// bootshell.cc
//
// v. 1.3
//
// A very (very!) limited shell intended to run as the boot prompt
// for a Linux390 system.  The goal here is to allow the VMOPER to
// halt the Linux390 system without knowing the root password, while
// still preserving system security.  The assumptions are made that:
// a) Your opers are trusted to halt the system
// b) Your VM account password is not your root password.
//
// When executed, prompts for either a HALT command or a LOGIN
// HALT will execute a system halt (however defined via HALT_CMD
// LOGIN will execute a password login prompt (however defined via LOGIN_CMD)
//
// Use CP SET SECUSER <ACCOUNT> before linux IPL (or after Linux IPL via
// HCP) to authorize an account that may use CP SEND to issue the halt command
//
// Edit /etc/inittab and replace
// 1:2345:respawn:/sbin/sulogin /dev/console
// with
// 1:2345:respawn:/sbin/bootshell
//
// Mike Kershaw (urmk@reason.marist.edu)
//
// v1.1 (07-21-2000) - Added patches by John Dalbec to fix loop
//                     on ^D and typo
//
// v1.3 (12-07-2000) - Added more patches from John to fix some very bad 
//                     behavior.  NULL-terminated is important!  Doh! 
