Yesterday, I faced initramfs boot error on my Linux Mint 9 box. I don't know what went wrong, but I remember that I forced restart my system, as it was not responding. It hung up in a command line terminal. I changed the terminal (ctrl+alt+[f1-f6]), and then unable to get back to the GUI (ctrl+alt+f7). The screen was showing some weird software error.
Code:
No init found. Try passing init= boot arg BusyBox v1.10.2 (Ubuntu 1:1.10.2.2ubuntu7) built-in shell (ash) (initramfs)