Solved
STM32F401 reserving flash sector for config
On STM32F401CCU6
I'm trying to reserve these 2sectors for user config in gcc linker script:
Sector - Address ini ~ Address end - Size
Sector 0 - 0x0800 0000 ~ 0x0800 3FFF - 16 Kbytes
Sector 1 - 0x0800 4000 ~ 0x0800 7FFF - 16 Kbytes RESERVE
Sector 2 - 0x0800 8000 ~ 0x0800 BFFF - 16 Kbytes RESERVE
Sector 3 - 0x0800 C000 ~ 0x0800 FFFF - 16 Kbytes
Sector 4 - 0x0801 0000 ~ 0x0801 FFFF - 64 Kbytes
Sector 5 - 0x0802 0000 ~ 0x0803 FFFF - 128 Kbytes
But the code posted somewhere else on the forum is not working.
Looking at the generated .bin at address 4000h seems to hold data, it's not FF/00
static const uint8_t __attribute__((section (".myDataStorage"))) memoryReserve[32768];
/* Entry Point */
ENTRY(Reset_Handler)
/* Highest address of the user mode stack */
_estack = 0x20010000; /* end of RAM */
/* Generate a link error if heap and stack don't fit into RAM */
_Min_Heap_Size = 0x0; /* required amount of heap */
_Min_Stack_Size = 0xF00; /* required amount of stack */
/* Specify the memory areas */
/* STM32F401CCU6: 4x16K,64K,128K==256K */
MEMORY
{
FLASH_ISR (rx) : ORIGIN = 0x08000000, LENGTH = 16K
FLASH_HOLE (rx): ORIGIN = 0x08004000, LENGTH = 32K
FLASH (rx) : ORIGIN = 0x080C0000, LENGTH = 256K-32K
RAM (xrw) : ORIGIN = 0x20000000, 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_ISR
.ARM.extab : { *(.ARM.extab* .gnu.linkonce.armextab.*) } >FLASH
.ARM : {
__exidx_start = .;
*(.ARM.exidx*)
__exidx_end = .;
} >FLASH_ISR
.preinit_array :
{
PROVIDE_HIDDEN (__preinit_array_start = .);
KEEP (*(.preinit_array*))
PROVIDE_HIDDEN (__preinit_array_end = .);
} >FLASH_ISR
.init_array :
{
PROVIDE_HIDDEN (__init_array_start = .);
KEEP (*(SORT(.init_array.*)))
KEEP (*(.init_array*))
PROVIDE_HIDDEN (__init_array_end = .);
} >FLASH_ISR
.fini_array :
{
PROVIDE_HIDDEN (__fini_array_start = .);
KEEP (*(SORT(.fini_array.*)))
KEEP (*(.fini_array*))
PROVIDE_HIDDEN (__fini_array_end = .);
} >FLASH_ISR
/* Reserve section 3 from flash memory. */
.myDataStorage :
{
. = ALIGN(4);
KEEP(*(.myDataStorage)) ;
. = ALIGN(4);
} > FLASH_HOLE
/* 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
/* 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 */
} >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(4);
PROVIDE ( end = . );
PROVIDE ( _end = . );
. = . + _Min_Heap_Size;
. = . + _Min_Stack_Size;
. = ALIGN(4);
} >RAM
/* Remove information from the standard libraries */
/DISCARD/ :
{
libc.a ( * )
libm.a ( * )
libgcc.a ( * )
}
.ARM.attributes 0 : { *(.ARM.attributes) }
}
map file also agrees
.text.HAL_RCC_OscConfig
0x08004020 0x7bc obj\stm32f4xx_hal_rcc.o
0x08004020 HAL_RCC_OscConfig
.text.HAL_RCC_ClockConfig
0x080047dc 0x560 obj\stm32f4xx_hal_rcc.o
0x080047dc HAL_RCC_ClockConfig