Re: linux 2.0.36

[Will Shackleford <shackle-at-cme.nist.gov>]

> Date: Fri, 5 May 2000 18:32:50 -0400 (EDT)
> Originator: emc-at-nist.gov
> From: Jon Elson <jmelson-at-artsci.wustl.edu>
> To: Multiple recipients of list <emc-at-nist.gov>
> Subject: Re: linux 2.0.36
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> 
> 
> Will Shackleford wrote:
> 
> > In response to complaints from Tim and Fred, I will reinstall RedHat 5.2 on
> > another partition and  try to get the May-5 version of EMC built for linux
> > 2.0.36. Although it probably won't be ready until May-8,
> > I'll still call it the May-5 version.
> 
> Much appreciate the effort!  Is it only the scripts that need to have the
> right directory names for some of the .h files, etc. for RT, or are there
> real differences in the code to be compatible with the 2 versions
> of Linux?
> 
> Thanks,
> 
> Jon
> 
> 

The differences that I can come up with of the top of my head are:


1. The 2.0.36 distribution comes with the RCS libary pre-compiled for 2.0.36 and 
rtlinux 09J.
2. The source code files are all the same, but within the files there are 
numerous sections that look something like this:


#ifdef linux_2_2_13

// Code for linux_2_2_13


#else

// Code for linux_2_0_36

#endif

The correct segment of code is included by the compiler by passing either 
-Dlinux_2_2_13 or -Dlinux_2_0_36 as a command-line option to gcc or g++.

3. In a few cases there are source files that are not compiled at all under one 
of the platforms. In order to control this the makefiles have lines that look 
like this:

ifeq (linux_2_0_36, $(PLAT))

# lists of files only for linux_2_0_36

else


endif

4. As you noted the install scripts are different.

5. The 2.2.13 uses a different set of fuctions to interface with rtlinux than 
2.0.36, they not only changed the header file names but most of the function 
names and data types.

6. 2.2.13 uses mbuff to access the shared memory between the real-time and 
non-realtime processes, where as 2.0.36 uses a static address.  (2.2.13 doesn't 
need append= flag added to lilo.conf and  won't use it if you add the append 
flag so adding it just wastes memory.) 

7. The simctrl and stripchart tools require GNOME libs so I will probably 
disable them in 2.0.36. Those libs come with the RedHat 6 distributions but not 
the earlier distributions. It might be possible to install them but I am not 
sure it is  worth it.

8. simmod was built using a seperate mbuff for simulation control and since this 
is hard to do with the static addresses, simmod will probably need to be 
disabled in 2.0.36.

-- will





---------------------------------------------------------------
William Penn Shackleford III			shackle-at-nist.gov
National Institute of Standards & Technology	Tel:	(301) 975-4286
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