To make the AARCH64 ipxe process work using bifrost, I had to
git clone https://github.com/ipxe/ipxe.git cd ipxe/src/ make bin-arm64-efi/snponly.efi ARCH=arm64 sudo cp bin-arm64-efi/snponly.efi /var/lib/tftpboot/ipxe.efi |
This works for the Ampere reference implementation servers that use a Mellanox network interface card, which supports (only) snp.