Can't flash ELF via UART bootloader, "write address was not acknowledged 0x20000060"

[aurelien-lupin]

Hello,

I can flash an HEX file via the CLI but not the ELF one.

More specifically, the flashing seems to succeed (if I reboot the board it works well), it's just at the end that an error message is displayed that I can't understand:

STM32_Programmer_CLI.exe -c port=COM4 br=115200 -d firmware.elf -g
[...]
File segment @0x20000064 is not 8-bytes aligned. It will be aligned to @0x20000060
[...]
Response received from device: NACK
Error: Write address not acknowledged: 0x20000060
Error: failed to download Sector[0]
Error: failed to download the File

Here's my linker script if it cal help to diagnose the issue (I have tried to remove the heap since we don't / must not use it) :

/* 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
{
  CCMSRAM    (xrw)    : ORIGIN = 0x10000000,   LENGTH = 10K
  RAM    (xrw)    : ORIGIN = 0x20000000,   LENGTH = 32K
  FLASH    (rx)    : ORIGIN = 0x8000000,   LENGTH = 128K
}

/* 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

  /* 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 (READONLY) : /* The "READONLY" keyword is only supported in GCC11 and later, remove it if using GCC10 or earlier. */
  {
    . = ALIGN(4);
    *(.ARM.extab* .gnu.linkonce.armextab.*)
    . = ALIGN(4);
  } >FLASH

  .ARM (READONLY) : /* The "READONLY" keyword is only supported in GCC11 and later, remove it if using GCC10 or earlier. */
  {
    . = ALIGN(4);
    __exidx_start = .;
    *(.ARM.exidx*)
    __exidx_end = .;
    . = ALIGN(4);
  } >FLASH

  .preinit_array (READONLY) : /* The "READONLY" keyword is only supported in GCC11 and later, remove it if using GCC10 or earlier. */
  {
    . = ALIGN(4);
    PROVIDE_HIDDEN (__preinit_array_start = .);
    KEEP (*(.preinit_array*))
    PROVIDE_HIDDEN (__preinit_array_end = .);
    . = ALIGN(4);
  } >FLASH

  .init_array (READONLY) : /* The "READONLY" keyword is only supported in GCC11 and later, remove it if using GCC10 or earlier. */
  {
    . = ALIGN(4);
    PROVIDE_HIDDEN (__init_array_start = .);
    KEEP (*(SORT(.init_array.*)))
    KEEP (*(.init_array*))
    PROVIDE_HIDDEN (__init_array_end = .);
    . = ALIGN(4);
  } >FLASH

  .fini_array (READONLY) : /* The "READONLY" keyword is only supported in GCC11 and later, remove it if using GCC10 or earlier. */
  {
    . = 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

  _siccmsram = LOADADDR(.ccmsram);

  /* CCM-SRAM section
  *
  * IMPORTANT NOTE!
  * If initialized variables will be placed in this section,
  * the startup code needs to be modified to copy the init-values.
  */
  .ccmsram :
  {
    . = ALIGN(4);
    _sccmsram = .;       /* create a global symbol at ccmsram start */
    *(.ccmsram)
    *(.ccmsram*)

    . = ALIGN(4);
    _eccmsram = .;       /* create a global symbol at ccmsram end */
  } >CCMSRAM 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

  /* Create a section in order to identify the end of the main stack */
  ._user_main_stack_end :
  {
    . = ALIGN(8);
  } >RAM

  PROVIDE(_user_main_stack_end = .);

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

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

 Any idea what's wrong?

Thanks for your help!

[Tesla DeLorean · Accepted solution]

RAM is not FLASH

You should double check what's getting into RAM. Review .ELF with objdump or fromelf type dumping tools.

Might be that STM32 Cube Programmer is ignoring NOLOAD / NOBITS type flagging on the sections being exported.

If it's a bug you could report that, or in the mean time you could interstage through a .HEX if that's working

You could use ALIGN(8) if that's what its complaining about, I don't think RAM cares, but the FLASH lines internally might.

[aurelien-lupin]

Hello,

Thanks for your help. I have managed to fix the issue by indeed adjusting the alignment of the .data section size.

I changed the latest ALIGN to 8 in this section:

  .data :
  {
    . = ALIGN(4);
    _sdata = .;        /* create a global symbol at data start */
    *(.data)           /* .data sections */
    *(.data*)          /* .data* sections */
    *(.RamFunc)        /* .RamFunc sections */
    *(.RamFunc*)       /* .RamFunc* sections */

    . = ALIGN(8);
    _edata = .;        /* define a global symbol at data end */
  } >RAM AT> FLASH

BEFORE the fix:

Sections:
Idx Name          Size      VMA       LMA       File off  Algn
  0 .isr_vector   000001d8  08000000  08000000  00001000  2**0
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  1 .text         00009cd4  08000200  08000200  00001200  2**6
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
  2 .rodata       00000294  08009ed4  08009ed4  0000aed4  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  3 .ARM.extab    00000000  0800a168  0800a168  0000c064  2**0
                  CONTENTS, READONLY
  4 .ARM          00000008  0800a168  0800a168  0000b168  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  5 .preinit_array 00000000  0800a170  0800a170  0000c064  2**0
                  CONTENTS, ALLOC, LOAD, DATA
  6 .init_array   00000004  0800a170  0800a170  0000b170  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  7 .fini_array   00000004  0800a174  0800a174  0000b174  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  8 .data         00000064  20000000  0800a178  0000c000  2**2
                  CONTENTS, ALLOC, LOAD, DATA
  9 .ccmsram      00000000  10000000  10000000  0000c064  2**0
                  CONTENTS
 10 .bss          00000c60  20000064  20000064  0000c064  2**2
                  ALLOC

AFTER the fix:

Sections:
Idx Name          Size      VMA       LMA       File off  Algn
  0 .isr_vector   000001d8  08000000  08000000  00001000  2**0
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  1 .text         00009cd4  08000200  08000200  00001200  2**6
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
  2 .rodata       00000294  08009ed4  08009ed4  0000aed4  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  3 .ARM.extab    00000000  0800a168  0800a168  0000c068  2**0
                  CONTENTS, READONLY
  4 .ARM          00000008  0800a168  0800a168  0000b168  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  5 .preinit_array 00000000  0800a170  0800a170  0000c068  2**0
                  CONTENTS, ALLOC, LOAD, DATA
  6 .init_array   00000004  0800a170  0800a170  0000b170  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  7 .fini_array   00000004  0800a174  0800a174  0000b174  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  8 .data         00000068  20000000  0800a178  0000c000  2**2
                  CONTENTS, ALLOC, LOAD, DATA
  9 .ccmsram      00000000  10000000  10000000  0000c068  2**0
                  CONTENTS
 10 .bss          00000c60  20000068  20000068  0000c068  2**2
                  ALLOC

And now it works well :smiling_face_with_smiling_eyes:

[Pavel A.]

The offending address was 20000064 and in "working" variant changed to something aligned on 8. From your section listings, it is something located between .data and .bss (which has not changed their addresses). But the listings do not show anything between .data and .bss.  So it looks to me like a bug in CubeProgrammer, it passes to the target weird bits of the ELF that should be discarded.