where to start reading boot scripts

[SaintDanBert]

I'm an olde RedHat guy new to ubuntu-family under Hardy v8.0.4. [Glad I made the change.] I'd like to read the boot scripts and cannot find how to do that. I believe that hardy uses something called 'upstart.'

I have the upstart docs, but what I read does not seem to match what I find installed. Can someone point out the first few bricks on this yellow brick road??

~~~ Saint 0;-D

[Diabolis]

Do you mean the services that are loaded when Ubuntu boots? All of them are in /etc/init.d/ And they are called depending on the run level that you want to use. The run levels, instead of being defined by a script, are defined by a folder /etc/rcX.d/ where X is the number of the run level.

[SaintDanBert]

I know about all of those scripts. What I don't find is a description of how things get started. BIOS loads files from /boot ... X,Y,Z happen ... script xxxxx runs first ... that script loads yyyyy, and so on.

Where is the default runlevel stored? My reading talks about /etc/inittab, but that does not exists by default
any longer.

I know that Kxx scripts run in ascending number order followed by Sxx scripts in ascending number order.

Am I correct about using the 'upstart' package? What I find on my install does not match what I read from the package docs.

I know that something runs as an initial process and that
other things proceed from there.

Stumpled,
~~~ Saint 0;-D

[Diabolis]

Yeah, Ubuntu uses Upstart. I would start by reading its original specification (http://upstart.ubuntu.com/misc/upstart.pdf).

The default runlevel in Ubuntu is the number 2. You can check it with the runlevel command.

To find out which scripts are loaded first and which other files they call etc, I would start with the bootloader, which is GRUB by default in Ubuntu. Maybe this will be helpful: http://ubuntuforums.org/showthread.php?p=4723298#post4723298
That thread has a link to a great post in Fedora forums: http://forums.fedoraforum.org/showthread.php?t=153679

I am also interested in finding a detailed "map" of how things happen when the machine boots, I just haven't spend enough time on that.