Microsoft reports several bootloader vulnerabilities

Good example of a nonideal approach, but I would settle for that since at least it's better than how UEFI has developed so far.

I think the "default" sequence for new (naturally Windows-preinstalled) PC's is simply UEFI > NT6 bootloader > Windows.

On mainstream PC's like this, for users to include Linux if they want to (without disturbing Windows) it should be a straightforward option to install Linux to its own partition, and end up with UEFI > NT6 bootloader > Windows or Linux. Your choice by paying attention to the built-in NT6 bootmenu upon power up, whenever you don't want to boot automatically to the default OS.

With exactly the same workflow as you used to be able to with BIOS. I know there are subsurface differences, but always hold out hope that maybe someone will be advanced enough to handle this much abstraction ;)

This deficiency was not a factor before UEFI struck, since the NT6 bootloader would start Linux under BIOS with no problem. Still will, and Grub will still start Windows, working smoother than ever even in UEFI. NT5 bootloader was even good enough, and you can probably go back to NT3.

>Windows supports setting a one time boot using a UEFI BootNext NVRAM variable, directly boots shim.efi, doesn't involve bootmgr.efi

Even better than that, both Windows and Linux are complete enough as an OS, that if either of their bootloaders are properly installed & configured, then no NVRAM variables need to be depended on whatsoever. Those variables are functionally just a shortcut or fallback which can compensate for lingering defects.

Plus I never thought Grub was required, I always prefer Syslinux.

No matter what, there's not supposed to be any need for a shim.

I don't see any advantage to involving Microsoft in the boot process.

>paying attention to the built-in NT6 bootmenu

UEFI firmware vendors provide a boot manager (the UI) for choosing what installed OS to boot. Apple has offered a graphical boot manager (option key at the boot chime) since forever.

NT6 isn't free or open source software so I don't see the various Linux projects wanting NT6 involved at all, in either the single or dual boot use case.

But in effect you're proposing different boot paths, and different UI/UX depending on whether the system is Linux-only or dual boot Windows Linux.

>This deficiency was not a factor before UEFI struck

I can't tell what deficiency you think UEFI has that BIOS didn't have. But maybe you don't like specs? Or are you referring to the much latter added UEFI Secure Boot?

>No matter what, there's not supposed to be any need for a shim.

You seem to think Microsoft wants to be in the business of executing arbitrary and unsigned code, despite all efforts proving the opposite.

Good point. Me neither, never have,

But if they're already there within the PC in some way or another, ideally they should gracefully be able to accomodate Linux under UEFI as easily as it still works when using BIOS.

>in effect you're proposing different boot paths, and different UI/UX depending on whether the system is Linux-only or dual boot Windows Linux.

Not proposing. Been living it for decades. It's only broken under UEFI.

Even on my average pure Windows machine, I normally have about 4 distinct boot paths for each OS using various instances of the NT6 bootloader. Not counting the option of whipping up an emergency boot floppy which can still be made for modern Windows use if all else failed.

Experience has shown, the more viable boot paths, and the fewer obstacles, the greater reliability.

>You seem to think Microsoft wants to be in the business of executing arbitrary and unsigned code

Nope, that's just how they started out and ended up outgrowing IBM. I remember it well, those days are long over.

Likewise, there should never have been any need for Linux to involve any Microsoft code or signing, like SecureBoot, in order to perform on the most secure new PC's without requiring any different default UEFI settings than Windows.