This is a top-level page for UEFI support in Ubuntu.
/OVMF has information about running UEFI under qemu. This is useful for testing.
/SecureBoot has information about using UEFI secure boot with Ubuntu
/EDK2 has information about Intel's EFI Development Kit, and how you can build EFI binaries yourself
/SecureBoot-PXE-IPv6 has information about how to netboot Ubuntu from the stock EFI bootloader images included in the archive, which works with SecureBoot enabled and also gives sample server configuration for both ipv4 and ipv6
/PXE-netboot-install has information about performing Ubuntu installs on UEFI machines over the network with a custom GRUB2 image
|/EDK2 /OVMF /PXE-netboot-install /SecureBoot /SecureBoot-PXE-IPv6|
Please consider reading https://wiki.archlinux.org/index.php/Unified_Extensible_Firmware_Interface for further information on configuring and modifying UEFI Ubuntu installations. The information contained therein may be particularly useful for configuring and repairing multi-boot environments.