Gentoo Linux & WinXP dual boot


I have a laptop (IBM T41) with Gentoo Linux installed, with GRUB as the boot loader. I wanted to make this a dual boot system, so I installed WinXP in another partition. I didn't realise winxp would write over the boot partition.

Using fdisk I was able to change the active partition, but if any other partition other than winxp is set active, I get an "error loading operating system" message.

Next I downloaded KNOPPIX (linux on disc), and this boots fine off the cd. I can access the linux partitions and the winxp partition, so, at least none of the information is lost.

I now need to make the original gentoo linux bootable. I presume this means rewriting over the MBR, but I have no idea how. Also, I don't have a linux boot disk...

Can anybody help?

Thanks in advance,
Who is Participating?
CichaConnect With a Mentor Commented:
You can use grup install of couse,
but I prefer use grub stages and dd utils:
first - load from KNOPPIX
secoud - mount gentoo root portision to /folder
then - make boot floppy disk
# cd /folder/usr/share/grub/i386-pc
# dd if=stage1 of=/dev/fd0 bs=512 count=1
# dd if=stage2 of=/dev/fd0 bs=512 seek=1
then reload from floppy
and in grub enter following commands:
root (hd0,0); #were hd0,0 your boot partition
setup (hd0); #This command will install the GRUB boot loader on the Master Boot Record (MBR) of  the first drive.

And boot from hda now ready
This will install grub on MBR of hda
grub-install /dev/hda (assume hda)

Edit the /etc/grub.conf
#(hd0,0) if you have the linux /boot partition on hda1
title Red Hat Linux (2.4.7-10)
      root (hd0,0)
      kernel /vmlinuz-2.4.7-10 ro root=/dev/hda6
      initrd /initrd-2.4.7-10.img

title Windows XP
# If you have linux on hda3
      rootnoverify (hd0,2)
      chainloader +1

Dont forget to chroot to the root of your orginal install of Gentoo
Before running the grub-intsall

Free Tool: Port Scanner

Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

ruadhanAuthor Commented:

Do I edit grub.conf before I run grub-install?

Currently in /mnt/hda1 I have a grub/ folder which contains a grub.conf file.

ruadhanAuthor Commented:
oh yeah, nearly forgot, the /boot folder is on the same partition as the rest of the linux stuff (hda4)
is this ok?

ruadhanAuthor Commented:
tried to execute, but I get the following output:
root@ttyp0[grub]# chroot /mnt/hda4/ grub-install
/sbin/grub-install: lin 59: cannot create temp file for here document: Read-only file system

Looks like knoppix doesn't want to write anything to the disk
what can I do now?


ruadhanAuthor Commented:
ok made the partitions writable

then i executed the following and got some output:

root@ttyp0[/]# chroot /mnt/hda4 grub-install /dev/hda
/dev/hda does not have any corresponding BIOS drive
Thats because you chroot i think, try writing the
grub-install --root-directory=/mnt/hda/boot /dev/hda
without chroot first.
ruadhanAuthor Commented:
Hi Cicha

Do I have to write directly to /dev/fd0? Currently the only floppy drive I have is an external pcmcia one, but KNOPPIX doesn't support it. I have a new one on order, but until it arrives...
Can I copy these files to a temp folder, transfer them to another machine, burn to cd, and then boot off the cd. How do I make the cd bootable if I do this?
Can you just start command grub ?
> root@ttyp0[/]# chroot /mnt/hda4 grub-install /dev/hda
> /dev/hda does not have any corresponding BIOS drive
This is because you changed root first.
just write the grubb-install /dev/hda
with out changeing root.
ruadhanAuthor Commented:

Thanks for all the help. I managed to get a USB floppy installed. KNOPPIX couldnt see it straight off, so had to mount it as a SCSI

# mkdir /mnt/usbdisk1
# mount -t vfat /dev/sda /mnt/usbdisk1

Then to make the boot disk was
# dd if=stage1 of=/dev/sda bs=512 count=1
# dd if=stage2 of=/dev/sda bs=512 seek=1

and the rest was just like cicha said.

Thanks again for all contributions
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.