This post is older than 2 years and might not be relevant anymore
More Info: Consider searching for newer posts

Segger Fixed Memory Allocation in Flash and SoftDevice compatibility.

Hi All,

New user here but couldn't find a concrete answer to the following question.

In PIC land I've usually allocated fixed memory using the _at_ or __attribute__ label but Segger doesn't support this. From googling I read to add a reference to the xml file, which I've done as shown below:

<!DOCTYPE Board_Memory_Definition_File>
<root name="nRF52810_xxAA">
  <MemorySegment access="ReadOnly" name="FLASH1" size="0x00030000" start="0x00000000" />
  <MemorySegment access="Read/Write" name="RAM1" size="0x00006000" start="0x20000000" />
  <MemorySegment access="Read/Write" name="CODE_RAM1" size="0x00006000" start="0x00800000" />

  <MemorySegment name="$(FLASH_NAME:FLASH)">
    <ProgramSection alignment="4" load="Yes" name=".settingsStore" start="0x00000000" />
  </MemorySegment>
</root>

You can see that the start is 0x0 which is probably a bad idea, likely the entry point of the application if it's like PIC's. A related question to ask at this point is where does a SoftDevice get placed in Flash?

Back to the main question, I then have the following to take up a 4kb page of flash (actual usage is 1kb so plenty for futureproofing).

static const union {
  struct settingsProto settings;
  uint8_t pad[FLASH_PAGE_SIZE_BYTES];
} store __attribute__((section(".settingsStore"))); // reserve flash page

Upon build I receive the error:

unplaced section: .settingsStore [config.o], size=4000, align=4



Parents
  • Hi Snoopy20, 

    the SoftDevice and MBR is placed from 0x0000 and upwards, see Memory resource map and usage. The APP_CODE_BASE will depend on which SoftDevice that is used and this can be found in the respective SoftDevice release notes. 

    So if you want to set a side one flash page to store settings, then you should place that at the end of flash, like we have done with our bootloader settings page in our bootloader example, see the attached flash_placement.xml file

