咨询下，这个板子上电时为何连接的串口终端会断开？
另外如何进到uboot console？
谢谢。
启动log如下：
Error reading from serial device
───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
Session stopped
- Press to exit tab
- Press R to restart session
- Press S to save terminal output to file
───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
Session stopped
- Press to exit tab
- Press R to restart session
- Press S to save terminal output to file
9rɩ▒H▒[ OK ] Started dbus.service - D-Bus System Message Bus.
Starting NetworkManager.service - Network Manager…
Starting wpa_supplicant.service - WPA supplicant…
[ OK ] Started avahi-daemon.service - Avahi mDNS/DNS-SD Stack.
[ OK ] Started systemd-logind.service - User Login Management.
[ OK ] Started polkit.service - Authorization Manager.
Starting ModemManager.service - Modem Manager…
[ OK ] Started bluetooth.service - Bluetooth service.
[ OK ] Reached target bluetooth.target - Bluetooth Support.
[ OK ] Started wpa_supplicant.service - WPA supplicant.
Starting systemd-hostnamed.service - Hostname Service…
[ OK ] Started systemd-hostnamed.service - Hostname Service.
[ OK ] Started NetworkManager.service - Network Manager.
[ OK ] Reached target network.target - Network.
Starting NetworkManager-wa…m - Network Manager Wait Online…
Starting ssh.service - OpenBSD Secure Shell server…
Starting systemd-user-sess…vice - Permit User Sessions…
[ OK ] Finished systemd-user-sess…ervice - Permit User Sessions.
Starting plymouth-quit-wai… until boot process finishes up…
Starting plymouth-quit.ser… Terminate Plymouth Boot Screen…