Flash memory storage using #pragma directives.

Hi,

I need store constant configuration data (sample below) to the flash memory starting address as 0x00080000.

Example :

Config string : 8bytes : char data : 0x00080000 (start address)

Config ID     : 2bytes : int data  : 0x00080008

unit_type     : 1byte  : int  data : 0x0008000A   

sensor_type   : 2byte  : int  data : 0x0008000B

filer_const   : 4byte  : floatdata : 0x0008000C

I created a .config data section in the linker directive which starts at 0x00080000.

I used the #pragmas  to do this task as below in one of the source file.

#pragma DATA_SECTION (CFG_STR , ".config" )

const int8            CFG_STR[8] = {'1','1','3','8','V','A','0','1'};

#pragma DATA_SECTION (CFG_ID , ".config" )

const     uint16   CFG_ID = 0xABCD;

#pragma DATA_SECTION (UNIT_TYPE , ".config" )

const     uint8      UNIT_TYPE = 0x00;

#pragma DATA_SECTION (SENSOR_TYPE , ".config" )

const     uint16   SENSOR_TYPE=0x02;

#pragma DATA_SECTION (FILTER_COEFF , ".config" )

const     float32  FILTER_COEFF = 6.5;

I can see this data in flash but not in the required address as mentioned above. I see that memory address allocation

of these variables is in the order of definition i.e top to bottom.( CFG_STR.. UNIT_TYPE .. FILTER_COEFF )

1) Does it always allocates memory in the order of declaraion in source file ? What is the gurantee ?

Ex :For the above sample code, the memory address allocation and order is as below observed in debugger.

(CFG_STR = 0x00080000 , CFG_ID = 0x00080008, UNIT_TYPE=0x0008000A, SENSOR_TYPE= 0x0008000C, FILTER_COEFF = 0x00080010)

Is there any chance that FILTER_COEFF allocated immediately after CFG_STR instead of CFG_ID ? If so how to handle it ?

2) In the debugger, i see that there are some holes in between these variables memory allocation.

Is there any way to suppress this padding ? Ex : SENSOR_TYPE requires 2 bytes, after that 2 bytes are filled with 0x00.

[ i found variable attributes (gcc extensions) for this purpose and not working as i expect]

3) Actual configuration data to be stored as per my requirement is around 20K. I tried with strucure to do this job.

I need to do the explict initialization for that too. Any other suggestion apart from the above method ?

Processor : TMS570LS20216 (Cortex R4), Code Composer Studio : 4.2.0.10018,  TMS470 C/C++ CODE GENERATION TOOLS 4.6.3