Noble uses EFI (extensible firmware interface) not MBR (Master Boot Record)

[cunnie]

• Requires a "boot" partition, "/boot/efi:
• must be partition type fat32, formatted as vfat, needs at least 6MB, 30MB should be enough
• typically /dev/sda1; root partition migrates to /dev/sda2.
• Enables certain features, such as accessing GPUs w/ > 16 GiB RAM

[ramonskie]

added efi support for aws,gcp,vsphere with the following commits

• e8d1cce201064731d34c514fb038b0df246dfde4
• 696e13392fc8f6fe0fe525745e6fa9a6cbd5763c
• a7adae7bb41eb60c50b2b9f22f31fddf7a4f947a