RE: Kernel woes...!

["Barry E. King" <beking-at-home.com>]

Patrick,

I compiled RTLinux 3.0 and RH 7.2 kernel version 2.4.2 each from scracth and
it worked very nicely.  There were a few glicthes to get EMC compiling
properly at the time but I believe those have been since addressed.

This is what I did and although from long-term memory but is more or less
accurate.

Acquire, install and confgure RH 7.2 on a clean system.

Acquire and install RT Linux 3.0.

Have grief with RT Linux 3.0 not running quite right.

Acquire and compile pristine 2.4.2 kernel sources from kernel.org.   If you
are having trouble with the compile use one of the readily available kernel
HOW-TOs or FAQs.  They work very well.  Note that RedHat suffers from a few
deviations from what others expect in the pathing.  Put your kernel sources
in /usr/src/linux-2.4.2 not /usr/src/redhat like my installation had.
Weird.  Use symlinks to make it all good as need to be to satisfy the kernel
build procedures.  eg, linux->linux-2.4.2

Install the new kernel using lilo saving the old one so you can recover to
this known good kernel at a later time.  Make sure new 2.4.2 works.

Buld from scratch rtlinux 3.0.  Start from make clean and on up.  I followed
the instructions and it worked properly as I recall.

Install the new rtlinux kernel using lilo and make sure you can boot the new
2.4.2 kernel in case things go awry.

Boot rtlinux and test it using the supplied test programs.  Location is in
the documentation.  Note that not all of them will necessarily work
properly.  If two or three work then you are probably good to go.

I ditched my realtek card that was in the box.  Although it worked great
under 2.4.1, 2.4.2 took some twiddling to make it work reliably, and rtlinux
simply rejected it.  I think I now know (corrrection, at one time I figured
it out but have since disgarded the solution) why but I took the easy route.
I installed a 3Com 3c509 based board and it worked flawlessly from the get
go.

Oh yeah.  the rtlinux install messed with my modules.conf.  I may have had
to do something to get that working.  Also, I think I had to disable SMP
during kernel build!!! even though the docs say explcitily to the contrary.
Why?  Or am I misremembering...

Get known good EMC sources from sourceforge.net.  I had an annoying problem
with rcs here.  It refused to get the newest versions of a few sources.  I
do not know why.  The command worked for 99.9% of the rest of the sources
and has worked reliably many times since.  Manuallly donwloading those few
sources remedied the problem.  If you get some bitching during EMC build
about missing symbols and kernel versions, you may have to adjust a define.
I cannot recall which one right now but can find it when or if you run into
the problem.

After that everything worked very well.  Start to finish took me two days.
It should have taken only the time required to compile the kernels and EMC.
I installed RH7.2 in about an hour.  The rest of the time was wrestling with
the fact that somehow RTLinux 3.0 did not like the RH kernel (fixed by
getting 2.4.2 from kernel.org) and wrestling with the fact that a few (two
as I recall) sources for EMC were not coming down in their latest and
greatest version.

Hope that helps.

I had tried some version of the BDI once too (not the latest though).  I did
get it working but found it less than satisfactory for my purposes.


Barry