uboot使用tftp下载文件时候遇到问题：for tftpd-hpa.service failed because the control process exited with error c

用正点原子linux开发板通过tftp服务器下载linux系统镜像时出现问题
Job for tftpd-hpa.service failed because the control process exited with error code. See "systemctl status tftpd-hpa.service" and "journalctl -xe" for details.
最后查找的时候发现是自己更改过tftp下载的路径，导致开发板找不到文件
修改sudo vim /etc/default/tftpd-hpa

  1 # /etc/default/tftpd-hpa
  2 
  3 TFTP_USERNAME="tftp"
  4 TFTP_DIRECTORY="/home/lala0903/linux/tftpboot"
  5 TFTP_ADDRESS=":69"
  6 TFTP_OPTIONS="-l -c -s"

修改sudo vim /etc/xinetd.d/tftp

  1 server tftp
  2 {
  3     socket_type     = dgram
  4     protocol        = udp
  5     wait            = yes
  6     user            = root
  7     server          = /usr/sbin/in.tftpd
  8     server_args     = -s /home/lala0903/linux/tftpboot/
  9     disable         = no
 10     per_source      = 11
 11     cps             = 100 2
 12     flags           = IPv4
 13 }
     

修改好之后 重启tftp服务器

sudo service tftpd-hpa restart