Function address fixing procedure in STM32F103 controller

[NandhakumarGanesan]

Hi,

 We are using STM32F103 family controllers.

how to fix the function address , 

i have tried below mentioned procedure ,but i am getting error .

Linker script source:

/* Linker script for STM32F4 series with fixed function address */

/* Specify the memory areas */
MEMORY
{
FLASH (rx) : ORIGIN = 0x08000000, LENGTH = 512K
RAM (rwx) : ORIGIN = 0x20000000, LENGTH = 128K
}

/* Define sections */
SECTIONS
{
/* .text section - code */
.text :
{
*(.text)
*(.text.*)
*(.rodata)
*(.rodata*)
*(.glue_7)
*(.glue_7t)
*(.gcc_except_table)
*(.gcc_except_table.*)
*(.eh_frame)
*(.eh_frame*)
KEEP(*(.isr_vector))
KEEP(*(.init))
KEEP(*(.fini))
. = ALIGN(4);
} > FLASH

/* .data section - initialized data */
.data :
{
_sdata = .;
*(.data)
*(.data.*)
. = ALIGN(4);
_edata = .;
} > RAM AT > FLASH

/* .bss section - uninitialized data */
.bss :
{
_sbss = .;
*(.bss)
*(.bss.*)
*(COMMON)
. = ALIGN(4);
_ebss = .;
} > RAM

/* Other sections */

/* Fix function address at 0x800500 */
.myFunctionSection :
{
KEEP(*(.myFunctionSection))
} > FLASH AT 0x800500

/* Heap and stack section (optional) */
.heap :
{
*(.heap)
. = ALIGN(4);
} > RAM

.stack :
{
. = ALIGN(4);
_estack = .;
PROVIDE(end = .);
} > RAM

Main function source:

// Function declaration with memory section attribute
void myFunction(void) __attribute__((section(".mySection")));

// Function definition
void myFunction(void) {
// Your code here
}

// Main function
int main(void) {
// Call your fixed address function
myFunction();

while (1) {
// Your main application code
}
}

so kindly give correct procedure for  function address fixing. 

[SofLit]

Hello,

I didn't see the declaration of .mySection section in your linker file.

[Tesla DeLorean]

WHY?

This is liable to be an ungodly nightmare.

0x800500 ?? You mean 0x08000500 ?

A better approach would be to put a TABLE of function pointers, like the Vector Table, and a established / consistent place for that to live. Say immediately after the vectors, perhaps in it's own FLASH_FNTBL memory section at the next 512-byte rounding after the vectors. Let the linker decide where in FLASH the function bodies and dependencies live.

FLASH_VECTBL (rx) : ORIGIN = 0x08000000, LENGTH = 512B

FLASH_FNTBL (rx) : ORIGIN = 0x08000200, LENGTH = 512B

FLASH (rx) : ORIGIN = 0x08000400, LENGTH = 512K-1K

[NandhakumarGanesan]

hi,

Thanks for your response. 

my linker script file:

/*
******************************************************************************
**
** @file : LinkerScript.ld
**
** @author : Auto-generated by STM32CubeIDE
**
** @brief : Linker script for STM32F103C8Tx Device from STM32F1 series
** 64KBytes FLASH
** 20KBytes 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) 2024 STMicroelectronics.
** All rights reserved.
**
** This software is licensed under terms that can be found in the LICENSE file
** in the root directory of this software component.
** If no LICENSE file comes with this software, it is provided AS-IS.
**
******************************************************************************
*/

/* Entry Point */
ENTRY(Reset_Handler)

/* Highest address of the user mode stack */
_estack = ORIGIN(RAM) + LENGTH(RAM); /* end of "RAM" Ram type memory */

_Min_Heap_Size = 0x200; /* required amount of heap */
_Min_Stack_Size = 0x400; /* required amount of stack */

/* Memories definition */
MEMORY
{
RAM (xrw) : ORIGIN = 0x20000000, LENGTH = 20K
FLASH (rx) : ORIGIN = 0x8000000, LENGTH = 64K

}

/* Sections */
SECTIONS
{
/* The startup code into "FLASH" Rom type memory */
.isr_vector :
{
. = ALIGN(4);
KEEP(*(.isr_vector)) /* Startup code */
. = ALIGN(4);
} >FLASH

/* The program code and other data into "FLASH" Rom type memory */
.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

.myFunctionSection :
{
KEEP(*(.myFunctionSection))
} > FLASH

/* Constant data into "FLASH" Rom type memory */
.rodata :
{
. = ALIGN(4);
*(.rodata) /* .rodata sections (constants, strings, etc.) */
*(.rodata*) /* .rodata* sections (constants, strings, etc.) */
. = ALIGN(4);
} >FLASH

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

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

.preinit_array :
{
. = ALIGN(4);
PROVIDE_HIDDEN (__preinit_array_start = .);
KEEP (*(.preinit_array*))
PROVIDE_HIDDEN (__preinit_array_end = .);
. = ALIGN(4);
} >FLASH

.init_array :
{
. = ALIGN(4);
PROVIDE_HIDDEN (__init_array_start = .);
KEEP (*(SORT(.init_array.*)))
KEEP (*(.init_array*))
PROVIDE_HIDDEN (__init_array_end = .);
. = ALIGN(4);
} >FLASH

.fini_array :
{
. = ALIGN(4);
PROVIDE_HIDDEN (__fini_array_start = .);
KEEP (*(SORT(.fini_array.*)))
KEEP (*(.fini_array*))
PROVIDE_HIDDEN (__fini_array_end = .);
. = ALIGN(4);
} >FLASH

/* Used by the startup to initialize data */
_sidata = LOADADDR(.data);

/* Initialized data sections into "RAM" Ram type memory */
.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 into "RAM" Ram type memory */
. = ALIGN(4);
.bss :
{
/* This is used by the startup in order to initialize the .bss section */
_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" Ram type memory left */
._user_heap_stack :
{
. = ALIGN(8);
PROVIDE ( end = . );
PROVIDE ( _end = . );
. = . + _Min_Heap_Size;
. = . + _Min_Stack_Size;
. = ALIGN(8);
} >RAM

/* Remove information from the compiler libraries */
/DISCARD/ :
{
libc.a ( * )
libm.a ( * )
libgcc.a ( * )
}

.ARM.attributes 0 : { *(.ARM.attributes) }
}

I will try this way error is not happen but I can add Address in this way error is happening .

.myFunctionSection :
{
KEEP(*(.myFunctionSection))
} > FLASH

modified script:

.myFunctionSection :
{
KEEP(*(.myFunctionSection))
} > FLASH AT 0x8005000

After this modification error will happening.

so kindly give correct way for address fix for a function.