process to monitor boot process and all necessary apps

[metzelplik]

Hello,

I have been building a remastered KNOPPIX. I want to know if anyone might have a good idea for placing a script or application VERY EARLY in the boot process which will allow me to watch ALL apps/processes being started during the boot process. The reason I ask is that I would like to remove many unnecessary apps from the system, and I want to make sure they are not needed prior to removing them. If I can "trace" all necessary apps, then I can determine which apps/files to remove from the system for the application specific build being worked on.

Thank you in advance for any help,

Metzelplik

[OErjan]

just go trough the /etc/rc files for the default runlevel (5 iirc) there it lists all things that are to start...

[metzelplik]

Thank you for the info, but I already understand that this takes place. I wanted to know if someone could recommend something that would save me time from going through all the scripts and "walking" through all the apps/programs/binaries that are called from this steip forward. Also, by the time the system gets to the rc part, I may have already missed something.

Thanks again. Much appreciated.

Metzelplik

[OErjan]

only kernelwise in that case. not much else happens before the rcfiles get read.
they mount the disk and read info from there on, before that only kernel and the bios/bootloader.
here is a more thuroug howto on booting linux diskettes, in general that goes for CD and dvd's aswell.
http://www.linux.org/docs/ldp/howto/Bootdisk-HOWTO/index.html
there is more if you look around.
hope it helps some.
EDIT here is a thurough description on the kernel level.
not useful if you do not know quite a bit about computerhardware and programing (kerneldevelopment).
http://www.linux.org/docs/ldp/howto/Linux-i386-Boot-Code-HOWTO/index.html
/EDIT

[metzelplik]

OErjan...

thank you for the information. I will take a look at the information in your post later tonight and get back to the forum as to its usefullness. What I want to do is figure out EXACTLY what files on the system are necessary for a very specific build... then, recreate an ISO image with ONLY those files in it. This will not only allow the application that I have written to work, but prevent the system from being used in any other manner. If someone can figure out a way to break into the system via remote attack, their hands will be tied as to what they do from the system.

I don't want the system to be used for anything else. This is a very specific app.
I am also curious as to how small of an image I can create using this thinking.

Thanks again. Your help is much appreciated.

Metzelplik

[OErjan]

in that case the floppy tutorial is just the thing for you. it gives ways to shrink everything and so. strace, awk, hexedit, less and grep are tools i recomend you to get familiar with.
they, either separate or together in diferent ways, can give you exactly the system calls sent from any given app and list them.

lfs is another good resource for basic linux knowledge.
lfs is a "recepie" how to make a working linuxdist from scratch, read a few times go trough the process and you know most there is to know about linux.
i have done it.
here is a link listing mirrors.
http://www.linuxfromscratch.org/

gentoo is another where you can customize but not quite as much.
their documentation is great though.
http://www.gentoo.org/main/en/mirrors.xml