Compiler/CC1310: Initialized variables not set properly

VICTOR VALENCIA

Part Number: CC1310

Tool/software: TI C/C++ Compiler

Hi Everyone,

I feel like I am missing something stupid here but I can't determine what is happening. I am using CCS v8.0 and the TI compiler.

I have the following snippet of code:

int8_t traceBuf[4096];
int8_t *tracePtr = traceBuf;
int8_t logStr[64];

void trace(char *buf)
{
    char   timeStr[32];
    int8_t len = sprintf(timeStr, " %d-", timeMs());
    if ((tracePtr + len) < &traceBuf[4095])

When I set a breakpoint on that last line and look at the value of tracePtr it is 0x00000109. I've seen other values as well.

In the linkmap I see the following:

20000208 traceBuf
20004bf4 tracePtr

Farther down in the code I try writing to *tracePtr and, of course, it crashes.

I've got another similarly-defined counter variable that should be initialized to 0 and it always starts out with some wild value.

This is just plain old C code. Am I missing something?

Victor

over 7 years ago

0 George Mock over 7 years ago

TI__Guru**** 253270 points

I presume you use the TI ARM compiler.

The function sprintf takes a lot of stack and heap. Make sure they are big enough.

Thanks and regards,

-George

0 VICTOR VALENCIA over 7 years ago in reply to George Mock

Expert 1070 points

Thanks for your quick response. The stack is 4k. The heap is 8k. I tried changing the heapsize and it did not

make a difference. I also verified that the --rom_model option is being used.

0 George Mock over 7 years ago in reply to VICTOR VALENCIA

TI__Guru**** 253270 points

At what point do the global variables like tracePtr go bad? Do they have the right value at the beginning of main?

Thanks and regards,

-George

0 Keith Barkley over 7 years ago in reply to VICTOR VALENCIA

Guru 43135 points

Why not just compare len to 4095?

Also, do you expect the len to be greater than 127? If so, you need a larger type than a signed 8 bit integer.

0 VICTOR VALENCIA over 7 years ago in reply to Keith Barkley

Expert 1070 points

The length of an individual log entry should not be more than 127 chars but I should probably make it bigger

just to be sure. The comparison takes into account that the buffer write pointer may not currently be at the

beginning of the buffer. I am appending to the buffer with wrap.

Victor

0 VICTOR VALENCIA over 7 years ago in reply to George Mock

Expert 1070 points

Hi George. Good question. I just checked and the value is correct at the beginning of main so it must be getting corrupted at some point. I will have to keep digging.

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Compiler/CC1310: Initialized variables not set properly