Hi
I've been having trouble with the debian installer for stretch. I've figured out how to fix it, but I don't exactly know why
it works like it does.
I wanted an
easy-to-maintain usb stick that could be used to install several different linux
distributions (see
https://wiki.archlinux.org/index.php/Multiboot_USB_drive). What it does is that it stores the isos on the usb stick, and mounts them on loopback and boots from the iso. Then to add a new linux installer, I simply add an iso to the usb stick and add a new grub entry for the iso.
However, I was having a lot of trouble with the debian-cdThe problem was that my usb stick was running off
an
efi grub. It had two partitions, one efi containing the grub shim, and
one ext4. I have a bunch of different linux isos with different
distributions distributions loaded in the ext4 partition, and one single
`/boot/grub/grub.cfg` file that loads the installers from these isos.
The debian
net-installer was the only one giving me trouble. It turned out that the
debian installer needed an extra grub needed a module called `efi_gop`
to be loaded. I don't know what it does, and would appreciate any
information.
The following grub2 entry
boots the debian net installer. I'd copied the hd-image
initrd and vmlinuz on to the ext4 partition as stated in the debian install guide.
Notice
here that grub2 is loading the ramdisk and linux kernel that reside on
the iso. If I removed the `insmod efi_gop` statement from either of
these, the installer would fail to boot.
Fine, it makes sense that grub would need efi_gop to boot the debian installer. However, this module wasn't needed for the ubuntu installer,
and nor was it needed to boot the debian live-cd. So I was wondering why this particular module was needed in one case, but not the other.
Arjun