GRUB bootloader configuration

phillys · n00b Joined: 23 Aug 2003 Posts: 16

HI guys,

It's my first post here

Well, I've just gotten Gentoo 1.4 for my Pentium 4 and i manage to configure everything just nice during the installation but I dont know how to configure my GRUB

I dont understand what is this (hd0,0) thing

So, what I did was i simple type in whatever I think is right :p well, of course, it turns out that neither one of my OS (WindowsXP and Gentoo) boot at all :lol:

So, in order to boot into Windows XP i have to reformat all my linux partitions and reinstall redhat 8 (which configurates GRUB automatically for me) and after that only i can boot into WinXP and post here looking for help :p

Okay, here's the situation right now... I have my WindowsXP partitioned as /dev/hda1 and the rest for Gentoo goes like this, /dev/hda2 for BOOT, /dev/hda3 for SWAP and /dev/hda4 for my ReiserFS partition(where Gentoo is suppose to be installed). So, what should I do to configurate this GRUB? I really dont understand about this (hd0,0) and crap like that

Please help...thanks

[/b]

phillys · n00b Joined: 23 Aug 2003 Posts: 16

oh yeah.... i forgot to tell you guys that i used genkernel to automatically compile my gaming-sources kernel

thanks

Garbz · Posted: Sat Aug 23, 2003 11:02 am Post subject:

THe kernel sources really make no difference.

Grub uses it's own disk addressing system in the form of (hdx,y) x being the disc number and y being the partition number.

These can directly map to:

hda = hd0
hdb = hd1
hdc = hd2

hda1 = hd0,0
hda2 = hd0,1
hda3 = hd0,2

So for ur grub:

title=Windows
rootnoverify (hd0,0)
chainloader +1

title=Linux
root (hd0,1)
kernel /bzImage root=/dev/hda4 vga=791

simple as that. Unless u have aditional controller cards

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phillys · n00b Joined: 23 Aug 2003 Posts: 16

okay...thanks a lot

in my situation, the below would work, right?

Papapishu · Posted: Sat Aug 23, 2003 2:58 pm Post subject:

I don't ise initrd myself, so I don't really know what it does.
If /boot/kernel-gaming-sources is your kernel, then it looks right to me.

Add the vga=791 for better graphics

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#359074

x20vmk4x · n00b Joined: 23 Aug 2003 Posts: 40

phillys · n00b Joined: 23 Aug 2003 Posts: 16

x20vmk4x · n00b Joined: 23 Aug 2003 Posts: 40

x20vmk4x · n00b Joined: 23 Aug 2003 Posts: 40

ok here's mine:

Papapishu · Posted: Sat Aug 23, 2003 4:04 pm Post subject:

Papapishu · Posted: Sat Aug 23, 2003 4:11 pm Post subject:

Here's mine:

phillys · n00b Joined: 23 Aug 2003 Posts: 16

so, ill take all the /boot/ off, is that right? so, here's how mine is going to look like when i reinstall gentoo tomorrow or sumthing

x20vmk4x · n00b Joined: 23 Aug 2003 Posts: 40

yea thats all correct, but i think you need the initrd line in there, too, if you used genkernel. thats what i read, IIRC.

so itll look like:

Papapishu · Posted: Sat Aug 23, 2003 8:08 pm Post subject:

One could acctually type /boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/boot/grub and it would work...

phillys: You don't need to reinstall gentoo.
Just put in the CD, log in, mount the partition, chroot as you did before, and go straight to the GRUB part of installation.
Finish the installation and you got your system
This is not Redhat, so you can resume your installation

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#359074

phillys · n00b Joined: 23 Aug 2003 Posts: 16

pap.... i tried to resume my installation before but when i try to do chroot /mnt/gentoo /bin/bash, it says something about /bin/bash was not found and not right

so, i had to fricking reformat all my linux partitions with stinking redhat(:p).... there goes all my hardwork...

okay...here's the final version

, i think.

phillys · n00b Joined: 23 Aug 2003 Posts: 16

btw, why is the chainloader (hd0,0)+1 needed by GRUB? What does it mean? thanks

Garbz · Posted: Sun Aug 24, 2003 7:01 am Post subject:

chainloader informs grub that what you are tying to boot does not contain a kernel directly.

The windows partiton in a way contains it's own bootloader.

