petalinux 2019.2里面不包含 aarch64-linux-gnu-gcc
从petalinux 2018.3 里拷贝过来 路径： /tools/linux-i386/aarch64-linux-gnu
或者也可以用gcc-linaro-7.5.0-2019.12-x86_64_aarch64-linux-gnu
export ARCH=arm64
export PATH=/opt/gcc-linaro-7.5.0-2019.12-x86_64_aarch64-linux-gnu/bin:$PATH
export CROSS_COMPILE=/opt/gcc-linaro-7.5.0-2019.12-x86_64_aarch64-linux-gnu/bin/aarch64-linux-gnu-