Preseeding the Debian Install: how do you disable the CDROM-detect from running, I'm installing from loop/ISO - also shared/enter_device etc?

[Veek M <vek.m1234@gmail.com>]

How do you disable the 'Detect and Mount CD-ROM' when preseeding via
grub cmdline.

I do:
loopback loop0 (hd0,3)/files/debian_9.5-amd64-DVD-1.iso
linux (loop0)/install.amd/vmlinuz locale=en_GB.UTF-8 etc...
initrd (loop0)/install.amd/initrd.gz

after pressing 'c' in GRUB

I get the very annoying cdrom-detect program running which prompts me
to insert a CD. Since this is a ISO install, I want to skip that.

Additionally, I am trying to preseed.cfg from
(hd0,3)/files/preseed.cfg and this does not work because /hd-media is
not created or mounted - how do i fix this?

Also, what's the purpose of shared/ask_device
and shared/enter_device
I couldn't find docs for this

Basically what I'm TRYING TO do is, use ONE USB to store the ISOs and
preseed.cfg (sdb3), and install to another partition (either sdb1 or
sdb2 depending on what I can get away with)
[usually you extract the ISO to sdb1 and manually shove the
pressed.cfg in there, AND THEN install to sdb2]