CODEWITHSUNDEEP
cprintf
uniquenamehere
uniquenamehere

Reputation: 1949

Value of address. Gives exception

I am trying to print a piece of memory on a microcontroller.

It complaines about the line:

stringLength += sprintf(buffer + stringLength, "0x%X, ", *(startAddress + i));

due to the:

*(startAddress + i)

Why is this not working? Should it not just give me the value at the address?

Working on a ARM microcontroller and it jumps to HardFault_Handler() (which usually indicates illegal memory access).

How can I get the value at the memory location else wise?

Entire function:

void printMemory(uint32_t *startAddress, uint32_t lengthInBytes)
{
    uint32_t stringLength = 0;
    uint32_t i;
    char buffer[1000];
    uint32_t start = (uint32_t) startAddress;

    for (i = start; i < (start + lengthInBytes); i++)
    {
        if ((i % 10) == 0)
        {
            stringLength += sprintf(buffer + stringLength, "\r\n");
        }

        stringLength += sprintf(buffer + stringLength, "0x%X, ", *(startAddress + i));
    }

    //Add line termination.
    stringLength += sprintf(buffer + strlen(buffer), "%c", '\0');

    //Printf buffer.
    printf("%s", &buffer[0]);
}

EDIT:

Working example:

void printMemory(uint32_t startAddress, uint32_t lengthInBytes)
{
    uint32_t i;
    char buffer[1000];
    uint32_t stringLength = 0;
    uint8_t *start;

    //Create a uint8_t pointer to address.
    start = (uint8_t *) startAddress;

    for (i = 0; i < lengthInBytes; i++)
    {
        if ((i % 10) == 0)
        {
            stringLength += sprintf(buffer + stringLength, "\r\n");
        }

        stringLength += sprintf(buffer + stringLength, "0x%X, ", *(start + i));
    }

    //Add line termination.
    stringLength += sprintf(buffer + strlen(buffer), "%c", '\0');

    //Printf buffer.
    printf("%s", &buffer[0]);
}

Upvotes: 0

Views: 64

Answers (1)

cutsoy
cutsoy

Reputation: 10251

You made a mistake:

i starts at start which is startAddress, so at the first iteration you are fetching:

*(startAddress + startAddress)

Upvotes: 3

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