Adding a bootable disk image to grub's boot menu

[Lars Noodén]

The new grub is fairly complex. How would I find instructions on adding a file (/boot/floppy.img) to the boot menu?

[Lars Noodén]

I've found this:
https://help.ubuntu.com/community/Grub2/CustomMenus

but even with that, it is unclear how to add a disk image.

[drs305]

By image do you mean a background image? GRUB accepts .png, .tga or 8-bit .jpg files. You can add an image to the /boot/grub folder and when you run 'update-grub' it will be added as the GRUB background.

https://help.ubuntu.com/community/Grub2/Displays#Installing_Splash_Images

[Lars Noodén]

By image do you mean a background image? GRUB accepts .png, .tga or 8-bit .jpg files. You can add an image to the /boot/grub folder and when you run 'update-grub' it will be added as the GRUB background.

https://help.ubuntu.com/community/Grub2/Displays#Installing_Splash_Images

I am trying to boot a FreeDOS disk image so that I can update the BIOS on an old laptop that lacks a floppy drive. It's old but not so old that it would still have a floppy.

[drs305]

I am trying to boot a FreeDOS disk image so that I can update the BIOS on an old laptop that lacks a floppy drive. It's old but not so old that it would still have a floppy.

Ok. The image (ISO) has to be constructed to allow GRUB to boot it. The Ubuntu family of ISOs has been GRUB-compatible for quite a while. I don't know if FreeDos is built to allow booting by Grub2 or not.

Here is the documentation on booting an ISO via Grub2:
https://help.ubuntu.com/community/Grub2/ISOBoot

I'll look at some of the posts in my old thread on the Ubuntu Forums and see if I can find a FreeDos entry.

[Lars Noodén]

I'll look at some of the posts in my old thread on the Ubuntu Forums and see if I can find a FreeDos entry.

Thanks. There's also a fair amount for Grub 1 and FreeDOS. I might be able to figure out how to apply it to Grub 2.

[drs305]

Thanks. There's also a fair amount for Grub 1 and FreeDOS. I might be able to figure out how to apply it to Grub 2.

I couldn't find a FreeDos entry in my main ISO booting thread. If you find it is bootable from G2 and get a working menuentry please let me know. I built a page on the Community documentation for working ISO menuentries and do not have one for FreeDos.

[Lars Noodén]

I've pieced together something that boots FreeDOS using notes from around the net. The package syslinux needs to be installed and then memdisk copied to /boot, along with the FreeDOS image which I renamed to /boot/floppy.img. Then I put the following into /etc/grub.d/41_custom used by update-grub:

cat <<EOT
menuentry "FreeDOS" {
    linux16 /boot/memdisk
    initrd16 /boot/floppy.img
}
EOT

I have no idea what I actually did, but it boots FreeDOS.

Edit: The whole point of this was to be able to update the BIOS on a machine lacking floppy drive.

[drs305]

Thanks. Happy Ubuntu-ing and FreeDos-ing !