nullIsrFunc exception handler issue

ismail ghazy

Other Parts Discussed in Thread: SYSBIOS

I am trying to add an exception handler for various exceptions. Here is what I have in the .cfg file:

var HwiM3 = xdc.useModule('ti.sysbios.family.arm.m3.Hwi');

HwiM3.nvicCCR.DIV_0_TRP = 1;
HwiM3.excHookFunc = "&FaultISR";
HwiM3.busFaultFunc = "&FaultISR";
HwiM3.hardFaultFunc =  "&FaultISR";
HwiM3.memFaultFunc =  "&FaultISR";
HwiM3.nullIsrFunc =   "&FaultISR";
HwiM3.debugMonFunc =  "&FaultISR";
HwiM3.nmiFunc =  "&FaultISR";
HwiM3.reservedFunc =  "&FaultISR";

When I build I get the following warning:

"package/cfg/project_pem4f.c", line 1480: error: declaration is incompatible with "void FaultISR(void)" (declared at line 1477)

in that pem4f c file:

/* --> FaultISR */
extern xdc_Void FaultISR(xdc_Void);

/* --> FaultISR */
extern xdc_Void FaultISR(ti_sysbios_family_arm_m3_Hwi_ExcContext*);

/* --> FaultISR */
extern xdc_Void FaultISR(ti_sysbios_family_arm_m3_Hwi_ExcContext*);

The highlighted portion is generated when I add:

HwiM3.nullIsrFunc =   "&FaultISR";

- Does nullisrfault not have exception context?

- Doesn't nullisrfault mean there was an interrupt enabled but there was no handler?

Thanks

over 10 years ago

0 ToddMullanix over 10 years ago

TI__Guru* 96960 points

What does your FaultISR look like?

excHookFunc is ExceptionHookFuncPtr

Void (*ExceptionHookFuncPtr)(ExcContext *);

The other ones you listed are of type VectorFuncPtr

Void (*VectorFuncPtr)(void);

Todd

0 ismail ghazy over 10 years ago in reply to ToddMullanix

Intellectual 420 points

Thank you for the quick reply Todd. This is the function prototype:

void FaultISR(void)

0 ToddMullanix over 10 years ago in reply to ismail ghazy

TI__Guru* 96960 points

Ok, so HwiM3.excHookFunc cannot be FaultISR. You need something like this in the .cfg

HwiM3.excHookFunc = "&myExcHook";
HwiM3.busFaultFunc = "&FaultISR";
...

and in the source code

#include <ti/sysbios/family/arm/m3/Hwi.h>

Void myExcHook(Hwi_ExcContext *excContent)
{
// your exception hook code...
}

0 ismail ghazy over 10 years ago in reply to ToddMullanix

Intellectual 420 points

it seems to get rid of the error, but Iam getting many incompatible redefinition warnings due to <ti/sysbios/hal/Hwi.h>

What is the defference between:

Maybe I can create the Hwi_ExcContext structure and not include <ti/sysbios/family/arm/m3/Hwi.h>

0 ToddMullanix over 10 years ago in reply to ismail ghazy

TI__Guru* 96960 points

You can turn off the short names for the family header file.

   #include <ti/sysbios/hal/Hwi.h>
   #define ti_sysbios_family_arm_m3_Hwi__nolocalnames
   #include <ti/sysbios/family/arm/m3/Hwi.h>

   Void myExcHook(ti_sysbios_family_arm_m3_Hwi_ExcContext *excContent)
   {
      ...

Todd

0 ismail ghazy over 10 years ago in reply to ToddMullanix

Intellectual 420 points

Ok .that seems to work. I probably should have mentioned this in my first post, but I am working off an example that looks like this:

void FaultDecoder(unsigned long *pulExceptionFrame)
{
    //
    // Here you have access to everything stored in the exception
    // via the pulExceptionFrame pointer.  
}

void FaultISR(void)
{
    __asm("    mov     r0, sp\n"
          "    bl      FaultDecoder\n"
          "    bx      lr");
}

Why is it using an assembly instruction to branch to a fault decoder instead of handleing everything in the FaultISR?

0 ToddMullanix over 10 years ago in reply to ismail ghazy

TI__Guru* 96960 points

I don't know. Where did you get the code?

0 ismail ghazy over 10 years ago in reply to ToddMullanix

Intellectual 420 points

Another project I based mine off of. Not a TI example. However I did come across this thread:

http://e2e.ti.com/support/microcontrollers/stellaris_arm/f/471/p/161501/637910#pi239031349=1

Which also gave those lines of code as an option. I am passed that point. I actually found out that I should be checking which stack pointer was being used when I enter the faultISR (the PSP or MSP). That way I could save the proper data.

Now I have a couple of related questions to the fault handler.

1- How do I know if what triggered the FaultISR is an svCall, nullIsr, or debugmon?

In the NVIC_INT_CTRL register, there is a interrupt pending vector number. Is that the way to find out?

2- In my initial post (HWI.excHookFunc) Is that for custom exception I raise in the code?

Thanks

0 ToddMullanix over 10 years ago in reply to ismail ghazy

TI__Guru* 96960 points

ismail ghazy said:
1- How do I know if what triggered the FaultISR is an svCall, nullIsr, or debugmon?

You can either write a unique function for each one or you can look at the ICSR register. Please refer to the data sheet for more details on ICSR.

ismail ghazy said:
2- In my initial post (HWI.excHookFunc) Is that for custom exception I raise in the code?

This handles the device exceptions. Please refer to the data sheet for more details about the exceptions.

Todd

0 ismail ghazy over 10 years ago in reply to ToddMullanix

Intellectual 420 points

I don't see much about nullisr. I think I have an idea though. For question 2, which datasheet? In the help section in ccs it explains excHookFunc as (Error raised when an exception occurs)

0 ToddMullanix over 10 years ago in reply to ismail ghazy

TI__Guru* 96960 points

Look in the device's data sheet to see what generates an exception.

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nullIsrFunc exception handler issue