Start:
https://openwrt.org/docs/start
/etc/config/system:
https://openwrt.org/zh/docs/guide-user/base-system/system_configuration
https://openwrt.org/docs/guide-user/base-system/system_configuration
hotplug:
https://openwrt.org/start?id=docs/guide-user/base-system/hotplug
log:
https://openwrt.org/docs/guide-user/base-system/log.essentials