From NRF52 SES Flash Placement File (.xml) to GNU Linker script file (.ld)

[KRD]

Hello,

I want to migrate from Segger project to gnu arm gcc project.

I Segger's project, I have add several RAM memory regions in flash_placement.xml. Now want to move all those memory regions in armgcc linker script (.ld).

Looking at linker script, it looks readable but difficult to add custom regions. Need your help understanding gnu linker script with examples.

For example, How to interpret below flash_placement.xml formatted region to GNU linker script.

<ProgramSection alignment="4" keep="Yes" load="No" name=".retained_section" address_symbol="__start_retained_section" end_symbol="__stop__retained_section" size="2048" />

[Vidar Berg]

Hello,

The Segger projects in our SDK are set up to use the GNU linker - it auto-generates the  *.ld script file (placed in build folder) based on the layout described by the flash_placement.xml.  But are you planning to work with the same linker script and makefiles as we use for the "armgcc" projects in the SDK?

[KRD]

Yes. I am planning to use `armgcc` project.

[Vidar Berg]

Ok, then it may look something like this:

/* Linker script to configure memory regions. */

SEARCH_DIR(.)
GROUP(-lgcc -lc -lnosys)

MEMORY
{
  FLASH (rx) : ORIGIN = 0x26000, LENGTH = 0x5a000
  RAM (rwx) :  ORIGIN = 0x20002bd0, LENGTH = 0xd430
  RETAINED_RAM (rwx) : ORIGIN = 0x2000F800, LENGTH = 0x800
}

SECTIONS
{
  .retained_section (NOLOAD) :
  {
	PROVIDE(__start_retained_section = .);
	KEEP(*(.retained_section))
	PROVIDE(__stop__retained_section = .);
   } > RETAINED_RAM
}

SECTIONS
{
  . = ALIGN(4);
  .mem_section_dummy_ram :
  {
  }
  .cli_sorted_cmd_ptrs :
  {
    PROVIDE(__start_cli_sorted_cmd_ptrs = .);
    KEEP(*(.cli_sorted_cmd_ptrs))
    PROVIDE(__stop_cli_sorted_cmd_ptrs = .);
  } > RAM
  .fs_data :
  {
    PROVIDE(__start_fs_data = .);
    KEEP(*(.fs_data))
    PROVIDE(__stop_fs_data = .);
  } > RAM
  .log_dynamic_data :
  {
    PROVIDE(__start_log_dynamic_data = .);
    KEEP(*(SORT(.log_dynamic_data*)))
    PROVIDE(__stop_log_dynamic_data = .);
  } > RAM
  .log_filter_data :
  {
    PROVIDE(__start_log_filter_data = .);
    KEEP(*(SORT(.log_filter_data*)))
    PROVIDE(__stop_log_filter_data = .);
  } > RAM

} INSERT AFTER .data;

SECTIONS
{
  .mem_section_dummy_rom :
  {
  }
  .sdh_soc_observers :
  {
    PROVIDE(__start_sdh_soc_observers = .);
    KEEP(*(SORT(.sdh_soc_observers*)))
    PROVIDE(__stop_sdh_soc_observers = .);
  } > FLASH
  .sdh_ble_observers :
  {
    PROVIDE(__start_sdh_ble_observers = .);
    KEEP(*(SORT(.sdh_ble_observers*)))
    PROVIDE(__stop_sdh_ble_observers = .);
  } > FLASH
  .pwr_mgmt_data :
  {
    PROVIDE(__start_pwr_mgmt_data = .);
    KEEP(*(SORT(.pwr_mgmt_data*)))
    PROVIDE(__stop_pwr_mgmt_data = .);
  } > FLASH
    .nrf_queue :
  {
    PROVIDE(__start_nrf_queue = .);
    KEEP(*(.nrf_queue))
    PROVIDE(__stop_nrf_queue = .);
  } > FLASH
  .sdh_req_observers :
  {
    PROVIDE(__start_sdh_req_observers = .);
    KEEP(*(SORT(.sdh_req_observers*)))
    PROVIDE(__stop_sdh_req_observers = .);
  } > FLASH
  .sdh_state_observers :
  {
    PROVIDE(__start_sdh_state_observers = .);
    KEEP(*(SORT(.sdh_state_observers*)))
    PROVIDE(__stop_sdh_state_observers = .);
  } > FLASH
  .sdh_stack_observers :
  {
    PROVIDE(__start_sdh_stack_observers = .);
    KEEP(*(SORT(.sdh_stack_observers*)))
    PROVIDE(__stop_sdh_stack_observers = .);
  } > FLASH
    .nrf_balloc :
  {
    PROVIDE(__start_nrf_balloc = .);
    KEEP(*(.nrf_balloc))
    PROVIDE(__stop_nrf_balloc = .);
  } > FLASH
    .cli_command :
  {
    PROVIDE(__start_cli_command = .);
    KEEP(*(.cli_command))
    PROVIDE(__stop_cli_command = .);
  } > FLASH
  .crypto_data :
  {
    PROVIDE(__start_crypto_data = .);
    KEEP(*(SORT(.crypto_data*)))
    PROVIDE(__stop_crypto_data = .);
  } > FLASH
  .log_const_data :
  {
    PROVIDE(__start_log_const_data = .);
    KEEP(*(SORT(.log_const_data*)))
    PROVIDE(__stop_log_const_data = .);
  } > FLASH
  .log_backends :
  {
    PROVIDE(__start_log_backends = .);
    KEEP(*(SORT(.log_backends*)))
    PROVIDE(__stop_log_backends = .);
  } > FLASH

} INSERT AFTER .text


INCLUDE "nrf_common.ld"

[KRD]

Thanks. This is perfect.