fih_panic_loop during debugging session from persistent_key_usage

[bkkim_ublox]

I am able to build the firmware without any errors from persistent_key_usage example as below condition

Board: NORA Evaluation Board
SDK Version: 3.1.0
Toolchain: 3.1.0
Board files: ubx_evknorab2 (path: C:\ncs\v3.1.0\zephyr\boards\u-blox\ubx_evknorab2)

I am able to build the firmware without any errors.

However, after flashing the firmware onto the MCU and starting a debug session, the program immediately jumps into this function fih_panic_loop.
I also confirm that I have not set a single breakpoint during debugging.

Could you please give some idea for solving this debugging issue?

[Sigurd Hellesvik]

Hi,

What if you flash without debugging?
Does the device then function as expected?

Regards,
Sigurd Hellesvik

[bkkim_ublox]

when I compiled with OK and it works well on flash side without debugging as expected.

I am trying to solve it with the below recommendation but it is still issue.

① Recommended: Debug without MCUboot (direct app boot)

This completely avoids secure boot integrity checks → no more FIH_PANIC.

Add to prj.conf:

Apache Config

CONFIG_BOOTLOADER_MCUBOOT=n

CONFIG_TFM_DISABLED=y

CONFIG_FIH_PROFILE_LOW=y

 

② If MCUboot must remain enabled (secure-boot mode):

You MUST do two things in your launch.json:

(A) Disable flash breakpoints

This prevents GDB/J-Link from altering flash:

JSON

"preLaunchCommands": [

"monitor flash breakpoints = 0"

]

(B) Load MCUboot ELF into the debugger

Without this, the PC jumps into the wrong region and triggers panic:

JSON

"loadFiles": [

"${workspaceFolder}/build/mcuboot/zephyr/zephyr.elf"

]

[Sigurd Hellesvik]

Is your goal to debug MCUboot itself, or the application?

Are you building with or without TF-M?