Mini-IOS

[gowdakssujan]

How does mini-IOS helps in boot process??

How/why do router enter/load into mini-IOS??

[balaji.bandi]

here is the good explanation for reference :

Mini-IOS

Mini-IOS is a fallback utility that contains a stripped down version of IOS. This is used in critical situations where IOS image in flash is not found. Mini-IOS contains only IP code that allows you to load IOS from other resources such as TFTP Server. Cisco IOS mode used by this stripped down IOS utility known as RXBOOT mode.

https://www.computernetworkingnotes.com/ccna-study-guide/cisco-router-booting-process-explained-with-examples.html