AMD HP Pavilon incompatible EFI Boot manager/ Can't boot on Cosmic Cuttlefish USB

I used Unetbootin to make a USB bootable disk with Cosmic Cuttlefish pre-release and post. It is the same USB stick I’ve used for at least 4 previous Linux systems, Ubuntu and Fedora. Immediately on boot it says it can’t find MMX64.efi. Looking in the boot directories there is no such efi file. Doing research I find I have to modify the EFI or turn off EFI in the BIOS. I have an HP Pavilion laptop with AMD A8 Elite Quad-core. Turning off the bios Legacy just makes the boot fail even before I get the Can’t find error message. Trying to use efibootmgr it says: “EFI variables are not supported on this system.” Doing more research efibootmgr is for Intel.

Any suggestions would be helpful. Trying to upgrade to my namesake, FeiWuzei 飞乌贼 is flying cuttlefish in Chinese.

I think you wronged the partition scheme making the USB bootable disk.
Try with Rufus it’s easier.

Our support channels, listed at, are full of skilled volunteers ready to offer a hand and good advice.

Since this is not a support channel, closing this thread. Sorry.