    <!DOCTYPE Linker_Placement_File>
    <Root name="Flash Section Placement">
      <MemorySegment name="FLASH" start="$(FLASH_PH_START)" size="$(FLASH_PH_SIZE)">
        <ProgramSection load="no" name=".reserved_flash" start="$(FLASH_PH_START)" size="$(FLASH_START)-$(FLASH_PH_START)" />
        <ProgramSection alignment="0x100" load="Yes" name=".vectors" start="$(FLASH_START)" />
        <ProgramSection alignment="4" load="Yes" name=".init" />
        <ProgramSection alignment="4" load="Yes" name=".init_rodata" />
        <ProgramSection alignment="4" load="Yes" name=".text" />
        <ProgramSection alignment="4" keep="Yes" load="Yes" name=".crypto_data" inputsections="*(SORT(.crypto_data*))" address_symbol="__start_crypto_data" end_symbol="__stop_crypto_data" />
        <ProgramSection alignment="4" keep="Yes" load="Yes" name=".log_const_data" inputsections="*(SORT(.log_const_data*))" address_symbol="__start_log_const_data" end_symbol="__stop_log_const_data" />
        <ProgramSection alignment="4" keep="Yes" load="Yes" name=".nrf_queue" inputsections="*(.nrf_queue*)" address_symbol="__start_nrf_queue" end_symbol="__stop_nrf_queue" />
        <ProgramSection alignment="4" keep="Yes" load="Yes" name=".dfu_trans" inputsections="*(SORT(.dfu_trans*))" address_symbol="__start_dfu_trans" end_symbol="__stop_dfu_trans" />
        <ProgramSection alignment="4" keep="Yes" load="Yes" name=".nrf_balloc" inputsections="*(.nrf_balloc*)" address_symbol="__start_nrf_balloc" end_symbol="__stop_nrf_balloc" />
        <ProgramSection alignment="4" keep="Yes" load="Yes" name=".svc_data" inputsections="*(.svc_data*)" address_symbol="__start_svc_data" end_symbol="__stop_svc_data" />
        <ProgramSection alignment="4" keep="Yes" load="Yes" name=".sdh_ble_observers" inputsections="*(SORT(.sdh_ble_observers*))" address_symbol="__start_sdh_ble_observers" end_symbol="__stop_sdh_ble_observers" />
        <ProgramSection alignment="4" keep="Yes" load="Yes" name=".sdh_state_observers" inputsections="*(SORT(.sdh_state_observers*))" address_symbol="__start_sdh_state_observers" end_symbol="__stop_sdh_state_observers" />
        <ProgramSection alignment="4" keep="Yes" load="Yes" name=".sdh_stack_observers" inputsections="*(SORT(.sdh_stack_observers*))" address_symbol="__start_sdh_stack_observers" end_symbol="__stop_sdh_stack_observers" />
        <ProgramSection alignment="4" keep="Yes" load="Yes" name=".sdh_req_observers" inputsections="*(SORT(.sdh_req_observers*))" address_symbol="__start_sdh_req_observers" end_symbol="__stop_sdh_req_observers" />
        <ProgramSection alignment="4" keep="Yes" load="Yes" name=".sdh_soc_observers" inputsections="*(SORT(.sdh_soc_observers*))" address_symbol="__start_sdh_soc_observers" end_symbol="__stop_sdh_soc_observers" />
        <ProgramSection alignment="4" keep="Yes" load="No" name=".nrf_sections" address_symbol="__start_nrf_sections" />
        <ProgramSection alignment="4" keep="Yes" load="Yes" name=".log_dynamic_data"  inputsections="*(SORT(.log_dynamic_data*))" runin=".log_dynamic_data_run"/>
        <ProgramSection alignment="4" keep="Yes" load="Yes" name=".log_filter_data"  inputsections="*(SORT(.log_filter_data*))" runin=".log_filter_data_run"/>
        <ProgramSection alignment="4" keep="Yes" load="Yes" name=".fs_data"  inputsections="*(.fs_data*)" runin=".fs_data_run"/>
        <ProgramSection alignment="4" load="Yes" name=".dtors" />
        <ProgramSection alignment="4" load="Yes" name=".ctors" />
        <ProgramSection alignment="4" load="Yes" name=".rodata" />
        <ProgramSection alignment="4" load="Yes" name=".ARM.exidx" address_symbol="__exidx_start" end_symbol="__exidx_end" />
        <ProgramSection alignment="4" load="Yes" runin=".fast_run" name=".fast" />
        <ProgramSection alignment="4" load="Yes" runin=".data_run" name=".data" />
        <ProgramSection alignment="4" load="Yes" runin=".tdata_run" name=".tdata" />
      </MemorySegment>
      <MemorySegment name="RAM" start="$(RAM_PH_START)" size="$(RAM_PH_SIZE)">
        <ProgramSection load="no" name=".reserved_ram" start="$(RAM_PH_START)" size="$(RAM_START)-$(RAM_PH_START)" />
        <ProgramSection alignment="0x100" load="No" name=".vectors_ram" start="$(RAM_START)" address_symbol="__app_ram_start__"/>
        <ProgramSection alignment="4" keep="Yes" load="No" name=".nrf_sections_run" address_symbol="__start_nrf_sections_run" />
        <ProgramSection alignment="4" keep="Yes" load="No" name=".log_dynamic_data_run" address_symbol="__start_log_dynamic_data" end_symbol="__stop_log_dynamic_data" />
        <ProgramSection alignment="4" keep="Yes" load="No" name=".log_filter_data_run" address_symbol="__start_log_filter_data" end_symbol="__stop_log_filter_data" />
        <ProgramSection alignment="4" keep="Yes" load="No" name=".fs_data_run" address_symbol="__start_fs_data" end_symbol="__stop_fs_data" />
        <ProgramSection alignment="4" keep="Yes" load="No" name=".nrf_sections_run_end" address_symbol="__end_nrf_sections_run" />
        <ProgramSection alignment="4" load="No" name=".fast_run" />
        <ProgramSection alignment="4" load="No" name=".data_run" />
        <ProgramSection alignment="4" load="No" name=".tdata_run" />
        <ProgramSection alignment="4" load="No" name=".bss" />
        <ProgramSection alignment="4" load="No" name=".tbss" />
        <ProgramSection alignment="4" load="No" name=".non_init" />
        <ProgramSection alignment="4" size="__HEAPSIZE__" load="No" name=".heap" />
        <ProgramSection alignment="8" size="__STACKSIZE__" load="No" place_from_segment_end="Yes" name=".stack"  address_symbol="__StackLimit" end_symbol="__StackTop"/>
        <ProgramSection alignment="8" size="__STACKSIZE_PROCESS__" load="No" name=".stack_process" />
      </MemorySegment>
      <MemorySegment name="mbr_params_page" start="0x0002E000" size="0x1000">
        <ProgramSection alignment="4" keep="Yes" load="No" name=".mbr_params_page" address_symbol="__start_mbr_params_page" end_symbol="__stop_mbr_params_page" start = "0x0002E000" size="0x1000" />
      </MemorySegment>
      <MemorySegment name="bootloader_settings_page" start="0x0002F000" size="0x1000">
        <ProgramSection alignment="4" keep="Yes" load="No" name=".bootloader_settings_page" address_symbol="__start_bootloader_settings_page" end_symbol="__stop_bootloader_settings_page" start = "0x0002F000" size="0x1000" />
      </MemorySegment>
      <MemorySegment name="uicr_bootloader_start_address" start="0x10001014" size="0x4">
        <ProgramSection alignment="4" keep="Yes" load="Yes" name=".uicr_bootloader_start_address" address_symbol="__start_uicr_bootloader_start_address" end_symbol="__stop_uicr_bootloader_start_address" start = "0x10001014" size="0x4" />
      </MemorySegment>
      <MemorySegment name="uicr_mbr_params_page" start="0x10001018" size="0x4">
        <ProgramSection alignment="4" keep="Yes" load="Yes" name=".uicr_mbr_params_page" address_symbol="__start_uicr_mbr_params_page" end_symbol="__stop_uicr_mbr_params_page" start = "0x10001018" size="0x4" />
      </MemorySegment>
    </Root>
    

