GRUB module query

Tod Merley todbot88 at gmail.com
Wed Aug 16 23:56:35 UTC 2006 

On 8/16/06, Dave S <ubuntu at pusspaws.net> wrote:
> On Wednesday 16 August 2006 21:42, Tod Merley wrote:
> > Look for comments inserted below:
> >
> > On 8/16/06, Dave S <ubuntu at pusspaws.net> wrote:
> > > On Tuesday 15 August 2006 22:47, you wrote:
> > > > On 8/15/06, Dave S <ubuntu at pusspaws.net> wrote:
> > > > > I have a raid array which needs the IT821X kernel module. My hda /
> > > > > hdc HDDs are plugged into the raid controller and so the IT821X has
> > > > > to be directly compiled into the kernel since it needs it to boot :)
> > > > >
> > > > > This is a pain since I have to make my own kernel & recompile it when
> > > > > kernel updates occur.
> > > > >
> > > > > Is there a way to load the kernel with modules right from boot ? I
> > > > > tried editing grub menu/lst with ...
> > > > >
> > > > > kernel  /boot/vmlinuz-2.6.15-26-386 root=/dev/md0 IT821X ro quiet
> > > > > splash
> > > > >
> > > > > but no luck
> > > > >
> > > > > all help gratefully received
> > > > >
> > > > > thanks in advance
> > > > >
> > > > > Dave
> > > > >
> > > > > --
> > > > > ubuntu-users mailing list
> > > > > ubuntu-users at lists.ubuntu.com
> > > > > https://lists.ubuntu.com/mailman/listinfo/ubuntu-users
> > > >
> > > > Hi Dave!
> > > >
> > > > I think I would first try my edits from the GRUB boot menu.  Press a
> > > > key during the countdown and follow the prompts on the screen to edit.
> > >
> > > Thank you so much for repling, sorry for the delay - work happened :(
> > >
> > > > I found this:
> > > >
> > > > Generally, GRUB can boot any Multiboot-compliant OS in the following
> > > > steps:
> > > >
> > > >    1. Set GRUB's root device to the drive where the OS images are
> > > > stored by the command @command{root} (see section root).
> > > >    2. Load the kernel image by the command @command{kernel} (see
> > > > section kernel).Generally, GRUB can boot any Multiboot-compliant OS in
> > > > the following steps:
> > > >
> > > >    1. Set GRUB's root device to the drive where the OS images are
> > > > stored by the command @command{root} (see section root).
> > > >    2. Load the kernel image by the command @command{kernel} (see
> > > > section kernel).
> > > >    3. If you need modules, load them with the command @command{module}
> > > > (see section module) or @command{modulenounzip} (see section
> > > > modulenounzip).
> > > >    4. Run the command @command{boot} (see section boot).
> > > >
> > > > module
> > > >
> > > > Command: module file ...
> > > >     Load a boot module file for a Multiboot format boot image (no
> > > > interpretation of the file contents are made, so that user of this
> > > > command must know what the kernel in question expects). The rest of
> > > > the line is passed as the module command-line, like the
> > > > @command{kernel} command. You must load a Multiboot kernel image
> > > > before loading any module. See also section modulenounzip.
> > > >
> > > > modulenounzip
> > > >
> > > > Command: modulenounzip file ...
> > > >     The same as @command{module} (see section module), except that
> > > > automatic decompression is disabled.
> > >
> > > Thanks for the info. I read the links and tried
> > >
> > > title           Ubuntu, kernel 2.6.15-26-386
> > > root            (hd0,0)
> > > kernel          /boot/vmlinuz-2.6.15-26-386 root=/dev/md0 ro quiet splash
> > > initrd          /boot/initrd.img-2.6.15-26-386
> > > module
> > > /lib/modules/2.6.15-26-386/kernel/drivers/ide/pci/it821x.ko savedefault
> > > boot
> > >
> > > On reboot I got a kernel panic ....
> > >
> > > kernal panic - not syncing: VFS unable to mount root fs on unknown block
> > > (0,0)
> >
> > Looks like you tried my "edited" version and do not have your root
> > partition on (hd0,0) as I do.  It probably would have panicked or
> > warned later with it did not find it821x.ko later (needs to be the
> > exact path!!!).  It was an "example" to be modified for your
> > environment.  Sorry for the confusion!!!
