Q: Should Cygwin/RTEMS-4.6.2/powerpc-rtems/psim pass these: s p12. exe and sp32.exe?

[Mills, John M.]

Joel -

Mills, John M. wrote:
 
> Following your note to Daniel Gustafsson and the contents of <confdefs.h>,
I
> edited
>  <RTEMS-srcdir>/c/src/tests/sptests/sp32/init.c to add the line:
> 
> "#define CONFIGURE_MICROSECONDS_PER_TICK
> RTEMS_MILLISECONDS_PER_MICROSECOND(xx)"
> 
> before the line: "#include <confdefs.h>" 
> 
> I still fail 'sp32.exe' for values of xx between 1 and 5000.

js> psim is pretty simple.  Each unit counted in the decrementer
js> register is 1 instruction.  There is a constant in the BSP
js> named PSIM_INSTRUCTIONS_PER_MICROSECOND which is set to 10000
js> in the CVS source.  The value put in the decrementer register
js> is calculated by this code.

js> PPC_DECREMENTER_CLICKS =
js>     (unsigned int)&PSIM_INSTRUCTIONS_PER_MICROSECOND;
js> PPC_DECREMENTER_CLICKS *=
js>     rtems_configuration_get_microseconds_per_tick();

js> So we are saying that there you need to execute at least 10000 * 5000
js> instructions per simulated millisecond to do the workload required
js> by this test.

I found the following in
 <RTEMS-srcdir>/c/src/lib/libbsp/powerpc/psim/startup/linkcmds:

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
++++
 ...
ENTRY(_start)
/* Do we need any of these for elf?
   __DYNAMIC = 0;    */
PROVIDE (PSIM_INSTRUCTIONS_PER_MICROSECOND = 100);
PROVIDE (CPU_PPC_CLICKS_PER_MS = 16667);
 ...
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
++++

Is that the right place to adjust psim's "bogomips" factor? Should there be
a matching adjustment made to "CPU_PPC_CLICKS_PER_MS"?

Also, where should I have looked for this information? I suppose it is
always a candidate for attention when you set up a BSP. I went through the
on-line docs and came up dry, but this kind of thing is surely there
somewhere.

js> Basically you can turn down the number of instructions per tick
js> to the point where you are not making forward progress on the test.

I'll try adjusting PSIM_INSTRUCTIONS_PER_MICROSECOND.

js> sp32.exe ran for me last night but sp12.exe failed on psim.

'sp12.exe' still dies for me, too. Looks like it's blowing up the priority
stack, else there's a misdefined constant or wrong storage class used to
link the priority 15 callback.

Thanks.
 - John

John M. Mills
Staff Engineer
EMS Technologies
660 Engineering Drive
Norcross, GA 30092
770.263.9200 ext4882