准备步骤如下：

cd ~/hiss928/kernel/ss928_kernel_v4.19/
# 拷贝相关文件
cp -rf ~/hiss928/sdk/ema_2.0.2.2/SS928V100_SDK_V2.0.2.2/open_source/trusted-firmware-a/ .
cd trusted-firmware-a/
# 解压源码包
tar -xf trusted-firmware-a-2.2.tar.gz
# 应用补丁文件
mv trusted-firmware-a-2.2.patch trusted-firmware-a-2.2
cd trusted-firmware-a-2.2
patch -p1 < trusted-firmware-a-2.2.patch
# 重命名目录
cd ../../
mv trusted-firmware-a/trusted-firmware-a-2.2 ./atf
# 移除无用文件
rm -rf atf/trusted-firmware-a-2.2.patch
rm -rf trusted-firmware-a/