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CLeo.1
Senior II
September 29, 2021
Solved

STM32H743ZI: Can't change where DMA Buffers are stored in memory region

  • September 29, 2021
  • 3 replies
  • 1811 views

Hi Guys,

I am in the mist of changing my linker file as I just recently found out that my DMA buffers are located in 0x2001FF0C region which is the DTCM (DMA can't access this region).

I have tried changing the "RAM" to "RAM_D2" that didn't do anything.

The only way I got it to change was change the DMA buffer to a static then change the linker, however I dont want it to be static.

I also notice when I change any of the linker .bss or .data anytime I try to insert a new() into an array it hardfaults now.

Linker file:

/*
******************************************************************************
**
** File : LinkerScript.ld
**
** Author : STM32CubeIDE
**
** Abstract : Linker script for STM32H7 series
** 2048Kbytes FLASH and 192Kbytes RAM
**
** Set heap size, stack size and stack location according
** to application requirements.
**
** Set memory bank area and size if external memory is used.
**
** Target : STMicroelectronics STM32
**
** Distribution: The file is distributed as is, without any warranty
** of any kind.
**
*****************************************************************************
** @attention
**
** Copyright (c) 2019 STMicroelectronics.
** All rights reserved.
**
** This software component is licensed by ST under BSD 3-Clause license,
** the "License"; You may not use this file except in compliance with the
** License. You may obtain a copy of the License at:
** opensource.org/licenses/BSD-3-Clause
**
****************************************************************************
*/
 
/* Entry Point */
ENTRY(Reset_Handler)
 
/* Highest address of the user mode stack */
_estack = 0x20020000; /* end of RAM */
/* Generate a link error if heap and stack don't fit into RAM */
_Min_Heap_Size = 0x200 ; /* required amount of heap */
_Min_Stack_Size = 0x400 ; /* required amount of stack */
 
/* Specify the memory areas */
MEMORY
{
 FLASH (rx) : ORIGIN = 0x08000000, LENGTH = 2048K
 RAM (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
}
 
/* Define output sections */
SECTIONS
{
 /* The startup code goes first into FLASH */
 .isr_vector :
 {
 . = ALIGN(4);
 KEEP(*(.isr_vector)) /* Startup code */
 . = ALIGN(4);
 } >FLASH
 
 /* The program code and other data goes into FLASH */
 .text :
 {
 . = ALIGN(4);
 *(.text) /* .text sections (code) */
 *(.text*) /* .text* sections (code) */
 *(.glue_7) /* glue arm to thumb code */
 *(.glue_7t) /* glue thumb to arm code */
 *(.eh_frame)
 
 KEEP (*(.init))
 KEEP (*(.fini))
 
 . = ALIGN(4);
 _etext = .; /* define a global symbols at end of code */
 } >FLASH
 
 /* Constant data goes into FLASH */
 .rodata :
 {
 . = ALIGN(4);
 *(.rodata) /* .rodata sections (constants, strings, etc.) */
 *(.rodata*) /* .rodata* sections (constants, strings, etc.) */
 . = ALIGN(4);
 } >FLASH
 
 .ARM.extab : { *(.ARM.extab* .gnu.linkonce.armextab.*) } >FLASH
 .ARM : {
 __exidx_start = .;
 *(.ARM.exidx*)
 __exidx_end = .;
 } >FLASH
 
 .preinit_array :
 {
 PROVIDE_HIDDEN (__preinit_array_start = .);
 KEEP (*(.preinit_array*))
 PROVIDE_HIDDEN (__preinit_array_end = .);
 } >FLASH
 .init_array :
 {
 PROVIDE_HIDDEN (__init_array_start = .);
 KEEP (*(SORT(.init_array.*)))
 KEEP (*(.init_array*))
 PROVIDE_HIDDEN (__init_array_end = .);
 } >FLASH
 .fini_array :
 {
 PROVIDE_HIDDEN (__fini_array_start = .);
 KEEP (*(SORT(.fini_array.*)))
 KEEP (*(.fini_array*))
 PROVIDE_HIDDEN (__fini_array_end = .);
 } >FLASH
 
