Creating a segment or symbol indicating end of memory used

Andre Maree

Hi TI staffers,

I need some help to optimize the use of available memory.

Firstly, I have changed the cc3200R1.cmd linker file to create a single block of memory where program code is automatically followed by data, this is working perfectly.

Secondly using FreeRTOS (v8.2.1) module heap5.c and function vPortDefineHeapRegions() I am creating a multi segment heap memory configuration for pvPortMalloc() and vPortFree() functionality, also working perfectly.

Thirdly, I am already reclaiming the section 0x2000-0000 to 0x2000-3FFF as 1st part of the multi segment heap but want to automate the determination of the second section to use ALL unused memory from symbol "__TI_static_base__" and ending at symbol "__stack". Using manually calculated values it runs perfectly starting with around 124kb of heap in total.

HeapRegion_t xHeapRegions[] = {
{ ( _u8 * ) 0x20000000UL, 0x04000 }, // portion of memory used by bootloader
{ ( _u8 * ) &__TI_static_base__, (size_t) &__stack },
{ NULL, 0 }
} ;

xHeapRegions[1].xSizeInBytes -= (size_t) xHeapRegions[1].pucStartAddress ;
vPortDefineHeapRegions(xHeapRegions) ;

My problem starts when I use the symbol "__TI_static_base__" in the xHeapRegions array, I get the compiler warning below although the code runs perfectly.

" warning #10229-D: output section ".data" refers to load symbol "__TI_static_base__" and hence cannot be compressed; compression "rle" is ignored "

My questions is:

How can I FORCE a segment created using the #pragma directive to always be located AFTER the LAST data segment?

Alternatively, how can I use the existing symbols to accurately and safely determine the start of unused memory that can be used as the start of the second heap segment?

Andre

over 10 years ago

0 Aashish Bhanawat over 10 years ago

TI__Genius 16085 points

HI Andre,

We will look into this and get back to you.

Regards,
Aashish

0 Andre Maree over 10 years ago in reply to Aashish Bhanawat

Intellectual 855 points

Thanks, much appreciated but fairly urgent...

0 Aashish Bhanawat over 10 years ago in reply to Andre Maree

TI__Genius 16085 points

Hi Andre,

Please share modified linker and map file. Also want to know question "How can I FORCE a segment created using the #pragma directive to always be located AFTER the LAST data segment?" is related to warning that you are getting?

Regards,
Aashish

0 Andre Maree over 10 years ago in reply to Aashish Bhanawat

Intellectual 855 points

HI Aashish,

MAP file attached below.

Linker CMD file I am essentially using default except with the CODE & DATA segment combined into a single segment., need to change this further should I be creating another segment.

The question on creating another segment is just based on the view that another segment, located after all code and data but before the stack, and containing the symbol used to mark the base of heap, will make the error go away.

If there is a simpler/cleaner way to create the symbol/marker required for the heap placement, and that also makes the warning go away, that will be perfect.

Andre

Fullscreen cc3200R1(m1).txt Download

--retain=g_pfnVectors

#define RAM_BASE 0x20004000

MEMORY
{
    SRAM_BLOCK (RWX) : origin = 0x20004000, length = 0x3C000
}

SECTIONS
{
    .intvecs:		> RAM_BASE
    .init_array:	> SRAM_BLOCK
    .vtable :		> SRAM_BLOCK
    .text   :		> SRAM_BLOCK
    .const  :		> SRAM_BLOCK
    .cinit  :		> SRAM_BLOCK
    .pinit  :		> SRAM_BLOCK
    .data   :		> SRAM_BLOCK
    .bss    :		> SRAM_BLOCK
    .sysmem :		> SRAM_BLOCK
    .stack  :		> SRAM_BLOCK(HIGH)
}

imacs.txt

0 Aashish Bhanawat over 10 years ago in reply to Andre Maree

TI__Genius 16085 points

Hi Andre,

Can you please try with following way

1. Define below lines in main.c file:

long g_usersection_start;
#pragma RETAIN(g_usersection_start)
#pragma DATA_SECTION(g_usersection_start, ".usersection")

2. In linker file add below lines:
.usersection : > SRAM_DATA
.stack : > SRAM_DATA(HIGH)
}

3. And define xHeapRegions in heap5.c in following way:

HeapRegion_t xHeapRegions[] = {
{ ( _u8 * ) 0x20000000UL, 0x04000 }, // portion of memory used by bootloader
{ ( _u8 * ) &g_usersection_start, (size_t) &__stack },
{ NULL, 0 }
} ;

Regards,
Aashish

0 Andre Maree over 10 years ago in reply to Aashish Bhanawat

Intellectual 855 points

Hi Aashish,

As expected your suggestion makes the linker warning go away (since no more reference to the symbol __TI_static_base__), but then the problem comes back that g_usersection_start is located somewhere in the middle of other variables and the heap thus corrupts memory.

Getting rid of the warning is the easy bit, locating the section created after all code and data, but in low memory opposite the stack, that is the challenge...

Andre

0 Andre Maree over 10 years ago in reply to Andre Maree

Intellectual 855 points

Hi Aashish,

Any update on this issue. I am continuing to use my workaround which makes the heap calculation work consistently, but (in addtion to the warning) also results in a larger binary file due to the disabled RLE compression/encoding.

André

0 Andre Maree over 10 years ago in reply to Andre Maree

Intellectual 855 points

HI TI staffers,

If somebody can PLEASE have a look at this and provide some constructive feedback. The query is almost 3.5 months old, and no resolution.

Maybe it can be better solved in the CCS or TI compiler forums, if so can you please move it there?

Thanks

0 Aashish Bhanawat over 10 years ago in reply to Andre Maree

TI__Genius 16085 points

Hi Andre,

Sorry for delayed response.

We have posted this query to TI compiler forum(here is link e2e.ti.com/.../444759). You can add any missing information there.

Regards,
Aashish

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Creating a segment or symbol indicating end of memory used