Re: making a smaller kernel

[Kamo Hiroyasu <wd@ics.nara-wu.ac.jp>]

Hello.

Removing "option CPU_I386" makes the kernel a little fat.  Unless
CPU_I386 exists, the compiler option -march=i486 is passed to GCC,
which generates a little larger code for each function.  This may be
the reason.

By the way, how did you measure the sizes of the kernels?  How did
the `size' command report?

			Kamo Hiroyasu
			[Kamo is the family name and Hiroyasu the given name.]

From: Andrew Falanga <afalanga@linora.com>
Subject: making a smaller kernel
Date: Thu, 07 Mar 2002 11:03:20 -0700

> Hello everybody,
> 
>      Well, I finally got to the bottom of my compiling SSH woes and all. 
>   It was in fact RAM.  Thankfully, though it wasn't bad RAM.  I just had 
> mixmatched RAM.  2 mod's were EDO, 2 other's weren't, and to top it all 
> off I think that one set was parity and the other non.
> 
>      Anyway, on to other things.  Although I know it's not necessary I 
> decided to build my own kernel using the FAQ and afterboot(8) as my 
> guide.  I used the GENERIC kernel as the foundation, created myself my 
> own building area copied over the GENERIC file to my build dir and 
> edited the file removing several options.  Stuff like, I have a 686 
> (PPro) so I removed all support for i<whatever> save i686.  I removed 
> support for all but Linux binaries, at this point I don't see myself 
> running binaries from any other platform on this box.
> 
>      Also, I removed the lines that specify sound card devices.  I only 
> left in sb, ecp and ess support.  At this point, I don't even have a 
> sound card in the box so I really don't need anything.  (Note, by 
> removing all I did was comment them out with a '#' sign.)  Then, did 
> make depend, make clean, make and walla out spit my own custom kernel. 
> It works pretty good to, at least it booted and all things are 
> functional.  However, here's my question, after removing all that stuff 
> why is my kernel 200k larger than the stock GENERIC kernel?
> 
>      GENERIC is 4.3mb, mine 4.5mb, what's up?  Why is that?  I would 
> have thought otherwise.
> 
> Andy