Help Setting Up New Embedded Linux System

Help Setting Up New Embedded Linux System

Post by Tom Vanderpoe » Mon, 08 Apr 2002 03:12:35



Hello,

I'm trying to learn how to get Linux running in an industrial PC
environment.  I have Linux running on a spare desktop PC (Pentium Pro).
After reading the Linux Bootdisk How-To, I got things working on another
desktop PC (Pentium 3).  The kernel runs, the compressed root fs image gets
copied from a second floppy to a ram disk and mounts ok, init runs, and I
get a shell.  So far so good.  The problem is that apparently init is not
running successfully on the target system.  After mounting the root fs, I
get a message that says "Freeing unused kernel memory" then nothing.  I'm
not sure what to be checking next.

Things work ok on two Pentium 3 machines I've tried, but don't work on
several 486 and Pentium (1) machines.  I'd like to see if I can make it work
on a 486 with 16 or even 8 MB ram.

1)  The kernel says 16 ram disks of 4096k each have been created.  Has 64MB
actually been consumed already?!? Please tell me this just means that
SUPPORT for up to 16 ram disks is available.

2) When I started out, the kernel itself wouldn't even run on the
486/Pentium target machines, only on the Pentium IIIs.  I rebuilt the kernel
for a 486 and it runs ok.  Do I have to rebuild everthing else, like init,
libc, a shell, etc. for a specific target?  I'm currently taking the
binaries for these off the desktop machine (Pentium Pro) where I installed
Red Hat 7.1 from a CD.

Any help or pointers to information would be helpful.  I'm sure there are
easier ways to accomplish this, but for a beginner, doing it the hard way at
least once is VERY instructive.

Tom

 
 
 

Help Setting Up New Embedded Linux System

Post by Robert Schwebe » Mon, 08 Apr 2002 18:42:55



> Things work ok on two Pentium 3 machines I've tried, but don't work on
> several 486 and Pentium (1) machines.  I'd like to see if I can make it work
> on a 486 with 16 or even 8 MB ram.

Did you compile some things on the target fs with optimization for the
wrong processor?

Quote:> 2) When I started out, the kernel itself wouldn't even run on the
> 486/Pentium target machines, only on the Pentium IIIs.  I rebuilt the kernel
> for a 486 and it runs ok.  Do I have to rebuild everthing else, like init,
> libc, a shell, etc. for a specific target?

This might be the case, see above. For the beginning, it might be a good
idea to compile just a C library (uClibc, glibc) and BusyBox (which
includes init) for testing.

Robert
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