 libs NUM_THREADS=64)
+        SET(OPTIONAL_ARGS "")
+        IF(CMAKE_SYSTEM_PROCESSOR MATCHES "^x86(_64)?$")
+            SET(OPTIONAL_ARGS DYNAMIC_ARCH=1 NUM_THREADS=64)
+        ENDIF()
     ENDIF()
 
     ExternalProject_Add(