Install FreeBSD using serial console

  1. Download FreeBSD memory stick image file (e. g. FreeBSD-13.0-CURRENT-amd64-20190531-r348447-memstick.img).
  2. Copy the image file on an USB memory device. On macOS: 
    $ sudo dd if=FreeBSD-13.0-CURRENT-amd64-20190531-r348447-memstick.img of=/dev/disk3 bs=1m conv=sync
  3. Connect serial cable to the host that needs the FreeBSD installation.
  4. Use a tool like screen to connect to that host. 
    $ sudo screen /dev/ttyUSB0 115200
  5. Start the host (e. g. connect power cable).
  6. When FreeBSD boot menu appears, type 3 to enter loader prompt.
  7. Set parameter and continue booting. 
    set comconsole_speed=115200
set console=comconsole
boot
  8. Install FreeBSD as you like, but answer the last question before reboot (“The installation is now finished. Before exiting the installer, would you like to open a shell in the new system to make any final manual modifications?”) with yes.
  9. Add these lines to the file /boot/loader.conf 
    comconsole_speed=115200
console=comconsole
  10. Type exit to reboot in your new FreeBSD system.