Experimental Physics and
Industrial Control System

Mark Rivers <[email protected]> · Tue, 21 Nov 1995 23:13:52 -0600 (CST)

Folks,

I would like to start a discussion on how best to handle the distribution of
EPICS for various platforms.  

As Janet Anderson pointed out yesterday, the distribution rules described in
the "EPICS: Distributed Development,  Distribution and Support" document
state that the distribution of R3.12.2 for each platform is the
responsibility of the "platform developer".  For example, I am responsible
for the distribution of SGI and VMS.  What the document does NOT describe is
exactly what the platform developer is supposed to distribute:
    /src ?
    /lib/"arch" ?
    /bin/"arch" ?

Several possibilities come to mind:

- In an ideal world, the platform developers would have been testing all of
  the beta releases and checking any changes back with the product developers.
  Thus, each "official release" would build with no problems on every
  platform, and all users could just fetch the source from ANL and build
  all of EPICS from scratch.  I think this option is unlikely to succeed for
  several reasons:
    1) Even "official releases" WILL have minor problems building on various
       platforms.  The platform developer should track down these problems and
       fix them.
    2) Many sites will not be able to build all of EPICS from scratch, because
       they lack the required libraries (xrtGraph, for example).
    3) Many sites would rather not spend the effort to build all of EPICS if
       they could download lib/"arch" and bin/"arch".

- The platform developer could just provide source code with any minor 
  modifications to build on that platform.  This option still has problems 2) 
  and 3) above.  In addition, for sites with multiple architectures, users 
  would be downloading several sets of source code, which will be 99.99% 
  identical, and maintaining separate source for each architecture is not a 
  good idea.

- The platform developer could provide the following:
    - A list of the source code modifications required to build the
      distribution on a specific platform.  One possibility would be a tar
      file of /src containing only the modified files.
    - Prebuilt versions of lib/"arch" and bin/"arch".

My feeling is that some variation on the last option would be the best.  Users
would always download the "official release" from ANL, and then download the
modified source files, prebuilt libraries and prebuilt executables from the
platform developer.

Comments?

____________________________________________________________
Mark Rivers                             (312) 702-2279 (office)
CARS                                    (312) 702-9951 (secretary)
Univ. of Chicago                        (312) 702-5454 (FAX)
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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System