Putting a variable in code memory

munger · ‎2014-06-04

Posted on June 04, 2014 at 22:15

Hi,

I want to declare an array of constant values and have them put into code memory.

Something like this:

const uint16_t my_array[4] = {0x3456, 0x789A, 0x1234, 0x9876};

I want to be able to download the code and then start up STM32 ST-LINK Utility and search for one of the values and find the whole array.

I'm pretty sure I can do it using #pragmas and/or attributes and maybe the scatter file ... but I just haven't figured out the right combo.

I'm using Keil uvision and a STM32F401.

I'd appreciate any help I can get.

Mike

Tesla DeLorean · ‎2014-06-04

Posted on June 04, 2014 at 22:47

const or static const should suffice, where does the .MAP file say the array is placed? Data copied to RAM might be compressed, but stuff held in ROM/FLASH should be visible

Are you searching for the right pattern? Try using some endian neutral values like 0x1111,0x2222, etc

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munger · ‎2014-06-04

Posted on June 05, 2014 at 00:34

Thanks clive1 (as always). I had looked at the .map file and swear I couldn't find it but now ... of course I can. I think my main problem is that in the STM32 ST-LINK there is a window for Size and it was set to something less than the full code area so when I did a search it did not go to the end, duh! Anyway, setting it to const is enough, it shows up just like I thought it should.

Mike