https://www.cisco.com/c/en/us/support/docs/routers/800-series-routers/15083-recovery-c800.html
ROMmon Recovery for the Cisco 800 Series Router - Cisco
This document describes how to recover a Cisco 800 series router if you are blocked in TinyRom.
for the800 seriesrommonrecoverycisco
https://www.cisco.com/c/en/us/support/docs/switches/catalyst-9300-series-switches/216944-troubleshoot-bootloader-rommon-and-pas.html
Troubleshoot Rommon on Catalyst 9000 Series Switches - Cisco
This document describes how to boot Catalyst 9000 Series switches out of the bootloader prompt (rommon) and how to recover a password.
9000 seriestroubleshootrommoncatalystswitches