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,

Do you enable NRF_LOG_ENABLED and NRF_LOG_BACKEND_RTT_ENABLED in the sdk_config.h? You can refer to the sdk_config.h in the _debug project. 

Do you use secure_bootloader(ble_debug) as the base? Are you able to use the secure_bootloader(ble_debug) for the test? Could you see the log from RTT viewer while only loading the secure_bootloader(ble_debug)? Does it advertise with the advertising name?

 -Amanda H.

[umrsraj]

Hi Amanda,

--> Yes i Enabled NRF_LOG_ENABLED and NRF_LOG_BACKEND_RTT_ENABLED in sdk_config.h and i can see my LOG output in RTT viewer(j-link RTT viewer) when i program my board other than DFU(segger- Build and Run)

--> just for the clarity i am telling you again that - my problem is to see log data while application is running after i do DFU,

That means i have written my NRF_LOG_INFO() in the Application program

--> Iam using secure_bootloader(ble) as the base not secure_bootloader(ble_debug) for the Bootloader of my Application, (when i was testing the secure bootloader firstly i have tried with secure_bootloader_ble_debug only and it was worked fine with RTT Log data)

Best Regards,

Rajender.

[umrsraj]

Hi Amanda,

Since we are ready to deploy our device at customer end we need solution for this RTT Log issue ASAP

so we are awaiting for your reply..

Best Regards,

Raj.

[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.