when is menu.lst read in grub process

when is menu.lst read in grub process

[Damon Register]

After a while of Googling, reading grub documentation and struggling
to understand some of grub, I am still stuck.  I have found in my own
life that understanding how something works is very important in
dealing with problems when they occur.  AT this point I don't have
any specific problems with grub, I just want to better understand the
grub process.  I suspect I am not the only one who has these kinds of
questions and I am hoping that this might be used to add some things
to the grub faq http://www.gnu.org/software/grub/grub-legacy-faq.en.html

1. am I correct in understanding that menu.lst and grub.conf are really
    the same thing?  Did menu.lst evolve into grub.conf?

2. what is a high level overview of the sequence for a simple boot
    sequence?  Am I correct in understanding that it goes something
    like this?
    a. stage1 is in the MBR and is the first thing seen at startup
    b. stage1 contains a pointer to stage2 which is in the filesystem

3. Just where does the menu.lst fit into the grub sequence?  At what
    point is it read?

4. is any part of the menu.lst read and inserted into either stage1
    or stage2 during the installation of grub?

5. are there any changes to menu.lst that require a re-installation
    of grub?

6. at http://www.freeos.com/articles/3482/ I read

    While LILO requires the physical location of the kernel on your
    drive, GRUB does not. Even the latest filesystem ReiserFS is
    supported. This means that you don't have to re-install GRUB every
    time you make a change to the config file or install a new kernel.

    Is that true?  Does that mean the answer to my question 5 is no?

Damon Register

Re: when is menu.lst read in grub process

[Pádraig Brady]

Damon Register wrote:
> After a while of Googling, reading grub documentation and struggling
> to understand some of grub, I am still stuck.

I had the same issue when I had to setup grub in a non standard way.
I read the source and documented the process here:
http://www.pixelbeat.org/docs/disk/

Pádraig.

Re: when is menu.lst read in grub process

[Damon Register]

Pádraig Brady wrote:
> I had the same issue when I had to setup grub in a non standard way.
> I read the source and documented the process here:
> http://www.pixelbeat.org/docs/disk/
That is really great.  Thanks.  I think this should be part of the
official grub documentation or at least a link should be provided,

Your process description seems to confirm what others have said,
that menu.lst is read by stage 2 and therefore menu.lst can be
tampered without reinstall of grub.  There is one thing that still
remains confusing for me.  You say about stage 1

  Bootloader jumps to location (sector num) of next stage.
  This sector num is stored at a particular location in the bootloader
  "code" at grub install time and usually points to a stage 1.5 located
  in the "DOS compat space" immediately after the MBR.

How does the grub install process know the correct number to store in
stage 1?  That location does not come from menu.lst?

Damon Register

when is menu.lst read in grub process

[Damon Register]

After a while of Googling, reading grub documentation and struggling
to understand some of grub, I am still stuck.  I have found in my own
life that understanding how something works is very important in
dealing with problems when they occur.  AT this point I don't have
any specific problems with grub, I just want to better understand the
grub process.  I suspect I am not the only one who has these kinds of
questions and I am hoping that this might be used to add some things
to the grub faq http://www.gnu.org/software/grub/grub-legacy-faq.en.html

1. am I correct in understanding that menu.lst and grub.conf are really
    the same thing?  Did menu.lst evolve into grub.conf?

2. what is a high level overview of the sequence for a simple boot
    sequence?  Am I correct in understanding that it goes something
    like this?
    a. stage1 is in the MBR and is the first thing seen at startup
    b. stage1 contains a pointer to stage2 which is in the filesystem

3. Just where does the menu.lst fit into the grub sequence?  At what
    point is it read?

4. is any part of the menu.lst read and inserted into either stage1
    or stage2 during the installation of grub?

5. are there any changes to menu.lst that require a re-installation
    of grub?

6. at http://www.freeos.com/articles/3482/ I read

    While LILO requires the physical location of the kernel on your
    drive, GRUB does not. Even the latest filesystem ReiserFS is
    supported. This means that you don't have to re-install GRUB every
    time you make a change to the config file or install a new kernel.

    Is that true?  Does that mean the answer to my question 5 is no?

Damon Register