preseed/wheezy/commands/late_commands.d/enable_serial_console

   1 #!/bin/sh
   2 echo "Enabling the serial console..."
   3 #683124 requires the cmdline patch, and #444026 is for GRUB_TERMINAL:
   4 sed -i -e '/^GRUB_CMDLINE_LINUX=/s/"$/ console=tty0 console=ttyS0,115200n8&/' \
   5        -e '/^GRUB_CMDLINE_LINUX=/s/=" /="/' \
   6        -e '/^GRUB_TERMINAL=/s/serial/"& console"/' \
   7        /etc/default/grub
   8 update-grub
   9 sed -i '/ttyS0/s/^#//;/ttyS0/s/9600 vt100/115200 linux/' /etc/inittab