Invalid Function pointer error

Joel Sherrill joel.sherrill at
Mon Aug 20 13:35:22 UTC 2001

Kiran C wrote:
> Hi,
>     I have a strange problem using RTEMS.I have  implemented a linked list
> Timer.
>     ie.A timer list is maintained.every time I call rtems_clock_get ..
>     get the time diffrence the elapsed time..and I call the callback
> function for the timer(ie the software timer I implemented).
>     The above mentioned code works  well..but as time passes ..say almost
> after 26 sec
>     I get the follwing error in the psim
> --------------------------------------------------
> cpu 1, cia 0xfff00700: double interrupt - MSR[RI] bit clear when attempting
> to deliver interrupt, cia=0xfff00700, msr=0x1040; srr0=0x0(cia),
> srr1=0x8b042(msr); trap-vector=0x700, trap-msr=0x1040
> ./o-optimize/tca.exe: Caught signal -1 at address 0xfff00700

This is a non-recoverable interrupt and the simulator is giving up.  I suspect
that looking at anything past this point is suspect.

I recall this being some type of FPU enable/disable problem but you don't 
given version information. 

> ----------------------------------------------------
> I tried debuggung this..what I found was that the callback function pointer
> is now 0x0.
> But earlier it had a valid pointer..and the call back function was
> called.What could be wrong?
> I tried running the same code in pc386 ,then I came across ,Exception
> 13,What does that mean.(I was running it in VMWare)

Look up Exception 13. I don't know what it is offhand. :)

> But it ran longer than in psim.
> Has it got any thing to do with how much RAM ,STACK SIZE et al is allocated
> for each task?

Not likely.

> Hoe you can help me..
> Kiran

Joel Sherrill, Ph.D.             Director of Research & Development
joel at                 On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
Support Available                (256) 722-9985

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