Amazon.com: FriendlyElec Nanopi R5S Mini Router OpenWRT with Three Gbps Ethernet Ports 4GB RAM LPDDR4X Based in RK3568 Soc for IOT NAS Smart Home Gateway (with Metal Case) Support U-Boot Linux Ubuntu :
CCNA Training » Cisco Router Boot Sequence Tutorial
Loading and Maintaining System Images Configuration Guide, Cisco IOS Release 15.1S - Rebooting and Reloading - Configuring Image Loading Characteristics [Support] - Cisco