> >
>
>
> No problem - I read the docs as well. My root partition is on 0,0 but can only
> be seen when the it821x driver is installed since the drives are plugged into
> a raid card. (Chicken & egg !) At present I am running a kernel with the
> it821x compiled directly into the kernal & it works great - just trying to
> get a more elegant solution so when kernal security updates come along I do
> not need to re-compile
>
> Dave
>
>
>
>
>
>
>
>
>
>
> > > > Here:
> > > >
> > > > http://www.linuxselfhelp.com/gnu/grub/html_chapter/grub_4.html
> > > >
> > > > http://www.linuxselfhelp.com/gnu/grub/html_chapter/grub_12.html#SEC87
> > > >
> > > > It is part of the GRUB Manual - better accessed here:
> > > >
> > > > http://www.gnu.org/software/grub/manual/
> > > >
> > > > My menu.lst file's default kernel boot section looks like:
> > > >
> > > >
> > > > title           Ubuntu, kernel 2.6.15-26-386
> > > > root            (hd0,0)
> > > > kernel          /boot/vmlinuz-2.6.15-26-386 root=/dev/hda1 ro quiet
> > > > splash initrd          /boot/initrd.img-2.6.15-26-386
> > > > savedefault
> > > > boot
> > > >
> > > > I think adding the module command might look something like this:
> > > >
> > > >
> > > > title           Ubuntu, kernel 2.6.15-26-386
> > > > root            (hd0,0)
> > > > kernel          /boot/vmlinuz-2.6.15-26-386 root=/dev/hda1 ro quiet
> > > > splash module
> > > > /lib/modules/2.6.15-26-386/kernel/drivers/ide/pci/it821x.ko initrd
> > > >     /boot/initrd.img-2.6.15-26-386
> > > > savedefault
> > > > boot
> > > >
> > > > Dave, please help me in that I am putting together a "Boot Camp"
> > > > presentation for a LUG or two I am involved with and need to
> > > > understand this myself.  Please tell me what you find.
> > > >
> > > > I also note with interest this:
> > > >
> > > > tod at tod-desktop:~$ cat /etc/modules
> > > > # /etc/modules: kernel modules to load at boot time.
> > > > #
> > > > # This file contains the names of kernel modules that should be loaded
> > > > # at boot time, one per line. Lines beginning with "#" are ignored.
> > > >
> > > > lp
> > > > psmouse
> > > > tod at tod-desktop:~$
> > >
> > > Ah I now about this. This is a list of modules to be loaded when the
> > > system starts - but a lot further on in the boot process.
> > >
> > > > Good Hunting - hope to hear from you!
> > > >
> > > > Tod
> > >
> > > However this is what I have found ....
> > >
> > > vi /etc/mkinitrd/modules ...
> > > add the 'it821x' module
> > >
> > > mkinitrd -o /boot/initrd.img-2.6.15-26-386 2.6.15-26-386
> > >
> > > on reboot the module is loaded - my raid works :) ... but .... I get
> > > a 'unknown filesystem devfs' It does not cause a kernal panic, I end up
> > > without X but with a loggin prompt.
> >
> > Excellent!!!  Adds much to my understanding and to the upcoming "Boot
> > Camp"!  Thank you!!!
> >
> > > Dave
> > >
> > > PS You send this to me off list - is it OK to copy it to the list so
> > > others can comment ?
> >
> > My original on in my mail (gmail web mail) shows it sent to the list
> > and to you. I reply to both here.
> >
> > Thanks much!
> >
> > Tod
>
> --
> ubuntu-users mailing list
> ubuntu-users at lists.ubuntu.com
> https://lists.ubuntu.com/mailman/listinfo/ubuntu-users
>

Hi Dave!

I do not understand.  If you need the raid driver to access the disk
then how can you even fully load GRUB?!?!

My limited understanding of GRUB is:

Stage one - Master Boot Record  (First 512 bytes of BIOS chosen boot device).

Stage "1.5" - Found by pointers in stage one - basically a chosen
"file system reader" based upon the configuration of the disk where
the ramdisk image (initrd) and Kernel can be found.

Stage two - GRUB and boot.

In your case I would be tempted to make my own little live CD's (see
the GRUB manual - it looks pretty easy).  Not only would it solve the
updates issue but it would be very secure.  No one could touch your
MBR, Kernel, etc...

Thanks for the information. This is quite interesting!

Tod

More information about the ubuntu-users mailing list