How to use RTT in bootloader project

[alivexiaoluo]

Hi,I want to use RTT in bootloader project. First,i add all files(SEGGER_RTT.c ,SEGGER_RTT_printf.c,RTT_Syscalls_KEIL.c) to my bootloader project(Picture 1). Second,I add nrf_log.c to my bootloader project and define NRF_LOG_USES_RTT(Picture 2). Then build,it tells me that "._build\nrf51422_xxac.axf: Error: L6985E: Unable to automatically place AT section bootloader_settings.o(.ARM.__AT_0x0003FC00) with required base address 0x0003fc00. Please manually place in the scatter file using the --no_autoat option. "(Picture 3)

I dont known how to handle error,Thanks!

Picture1.png Picture2.png Picture3.png

SDK Version is nRF5_SDK_11.0.0_89a8197.

[Sigurd]

Hi,

You will need to allocate more flash so the image can fit. Instructions on how to do that can be found in this thread here. You can first try to set the IROM settings to IROM1 Start: 0x3A000; IROM Size: 0x5C00;

[alivexiaoluo]

Thanks,Sigurd.I have already set the IROM1 Start:0x3A000 , IROM Size:0x5C00,and #define BOOTLOADER_REGION_START 0x0003A000. Build is OK,Download is OK,but I can not see my printfs in RTT View terminal. NRF_LOG_USES_RTT is defined.Do I miss something?

[Sigurd]

You are no longer getting the " Error: L6985E: Unable to automatically place AT section " ?

For printing; do you have #define NRF_LOG_ENABLED 1 in sdk_config.h ?

[alivexiaoluo]

Yes,I do not get the error any more. There is no sdk_config.h file in my bootloader project( or I can not find it?). my bootloader project is transplanted from nRF5_SDK_11.0.0_89a8197 / examples/dfu/bootloader/pca10028/dual_bank_ble_s130/arm5_no_pack/dfu_dual_bank_ble_s130_pca10028.

I have define NRF_LOG_USES_RTT in nrf_log.h and add NRF_LOG_USES_RTT in Keil configuration window. What can i do for printf works,Thanks!

[Sigurd]

SEGGER_RTT_printf() is not working ? Have you tried the steps shown in the RTT tutorial ?