*** Booting Zephyr OS build v2.7.99-ncs1-1 *** I: Starting bootloader I: Primary image: magic=good, swap_type=0x4, copy_done=0x1, image_ok=0x1 I: Secondary image: magic=unset, swap_type=0x1, copy_done=0x3, image_ok=0x3 I: Boot source: none I: Swap type: none I: Bootloader chainload address offset: 0x10000 I: Jumping to the first image slot *** Booting Zephyr OS build v2.7.99-ncs1-1 *** I am running! lte_lc_init: 0 lte_lc_connect: 0 date_time_update_async: 0 Waiting... [00146596]  os: ***** USAGE FAULT ***** [00146597]  os: Stack overflow (context area not valid) [00146597]  os: r0/a1: 0x00038fc4 r1/a2: 0x41000000 r2/a3: 0xa8044105 [00146597]  os: r3/a4: 0xadffbd6b r12/ip: 0x48fc6800 r14/lr: 0x6fedee7e [00146598]  os: xpsr: 0x00038800 [00146598]  os: Faulting instruction address (r15/pc): 0x20010808 [00146599]  os: >>> ZEPHYR FATAL ERROR 2: Stack overflow on CPU 0 [00146600]  os: Current thread: 0x2000e2c0 (unknown) [00148295]  fatal_error: Resetting system