OAD binary size

[Lakshmikanth Satyavolu]

Hi All,

I have integrated DFU service into my application. I am successfully able to use OAD so far. Today I have added a piece of code to my application. So, my binary size has been increased. 

After transfer this binary to my device, application hangs and not even advertising DFU or my application services. 

What could go wrong here?  I assume if the app is not properly downloaded, it supposed to advertise DFU services. But my application hangs somewhere. 

Please help. 

Regards

Lakshmi

[Vidar Berg]

Hi,

Are you able to debug the application after completing DFU? That should help you determine where the app gets stuck.

A common reason for issues like this is that the bootloader is overwriting parts of the 'application data' region during DFU that leads to initialization problems next time the app is booted (see Memory layout). You may want to verify if the NRF_DFU_APP_DATA_AREA_SIZE config in your bootloader matches the size of the 'application data' region used by the app first as that will prevent the possibility of getting overwrites. 

[Lakshmikanth Satyavolu]

Hi Vidar,

I found, NRF_DFU_APP_DATA_AREA_SIE of dfu bootloader, it is 12288. 

Where to find application data region to match with? 

Regards

Lakshmi

[Vidar Berg]

Thanks for confirming. I think the next step is to try debugging the application after you have completed the DFU to find out where it hangs.

[Lakshmikanth Satyavolu]

Hi Vidar, 

I have tested my application standalone without DFU programmed. It is working alright. 

I have no idea how to debug dfu+appilcation  using a JLINK step by step. Can you please help?

-Lakshmi

[Lakshmikanth Satyavolu]

Hi Vidar,

Please suggest about debugging OAD application. 

Best

Lakshmi

[Vidar Berg]

What do you use to debug, Segger embedded studio? In any case, I would start by running the "nrfjprog --readregs" command after the app has started to hang (nrfjprog is a part of our nRF5x Command Line Tools package). This will return CPU registers such as the Program counter value that may help us figure out exactly where it hangs.

[Lakshmikanth Satyavolu]

Hi Vidar, 

Sorry for late response. Been busy with some other stuff. I have run this command. Below is the output for your reference. Please suggest a fix. 

R0: 0x00004001
R1: 0x00004001
R2: 0x0003CB2C
R3: 0x00000001
R4: 0x00001000
R5: 0x200077D4
R6: 0x10001000
R7: 0x0007E000
R8: 0x00000000
R9: 0x00000000
R10: 0x00000000
R11: 0x00000000
R12: 0x20003A11
SP: 0x2000FED0
LR: 0x00026D03
PC: 0x00026CC8
xPSR: 0x21000000
MSP: 0x2000FED0
PSP: 0x00000000

Best

Lakshmi

[Vidar Berg]

It appears to be stuck in your application code (around address 0x00026CC8). So you need to debug the application.

[Lakshmikanth Satyavolu]

Hi Vidar,

I got that. But the issue is, the same application working perfectly when it run standalone. Another thing is If i reduce the code size by removing few modules, this works with boot loader service too. 

There is something with code size it seems. How can we debug that? 

Best

Lakshmi

[Vidar Berg]

Hi Lakshmi,

Yes, but that's why I need you to debug the application to see what happens. It might be a problem with the code size as you say, but there may be other reasons for this as well.