LFS Init scripts?

Mark Knecht markknecht at gmail.com
Thu Sep 30 13:32:09 PDT 2010


On Thu, Sep 30, 2010 at 1:22 PM, Bruce Dubbs <bruce.dubbs at gmail.com> wrote:
> Mark Knecht wrote:
>> Hi,
>>    I've recently found LFS. Thanks to those that feed and care for it.
>> Nice project.
>>
>>    I've read through the book once and started my first build. It's
>> proceeding fine. I'm typically a Gentoo user so most of what's going
>> on in terms of building software is relatively familiar and I'm not
>> having any trouble. (Yet!)
>>
>>    That said my reason for searching out and trying LFS is to learn
>> more about init scripts. It seems that the LFS init scripts - if I
>> understand them and likely I don't - sort of leave the init scripts
>> alone and as a result they remain sort of generic. They handle lots of
>> different file system types and many conditions I don't think will be
>> important to me.
>>
>>    My personal goal is to understand, for a _very_ minimal system with
>> just a couple of partitions and most all of the drivers built into the
>> kernel, how to boot the kernel and then load everything by hand, one
>> command at a time. I.e. = I'd like to mount /proc, mount /dev, mount
>> /sys all by hand and then work through understanding what the scripts
>> do step by step. I don't care about X for now. I do need networking.
>>
>>    I'm wondering if there might be a good doc around, either LFS
>> specific or even a for-sale Linux book I could buy, that covers what
>> has to happen to get from that last stage of the kernel booting to a
>> bash prompt that allows a user to login?
>
> The first program to run in linux is init.  We use sysvinit.  That reads
> /etc/inittab.
>
>  From there thee are really three lines that are significant:
>
> id:3:initdefault:
> si::sysinit:/etc/rc.d/init.d/rc sysinit
> l3:3:wait:/etc/rc.d/init.d/rc 3
>
> The second and third line run the /etc/rc.d/init.d/rc scripts.  The
> third line is run because of the first.
>
> Read the rc script to trace what is happening.  The scripts are written
> for LFS, but the functionality is close to RedHat's scripts.  Generally
> the scripts have been pretty stable.  We have not made significant
> changes in years.
>
>   -- Bruce

Thanks Bruce. I'm sure that will help me move forward.

Am I fooling myself in thinking that for a very simple hardware
system, maybe just an EXT2 boot, EXT3 / and a swap partition, that for
this specific machine the init scripts might be reduced to something
like 10-20 bash commands which get me to the bash command line where
as root I could use the system?

As a user type I've used Linux for 15 years, Gentoo for 10-11, Redhat
before that, but I've never paid attention to what goes on after the
kernel starts the init process. I'm thinking maybe it's time to learn
a little more.

Thanks,
Mark



More information about the lfs-support mailing list