    Best regards

    Bjørn

  • I've added that file (which already existed but wasn't part of the project) and appended the following:

      <MemorySegment name="settingsStore" start="0x0002F000" size="0x1000">
        <ProgramSection alignment="4" keep="Yes" load="No" name=".settingsStore" address_symbol="__start_main_settings_page" end_symbol="__stop_main_settings_page" start = "0x0002F000" size="0x1000" />
      </MemorySegment>

    Which seems good as likewise I only need a page of flash.

    Unfortunately the error persists - "unplaced section: .settingsStore [config.o], size=4000, align=2"

    static const union {
      struct settingsProto settings;
      uint8_t pad[FLASH_PAGE_SIZE_BYTES];
    } store __attribute__((section(".settingsStore"))); // reserve flash page

  • DId you remove the old Memory Segment for .settingsStore from the flash_placement.xml file?

    <MemorySegment name="$(FLASH_NAME:FLASH)">
        <ProgramSection alignment="4" load="Yes" name=".settingsStore" start="0x00000000" />
      </MemorySegment>

  • I did, still errors. Currently:

    <!DOCTYPE Linker_Placement_File>
    <Root name="Flash Section Placement">
      <MemorySegment name="$(FLASH_NAME:FLASH);FLASH1">
        <ProgramSection alignment="0x100" load="Yes" name=".vectors" start="$(FLASH_START:)" />
        <ProgramSection alignment="4" load="Yes" name=".init" />
        <ProgramSection alignment="4" load="Yes" name=".init_rodata" />
        <ProgramSection alignment="4" load="Yes" name=".text" />
        <ProgramSection alignment="4" load="Yes" name=".dtors" />
        <ProgramSection alignment="4" load="Yes" name=".ctors" />
        <ProgramSection alignment="4" load="Yes" name=".rodata" />
        <ProgramSection alignment="4" load="Yes" name=".ARM.exidx" address_symbol="__exidx_start" end_symbol="__exidx_end" />
        <ProgramSection alignment="4" load="Yes" runin=".fast_run" name=".fast" />
        <ProgramSection alignment="4" load="Yes" runin=".data_run" name=".data" />
        <ProgramSection alignment="4" load="Yes" runin=".tdata_run" name=".tdata" />
      </MemorySegment>
      <MemorySegment name="$(RAM_NAME:RAM);SRAM;RAM1">
        <ProgramSection alignment="0x100" load="No" name=".vectors_ram" start="$(RAM_START:$(SRAM_START:))" />
        <ProgramSection alignment="4" load="No" name=".fast_run" />
        <ProgramSection alignment="4" load="No" name=".data_run" />
        <ProgramSection alignment="4" load="No" name=".bss" />
        <ProgramSection alignment="4" load="No" name=".tbss" />
        <ProgramSection alignment="4" load="No" name=".tdata_run" />
        <ProgramSection alignment="4" load="No" name=".non_init" />
        <ProgramSection alignment="4" size="__HEAPSIZE__" load="No" name=".heap" />
        <ProgramSection alignment="8" size="__STACKSIZE__" load="No" place_from_segment_end="Yes" name=".stack" />
        <ProgramSection alignment="8" size="__STACKSIZE_PROCESS__" load="No" name=".stack_process" />
      </MemorySegment>
      <MemorySegment name="$(FLASH2_NAME:FLASH2)">
        <ProgramSection alignment="4" load="Yes" name=".text2" />
        <ProgramSection alignment="4" load="Yes" name=".rodata2" />
        <ProgramSection alignment="4" load="Yes" runin=".data2_run" name=".data2" />
      </MemorySegment>
      <MemorySegment name="$(RAM2_NAME:RAM2)">
        <ProgramSection alignment="4" load="No" name=".data2_run" />
        <ProgramSection alignment="4" load="No" name=".bss2" />
      </MemorySegment>
      <MemorySegment name="settingsStore" start="0x0002F000" size="0x1000">
        <ProgramSection alignment="4" keep="Yes" load="No" name=".settingsStore" address_symbol="__start_main_settings_page" end_symbol="__stop_main_settings_page" start = "0x0002F000" size="0x1000" />
      </MemorySegment>
    </Root>

