GRUB_CMDLINE_LINUX_DEFAULT="console=tty0 console=ttyS0,115200n8"GRUB_TERMINAL="console serial"GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1"GRUB_CMDLINE_LINUX_DEFAULT applies this configuration only to the default menu entry, use GRUB_CMDLINE_LINUX to apply it to all the menu entries. Each line should only appear once within the /etc/default/grub. If the line al