http://smcijohnny.blogspot.com/2015/06/linuxsolserial-over-lan.html
https://www.hiroom2.com/2016/06/07/centos-7-grub2-and-linux-with-serial-console
https://kernelmanic.com/2015/10/14/enable-serial-console-on-centosrhel-7
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/System_Administrators_Guide/sec-GRUB_2_over_a_Serial_Console.html
https://wiki.archlinux.org/index.php/working_with_the_serial_console
https://www.certdepot.net/rhel7-get-started-grub2
http://strugglers.net/~andy/blog/2015/12/11/installing-debian-by-pxe-using-supermicro-ipmi-serial-over-lan/
bios设置
开启COM1
开启SOL
/etc/default/grub (centos7)
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"
GRUB_DEFAULT=saved
GRUB_DISABLE_SUBMENU=true
GRUB_CMDLINE_LINUX="crashkernel=auto rhgb quiet console=ttyS1,115200"
GRUB_DISABLE_RECOVERY="true"
GRUB_TERMINAL="serial"
GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1"
unit: 0 COM1, 1 COM2
ttyS0: COM1
ttyS1: COM2
服务器由于COM1物理占用，连接需要用ttyS1
grub2-mkconfig -o /boot/grub2/grub.cfg