SDRAM and a global struct.

[Hector_R]

Hi.

I am using TouchGFX and it works fine,

My MCU is STM32H743

But when I use the SDRAM for other things the code does not work.

My question is:

Can I use struct in the  SDRAM.?

I have this one in my c file.

SD_CARD SdCard __attribute__((section("\"SDCardSection\""))) __attribute__((aligned(4)));

In my h file as follows:

typedef struct {
	char Name[256];
	char Path[1000];
	char File[2000];
	uint8_t LogicalDrive;
}SD_CARD;
extern SD_CARD SdCard __attribute__((section("\"SDCardSection\""))) __attribute__((aligned(4)));

 My Linker file is as follows:

/* Entry Point */
ENTRY(Reset_Handler)

/* Highest address of the user mode stack */
_estack = ORIGIN(RAM_D1) + LENGTH(RAM_D1);    /* end of RAM */
/* Generate a link error if heap and stack don't fit into RAM */
_Min_Heap_Size = 0x400;      /* required amount of heap  */
_Min_Stack_Size = 0x800; /* required amount of stack */

/* Specify the memory areas */
MEMORY
{
  FLASH (rx)     : ORIGIN = 0x08000000, LENGTH = 2048K
  DTCMRAM (xrw)  : ORIGIN = 0x20000000, LENGTH = 128K
  RAM_D1 (xrw)   : ORIGIN = 0x24000000, LENGTH = 512K
  RAM_D2 (xrw)   : ORIGIN = 0x30000000, LENGTH = 288K
  RAM_D3 (xrw)   : ORIGIN = 0x38000000, LENGTH = 64K
  ITCMRAM (xrw)  : ORIGIN = 0x00000000, LENGTH = 64K
  QUADSPI (r)    : ORIGIN = 0x90000000,  LENGTH = 16M
  SDRAM   (xrw)  : ORIGIN = 0xC0000000,  LENGTH = 32M  
}

etc
etc
etc
  .ARM.attributes 0 : { *(.ARM.attributes) }
    
  BufferSection (NOLOAD) :
  {
    *(Video_RGB_Buffer Video_RGB_Buffer.*)
    *(.gnu.linkonce.r.*)
    . = ALIGN(0x4);

    *(TouchGFX_Framebuffer TouchGFX_Framebuffer.*)
    *(.gnu.linkonce.r.*)
    . = ALIGN(0x4);
   } >SDRAM
   
   SDCardSection (NOLOAD) :
  {
    *(SDCardSection SDCardSection .*)
    *(.gnu.linkonce.r.*)
    . = ALIGN(0x4);
   } >SDRAM

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 Best Regards.

[Hector_R]

Hi there.

The problem was that TouchGFX uses Unicode.

I was using char buffer and pointers to update the buffer of a scrollWheel.

But TouchGFX describes that we should use the Unicode library.

So,  I updated my buffers to datatype uint16_t, and then used the Unicode library.

void CustomContainer2_1::UpdateText(uint16_t value)
{
	Unicode::snprintf(textArea1Buffer, TEXTAREA1_SIZE, "%s", &SdCard.File);
...
...
...
...
    textArea1.invalidate();
}