[求助] 在ubuntu中使用make编译内核出现下面的错误，希望帮忙解决一下！

rm -f /usr/local/src/nios2-linux/uClinux-dist/linux-2.6.x/usr/initramfs_data.cpio.gz
make ARCH=nios2 CROSS_COMPILE=nios2-linux-uclibc- -C /usr/local/src/nios2-linux/uClinux-dist/../linux-2.6 O=/usr/local/src/nios2-linux/uClinux-dist/linux-2.6.x -j1 zImage || exit 1
make[1]: Entering directory `/usr/local/src/nios2-linux/linux-2.6'
  no emulation specific options.
  CHK     include/asm-nios2/nios2.h
perl -I/usr/local/src/nios2-linux/linux-2.6/arch/nios2/scripts /usr/local/src/nios2-linux/linux-2.6/arch/nios2/scripts/gen_nios2.h.pl cpu_0 sdram_0  < /usr/local/src/mycpu.ptf > include/asm-nios2/nios2.h.tmp; if [ -r include/asm-nios2/nios2.h ] && cmp -s include/asm-nios2/nios2.h include/asm-nios2/nios2.h.tmp; then rm -f include/asm-nios2/nios2.h.tmp; else echo '  UPD     include/asm-nios2/nios2.h'; mv -f include/asm-nios2/nios2.h.tmp include/asm-nios2/nios2.h; fi
  Using /usr/local/src/nios2-linux/linux-2.6 as source for kernel
  /usr/local/src/nios2-linux/linux-2.6 is not clean, please run 'make mrproper'
  in the '/usr/local/src/nios2-linux/linux-2.6' directory.
make[2]: *** [prepare3] Error 1
make[1]: *** [sub-make] Error 2
make[1]: Leaving directory `/usr/local/src/nios2-linux/linux-2.6'
make: *** [linux] Error 1