Hello,

I have a SDRAM linked to my STM32F4. So I edited the linkerscript and startupfile:

/* Generated by LinkerScriptGenerator [http://visualgdb.com/tools/LinkerScriptGenerator]
* Target: STM32F429IG
* The file is provided under the BSD license.
*/

ENTRY(Reset_Handler)

MEMORY
{
FLASH (RX) : ORIGIN = 0x08000000, LENGTH = 1M
SRAM (RWX) : ORIGIN = 0x20000000, LENGTH = 192K
CCM (RWX) : ORIGIN = 0x10000000, LENGTH = 64K
BACKUP_SRAM (RWX) : ORIGIN = 0x40024000, LENGTH = 4K
SDRAM (RWX) : ORIGIN = 0xD0000000, LENGTH = 8M
}

_estack = 0x20030000;

SECTIONS
{
.isr_vector :
{
. = ALIGN(4);
KEEP(*(.isr_vector))
. = ALIGN(4);
} > FLASH

.text :
{
. = ALIGN(4);
_stext = .;

*(.text)
*(.text*)
*(.rodata)
*(.rodata*)
*(.glue_7)
*(.glue_7t)
KEEP(*(.init))
KEEP(*(.fini))
. = ALIGN(4);
_etext = .;

} > FLASH

.ARM.extab :
{
. = ALIGN(4);
*(.ARM.extab)
*(.gnu.linkonce.armextab.*)
. = ALIGN(4);
} > FLASH

.exidx :
{
. = ALIGN(4);
PROVIDE(__exidx_start = .);
*(.ARM.exidx*)
. = ALIGN(4);
PROVIDE(__exidx_end = .);
} > FLASH

.ARM.attributes :
{
*(.ARM.attributes)
} > FLASH

.preinit_array :
{
PROVIDE(__preinit_array_start = .);
KEEP(*(.preinit_array*))
PROVIDE(__preinit_array_end = .);
} > FLASH

.init_array :
{
PROVIDE(__init_array_start = .);
KEEP(*(SORT(.init_array.*)))
KEEP(*(.init_array*))
PROVIDE(__init_array_end = .);
} > FLASH

.fini_array :
{
PROVIDE(__fini_array_start = .);
KEEP(*(.fini_array*))
KEEP(*(SORT(.fini_array.*)))
PROVIDE(__fini_array_end = .);
} > FLASH

. = ALIGN(4);
_sidata = .;
.data : AT(_sidata)
{
. = ALIGN(4);
_sdata = .;

PROVIDE(__data_start__ = _sdata);
*(.data)
*(.data*)
. = ALIGN(4);
_edata = .;

PROVIDE(__data_end__ = _edata);
} > SRAM

.bss :
{
. = ALIGN(4);
_sbss = .;

PROVIDE(__bss_start__ = _sbss);
*(.bss)
*(.bss*)
*(COMMON)
. = ALIGN(4);
_ebss = .;

PROVIDE(__bss_end__ = _ebss);
} > SRAM

. = ALIGN(4);
_sisdraminit = .;
.sdraminit : AT( _sisdraminit )
{
. = ALIGN(4);
_ssdraminit = .;

*(.sdraminit)
*(.sdraminit*)
. = ALIGN(4);
_esdraminit = .;
} > SDRAM

.sdram (NOLOAD) :
{
. = ALIGN(4);
*(.sdram)
*(.sdram.*)
. = ALIGN(4);
} > SDRAM

PROVIDE(end = .);

}

extern void *_sidata, *_sdata, *_edata;
extern void *_sbss, *_ebss;
extern void *_sisdraminit, *_ssdraminit, *_esdraminit;

void __attribute__((naked, noreturn)) Reset_Handler()
{
//Normally the CPU should will setup the based on the value from the first entry in the vector table.
//If you encounter problems with accessing stack variables during initialization, ensure the line below is enabled.
#ifdef sram_layout
asm(“ldr sp, =_estack”);
#endif

void **pSource, **pDest;
for (pSource = &_sidata, pDest = &_sdata; pDest != &_edata; pSource++, pDest++)
*pDest = *pSource;

for (pDest = &_sbss; pDest != &_ebss; pDest++)
*pDest = 0;

SystemInit();
FmcInit();
__libc_init_array();

pSource = &_sisdraminit;
for (pDest = &_ssdraminit; pDest < &_esdraminit;)
*(pDest++) = *(pSource++);

(void)main();
for (;;);
}

Then, with:

// SDRAM
#define DEF_IN_SDRAM __attribute__((section(".sdram")))
#define INIT_IN_SDRAM __attribute__((section(".sdraminit")))

i can initialize an array:

static INIT_IN_SDRAM char OBJECTS_BUFFER1[5] = { 1,2,3,4,5 };

The problem is, when I initialize an array 1MB of size, i get an error, although, the array is created:

The memory location used for the stack (0x2002fffc) is not writeable. Please check the selected device type and the linker script. You can disable automatic stack checking via VisualGDB Project Properties.

And: Is there a help for this forum in terms of formating :>

• This topic was modified 8 years, 3 months ago by Rumchiller.
• This topic was modified 8 years, 3 months ago by Rumchiller.