Reply
  • I did, still errors. Currently:

    <!DOCTYPE Linker_Placement_File>
    <Root name="Flash Section Placement">
      <MemorySegment name="$(FLASH_NAME:FLASH);FLASH1">
        <ProgramSection alignment="0x100" load="Yes" name=".vectors" start="$(FLASH_START:)" />
        <ProgramSection alignment="4" load="Yes" name=".init" />
        <ProgramSection alignment="4" load="Yes" name=".init_rodata" />
        <ProgramSection alignment="4" load="Yes" name=".text" />
        <ProgramSection alignment="4" load="Yes" name=".dtors" />
        <ProgramSection alignment="4" load="Yes" name=".ctors" />
        <ProgramSection alignment="4" load="Yes" name=".rodata" />
        <ProgramSection alignment="4" load="Yes" name=".ARM.exidx" address_symbol="__exidx_start" end_symbol="__exidx_end" />
        <ProgramSection alignment="4" load="Yes" runin=".fast_run" name=".fast" />
        <ProgramSection alignment="4" load="Yes" runin=".data_run" name=".data" />
        <ProgramSection alignment="4" load="Yes" runin=".tdata_run" name=".tdata" />
      </MemorySegment>
      <MemorySegment name="$(RAM_NAME:RAM);SRAM;RAM1">
        <ProgramSection alignment="0x100" load="No" name=".vectors_ram" start="$(RAM_START:$(SRAM_START:))" />
        <ProgramSection alignment="4" load="No" name=".fast_run" />
        <ProgramSection alignment="4" load="No" name=".data_run" />
        <ProgramSection alignment="4" load="No" name=".bss" />
        <ProgramSection alignment="4" load="No" name=".tbss" />
        <ProgramSection alignment="4" load="No" name=".tdata_run" />
        <ProgramSection alignment="4" load="No" name=".non_init" />
        <ProgramSection alignment="4" size="__HEAPSIZE__" load="No" name=".heap" />
        <ProgramSection alignment="8" size="__STACKSIZE__" load="No" place_from_segment_end="Yes" name=".stack" />
        <ProgramSection alignment="8" size="__STACKSIZE_PROCESS__" load="No" name=".stack_process" />
      </MemorySegment>
      <MemorySegment name="$(FLASH2_NAME:FLASH2)">
        <ProgramSection alignment="4" load="Yes" name=".text2" />
        <ProgramSection alignment="4" load="Yes" name=".rodata2" />
        <ProgramSection alignment="4" load="Yes" runin=".data2_run" name=".data2" />
      </MemorySegment>
      <MemorySegment name="$(RAM2_NAME:RAM2)">
        <ProgramSection alignment="4" load="No" name=".data2_run" />
        <ProgramSection alignment="4" load="No" name=".bss2" />
      </MemorySegment>
      <MemorySegment name="settingsStore" start="0x0002F000" size="0x1000">
        <ProgramSection alignment="4" keep="Yes" load="No" name=".settingsStore" address_symbol="__start_main_settings_page" end_symbol="__stop_main_settings_page" start = "0x0002F000" size="0x1000" />
      </MemorySegment>
    </Root>

Children
No Data
Related