Sla Va

How i can place buffer at .noinit section?

Discussion created by Sla Va on May 4, 2017
Latest reply on May 8, 2017 by Sla Va

I'm using LPCXpresso IDE and MCU is LPC1759.

I want to allocate a static array which will be used as heap for RTOS. The size of this array is 32 KB and the size of firmware (.bin file) increases by 32 KB, because initialization of buffer will be placed in .data section. So i want to move it into .noinit section:

__NOINIT(RAM2) uint8_t ucHeap[ configTOTAL_HEAP_SIZE ];

But after this directive, this initiailization moved from .data section into .bss section and size of firmware wasn't changed.

Below is my linker script:

ENTRY(ResetISR)

SECTIONS
{
/* MAIN TEXT SECTION */
.text : ALIGN(4)
{
FILL(0xff)
__vectors_start__ = ABSOLUTE(.) ;
KEEP(*(.isr_vector))
/* Global Section Table */
. = ALIGN(4) ;
__section_table_start = .;
__data_section_table = .;
LONG(LOADADDR(.data));
LONG( ADDR(.data));
LONG( SIZEOF(.data));
LONG(LOADADDR(.data_RAM2));
LONG( ADDR(.data_RAM2));
LONG( SIZEOF(.data_RAM2));
__data_section_table_end = .;
__bss_section_table = .;
LONG( ADDR(.bss));
LONG( SIZEOF(.bss));
LONG( ADDR(.bss_RAM2));
LONG( SIZEOF(.bss_RAM2));
__bss_section_table_end = .;
__section_table_end = . ;
/* End of Global Section Table */

*(.after_vectors*)

} >MFlash512

.text : ALIGN(4)
{
*(.text*)
*(.rodata .rodata.* .constdata .constdata.*)
. = ALIGN(4);
/* C++ constructors etc */
. = ALIGN(4);
KEEP(*(.init))

. = ALIGN(4);
__preinit_array_start = .;
KEEP (*(.preinit_array))
__preinit_array_end = .;

. = ALIGN(4);
__init_array_start = .;
KEEP (*(SORT(.init_array.*)))
KEEP (*(.init_array))
__init_array_end = .;

KEEP(*(.fini));

. = ALIGN(4);
KEEP (*crtbegin.o(.ctors))
KEEP (*(EXCLUDE_FILE (*crtend.o) .ctors))
KEEP (*(SORT(.ctors.*)))
KEEP (*crtend.o(.ctors))

. = ALIGN(4);
KEEP (*crtbegin.o(.dtors))
KEEP (*(EXCLUDE_FILE (*crtend.o) .dtors))
KEEP (*(SORT(.dtors.*)))
KEEP (*crtend.o(.dtors))
. = ALIGN(4);
/* End C++ */
} > MFlash512
/*
* for exception handling/unwind - some Newlib functions (in common
* with C++ and STDC++) use this.
*/
.ARM.extab : ALIGN(4)
{
*(.ARM.extab* .gnu.linkonce.armextab.*)
} > MFlash512
__exidx_start = .;

.ARM.exidx : ALIGN(4)
{
*(.ARM.exidx* .gnu.linkonce.armexidx.*)
} > MFlash512
__exidx_end = .;

_etext = .;

/* DATA section for RamAHB32 */
.data_RAM2 : ALIGN(4)
{
FILL(0xff)
PROVIDE(__start_data_RAM2 = .) ;
*(.ramfunc.$RAM2)
*(.ramfunc.$RamAHB32)
*(.data.$RAM2*)
*(.data.$RamAHB32*)
. = ALIGN(4) ;
PROVIDE(__end_data_RAM2 = .) ;
} > RamAHB32 AT>MFlash512

/* MAIN DATA SECTION */
.uninit_RESERVED : ALIGN(4)
{
KEEP(*(.bss.$RESERVED*))
. = ALIGN(4) ;
_end_uninit_RESERVED = .;
} > RamLoc32
/* Main DATA section (RamLoc32) */
.data : ALIGN(4)
{
FILL(0xff)
_data = . ;
*(vtable)
*(.ramfunc*)
*(.data*)
. = ALIGN(4) ;
_edata = . ;
} > RamLoc32 AT>MFlash512
/* BSS section for RamAHB32 */
.bss_RAM2 (NOLOAD): ALIGN(4)
{
PROVIDE(__start_bss_RAM2 = .) ;
*(.bss.$RAM2*)
*(.bss.$RamAHB32*)
. = ALIGN (. != 0 ? 4 : 1) ; /* avoid empty segment */
PROVIDE(__end_bss_RAM2 = .) ;
} > RamAHB32
/* MAIN BSS SECTION */
.bss : ALIGN(4)
{
_bss = .;
*(.bss*)
*(COMMON)
. = ALIGN(4) ;
_ebss = .;
PROVIDE(end = .);
} > RamLoc32
/* NOINIT section for RamAHB32 */
.noinit_RAM2 (NOLOAD) : ALIGN(4)
{
*(.noinit.$RAM2*)
*(.noinit.$RamAHB32*)
. = ALIGN(4) ;
} > RamAHB32
/* DEFAULT NOINIT SECTION */
.noinit (NOLOAD): ALIGN(4)
{
_noinit = .;
*(.noinit*)
. = ALIGN(4) ;
_end_noinit = .;
} > RamLoc32

PROVIDE(_pvHeapStart = DEFINED(__user_heap_base) ? __user_heap_base : .);
PROVIDE(_vStackTop = DEFINED(__user_stack_top) ? __user_stack_top : __top_RamLoc32 - 0);

/* ## Create checksum value (used in startup) ## */
PROVIDE(__valid_user_code_checksum = 0 -
(_vStackTop
+ (ResetISR + 1)
+ (NMI_Handler + 1)
+ (HardFault_Handler + 1)
+ (( DEFINED(MemManage_Handler) ? MemManage_Handler : 0 ) + 1) /* MemManage_Handler may not be defined */
+ (( DEFINED(BusFault_Handler) ? BusFault_Handler : 0 ) + 1) /* BusFault_Handler may not be defined */
+ (( DEFINED(UsageFault_Handler) ? UsageFault_Handler : 0 ) + 1) /* UsageFault_Handler may not be defined */
) );
}

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