Re: Grub.cfg help request

[Andrei Borzenkov]

On 05.03.2023 00:26, shelly16@posteo.de wrote:
> hello
>
> I've been trying to write a grub.cfg that does what I want, without
> having to patch the source code but I don't think it's doable.
> Can you advise ?
>
> here is the synopsis:
>
> if shift not pressed

There is no generic way to do it. As extreme example - with serial 
terminal there is simply no way to query SHIFT (or any other modifier) 
state. On UEFI support for querying modifiers state was added relatively 
recently and as far as I can tell it is still incomplete and may not 
work. Other platforms may have similar limitations.

> try
> find a luks2 partition named foobar on the sata bus
> mount it (ask for the passphrase)
> load mygrub.cfg from this partition
> boot the default boot option
> endtry
> endif
> display a password protected menu

This all is fairly normal grub.cfg code.

> - boot seabios
> - boot tianocore

I am not sure I understand it; if you are in grub, you are already past 
the BIOS, so what "boot BIOS" means exactly?

> - grub command line

Not sure if there is any command to do it. Usually grub switches to 
command line when you press ESC in menu.

> do you see something not doable by a grub.cfg ?