[ale] custom boot disk woes

[Christopher Fowler]

Oh yea one more thing.  glibc will not fit.  If you create a static binary
it will be about 400k.  What you need to look at is busybox and uClibc.
Use uClibc to compile busybox.  This is a stripped down version of
libc for use in tight spaces.  You iptables program may be a issues.  It may or 
may not be able to compile under uClibc.  In that case you may
have to compile it statically.  

In the past if I had to compile many things statically liked this I used
a concept called a "mulit-call" binary.  Like busybox.  It keeps all the
objects in one file.  You use symbolic links to point to the main 400k 
executable.  The main() function looks at argv[0] to see what reall
function has to be called.  This approach allowed me to place many programs
in the same 400k+ space.  The downside you'll have to modify the iptables source
to not have a main() and to be called by the mult-call binary

crudy example:

if(strcmp(argv[0], "iptables") == 0) {
	return iptables_main(argc, argv);
} else if (strcmp(argv[0], "netstat") == 0){
	return netstat_main(argc,argv);
}

fpritnf(stderr, "module %s not found!\n", argv[0]);
exit(1);


On Wed, Sep 03, 2003 at 07:14:53AM -0500, Kevin Krumwiede wrote:
> I'm just messin' around with an old P75 I found in the trash.  Right now all it has is a floppy drive and a couple EtherExpress/10s... and wow, it's QUIET.  I'm hoping to make it into a firewall.
> 
> I built a 2.4 kernel and wrote it to a floppy.  It boots OK and of course hangs when it can't find init.
> 
> I then made a root filesystem containing only /sbin/init and /dev/tty0 and added it to the floppy.  The kernel finds and loads the compressed disk image, but then I get this message:
> 
> Warning: unable to open an initial console
> 
> I don't know if my init is running.  This might be pretty naive, but here's what I'm using for /sbin/init (compiled with -static):
> 
> #include <stdio.h>
> int main(int argc, void* argv[]) {
> 	puts("init executed successfully");
> 	while(1) { }
> }
> 
> I'm not seeing that message.  I'm assuming that's because there's no console.
> 
> BTW, I originally tried using a 2.2 kernel to save space, but I can't get it to boot at all.  It oopses right away with a null pointer exception.  I Googled for that error, and the results seemed to suggest a bad memory chip or something.  But 2.4 boots fine and MS-DOS was working on the machine when I got it, so I don't think that's the problem.  This happens with a fresh bzImage, before I mess with the ramdisk word or anything.  Ideas?
> 
> Thanks,
> Krum
> _______________________________________________
> Ale mailing list
> Ale at ale.org
> http://www.ale.org/mailman/listinfo/ale
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