Configure Grub2 with Multiple Boot Options?

[Jeffrey Walton <noloader@gmail.com>]

I'm having trouble learning how to add multiple boot configurations to
Debian's Grub2.

Debian has Grub pages at https://wiki.debian.org/Grub and
https://wiki.debian.org/GrubConfiguration, but they lack practical
examples for multiple boot configurations.

Would someone please update update the pages and discuss multiple boot
configurations like detailed below?

Thanks in advance.

*****

Here's the back story... A Debian maintainer broke us under X32
(https://wiki.debian.org/X32Port). We needed to enable X32 under
Debian 8 and perform specific testing in that configuration. But we
also want to retain the original Debian 8 for testing, too.

So what I want in my Grub menu during boot is:

  * Debian GNU/Linux
  * Debian GNU/Linux (X32)
  * Advanced Options ...
  * Memory Test ...

Debian GNU/Linux should boot with default options.

Debian GNU/Linux (X32) is new, and it should boot with
GRUB_CMDLINE_LINUX="syscall.x32=y" in accordance with
https://wiki.debian.org/X32Port.

The configuration changes should also survive various updates and dist-updates.

Trying to get Grub into a "multiple boot options" based on the docs is
proving to be difficult.

*****

And to be clear, I don't care about examples like below. I don't boot
like that; rather I select a Grub menu item.

  grub> kernel (hd0,0)/vm