我正在运行带有内核 5.4.103-1-pve 的 Proxmox 6.4（我已经在他们的论坛中问过这个问题，但没有运气）。我的主板有一个 COM 接头，因此我最近获得了连接它并通过串行进行管理所需的设备。但是，系统启动后无法使用串口。港口位于ttyS0.我在 GRUB 中进行了设置（请注意，在 SSH 出现之前，我的设置是仅串行的，系统中唯一的 GPU 实际上并未被 GRUB 或 Linux 使用，仅用于直通）：
GRUB_TERMINAL=serial
GRUB_SERIAL_COMMAND="serial --unit=0 --speed=115200"
console=ttyS0,115200然后我通过添加到内核命令行来为 Linux 设置它。现在，当我启动主机时，我首先看到 GRUB 菜单，并且可以与其完全交互，然后我看到正常加载 initramfs 消息，接下来是大部分正常的 Linux 启动过程。但是，一旦到达“登录服务”，就不再有任何输出，我无法与终端交互：
...
Starting Proxmox VE Login Banner...
Starting Enable support fo…l executable binary formats...
[ OK ] Reached target ZFS volumes are ready.
[ OK ] Started Preprocess NFS configuration.
[ OK ] Started Set console font and keymap.
[ OK ] Started Create Volatile Files and Directories.
[ OK ] Started Load AppArmor profiles.
[ OK ] Started Proxmox VE firewall logger.
Mounting Arbitrary Executable File Formats File System...
Starting Raise network interfaces...
[ 17.623601] Generic FE-GE Realtek PHY r8169-800:00: attached PHY driver [Generic FE-GE Realtek PHY] (mii_bus:phy_addr=r8169-800:00, irq=IGNORE)
Starting Network Time Synchronization...
Starting Update UTMP about System Boot/Shutdown...
Starting RPC bind portmap service...
[ OK ] Reached target NFS client services.
[ OK ] Started Proxmox VE Login Banner.
[ OK ] Started Commit Proxmox VE network changes.
[ OK 17.739718] r8169 0000:08:00.0 enp8s0: Link is Down
0m] Mounted Arbitrary Executable File Formats File System.
[ OK ] Started 17.760897] 8021q: 802.1Q VLAN Support v1.8
1;39mRPC bind portmap service.
[ OK ] Started Network Time Synchronization.
[ OK ] Started Enable support for…nal executable binary formats.
[ OK ] Reached target System Time Synchronized.
[ OK ] Reached target RPC Port Mapper.
[ OK ] Started Update UTMP about System Boot/Shutdown.
[ OK ] Reached target System Initialization.
[ OK ] Listening on D-Bus System Message Bus Socket.
[ OK ] Reached target Sockets.
[ OK ] Reached target Basic System.
Starting Proxmox VE LXC Syscall Daemon...
[ OK ] Started D-Bus System Message Bus.
Starting PVE Qemu Event Daemon...
[ OK ] Started ZFS Event Daemon (zed).
Starting System Logging Service...
[ OK ] Started Daily apt download activities.
[ OK ] Started Daily apt upgrade and clean activities.
Starting LSB: The monitor UPS software....
[ OK ] Started Daily rotation of log files.
[ OK ] Started Daily man-db regeneration.
Starting Login Service...
[ OK ] Started Proxmox VE [ 18.118065] softdog: initialized. soft_noboot=0 soft_margin=60 sec soft_panic=0 (nowayout=0)
watchdog multiplexer.
Starting Kernel Samepage Merging (KSM) Tuning Daemon...
[ OK ] Started Daily Cleanup of Temporary Directories.
[ OK ] Started Daily PVE download activities.
Starting Self Monitoring a…g Technology (SMART) Daemon...
Starting ZFS file system shares...
[ OK ] Started Proxmox VE replication runner.
[ OK ] Reached target Timers.
[ OK ] Started FUSE filesy[ 18.258047] new mount options do not match the existing superblock, will be ignored
stem for LXC.
Starting Initialize hardware monitoring sensors...
[ OK ] Started Proxmox VE LXC Syscall Daemon.
[ OK ] Started System Logging Service.
[ OK ] Started PVE Qemu Event Daemon.
[ OK ] Started Kernel Samepage Merging (KSM) Tuning Daemon.
[ OK ] Started ZFS file system shares.
[ OK ] Reached target ZFS startup target.
[ OK ] Started Initialize hardware monitoring sensors.
[ OK ] Started Login Service.
如果我通过 SSH 登录，我可以看到该serial-getty@ttyS0服务正在运行，并且其日志显示零错误或警告。同样，dmesg系统日志也没有关于此的错误。即使我重新启动服务，串行终端仍然无法工作。如果我运行stty -a -F /dev/ttyS0，我可以看到由于某种原因，波特率设置为 2400，即使它在启动期间是正确的。我可以手动将其设置回 115200 波特，但如果我这样做，然后在终端的客户端上键入任何内容，它会在显示该字符后立即恢复为 2400。但是，如果我手动重置它然后重新启动serial-getty@ttyS0，它会保持 115200 波特并保持交互。
我无法在互联网上的任何地方找到解决方案，也许我的 Google-fu 不够强大，但很难找到部分有效的类似问题，这与大多数人的经历不同，它根本不起作用。
编辑:
感谢 telcoM，现在这个问题已经解决了。作为参考，默认ExecStart行是：
ExecStart=-/sbin/agetty -o '-p -- \\u' --keep-baud 115200,38400,9600 %I $TERM
因此运行systemctl edit serial-getty@ttyS0并添加以下行修复了它：
[Service]
ExecStart=
ExecStart=-/sbin/agetty -o '-p -- \\u' 115200 %I $TERM
答案1
您需要找出您的serial-getty@ttyS0服务定义为实际agetty流程指定了哪些选项。请运行systemctl cat serial-getty@ttyS0并将输出编辑到您的问题中。
如果该ExecStart行包含一个--keep-baud选项agetty（缩写形式为-s），那么您可能需要创建一个覆盖文件来调整选项agetty，因为您似乎将 115200 的固定波特率作为您的目标。
我必须做一些非常类似的事情，因为我的 Debian 10 的串行端口默认行ExecStart是agetty：
ExecStart=-/sbin/agetty -o '-p -- \\u' --keep-baud 115200,38400,9600 %I $TERM
在这种特定情况下，我希望选项是/sbin/agetty -o '-p -- \\u' 57600 %I vt-utf8.
（硬件有一个远程控制台处理器，其固件只能以 57600 bps 的速率工作。使用此 mod，我可以通过 SSH 进入远程控制台处理器，激活虚拟串行控制台模式，并访问串行控制台，而不会出现键盘布局问题基于 Java 的虚拟 KVM 控制台。）
由于服务可以有多ExecStart行，因此ExecStart=如果您想要代替现有线路而不是添加第二个。所以我制作了一个包含以下内容的文件：/etc/systemd/system/[email protected]/override.conf
[Service]
ExecStart=
ExecStart=-/sbin/agetty -o '-p -- \\u' 57600 %I vt-utf8
您可能需要做类似的事情，尽管在您的情况下显然波特率为 115200。