[Bug 1001143] Ecos crashes when using "nop" instead of "wfi"

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--- Comment #8 from Andreas Schwarz <aschwarz@unifire.ch> 2011-03-04 10:33:43 GMT ---
(In reply to comment #6)

Hi John

We had some problems to explain the error. Basically the device crashes under
heavy load or special circumstances like having to interrupts overlapping or
one with a busy loop in it.

Recently, Stanislav Meduna mentioned a bug in the mailing list regarding the  
HAL_DISABLE_INTERRUPTS macro for Cortex-M3. The result of this macro in
Assembler is that the BASEPRI register is not changed.

We checked our Assembler code and found a lot of this faulty code:

f04f 0320       mov.w   r3, #32
f3ef 8311       mrs     r3, BASEPRI
4619            mov     r1, r3
f381 8811       msr     BASEPRI, r1
613b            str     r3, [r7, #16]

The solution is:

> # define HAL_DISABLE_INTERRUPTS(__old)          \
>     __asm__ volatile (                          \
>         "mrs    %0, basepri             \n"     \
>         "mov    r1,%1                   \n"     \
>         "msr    basepri,r1              \n"     \
>         : "=r" (__old)                          \
>         :  "I" (CYGNUM_HAL_CORTEXM_PRIORITY_MAX)\
>         : "r1"                                  \
>         );

As we fixed this, we were not able to reproduce this behavior any more.

I was looking for a bug report describing this fault. As there is still no bug
report: should I replay on the mailing list (02/16/11) or just add new one
based on our findings?

- Andreas

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