# vi /etc/default/grub

#if you want both serial and vga console:
GRUB_CMDLINE_LINUX='console=tty0 console=ttyS0,115200n8'

#if you want only serial console (like SS4200 which doesn't have vga)
GRUB_CMDLINE_LINUX='console=ttyS0,115200n8'
GRUB_TERMINAL=serial
GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1"

# update-grub


#activate getty at serial console

# vi /etc/inittab

T0:23:respawn:/sbin/getty -L ttyS0 115200 vt100


#to allow root to login: Make sure UART serial ports /dev/ttyS0 is listed:

# vi /etc/securetty
ttyS0


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