phycore_mpc5554 idle thread exits when GDB invoked

Peter Dufault dufault at
Fri May 30 13:03:28 UTC 2014

On the Phytec MPC5554 with the current head as of yesterday I'm having funny problems with GDB and the McGraigor wiggler.  I don't need to use this setup that often so everything has changed since I last used it: GCC, GDB, RTEMS, the version of Linux, the McGraigor driver...  So I'm at basic principles.

If I just start the program, interrupt with ^C, and continue it exits.

I start, hit ^C, and enter GDB.  I'm in the idle thread, as you would expect.  I have a hardware breakpoint set in bsp_reset(), which is the fatal handler.  This "c" below is the initial setup and will start the program.  Then I type the ^C:
(gdb) c
Program received signal SIGTRAP, Trace/breakpoint trap.
bsp_idle_thread (arg=0x0)
    at ../../../../../../../../rtems/c/src/lib/libbsp/powerpc/mpc55xxevb/startup/idle-thread.c:30
30	    mpc55xx_wait_for_interrupt();

Now when I continue I will hit the breakpoint in bsp_reset:
(gdb) c

Breakpoint 2, bsp_reset ()
    at ../../../../../../../../rtems/c/src/lib/libbsp/powerpc/mpc55xxevb/startup/bspreset.c:35
35	      SIU.SRCR.R = 1U << (31 - 0);

The stack backtrace shows _Heap_Iterate returning to _Thread_Handler(), and then that exits:
#0  bsp_reset () at ../../../../../../../../rtems/c/src/lib/libbsp/powerpc/mpc55xxevb/startup/bspreset.c:35
#1  0x000a80b0 in _User_extensions_Iterate (arg=arg at entry=0x21056580, 
    visitor=0xa8008 <_User_extensions_Fatal_visitor>)
    at ../../../../../../rtems/c/src/../../cpukit/score/src/userextiterate.c:155
#2  0x000a3f4c in _User_extensions_Fatal (error=0x5, is_internal=0x1, source=INTERNAL_ERROR_CORE)
    at ../../cpukit/../../../phycore_mpc5554/lib/include/rtems/score/userextimpl.h:253
#3  _Terminate (the_source=the_source at entry=INTERNAL_ERROR_CORE, is_internal=is_internal at entry=0x1, 
    the_error=the_error at entry=0x5) at ../../../../../../rtems/c/src/../../cpukit/score/src/interr.c:44
#4  0x000f0078 in _Thread_Handler ()
    at ../../../../../../rtems/c/src/../../cpukit/score/src/threadhandler.c:230
#5  0x000effdc in _Heap_Iterate (heap=<optimized out>, visitor=<optimized out>, visitor_arg=<optimized out>)
    at ../../../../../../rtems/c/src/../../cpukit/score/src/heapiterate.c:48
Backtrace stopped: frame did not save the PC

It's exiting because it thinks the thread exited at line 230 in threadhandler.c:

What it says is exiting is the idle thread:
(gdb) print executing->Wait.return_argument
$6 = (void *) 0x0 <bsp_section_start_begin>
(gdb) print executing->Start.entry_point
$7 = (Thread_Entry) 0x6fee8 <bsp_idle_thread>

Anybody have some clues on what might be happening or what info I need to collect?

Peter Dufault
HD Associates, Inc.      Software and System Engineering

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