2021-04-23 03:12 PM
Hi every body! I chose STM32H755ZI MCU mainly because it has 1MB of RAM. In my project, I need to at least store 180 KB of Data. 45000 of float samples. I use the M7 Core which accesses the AXI RAM the size of which is 512KB; on the other hand, the Build analyzer shows the amount of RAM around 128KB and in STM32H755ZITX_FLASH.ld file the ram size is defined 128KB.
I decided to expand this area based on the memory file were presented in data sheet of the MCU but the program could not even be started and debugged. I got hard-fault error.
in STM32H755ZITX_FLASH.ld file the default memory setting was like this:
_estack = 0x20020000; /* end of RAM */ /* _estack = 0x20020000; */
/* Generate a link error if heap and stack don't fit into RAM */
_Min_Heap_Size = 0x200 ; /* required amount of heap */ /* _Min_Heap_Size = 0x200 */
_Min_Stack_Size = 0x400 ; /* required amount of stack */ /* _Min_Stack_Size = 0x400 */
/* Specify the memory areas */
MEMORY
{
FLASH (rx) : ORIGIN = 0x08000000, LENGTH = 1024K
RAM (xrw) : ORIGIN = 0x20000000, LENGTH = 128K
ITCMRAM (xrw) : ORIGIN = 0x00000000, LENGTH = 64K
}
I thought that maybe if I change the RAM (xrw) : ORIGIN = 0x20000000, LENGTH = 128K
to RAM (xrw) : ORIGIN = 0x20000000, LENGTH = 256K and also change this line
_estack = 0x20020000; to _estack = 0x20040000; I may be able to expand the accessed RAM area.
Here is also the memory mapped file of my MCU:
I would really appreciate if you inform me What is my mistake ?
Thanks in advance.
Solved! Go to Solution.
2021-04-23 05:48 PM
AXIMRAM (xrw) : ORIGIN = 0x24000000, LENGTH = 512K
SRAM123 (xrw) : ORIGIN = 0x30000000, LENGTH = 288K
2021-04-23 03:30 PM
Doesn't it say 0x20020000 thru 0x23FFFFFF is reserved? DTCM being 128 KB
There are other memories which should have their clocks enabled.
; Reset handler
Reset_Handler PROC
EXPORT Reset_Handler [WEAK]
IMPORT SystemInit
IMPORT __main
LDR R0, =0x580244DC ; Enable D2SRAM clocks in RCC_AHB2ENR
LDR R1, [R0]
ORR R1, #0xE0000000
STR R1, [R0]
LDR R0, =SystemInit
BLX R0
LDR R0, =__main
BX R0
ENDP ; Reset_Handler
2021-04-23 03:33 PM
2021-04-23 04:19 PM
No I did not see such a message... I am pretty confused and have no idea where should I start from to solve this problem .... Maybe that is too much to be asked but could you please tell me more simple that what are the steps should I take to solve this problem ?
what should I do with the reset handler you sent me ?
I think the problem I have is that I only access 128KB of Ram using M7 Core (based on what I see in Build analyzer and in STM32H755ZITX_FLASH.ld file). when I define global variables (three float arrays each of which has 15000 elements) I get RAM overflow error and when I define them In main ram overflow error disappears but after storing 12450 samples in RAM the program crashes and get the hard fault error. If I find a way so that I understand how can I use other bigger blocks of SRAM the problem will be solved. any idea :)?
2021-04-23 05:48 PM
AXIMRAM (xrw) : ORIGIN = 0x24000000, LENGTH = 512K
SRAM123 (xrw) : ORIGIN = 0x30000000, LENGTH = 288K
2021-04-23 07:55 PM
Thank you Tesla. that was a nice reply! I changed the FLASH.ld file as you explained , which is presented as follows:
/*
******************************************************************************
**
** File : LinkerScript.ld
**
**
** Abstract : Linker script for STM32H7 series
** 1024Kbytes 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 */ /* _estack = 0x20020000; */
/* Generate a link error if heap and stack don't fit into RAM */
_Min_Heap_Size = 0x200 ; /* required amount of heap */ /* _Min_Heap_Size = 0x200 */
_Min_Stack_Size = 0x400 ; /* required amount of stack */ /* _Min_Stack_Size = 0x400 */
/* Specify the memory areas */
MEMORY
{
FLASH (rx) : ORIGIN = 0x08000000, LENGTH = 1024K
AXIMRAM (xrw) : ORIGIN = 0x24000000, LENGTH = 512K /* RAM (xrw) : ORIGIN = 0x20000000, LENGTH = 128K previuous value */
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 */
. = ALIGN(4);
_edata = .; /* define a global symbol at data end */
} >AXIMRAM AT> FLASH /* I changes this part !!!!! carefull sina!!!!! it was >RAM } >RAM */
/* 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;
} >AXIMRAM /* I changes this part !!!!! careful sina!!!!! it was >RAM } >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);
} >AXIMRAM /* I changes this part !!!!! careful sina!!!!! it was >RAM } >RAM */
/* Remove information from the standard libraries */
/DISCARD/ :
{
libc.a ( * )
libm.a ( * )
libgcc.a ( * )
}
.ARM.attributes 0 : { *(.ARM.attributes) }
}
something that I forgot to take it into consideration was correct calculation of end of the RAM in my case it is : _estack = 0x24080000; /* end of RAM */
previously, it was _estack = 0x20020000; this parameter should be changed in FLASH.ld and also RAM.ld file of the MCU. Now, everything works correctly and I could store the whole data into 512KB RAM which can be accessed by M7 core.
Thank you Tesla !