How to add lines to kernel configuration file and to rebuild the kernel

[Alan's Home for Wayward Notes File.]

In article <28550.27b82109 at kuhub.cc.ukans.edu>, jian at kuhub.cc.ukans.edu writes:
> Hi, 
> [ Customer wants to add the packet filter to his kernel ].

	Step 1.  Read the "Guide to System Configuration File
	Maintainence".  If you need to know more or don't have
	one, save this reply and refer back to it.
> 
>         options     PACKETFILTER
>         .....
>         psedo-device packetfilter

	That should be "pseudo-device packetfilter".  Config is very
	picky about spelling.

> 
> I don't know what is the name of the kernel configuration file and where it
> locates, /sys/config or /sys/config/mips?

	The configuration file lives in /sys/conf/{vax,mips}.  The
	filename is typically the hostname all in upper case.  For
	this system (shodha) would be /sys/conf/vax/SHODHA (it's a
	VAX).

>  I also don't know what is the 
> procedure to modify the kernel configuration file and to rebuild the
> kernel based on the modifications. I would appreciate someone can point
> me how to do that. Thanks in advance.

	This is the simple way; edit the configuration file as desired
	and run:

		# doconfig -c configuration-file-name

	Example:

		# doconfig -c SHODHA

	On V4.0 and later systems it will tell you where the new
	kernel is.  Save the old one somewhere, copy the new one
	to /vmunix and reboot.

		# cp /vmunix /oldvmunix
		# cp /sys/VAX/SHODHA/vmunix /vmunix
		# shutdown -r now "Boot new kernel"

	If there are users on the system, it is considerably more
	courteous to give them some warning of the system going
	away.

	The arcane way: edit the configuration file and run the
	following commands:

	    If a first time build.

		# mkdir /sys/{VAX,MIPS}/HOSTNAME

	    Else

		# cd /sys/{VAX,MIPS}/HOSTNAME
		# make clean

	    In either case

		# cd /sys/conf/{vax,mips}
		# config HOSTNAME
		# cd /sys/{VAX,MIPS}/HOSTNAME
		# make depend
		# make vmunix

	This will leave a new kernel in the current directory.
> 
> Jian Q. Li
> 
> jian at kuhub.cc.ukans.edu

-- 
Alan Rollow				alan at nabeth.cxn.dec.com