Because I poked further upon discovering a bug with my script and ubuntu 16.04.
Created the USB key with 'sudo UBUNTU_RELEASE=18.04.3 ./usbinstaller /dev/sdd'
Terminal via 'sudo minicom -o -D /dev/serial/by-id/usb-Silicon_Labs_CP2104_USB_to_UART_Bridge_Controller_018B2BE4-if00-port0 -b 115200'
Powered on APU
Hit F10 when it appeared on minicom.
Selected USB key
Selected "Boot and Install with the HWE kernel"
Hit "e" next to "Install Ubuntu Server"
Cursored to linux line (See https://www.gnu.org/software/emacs/refcards/pdf/refcard.pdf for cursor control keys).
Deleted "quiet" and added "console=ttyS0,115200n8" (Warning, use control-H to delete character to left. Backspace key deletes character to right)
Waited about 10 seconds for kernel output to begin.
Waited too long for the Welcome screen.
Took defaults until "Confirm destructive action" selected "continue"
Gave it a name, servername, username, password
Hit space to mark an X on "Install OpenSSH server" then went down and hit enter on "Done"
Went down and hit enter on "Done" on Feature Server Snaps page
Waited for install to finish
Hit enter on reboot
Hit enter when prompted to remove media
Wait for login prompt (Which is obscured by cloud-init output). Took about 60 seconds on an APU4C4
Richard - Posted 47 Hours Ago
I tried again with your new script and with 18.04.3-live-server but this time I get even less far.
I add the console config to the kernel command when booting and tell it to install. After that nothing arrives at the minicom window.
No idea how to debug this.