Linux Fedora20无法使用串行端口启动

我正在尝试使用串行输出引导Fedora 20，因此我使用以下命令修改引导命令行：

menuentry 'Fedora (3.18.0) 20 (Heisenbug)' --class fedora --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-0-rescue-690525b7662a4bbca483ccdfdac3f6dc-advanced-d27ee4d5-522c-48e8-abc5-73b42bd81ae4' {
load_video
insmod gzio
insmod part_gpt
insmod ext2
set root='hd1,gpt2'
if [ x$feature_platform_search_hint = xy ]; then
  search --no-floppy --fs-uuid --set=root --hint-bios=hd1,gpt2 --hint-efi=hd1,gpt2 --hint-baremetal=ahci1,gpt2  86088439-feab-4ac8-9cca-792414d9fff0
else
  search --no-floppy --fs-uuid --set=root 86088439-feab-4ac8-9cca-792414d9fff0
fi
linuxefi /vmlinuz-3.18.0 root=UUID=d27ee4d5-522c-48e8-abc5-73b42bd81ae4 ro text no_console_suspend hpet=disable console=ttyS0,115200 console=tty0
initrdefi /initramfs-3.18.0.img
}

串行输出似乎在以下位置停止： '正在为Show Plymouth引导屏幕运行启动作业'， 没有继续下去。 以下是journalctl的信息：

Jan 06 19:02:13 localhost.localdomain systemd[1]: Mounted /boot.
Jan 06 19:02:13 localhost.localdomain systemd[1]: Mounting /boot/efi...
Jan 06 19:02:13 localhost.localdomain systemd[1]: Started Activation of DM RAID sets.
Jan 06 19:02:13 localhost.localdomain systemd[1]: Starting Encrypted Volumes.
Jan 06 19:02:13 localhost.localdomain systemd[1]: Reached target Encrypted Volumes.
Jan 06 19:02:13 localhost.localdomain systemd[1]: Mounted /boot/efi.
Jan 06 19:02:13 localhost.localdomain systemd[1]: Starting Local File Systems.
Jan 06 19:02:13 localhost.localdomain systemd[1]: Reached target Local File Systems.
Jan 06 19:02:13 localhost.localdomain systemd[1]: Started Mark the need to relabel after reboot.
Jan 06 19:02:13 localhost.localdomain systemd[1]: Started Reconfigure the system on administrator request.
Jan 06 19:02:13 localhost.localdomain systemd[1]: Started Relabel all filesystems, if necessary.
Jan 06 19:02:13 localhost.localdomain systemd[1]: Starting Tell Plymouth To Write Out Runtime Data...
Jan 06 19:02:13 localhost.localdomain systemd[1]: Starting Trigger Flushing of Journal to Persistent Storage...
Jan 06 19:02:13 localhost.localdomain systemd[1]: Starting Recreate Volatile Files and Directories...
Jan 06 19:02:13 localhost.localdomain systemd[1]: Starting Security Auditing Service...
Jan 06 19:02:13 localhost.localdomain auditd[468]: Error - audit support not in kernel
Jan 06 19:02:13 localhost.localdomain auditd[468]: Cannot open netlink audit socket
Jan 06 19:02:13 localhost.localdomain auditd[468]: The audit daemon is exiting.
Jan 06 19:02:13 localhost.localdomain auditctl[469]: Error - audit support not in kernel
Jan 06 19:02:13 localhost.localdomain auditctl[469]: Error - audit support not in kernel
Jan 06 19:02:13 localhost.localdomain auditctl[469]: Cannot open netlink audit socket
Jan 06 19:02:13 localhost.localdomain systemd[1]: Started Recreate Volatile Files and Directories.
Jan 06 19:02:13 localhost.localdomain systemd[1]: auditd.service: main process exited, code=exited, status=1/FAILURE
Jan 06 19:02:13 localhost.localdomain systemd[1]: Failed to start Security Auditing Service.
Jan 06 19:02:13 localhost.localdomain systemd[1]: Unit auditd.service entered failed state.
Jan 06 19:02:13 localhost.localdomain systemd[1]: Starting Update UTMP about System Reboot/Shutdown...
Jan 06 19:02:13 localhost.localdomain systemd-journal[394]: Permanent journal is using 24.0M (max 601.3M, leaving 902.0M of free 2.1G, current limit 601.3M).
Jan 06 19:02:13 localhost.localdomain systemd-journal[394]: Time spent on flushing to /var is 172.987ms for 1168 entries.
Jan 06 19:02:13 localhost.localdomain systemd[1]: Started Trigger Flushing of Journal to Persistent Storage.
Jan 06 19:02:13 localhost.localdomain systemd[1]: Started Update UTMP about System   Reboot/Shutdown.
Jan 06 19:02:17 localhost.localdomain kernel: random: nonblocking pool is initialized

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最后，我通过添加以下内容解决了此问题： 控制台=tty控制台=TTYS0115200N8 而不是： 控制台=tty0控制台=TTYS0115200 在引导命令行中 我不知道为什么，但它起作用了，感谢上帝