Originally Posted by rweaver
I'm curious why you would want to do this? Typically I'd just boot using a live cd then mount things as i wanted them...
Partially because its how it was done before and I'm not sure how to change everything
However for a slightly better explanation the idea is that when the PC boots the first time it extracts a collection of .tgz files to create a standard filesystem on the machine. The linuxrc script would also install and configure some custom machine specific software. For further boots the user would skip the install option to open /bin/sh and just boot from the CD finding the extracted filesystem on the hard drive.
When new software has been developed a new CD burnt with new .tgz files and the install script is run again wiping everything and extracting an updated file system with the new software.