Simultaneous EFI and Legacy bootloader installation
I was briefly discussing this with Steve McIntyre and wanted to bring it to a wider discussion. Currently users need to make a selection at installation time whether to install in UEFI mode or in Legacy mode. If they installed in legacy mode and later discovered that their system supported extra features in UEFI mode (For example firmware updates) they are penalized and need to redo the installation in order to switch modes.
I'd like to propose changing this and by default install both legacy and UEFI bootloaders on architectures that support both regardless of which mode the system is running in at installation. Making this change has a few obvious implications:
* The installation disk would always be formatted GPT.
* An ESP would always be created.
* If the user is in legacy at installation time, it's not possible to create an EFI boot entry since EFI runtime services aren't present. The removable media fallback path (\efi\boot\boot$ARCH.efi) will need to be used to boot the system at this point and at some point create a "debian" NVRAM boot entry
I'm not aware of any modern systems that are unable to boot a GPT partitioned disk. If there are systems like this in the wild, it would be worthwhile to leave support to install in MBR mode when doing an expert install so that people can still use them.