Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Mon, 18 Aug 2014 11:53:34 -0500

I would like to ask the EPICS community to discuss the minimum
requirements to be able to run IOCs in the future. I have two specific
areas, but feel free to discuss others if you know of any.

Memory
------
Currently (with Base 3.14.12.x and the up-coming 3.15.1 releases) an IOC
can be run on an embedded system (RTEMS or VxWorks) with as little as
8MB of RAM, although in practice you probably need more than that for
record instances, device support and driver code, and to allow for
client CA connections. Are any labs designing IOC systems to use small
amounts of RAM, or can we assume that future IOCs (3.16 and later) will
have at least 32MB available (for the OS and application)?

VxWorks
-------
Base 3.14.12.x releases can still be built against VxWorks 5.4.2, which
has a very old (pre-ANSI) C++ compiler. The next major release of Base
version 3.15.1 will require VxWorks 5.5.x. Who would be significantly
affected if later releases were to require VxWorks 6.6 (i.e. gcc 4.1.2)
or later?

This switch would preclude 680x0-based IOCs since Wind River dropped
support for the 68k family in moving to VxWorks 6.x. VxWorks 6.x also
provides a much better memory allocator, earlier versions fragmented
memory unless significant care was taken.

The EPICS core developers would like IOCs to be able to use more memory
and modern compilers, so please discuss the above requirement changes if
they will adversely affect your site.

- Andrew
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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System