Having the RTT viewer after DFU

[umrsraj]

Hello there,

I have been using RTT viewer since a while and its works fine only if i program that board without DFU, and if i program this board with DFU it says "could not connect to target" as below...

and it disturbs my BLE Connection also, then i need to restart my board.

finally my problem is, i need to check(view/Debug) my data after DFU also, how can i do that please help me

Best Regards,

Rajender.

[Amanda Hsieh]

Hi Rajender, 

 Are you using the bootloader example? If so, there are two types of examples and only the bootloaders with debug version provide the RTT log function.

May I know which example/code/image are you using?

-Amanda H. 

[umrsraj]

Hi Amanda,

Thanks for the replay,

I'm using modified code of ble_app_uart example, Buttonless DFU, and secure_bootloader(ble).

when i program my Custom board without bootloader(using j-link of DK board) the RTT viewer works fine, but when i program using DFU method(using bootloader) it wont work, i.e., when i try to connect in RTT viewer app the BLE disconnects and program stops working.

 Best Regards,

Rajender.

[Amanda Hsieh]

Hi Rajender, 

It happens because the bootloader and application have placed the RTT buffer in different sections in RAM and Jlink doesn't know this. It expects it to stay at the same address. The solution is to configure the linker settings so that both the bootloader and app places the buffer at the same place in RAM. Here is the example https://devzone.nordicsemi.com/f/nordic-q-a/30310/easy-way-to-merge-bootloader-and-application-rtt-output

-Amanda H.

[umrsraj]

Hi Amanda,

I am Very sorry for the late replay,

but i have tried very much to implement same thing in my code as you suggested in the reference link,

but still i am having compilation errors to implement those steps like adding 

#define SEGGER_RTT_SECTION ".rtt"

so please give me more explanation that where we need to add these steps,(sorry for requesting very basic procedure)
and then i will start testing in my code.


Best Regards,
Raj.

[Amanda Hsieh]

Hi Rajender, 

What SDK version you are using?

-Amanda H.

[umrsraj]

I am using SDK 15.1.0

[Amanda Hsieh]

Hi Rajender, 

Define the macros in your app/sdk_config.h:

#define SEGGER_RTT_ALIGNMENT 4
#define SEGGER_RTT_BUFFER_ALIGNMENT 4
#define SEGGER_RTT_SECTION ".rtt"

Allocate section in the linker script file. In nrf5x_common.ld as that post. 

The corresponding sections in the linker file look like this:

SECTIONS
{
  . = ALIGN(4);
  .mem_section_dummy_ram :
  {
  }
  .log_dynamic_data :
  {
    PROVIDE(__start_log_dynamic_data = .);
    KEEP(*(SORT(.log_dynamic_data*)))
    PROVIDE(__stop_log_dynamic_data = .);
  } > RAM
  .fs_data :
  {
    PROVIDE(__start_fs_data = .);
    KEEP(*(.fs_data))
    PROVIDE(__stop_fs_data = .);
  } > RAM
  
  .rtt :
  {
    KEEP(*(.rtt))
  } > RAM

  
} INSERT AFTER .data;

After updating with the app via DFU, reconnect to RTT view. You will see the log of the application. You might need to adjust the ram size as that post indicate. 

-Amanda H.

[umrsraj]

Hi Amanda,

I am still can't define that definition without error, and getting same error as before.

I am using nrf52840(pca10056), SDKv15.1.0, SEGGER Embedded Studio v5.20(with nordic free license).

and i have changed linker script files nrf5_common.ld, nrf52_common.ld as referred post suggested.

then do i need to move the RTT related definitions as suggested in the 3rd point, if yes please help me to understand it clearly(i am confusing what he suggesting to do).

Best Regards,

Raj.

[Amanda Hsieh]

Hi Rajender, 

That post was for GCC. After the modification, you can build the project under \armgcc to get the image by typing "make" in the command window. If you want to use segger, I will take time to look into how to set in the segger project.

-Amanda H. 

[umrsraj]

Hi Amanda,

Since our project is ready to deploy in the location its very much important to conclude this issue ASAP

so  i am requesting you to make this SES compatible ASAP.

Best Regards,

Raj.

[Amanda Hsieh]

Hi Rajender, 

Add .rtt region into flash_placement.xml as the figure

-Amanda H.