I think it technically has something to do with loading the first 512k from that partition in the boot sector.
_________________
Every begining is another begining's end.

phillys · n00b Joined: 23 Aug 2003 Posts: 16

aww...man... i ran into trouble again

okay, its like this, i manage to install everything gentoo spick and span and im also able to boot into windows XP with no problem at all

but the problem is, i keep getting the kernel not found error

i think i got my kernel name wrongly so, is there anyway i can go back in installation to reconfigure my GRUB boot loader and also check my kernel name? and oh btw, in case any of you want to know, im using the gaming-sources kernel so, any ideas?

x20vmk4x · n00b Joined: 23 Aug 2003 Posts: 40

just boot up the live-cd, mount ur boot partition somewhere, ls the boot directory to find out what the name of ur kernel is, then nano -w /path/to/grub.conf and correct your problem. umount the boot partition and reboot ur computer, and everythign should work. if that doesnt help, make sure u have the drive correct in ur grub.conf, as its kinda tricky

. hd(0,1) is hda2, and that confused me for a while.

HTH

bryan

phillys · n00b Joined: 23 Aug 2003 Posts: 16

xm, i just tried what u asked me to do but it didnt work

okay, lemme explain my what i did here together with comments on the error...

1. boot in live-cd
2. # mount /dev/hda2 /mnt/gentoo/boot
/mnt/gentoo/boot dir not found
3. if i ls the boot dir, i would get only 3 files listed:
-grub
-boot
-lost+found

and after checking them with nano, they are all empty

DARNIT!

x20vmk4x · n00b Joined: 23 Aug 2003 Posts: 40

if the dir isnt found, make it then mount again. the files listed are actually directories, so nano wont show anything, if it even opens them. sounds to me like u need to chroot to /mnt/gentoo after you mount your root partition there, then emerge a kernel, build it, and configure grub again.
er... first, did you move your bzImage and intrd to the boot dir? i dont know how genkernel works, but if it doesnt move them there automatically, move them there, and if it does, maybe you didnt have the /boot partition mounted when you ran it.

bryan

phillys · n00b Joined: 23 Aug 2003 Posts: 16

my goodness...maybe it's just me but can someone or could you explain that in a more 'simple' and easy to understand way? im too silly to understand that

Garbz · Posted: Mon Aug 25, 2003 9:01 am Post subject:

hey phillys.

A translation:

try mounting /mnt/gentoo that needs to be done before /mnt/gentoo/boot is mounted.
Follow the exact same instructions for mounting and chroot as outlined in the installation guide.

i.e. mount /mnt/gentoo
mount /mnt/gentoo/boot
and mount /mnt/gentoo/proc
then chroot

after you have sucessfully chrooted into gentoo check the following:

in /boot you should have a file bzImage or gentoo-sources or something which resembles a kernel. You may also have an initrd file somewhere.

whereever they are the following needs to be in ur /boot/grub/grub.conf

root (hd0,x) (x is the number of the partition of /boot)
kernel /bzImage root=/dev/hda4 (this is the default replace bzImage with ur kernel)
initrd /initrd (if initrd is used then point to it here.)

Remeber that becuase root was pointed to the /boot partition all the kernel and initrd locatsion are now / i.e. /kernel in grub is the same as /boot/kernel after linux is acutally running.

try fiddleing around on the commandline to save you from rebooting.

after grub starts hit "c"
type "root (hd0,x)"
kernel etc.etc.etc

if ti works correctly it should say:

after root command:
"Filesystem type is ext2fs, partition type 0x83"
after kernel commmand:
"[Linux-bzImage, setup=0x1400, size=0x1275e2]" (actual values may differ)
and after initrd if needed:
"[Linux-initrd @ 0xffc2000, 0x93e bytes]" Once again values will be differnt.

If u saw all of this type "boot" and hope for the best !
_________________
Every begining is another begining's end.

phillys · n00b Joined: 23 Aug 2003 Posts: 16

Garbz, it seems like what you're telling me is for people who compile their own kernels. i used genkernel to compile my kernel

if i leave everything at default without changing anything when i compile the kernel, would my grub.conf look like this?

Garbz · Posted: Mon Aug 25, 2003 11:58 am Post subject:

i don't use genkernel but i have tips to help you find out how to config it:

remove the "(hd0,1)" from these lines:

kernel (hd0,1) /kernel-bzImage root=/dev/hda4 vga=791
initrd (hd0,1) /initrd-bzImage

because they will automatically be assumed to be the root location thanks to the "root (hd0,1)" line.

Also that is correct IF and ONLY IF:

1. /boot is mounted on /dev/hda2
2. /boot/kernel-bzImage exists and is the correct kernel
3. /boot/initrd-bzImage exists and is the correct ramdisk.

In all theory that will work and you're final config will look like