I downloaded the log of an AP in Virtual SmartZone 3.6.0.222. He was off for 30 minutes on 02/07/2020, starting at 2.15PM. I once saw that it is in the Himem session of the log (I may be mistaken), well, in this session what you have is:
### Himem ###
mem_top = 0xa8000000
High Mem (0xA7FFFC00) size=392
magic: 0x54545454 0x52434B53
reset: 0 factory: 0 sw2_reset: 0 sw2_event: 0 post_fail: 0 recovery: 0
reboot_cnt: 0 total_boot: 20
reboot_reason: watchdog timeout
type: 2 index: 5 fis.image: rcks_wlan.bkup
BootRom:
GD36 1.0.1.26 - built 16:49:20, Feb 27 2013
pci reboot: 0
miniboot:
magic: 0x6D696E69
reboot_cnt: 0
No Bootline