 /* used by the startup to initialize data */
 _sidata = LOADADDR(.data);
 
 /* Initialized data sections goes into RAM, load LMA copy after code */
 .data :
 {
 . = ALIGN(4);
 _sdata = .; /* create a global symbol at data start */
 *(.data) /* .data sections */
 *(.data*) /* .data* sections */
 *(.RamFunc) /* .RamFunc sections */
 *(.RamFunc*) /* .RamFunc* sections */
 
 . = ALIGN(4);
 _edata = .; /* define a global symbol at data end */
 } >RAM AT> FLASH
 
 /* Uninitialized data section */
 . = ALIGN(4);
 .bss :
 {
 /* This is used by the startup in order to initialize the .bss secion */
 _sbss = .; /* define a global symbol at bss start */
 __bss_start__ = _sbss;
 *(.bss)
 *(.bss*)
 *(COMMON)
 
 . = ALIGN(4);
 _ebss = .; /* define a global symbol at bss end */
 __bss_end__ = _ebss;
 } >RAM
 
 /* User_heap_stack section, used to check that there is enough RAM left */
 ._user_heap_stack :
 {
 . = ALIGN(8);
 PROVIDE ( end = . );
 PROVIDE ( _end = . );
 . = . + _Min_Heap_Size;
 . = . + _Min_Stack_Size;
 . = ALIGN(8);
 } >RAM
 
 /* Remove information from the standard libraries */
 /DISCARD/ :
 {
 libc.a ( * )
 libm.a ( * )
 libgcc.a ( * )
 }
 
 .ARM.attributes 0 : { *(.ARM.attributes) }
}
 
 
Where DMA buffer gets delcared
/*
 * CLI.h
 *
 * Created on: Sep 22, 2021
 * Author: Chris
 */
 
#ifndef TOOLS_CLI_CLI_H
#define TOOLS_CLI_CLI_H
 
#include <stdint.h>
 
#include "stm32h743xx.h"
#include "../../Constants/projectConfigure.h"
#include "../../Constants/functionReturnStates.h"
#include "../../Drivers/STM32H7xx_HAL_Driver/Inc/stm32h7xx_ll_usart.h"
#include "../../Drivers/STM32H7xx_HAL_Driver/Inc/stm32h7xx_ll_bus.h"
#include "../../Drivers/STM32H7xx_HAL_Driver/Inc/stm32h7xx_ll_dma.h"
#include "../../Drivers/STM32H7xx_HAL_Driver/Inc/stm32h7xx_ll_gpio.h"
#include "CMD/CMD.h"
 
class CLI {
 
private:
	 char CLI_TxBuff[CLI_buffLength] = {0};
	 char CLI_RxBuff[CLI_buffLength] = {0};
	 uint32_t baudRate;
 
	void enableTx();
 
public:
 
	CLI();
	void execute(CMD * CMDs, char * CLI_TxBuff);
	char * getCLITxBuff(void);
};
 
 
 
#endif /* TOOLS_CLI_CLI_H_ */

This topic has been closed for replies.
Best answer by TDK

Replace all three instances of ">RAM" with ">RAM_D1" and change the _estack definition to "_estack = ORIGIN(RAM_D1) + LENGTH(RAM_D1);"

3 replies

TDK
TDKBest answer
September 29, 2021

Replace all three instances of ">RAM" with ">RAM_D1" and change the _estack definition to "_estack = ORIGIN(RAM_D1) + LENGTH(RAM_D1);"

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CLeo.1
CLeo.1Author
Senior II
September 29, 2021

Well, that did it good sir, went from 0x2001 -> 0x2400

CLeo.1
CLeo.1Author
Senior II
September 29, 2021

@TDK​ Only problem now is that the DMA isnt transferring anything from the buffer to the peripheral