今天移植debian的根文件系统到开发板上，根文件系统启动时一堆红色报警，很扎眼。
[FAILED] Failed to start Create Volatile Files and Directories.
See 'systemctl status systemd-tmpfiles-setup.service' for details.
[FAILED] Failed to start Network Time Synchronization.
See 'systemctl status systemd-timesyncd.service' for details.
[ OK ] Reached target System Time Synchronized.
Starting Update UTMP about System Boot/Shutdown...
[FAILED] Failed to start Update UTMP about System Boot/Shutdown.
See 'systemctl status systemd-update-utmp.service' for details.
[DEPEND] Dependency failed for Update UTMP about System Runlevel Changes.
[ OK ] Stopped Network Time Synchronization.
[FAILED] Failed to start Network Time Synchronization.
See 'systemctl status systemd-timesyncd.service' for details.
[ OK ] Stopped Network Time Synchronization.
[FAILED] Failed to start Network Time Synchronization.
See 'systemctl status systemd-timesyncd.service' for details.
[ OK ] Stopped Network Time Synchronization.
[FAILED] Failed to start Network Time Synchronization.
See 'systemctl status systemd-timesyncd.service' for details.
[ OK ] Stopped Network Time Synchronization.
[FAILED] Failed to start Network Time Synchronization.
See 'systemctl status systemd-timesyncd.service' for details.
[ OK ] Stopped Network Time Synchronization.
[FAILED] Failed to start Network Time Synchronization.
点开第一个报警[FAILED] Failed to start Create Volatile Files and Directories.的提示systemctl status systemd-tmpfiles-setup.service，发现如下信息。
意思是提示我们，启动时程序操作文件，但是系统是read-only只读文件系统，导致发生错误，查找原因后，发现在boot里面有如下参数。
bootargs=root=/dev/mmcblk0p2 rootwait ro
我尼玛。。。。。出场设定就这样，按照网上大神的介绍，改为如下参数
setenv bootargs root=/dev/mmcblk0p2 rootwait rw
之后保存
saveenv
之后再次重启，相关错误消失。但是还剩下一堆其他错误。慢慢解决。