Tool/software: Code Composer Studio

This may be a simple code question, or something else. C is still somewhat uncharted territory for me.

I a trying to read in a 32 bit binary word from GPIO ports. (seems to work)

And then send that word onto ethernet using UDP..

However, there seems to be a problem preparing the data for UDP.

I have this code below:

int main(void)
{
    int Indicator;
    struct pbuf* pdat = pbuf_alloc(PBUF_TRANSPORT,40,PBUF_RAM);
    u32_t data;


    Setup();

    Indicator=0;

    while (1) {
        data=Get32();
        memcpy(pdat->payload,&data,4);

        Indicator^=4;
        GPIOPinWrite(GPIO_PORTN_BASE,GPIO_PIN_2,Indicator);
    }

} 

The code compiles but crashes at run time immediately after the memcpy instruction. Comment that line out, and the rest runs OK.

I suspect something not quite right around my use of the pointers involved, but ...

Below is, what the disassembler tells me:

          main():
00000f44:   2000                movs       r0, #0
00000f46:   B538                push       {r3, r4, r5, r14}
00000f48:   2128                movs       r1, #0x28
00000f4a:   4602                mov        r2, r0
00000f4c:   F7FFFB82            bl         pbuf_alloc
00000f50:   4605                mov        r5, r0
333           Setup();
00000f52:   F7FFF955            bl         Setup
335           Indicator=0;
00000f56:   2400                movs       r4, #0
338               data=Get32();
          $C$L4:
00000f58:   F7FFFFD6            bl         Get32
339               memcpy(pdat->payload,&data,4);
00000f5c:   466A                mov        r2, r13
00000f5e:   6869                ldr        r1, [r5, #4]
338               data=Get32();
00000f60:   9000                str        r0, [r13]
339               memcpy(pdat->payload,&data,4);
00000f62:   6812                ldr        r2, [r2]
00000f64:   4608                mov        r0, r1
00000f66:   6002                str        r2, [r0]
343               GPIOPinWrite(GPIO_PORTN_BASE,GPIO_PIN_2,Indicator);
00000f68:   4803                ldr        r0, [pc, #0xc]
00000f6a:   F0840404            eor        r4, r4, #4
00000f6e:   2104                movs       r1, #4
00000f70:   B2E2                uxtb       r2, r4
00000f72:   F000F93F            bl         GPIOPinWrite
337           while (1) {
00000f76:   E7EF                b          $C$L4

 

The crash happens at address 0x0F68, at which time, the processor jumps to some default FaultISR for an eternal loop.

I know too little (near to nothing, actually) about the assembly code for this processor to fully understand, what is going on. x86 code would have been another matter.

LATEST update:

The instruction at 0x0F66 apparently tries to drop something at the address set aside for ResetISR !!!

That does NOT seem right. There is not any RAM there, I think.