Hello!
This page contains a lot of great information on NI Linux Real-Time on our controllers:
NI Linux Real-Time FAQ: https://forums.ni.com/t5/NI-Linux-Real-Time-Documents/NI-Linux-Real-Time-FAQ/ta-p/3495630
Specifically, if the Real-Time OS appears to be corrupted or damaged, you can put the controller in Safe Mode (a protected image), then reformat the controller in NI MAX, and then reinstall the NI Linux Real-Time OS and software.
https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000P9Y3SAK&l=en-US
However, if you attempt to put your device into Safe Mode and it fails and the status shows an unrecoverable error (continuously blinking Status LED), then you may need to recover the Safe Mode image as well. (To put your device in Safe Mode, press and hold reset button until the Status light turns on, then release. When the sbRIO reboots, the Status LED will blink in sets of three to indicate successful boot into Safe Mode). If you receive an unrecoverable error in Safe Mode, you can contact the Technical Support department at National Instruments to receive assistance in recovering Safe Mode on the controller.
If you are asking more because you are trying to modify the Linux kernel, the first link also shares some great information on what modifying the kernel can affect, as well as what NI can support you on.
Hope this answers your questions!
R Dahlman
National Instruments
