GRUB disk, can somebody help?

mystran · Post by **mystran** » Thu Dec 06, 2007 6:12 pm

I am under the impression, that GRUB 0.97 supports the multiboot part which has to do with setting VESA modes on boot. Unfortunately, when I last created GRUB boot floppy image, that was with 0.94... and... I don't have a floppy drive on any box where I could reasonably expect to create a new floppy image, yet I'd love to have that support so I could get my kernel to support some sort of graphical user interface (at least a spash or something) before I go messing with drivers..

So, mm.. what I'm asking, if somebody has a FAT12 floppy with sufficiently recent GRUB (and preferably nothing else) installed, mind sharing?

If not, then I'll have to do some sort of magic (wouldn't be the first time) but thought I'd ask anyway...

Yes, I could write the required VESA startup code into my kernel (and I will if the support isn't in GRUB 0.97 for real) but since I have no intention to write anything but a dirty hack, I could just as well use the GRUB support, until I have time to do something better..

So.. mm.. yes, please tell if you got a suitable image

elfenix · Post by **elfenix** » Thu Dec 06, 2007 9:11 pm

I use grub ISO's. Do you need a floppy image? An ISO will let you have a significantly larger kernel, and gains you the ability to also load an initial ramdisk with any number of utilities/programs/etc... on it before you have disk IO working.

mystran · Post by **mystran** » Thu Dec 06, 2007 9:22 pm

Fate wrote:I use grub ISO's. Do you need a floppy image? An ISO will let you have a significantly larger kernel, and gains you the ability to also load an initial ramdisk with any number of utilities/programs/etc... on it before you have disk IO working.

I got FAT12 support in my kernel and I'm not in the mood to support ISO9660 right now, so I'd prefer a floppy image at this point.

Have to think. Anyway, is there a method to trick Grub into installing itself into an image of whatever sort? Can't figure it out

elfenix · Post by **elfenix** » Thu Dec 06, 2007 9:35 pm

Are you in linux, windows, something else?

You can probably use any number of grub boot disks.

If you want to make one on your own, you can take an image file, and use losetup to create a block device, then manipulate it however you like.

mystran · Post by **mystran** » Thu Dec 06, 2007 9:43 pm

Fate wrote:Are you in linux, windows, something else?

You can probably use any number of grub boot disks.

If you want to make one on your own, you can take an image file, and use losetup to create a block device, then manipulate it however you like.

Well, I got Vista, w2k and a couple of Linux boxes available.. mm.. oh ok, didn't realize grub would work with losetup.. have to try.. thanks for the tip..

elfenix · Post by **elfenix** » Thu Dec 06, 2007 9:54 pm

you'll need to not use the regular device map

the command

device (fd0) /dev/loopN will let you specify

full instructions:
http://sig9.com/bochs-grub

I _THINK_ that you can also use a grub shell obtained from a hard drive or CD-ROM to load a kernel from a floppy. (And you could also use your kernel to access the floppy after your image is loaded).

Good luck!