Serial terminal embedded configuration

[Matthias-Christian Ott]

If GRUB's prefix is on an encrypted disk, it prompts for a passphrase
for the disk. I have an i386 machine without a monitor and without a
BIOS that can use the serial port as a console and want GRUB to display
its prompt and read the passphrase from a serial port. Since grub.cfg is
not loaded without the passphrase the serial port configuration would
have to be embedded into the core image.

grub-install does not allow to customize the configuration, so I created
an image via grub-mkimage with the parameters grub-install generated a
simple serial port configuration similar to the example in the manual
that works within grub.cfg. Unfortunately it didn't work when embedded
into the core image.

Is it possible to embed serial port configuration in the core image? If
so, how do I do it?

Are there plans to support custom embedded configuration in
grub-install? If not, would patches be accepted? I don't want to
manually regenerate the core image after each GRUB update when the
package manager runs grub-install overwrites a core image with the
embedded configuration.

Regards,
Matthias-Christian