Boot Commands Stuff

[aRustyDev]

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Description

There's a few things I'm hoping for from this.

1. Compound 'boot commands' ie <ctrl+key> or <ctrl+shift+key> or <<ctrl><shift><key>>
2. More boot commands <a>, <b>, <c>
3. Boot command repetitions ie <bs99>

Use Case(s)

I'm currently working to get ubuntu-21.10-live-server-amd64 to AutoInstall. I just recently completed one for 20.04, but there's a change in how they do Boot Commands in 21. Instead of the GRUB command-line just accepting GRUB commands, they have a "bash-like" command-line that seems to accept a subset of the commands. Which don't include things like autoinstall. However they do have the option to enter e to open an emacs editor that "edits the commands before booting" which is what the GRUB commandline did in 20.04.

I can get this to work by just retyping the keystroke commands ( literally 99 times), but this is obviously not ideal.

If key strokes for every alphanumeric could be added and compound keystrokes were a thing then we could take advantage of the Emacs language features. If nothing else having boot command repetition would significantly cut down on the ugliness and errors involved in configuration files.

Potential references/configs

I think this may need to be fixed/extended somewhere in here
https://github.com/hashicorp/packer-plugin-sdk/tree/main/bootcommand

I'd love to be able to extend this myself, but I don't have the confidence with GoLang to make it happen just yet.
I also submitted this in the packer-plugin-proxmox repo too, since that's what I've found the need in.