Use ^A O to enter "Serial port setup".
Set "Serial Device".
Set "Hardware Flow Control: to no." Set "Software Flow Control: to no."
Use DEL or TAB after the beep to enter the BIOS.
Set to boot from the USB drive using EFI, unless non-grub boot menu config files have been changes.
Press F9 to customize boot parameters. Remove 'silent' and 'splash', add:
console=tty0 console=ttyS0,115200n8
After install, but before edit '/etc/default/grub':
GRUB_CMDLINE_LINUX_DEFAULT=""
GRUB_CMDLINE_LINUX="console=tty0 console=ttyS0,115200n8"
Update grub.