While trying to install the offical Ubuntu 20.04 LTS Live server image on an apu board I encountered the following error.

graphics initialization failed
Error setting up gfxboot
boot:

It seems that this error comes from the fact that the apu board only provides a serial interface for installation. A quick online search suggests to use the network installer mini.iso from the alternative downloads instead.

Previously (Ubuntu 19.10) in order to successfully boot, only the kernel boot parameters need to be changed for the network installer. This was performed by selecting Install and hitting <Tab>.

linux vga=off initrd=initrd.gz --- console=ttyS0,115200u8

With the release of Ubuntu 20.04 LTS support for the network installer was dropped in favor of the standard Ubuntu Live server image.

For 20.04 LTS, users can use the new Ubuntu Live installer to setup and configure a network install.

Trying to boot by manually entering the boot parameters didn’t work and resulted in memory allocation errors.

boot: /casper/vmlinuz vga=off initrd=/casper/initrd --- console=ttyS0,115200u8
Loading /casper/vmlinuz... ok
Loading /casper/initrd...ok
Booting kernel failed: Invalid argument
boot:
Could not allocate memory.
boot:
Could not allocate memory.
boot:
Could not allocate memory.
boot:
...

It’s still possible to install Ubuntu 20.04 LTS on an apu board by setting up a network installation using PXE. This note contains the required instructions.