Re: Very frustrating
Don Cavaiani wrote:
>
> Does anyone have a "document" or paragraph that they can cut and paste
> and mail to me so that I will know what happens when Debian Linux starts
> up ??
>
> I am looking for the SEQUENCE of the start up, the PROGRAMS that are
> executed, and the EXACT names of the configuration files (whether HIDDEN
> or not).
>
> For example, I have NO IDEA where to go to set the DEFAULT window
> manager to ICEWM (which I have found to my liking).
>
> Finally, is it possible to put a new icon on the window desktop so that
> I can start a favorite program with just a click?
>
> Help will be greatly appreciated.
I don't know off-hand of any such document, although I'm sure they
exist. The start-up sequence is considerably complex, especially for
someone coming from the DOS/Windows world. But here's a rough outline:
The Power-On-Self-Test (POST) runs from the BIOS when power is applied.
Then the BIOS looks for the boot record on floppy, hard drive, or CD-ROM
(or on the network, etc). It finds the LILO boot manager, and from there
loads the kernel, named something like /boot/vmlinuz (although LILO
usually points to /vmlinuz, which is a link to /boot/vmlinuz). The
kernel loads, doing some testing of its own and setting up stuff that's
compiled into the kernel (such as sound drivers, etc). Then the kernel
run /etc/inittab.
/etc/inittab basically tells the system what to run when entering a
runlevel. Usually level 2 is defined early in this file as the default
runlevel, and then later, run level 2 is defined to run /etc/init.d/rc
with the paramater 2. The /etc/inittab also specifies such things as how
many virtual terminals you have and starts a getty (a program that makes
the virtual terminal "active"), and what happens when power is lost, and
what happens when Ctrl-Alt-Delete is pressed, etc. But the big thing is
that it runs /etc/init.d/rc with the appropriate run level passed to it
as a parameter.
So then you'd look at /etc/init.d/rc. This file simply runs the various
scripts that are supposed to run when entering a runlevel. It checks to
see if there's an init directory for the runlevel, and if so it then
runs the scripts in that directory, starting with the "K" scripts (which
kill processes), in order from lowest number to highest, and then it
runs the "S" scripts (which start processes), again, in order from
lowest number to highest.
So in the case of runlevel 2 (normal operation), it looks for
/etc/rc2.d. Finding that directory, it runs the scripts in there,
starting with K[low-number] and ending with S[high-number].
In the case of my home box, I don't have any K scripts in this
directory, but I do have a "S10sysklog" script, which starts the system
and kernel log daemons, a bunch of other S scripts, and a final "S99wdm"
script which starts the wdm X display manager. The "S99wdm" script
starts X for me automatically so I don't have to log in at a console
prompt and then manually start X with "startx".
Starting up X is a separate process from booting up. The boot-up process
is now finished, but the process of starting X is "tied" to the tail-end
of the boot-up process with wdm.
I have less of a clue about how X starts up, so I won't even try to go
into that at the moment. However, to answer your question of how to
specify which window manager to use:
If you want to set the default wm for all users, you'd specify it on the
first non-commented line in /etc/X11/window-managers. Just add, move, or
change the lines in this file so the first line points to the wm of your
choice.
Each user can over-ride this default by creating/editting the
~/.xsession file. For example, my .xsession file looks like:
xterm -geometry +2+2 &
# icewm
startkde
This starts an xterm window that is offset from the top left corner just
a smidgeon, and then starts the kde environment (which starts other
stuff, like kaudio server, etc). If I want a leaner wm, I just comment
out the "startkde" line and uncomment the "icewm" line.
Some window managers will allow you to create desktop icons. I've never
found icewm to be capable of this, which is why I'm currently running
kde. Other than that, I usually prefer icewm to kde.
Hope this helps answer some of your questions.
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