Dual booting Gentoo and XP using grub
 

Alright, when I boot my computer it stops at a prompt like this:

GRUB:

I installed WinXP on the primary master hard drive, and Gentoo on the primary slave hard drive. In the Gentoo installation, I decided to go with Grub as a boot loader, and shoved it into the MBR. When telling grub where to install and setup I ran into this, which is probably the problem:

grub> root (hd0,0)
Filesystem type unknown, partition type 0x7
grub> setup (hd0)
Error 17: Cannot mount selected partition

At this point, I figured I should try using grub as a secondary loader begining where Gentoo was installed. I previously had Red Hat 9 where Gentoo was installed, and used GRUB as the loader then, and it worked fine. I figured I'd get to the first (working) instance of grub that would refer to this one at bootup.

grub> root (hd1,0)
Filesystem type is ext2f3, partition type 0x83
grub> setup (hd1,2)
#checking and running blah everything looks successful

Using the Gentoo Live CD I can still get into my newly installed Gentoo kernel and modify boot sectors and loaders, so I still think the problem is fixable. To me, it seems that GRUB gets started when the MBR is consulted at bootup, but since it was never set up, it dies. Does anybody know why my MBR is not mountable?

Boot loaders aren't exactly my cup of tea, so if you have a solution, please walk me through it slowly.

Thanks in advance.

grub is not trying to mount the MBR... that's never possible, as it's not a filesystem... you've just blindly copied the comands in the docs haven't you ;)

1) define the root partition for grub's configuration, i.e. your boot partition "root(hd1,0)" for hdb1 etc...

2) install to MBR "setup(hd0)"

root (hd0,0) - this should be your /boot partition if you have one, if not it should be your root partition. You said you had Windows XP on your primary master so you're trying to install Grub on that - hd0,0 is the first partition on your first hard drive, and that's the one Grub fails to mount. Review your partition configuration and re-read the Gentoo docs on Grub. :)

Håkan

uhhh
 

Alright, I reconfigured grub like you said, and I get the pretty splash screen, Gentoo seems to start fine, but booting to windows brings up an error:

root (hd0,0)
Filesystem type unknown, partition type 0x7
chainloader (hd0,1)+1
Error 22: No such partition

Press any key to continue...

Thanks for your help so far!!

you probably want to use rootnoverify (hd0,0) if xp is on that partition. but why are you then changing to (hd0,1) ? that makes no sense.... just try changing that bit to "chainloader +1"

Thanks, the booting problem is fixed!

But now I have another, Gentoo related issue. I tried a different kernel source (ck-sources), but when I try to compile it, it dies in the middle with a compilation error. How should I fix this?

-emerge the source again?
-check out the C code myself?

It seems to me that compilation errors shouldn't happen when compiling kernel, what could cause that? Bad download?

Seriously though, thanks for your help, you saved me a lot of time!!!

Although I run Gentoo (as of recently) I am not very familiar with the Gentoo-specific kernel sources. What error message do you get? And did you search the Gentoo forums for the error message? Most questions that usually arise have already been asked and answered there. The search function is really a blessing. :)

Håkan

well yes post the actual error messages, we're not psychic. personally i'd say go with the gentoo-dev-sources for a 2.6.1 kernel.