Add "Boot CD" to GRUB menu

Napalm Llama · 06-09-2005, 07:10 AM

I've Googled this, but all I get is pages telling you how to make a bootable CD with GRUB installed on it.

All I want is a way of adding "Boot from CD" to my list of other bootable things when GRUB appears. Is there any way of doing this?

trevelluk · 06-09-2005, 07:18 AM

I have to ask why you'd want it. If you want to boot from a CD, just make sure that the boot order in your BIOS is configured to boot from your CD drive before you're hard disk. GRUB doesn't have to be involved at all.

Napalm Llama · 06-09-2005, 08:18 AM

Sometimes I like to keep Knopppix or my Gentoo install CD in the drive, just in case I need it.. If I press Esc during POST to get the 'boot from' box, my BIOS is a bit funny, and only gives me the box if it feels like it - otherwise it just boots from the default drive.

It'd just be simpler to have the HD as the default drive, and have something I trust (GRUB) ask me where I want to boot from. Also it looks nicer

So is it possible?

I've written my own grub.conf file, so it's not like I don't know what I'm doing - I just can't find out how to do it

trevelluk · 06-09-2005, 08:31 AM

Well, I think you could probably do this via the chainloader feature of GRUB (which should boot you to the CDs boot menu). The problem is, you'll need to know how GRUB addresses your CD drive. I think that something like this should work, but I can't offer any guarantees:

Code:

title Boot from CD
    root (hdx,0) # The trouble is finding out what x should be.
    makeactive
    chainloader +1

Once again, I can't promise that this will work, but I hope it will give you a starting point at least.

Napalm Llama · 06-09-2005, 11:51 AM

Wellll... My CD (DVD) drive is is the only IDE thing in there (I have SATA) - so it's Master on IDE0 and /dev/hda in Linux.

I have my boot order so that my HD starts first, so in GRUB terms that becomes (hd0,0)... I guess I'll just have to muck around on the GRUB command line 'til I find something that works

Oh, while I'm at it, I have another GRUB question - how do I replace the default Gentoo splash image? I know about the splashimage=(hd0,0)/path/to/pic syntax, and I've been saving in the XPM format, because that's what was already there. I can't find any documentation about it in the GRUB website though, and none of my XPMs work - I get the top-right corner of the image, blown up to about twice its real size, and in funny colours. I've tried saving in all the different colour depths from 2 to 24 bit, but it makes no difference to the outcome.

I've been using ImageMagick to change the depth and format from the PNG I saved in GIMP.

Any ideas?

Thanks

keefaz · 06-09-2005, 11:54 AM

Read : http://jaeger.morpheus.net/linux/grubsplash.html

fatblueduck · 06-10-2005, 03:24 AM

I changed my grub background. Just take an image. open it up in the gimp and go to "image" > "mode" > "indexed" and change the number to 16. then save the file and turn it into the same format that the gentoo splash screen is in. Put it into your /boot directory and edit your grub.conf to include that image instead of the gentoo image.

Anyway I hope you find out how to configure grub to have a "boot from cd" option. I don't think it is entirely necessary, but it would be really cool and I would like to do it. If you find out how, post the answer here please. I'm drunk.

good luck

Napalm Llama · 06-10-2005, 08:56 AM

16 colours? The website said 14...

16 makes more sense, I guess.

Anyway, I followed the instructions on the webvsite, and it worked wonderfully!

I shall be trying it with 16 very shortly.

Thankyou both!

Sadly, I don't think there is a way to get GRUB to boot a CD. It doesn't understand ATAPI or something... Maybe they'll put it into GRUB 2