$ west flash
-- west flash: rebuilding
[0/12] Performing build step for 'tfm'
ninja: no work to do.
-- west flash: using runner nrfjprog
Using board 960027662
-- runners.nrfjprog: Flashing file: /path/to/zephyrproject/zephyr/samples/basic/blinky/build/tfm_merged.hex
Parsing image file.
Verifying programming.
Verified OK.
Applying pin reset.
-- runners.nrfjprog: Board with serial number 960027662 flashed successfully.
$ west debug
-- west debug: rebuilding
[0/12] Performing build step for 'tfm'
ninja: no work to do.
-- west debug: using runner jlink
-- runners.jlink: JLink version: 7.58b
-- runners.jlink: J-Link GDB server running on port 2331; no thread info available
SEGGER J-Link GDB Server V7.58b Command Line Version

JLinkARM.dll V7.58b (DLL compiled Nov 16 2021 15:04:27)

-----GDB Server start settings-----
GDBInit file:                  none
GDB Server Listening port:     2331
SWO raw output listening port: 2332
Terminal I/O port:             2333
Accept remote connection:      yes
Generate logfile:              off
Verify download:               off
Init regs on start:            off
Silent mode:                   on
Single run mode:               on
Target connection timeout:     0 ms
------J-Link related settings------
J-Link Host interface:         USB
J-Link script:                 none
J-Link settings file:          none
------Target related settings------
Target device:                 nRF9160_xxAA
Target interface:              SWD
Target interface speed:        4000kHz
Target endian:                 little

GNU gdb (Zephyr SDK 0.14.2) 9.2
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "--host=x86_64-build_pc-linux-gnu --target=arm-zephyr-eabi".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<https://github.com/zephyrproject-rtos/sdk-ng/issues>.
Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from /path/to/zephyrproject/zephyr/samples/basic/blinky/build/zephyr/zephyr.elf...
Remote debugging using :2331
arch_cpu_idle () at /path/to/zephyrproject/zephyr/arch/arm/core/aarch32/cpu_idle.S:105
105             cpsie   i
Resetting target
Loading section rom_start, size 0x544 lma 0x50000
Loading section text, size 0x43f8 lma 0x50544
Loading section .ARM.exidx, size 0x8 lma 0x5493c
Loading section initlevel, size 0x38 lma 0x54944
Loading section devices, size 0x48 lma 0x5497c
Loading section sw_isr_table, size 0x208 lma 0x549c4
Loading section device_handles, size 0x12 lma 0x54bcc
Loading section rodata, size 0x180 lma 0x54be0
Loading section datas, size 0x94 lma 0x54d60
Loading section device_states, size 0xc lma 0x54df4
Start address 0x000518cc, load size 19966
Transfer rate: 9749 KB/sec, 1815 bytes/write.
(gdb) b main
Breakpoint 1 at 0x5081c: file /path/to/zephyrproject/zephyr/samples/basic/blinky/build/zephyr/include/generated/syscalls/device.h, line 55.
(gdb) c
Continuing.