Stack Checker in rtems-4.8.0 - is it broken?

[Joel Sherrill]

Robert S. Grimes wrote:
> Hi,
>
> Does the stack checker still work?  My app using powerpc/virtex BSP
> seems to fail on startup when the stack checker task is created in
> taskinitusers.c/_RTEMS_tasks_Initialize_user_tasks_body().  I get an
> exception 7 - here is the dump:
>
>   
There is no stack checker task.  It is a user extension. 

It works in 4.8 as far as the test program stackchk.exe goes.

You are on the "BSP initialization stack" at this point in the program
initialization.  I suspect you have blown your initialization stack
or the RTEMS workspace and the BSP initialization stack overlap.
Thus when the stack checker writes the pattern for the first
created task, it destroys the stack you are running on.

Does this make sense?
>     Exception handling initialization done
>     opb_intc_init: m
exception handler called for exception 7
>          Next PC or Address of fault = A5A5A5A4
>          Saved MSR = 0
>          R0 = A5A5A5A5
>          R1 = 4A7EB4
>          R2 = 4853A8
>          R3 = 1
>          R4 = A5
>          R5 = 0
>          R6 = FEFFFFFF
>          R7 = 490000
>          R8 = 490AAC
>          R9 = 4A9C78
>          R10 = 1
>          R11 = 4A9C78
>          R12 = 0
>          R13 = FFFEAAFC
>          R14 = FFFFFFFF
>          R15 = FFFFFFFF
>          R16 = FFFFFFFF
>          R17 = FFFFFFFF
>          R18 = FFFFFFFF
>          R19 = FFFFFFFF
>          R20 = FFFFFFFF
>          R21 = FFFE2E6C
>          R22 = FFFE0000
>          R23 = FFFE0000
>          R24 = 0
>          R25 = 490984
>          R26 = 1
>          R27 = 0
>          R28 = 490000
>          R29 = 490C2C
>          R30 = 4A0F38
>          R31 = A5A5A5A5
>          CR = 28008022
>          CTR = 0
>          XER = 20000000
>          LR = A5A5A5A5
>          MSR = 0
>          DAR = 0
>     Stack Trace:
>       IP: 0xA5A5A5A4, LR: 0xA5A5A5A5
>     --^ 0x00000000
>     unrecoverable exception!!! Push reset button
>
> Turning off the stack checker allows my application to proceed normally...
>
> Any ideas?  Thanks!
> -Bob
>
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-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel.sherrill at OARcorp.com        On-Line Applications Research
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