Experimental Physics and
Industrial Control System

Till Straumann <[email protected]> · Fri, 23 Jan 2009 14:19:18 -0800

Matt Rippa wrote:

Hi Till, Kate -

Thanks for the responses. It turns out the keyboard reset was
not actually causing trouble --that code was never executing.

?? I thought it would execute (but not have any effect). Didn't it look like
this:

 printk("Printing a stack trace for your convenience :-)\n");
 CPU_print_stack();
 /* shutdown and reboot */
#if defined(BSP_KBD_IOBASE)
 kbd_outb(0x4, 0xFE);      /* use keyboard controler to do the job... */
#endif
#if defined(mvme2100)
 *(unsigned char*)0xffe00000 |= 0x80;
#endif

And in bsp.h

#if defined(mvme2100)
...
#else
...
#define BSP_KBD_IOBASE       ((_IO_BASE)+0x60)
#endif

So I guess the code just didn't do anything.
The winbond w83c553 simply has nothing mapped at
the kbd register address (0x60).

I'm not sure if a VME sysreset is the best solution.
Unfortunately, the semantics of 'bsp_reset' are not
fully defined (board reset, yes, but what happens
at the system level?). On a VME system it would
be desirable to have 3 variants:

board reset only, no VME reset
board + VME reset
board reset, VME reset only if board is the system controller

You can try setting bit 1 of port 0x92 which should
perform a board reset -- it would be interesting to
know if that also causes a VME sysreset, especially
if the board is not the SYSCON.

-- Till

In

fact (for the 2700) no reset of any kind was attempted. The stackTrace

seems to just have been called for debugging reasons.

Adding vmeUniverseResetBus() works great and now exit perform as

expected. I've attached a patch, but it still includes the stack trace

in case whom ever included it still wants it.

If it's ok, I'll request this be added to the 4.10 release on
the rtems site.

Thanks!

-Matt

Till Straumann wrote:

Matt Rippa wrote:

Running 'exit' on an RTEMS ioc I get a stack trace. Is exit the

intended mechanism for a soft reboot?

Well - 'exit' should bring you back to the point where you
started RTEMS. However, this is not really possible on all
boards because the environment that booted RTEMS may
have been destroyed (in your case, RTEMS overwrites
critical memory that was used by PPCBug) and in this case
a hard reset may be required (IIRC, 'exit' should in these
cases do that for you so you may have encountered a bug).

Different BSPs used to have their own API to reset the board
(PPC/shared boards used to call this rtemsReboot(), IIRC)
but, again IIRC, this should have been made more consistent
(don't recall if this happened before or after forking 4.9) and
renamed 'bsp_reset()' across multiple architectures/boards.

Now that I write all this I believe I remember that the old
motorola BSP (mvme2300..2700) indeed has a bug; it tries
to reset via the KBD controller and (again IIRC) that doesn't
work. If it did, rtemsReboot()/bsp_reset() or 'exit()' should both
do the job...

You should be able to reset the board via a VME sysreset
(vmeUniverseResetBus())

-- T.

I've shown gdb output below. This is running on an MVME-2700.

Thanks,
-Matt

EPICS 3.14.10 /RTEMS 4.9.1
------
10.1.5.253> exit
Printing a stack trace for your convenience :-)

0x0011A8E0--> 0x0010F55C--> 0x0010A888--> 0x0010A76C--> 0x0000322C

gdb shows:
(gdb) x 0x0000322C

0x322c <enter_C_code+68>:       0x4800004d

(gdb)

0x3230 <MMUon>: 0x7c0000a6

(gdb)

0x3234 <MMUon+4>:       0x6000a972

(gdb)

0x3238 <MMUon+8>:       0x68008940

(gdb)

0x323c <MMUon+12>:      0x7d6802a6

(gdb)

0x3240 <MMUon+16>:      0x7d7a03a6

(gdb)

0x3244 <MMUon+20>:      0x7c1b03a6

(gdb)

0x3248 <MMUon+24>:      0x7c0004ac

(gdb)

0x324c <MMUon+28>:      0x4c00012c

(gdb)

0x3250 <MMUon+32>:      0x4c000064

(gdb)

0x3254 <MMUoff>:        0x7c0000a6

(gdb)

0x3258 <MMUoff+4>:      0x60000070

(gdb)
0x325c <MMUoff+8>:      0x7d6802a6
(gdb)
0x3260 <MMUoff+12>:     0x68000030
(gdb)
0x3264 <MMUoff+16>:     0x7d7a03a6
(gdb)
0x3268 <MMUoff+20>:     0x7c1b03a6
(gdb)
0x326c <MMUoff+24>:     0x7c0004ac
(gdb)
0x3270 <MMUoff+28>:     0x4c00012c
(gdb)
0x3274 <MMUoff+32>:     0x4c000064
(gdb)
0x3278 <_return_to_ppcbug>:     0x7fc802a6
(gdb)

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System