RTX166: Error 127 (Unresolved External Symbol) From Linker

Information in this article applies to:

• C166 Version 3 and Later
• RTX166 Version 3.10a

SYMPTOMS

I'm starting to create my first RTX166 program. However, when I compile and link my program, I receive a lot of linker errors.

*** ERROR 127: UNRESOLVED EXTERNAL SYMBOL
    SYMBOL:  rtx_stktrap_ver
    MODULE:  Rtxconf.obj (RTXCONF)

*** ERROR 127: UNRESOLVED EXTERNAL SYMBOL
    SYMBOL:  rtx_common_entry167
    MODULE:  Rtxconf.obj (RTXCONF)

*** ERROR 127: UNRESOLVED EXTERNAL SYMBOL
    SYMBOL:  rtx_psreq_init
    MODULE:  Rtxconf.obj (RTXCONF)

*** ERROR 127: UNRESOLVED EXTERNAL SYMBOL
    SYMBOL:  rtx_post_mbx_service
    MODULE:  Rtxconf.obj (RTXCONF)

*** ERROR 127: UNRESOLVED EXTERNAL SYMBOL
    SYMBOL:  rtx_pool_init
    MODULE:  Rtxconf.obj (RTXCONF)

*** ERROR 127: UNRESOLVED EXTERNAL SYMBOL
    SYMBOL:  rtx_sem_init
    MODULE:  Rtxconf.obj (RTXCONF)

*** ERROR 127: UNRESOLVED EXTERNAL SYMBOL
    SYMBOL:  rtx_mbx_init
    MODULE:  Rtxconf.obj (RTXCONF)

*** ERROR 127: UNRESOLVED EXTERNAL SYMBOL
    SYMBOL:  os_error_handler
    MODULE:  Rtxconf.obj (RTXCONF)

*** ERROR 128: REFERENCE MADE TO UNRESOLVED EXTERNAL
    SYMBOL:  rtx_post_mbx_service
    MODULE:  Rtxconf.obj (RTXCONF)
    ADDRESS: 4006H

*** ERROR 128: REFERENCE MADE TO UNRESOLVED EXTERNAL
    SYMBOL:  rtx_post_mbx_service
    MODULE:  Rtxconf.obj (RTXCONF)
    ADDRESS: 4008H

*** ERROR 128: REFERENCE MADE TO UNRESOLVED EXTERNAL
    SYMBOL:  rtx_pool_init
    MODULE:  Rtxconf.obj (RTXCONF)
    ADDRESS: 401EH

*** ERROR 128: REFERENCE MADE TO UNRESOLVED EXTERNAL
    SYMBOL:  rtx_pool_init
    MODULE:  Rtxconf.obj (RTXCONF)
    ADDRESS: 4020H

*** ERROR 128: REFERENCE MADE TO UNRESOLVED EXTERNAL
    SYMBOL:  rtx_mbx_init
    MODULE:  Rtxconf.obj (RTXCONF)
    ADDRESS: 402CH

*** ERROR 128: REFERENCE MADE TO UNRESOLVED EXTERNAL
    SYMBOL:  rtx_mbx_init
    MODULE:  Rtxconf.obj (RTXCONF)
    ADDRESS: 402EH

*** ERROR 128: REFERENCE MADE TO UNRESOLVED EXTERNAL
    SYMBOL:  rtx_psreq_init
    MODULE:  Rtxconf.obj (RTXCONF)
    ADDRESS: 4034H

*** ERROR 128: REFERENCE MADE TO UNRESOLVED EXTERNAL
    SYMBOL:  rtx_psreq_init
    MODULE:  Rtxconf.obj (RTXCONF)
    ADDRESS: 4036H

*** ERROR 128: REFERENCE MADE TO UNRESOLVED EXTERNAL
    SYMBOL:  rtx_sem_init
    MODULE:  Rtxconf.obj (RTXCONF)
    ADDRESS: 403AH

*** ERROR 128: REFERENCE MADE TO UNRESOLVED EXTERNAL
    SYMBOL:  rtx_sem_init
    MODULE:  Rtxconf.obj (RTXCONF)
    ADDRESS: 403CH

*** ERROR 128: REFERENCE MADE TO UNRESOLVED EXTERNAL
    SYMBOL:  rtx_stktrap_ver
    MODULE:  Rtxconf.obj (RTXCONF)
    ADDRESS: 0010H

*** ERROR 128: REFERENCE MADE TO UNRESOLVED EXTERNAL
    SYMBOL:  rtx_common_entry167
    MODULE:  Rtxconf.obj (RTXCONF)
    ADDRESS: 0016H

*** ERROR 128: REFERENCE MADE TO UNRESOLVED EXTERNAL
    SYMBOL:  os_error_handler
    MODULE:  Rtxconf.obj (RTXCONF)
    ADDRESS: 060EH

*** ERROR 128: REFERENCE MADE TO UNRESOLVED EXTERNAL
    SYMBOL:  os_error_handler
    MODULE:  Rtxconf.obj (RTXCONF)
    ADDRESS: 06C0H

Why do I receive these error messages?

CAUSE

This error indicates that the specified RTX166 symbols could not be resolved. These errors typically occur when you begin creating an RTX166 program but do not declare any task functions.

RESOLUTION

Add at least one task to your program and these error messages should go away. For example:

static void do_nothing_task (void) _task_ 1
{
while (1)
  {
  }
}

SEE ALSO

• RTX166: Starting a new Project
• RTX166: Operating System Initialization
• RTX51: Linker Gives Unresolved Extern Error on Os Calls

Last Reviewed: Thursday, February 25, 2021