tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: c7d4c1fd91ab4a6d2620497921a9c6bf54650ab8 commit: 0652035a57945e14e611dafae2ec5b46a05bc1d1 [1092/10489] asm-generic: unaligned: remove byteshift helpers config: mips-randconfig-r014-20210617 (attached as .config) compiler: mipsel-linux-gcc (GCC) 9.3.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commi... git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git fetch --no-tags linux-next master git checkout 0652035a57945e14e611dafae2ec5b46a05bc1d1 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=mips If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): mipsel-linux-ld: arch/mips/boot/compressed/decompress.o: in function `decompress_kernel': mipsel-linux-ld: decompress.c:(.text+0x6cc): undefined reference to `__bswapsi2' --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org