How to stop GDB from initializing a particular piece of FLASH?


I'm using a SEGGER J-Link with Windows 10 and GNU ARM GCC / Eclipse.  In my C source code I have this line where I declare a flash based structure (so only reading is possible by regular code -- I have other code that erases and writes it).     I wrote a bootloader for an STM32F030 device which occupies ::

8000000 to 8002FFF  is  bootloader

8003000 to 8003FFF  is  "calibration storage"

8004000 to 800FFFF  is my main application code

So I declared this structure (it's 42 bytes in size)

const cal_t cal_primary __attribute__((__section__(".section_cal_pri")));

this is from my linker script :-

FLASH_PRI_CAL (r) : ORIGIN = 0x08003800, LENGTH = 1k

.cal_flash_section_pri (NOLOAD) :
. = ALIGN(4);
__mysection_start1__ = .;
__mysection_end1__ = .;

However whenever I start a debug session, GDB / Eclipse erases this structure (to zeros) the area of flash corresponding to
the "cal_primary" variable.  I am not sure how to stop this happening (I tried using NOLOAD in the linker script)  The equivalent thing for RAM would be to use the .noinit section,   

I dont want this DEBUG flash initialisation to happen because this area contains calibration data I want to keep.

Interestingly the HEX file I build does not have any initialisaition data for 8003800 defined,

BUT GDB is erasing it at debug session start -- how can I stop this?

Thanks, Nick

More questions in this forum