Experimental Physics and
Industrial Control System

On Jul 16, 2021, at 2:08 PM, Siddons, David via Tech-talk <tech-talk at aps.anl.gov> wrote:

I have an RTEMS test IOC (generated using makeBaseApp) to which I've added a source file which declares a large array (actually, a compiled-in file system). The Makefile has:

......

# rather than directly into the IOC application, that

# causes problems on Windows DLL builds

myexampleSupport_SRCS += dbSubExample.c

myexampleSupport_SRCS += devmyexampleVersion.c

myexampleSupport_SRCS += myexampleHello.c

myexampleSupport_SRCS += initTrace.c

myexampleSupport_SRCS += tarball.h

myexampleSupport_SRCS += tarball.c

where the tarball files are my additions. The C file contains:

/*

 *  Declarations for C structure representing binary file epicsRtemsFSImage

 *

 *  WARNING: Automatically generated -- do not edit!

 */

#include <sys/types.h>

const unsigned char epicsRtemsFSImage[] = {

  0x74, 0x61, 0x72, 0x62, 0x61, 0x6c, 0x6c, 0x2f, 0x00, 0x00, 0x00, 0x00, 

  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 

  .....etc, then:

const size_t epicsRtemsFSImage_size = sizeof(epicsRtemsFSImage);

The EPICS base libraries contain a weak reference to this same symbol (from libcom/RTEMS/init.c) , and I expected this definition to overwrite the weak one, but inspection of the executable only shows the weak one, and the size variable is not referenced at all. What am I missing? It seems that the tarball file is compiled, but not linked.

Pete.