1.mkdir project
2.cd project
3.git clone https://gitlab.com/buildroot.org/buildroot.git
5.cd buildroot
6.make raspberrypi4_defconfig
7.Target option --->
Target Architecture (ARM (little endian)) --->
Target Architecture Variant (cortex-A72) --->
Target Binary Format (ELF) --->
8.Toolchain --->
\*\] Copy gdb server to target   9.System configuration ---\> Root password (123456) 登录密码设置为123456    10.Kernel ---\> \[\*\] Linux Kernel Kernel version (Custom tarball)  11.Target Package ---\> \[\*\] *Show packages that are also provided by BusyBox* Networking applications ---\> \[\*\] *openssh*      12.查看可用CPU核心数；  13.编译；   14.生成固件sdcard.img;  **问题：ssh无法登录**  1.vi /etc/network/interfaces   2.vi /etc/ssh/sshd_config  以上文件修改完之后保存再重启； 可以看到ssh打开成功。 