#!/bin/sh
#
# altboot provides a simple bootmenu before init is beeing run.
# There are two default menu entries: "Normal boot" and "Single user mode"
# New menu entries can be created be putting files into /etc/altboot-menu.
#

test -e /etc/altboot.func && . /etc/altboot.func || die "ERROR: /etc/altboot.func not found. Check your installation!"

CURRENT_ENV="`set`"
VERSION="DEVELOPER SNAPSHOT"

# Set some defaults in case altboot.cfg is missing
REAL_INIT="/sbin/init.sysvinit"

# Read default runlevel from inittab
INIT_RUNLEVEL="`cat /etc/inittab | sed -n "/^id\:/s/id\:\([0-9]\)\:.*$/\1/p"`"
test -z "$INIT_RUNLEVEL" && INIT_RUNLEVEL=5

case "`uname -r`" in
2.6*)	ALTBOOT_CFG_FILE="/etc/altboot-2.6.cfg";;
2.4*)	ALTBOOT_CFG_FILE="/etc/altboot-2.4.cfg";;
*)	echo "Warning: Unknown kernel [`uname -r`], using kernel 2.6 configuration!"
	ALTBOOT_CFG_FILE="/etc/altboot-2.6.cfg";;
esac

test -e "$ALTBOOT_CFG_FILE" && . "$ALTBOOT_CFG_FILE" || echo "WARNING: No $ALTBOOT_CFG_FILE found! Check your installation of Altboot!" > /dev/tty1

C_RED="\033[31m"
C_YELLOW="\033[33m"
C_BLUE="\033[34m"
C_WHITE="\033[37m"
C_RESET="\033[0m"


die() {
	echo -e "${C_RED}ERROR: $1${C_RESET}" >/dev/tty0
	exec $SH_SHELL </dev/tty0 >/dev/tty0 2>&1
}

debug_shell() {		
	# VT 2 = Opie, VT 3 = GPE
	test -z "$1" && VT=4 || VT=$1
	
	echo -e "\033c" > /dev/tty$VT

	echo -en "\nPress <ENTER> to activate the debug shell." > /dev/tty$VT
	read junk </dev/tty$VT
		
	echo "" > /dev/tty$VT	
	/bin/sh  </dev/tty$VT >/dev/tty$VT 2>&1
	
	#openvt -lf -c$VT -- /bin/sh </dev/tty$VT >/dev/tty$VT 2>&1
}

# This function prints the boot-menu
# $1: Directory containing the scripts for the menu-items
show_menu() {
	test -z "$1" && die "DEBUG: Parameter 1 is empty in show_menu"
	! test -d "$1" && die "show_menu: [$1] not found or no directory."

	echo "" 
	echo -e "altboot v$VERSION\n" 

	
	m_entry=""
	# Build "m_entry" for scripts in /etc/altboot-menu
	cd $1

	cnt=0 ; reset_pref "menu_filelist"
	for file in `ls -1`
	do	
		if ! test -d "$1/$file"
		then			
			M_TITLE="`$1/$file title`"
			if ! test -z "$M_TITLE"
			then
				let cnt=$cnt+1
				# Keep a list of existing "modules" together with an index number
				# This sure is ugly, but Busybox sh doesn't do arrays....
				#m_entry="`echo -e "$m_entry\n$cnt:$file\n"`"
				
				set_pref "menu_filelist" "$cnt" "$file"
				echo -e "\t\t[$cnt] $M_TITLE"					
			fi
			M_TITLE=""
		fi
	done

	# Display directories below /etc/altboot-menu as menu-item
	# and add all scripts inside the directory to m_entry
	for dir in `ls -1`
	do	
		if test -d "$1/$dir"
		then			
			M_TITLE="`basename "$1/$dir"`"
			if ! test -z "$M_TITLE"
			then
				let cnt=$cnt+1
				# Keep a list of existing "modules" together with an index number
				# This sure is ugly, but Busybox sh doesn't do arrays....
				#m_entry="`echo -e "$m_entry\n$cnt:$dir:DIR\n"`"
				
				set_pref "menu_filelist" "$cnt" "$dir:DIR"
				echo -e "\t\t[$cnt] $M_TITLE"					

				OLD_PWD="$PWD"
				cd "$1/$dir"
				for file in `ls -1`
				do	
					if ! test -d "$1/$dir/$file"
					then			
						M_TITLE="`$1/$dir/$file title`"
						if ! test -z "$M_TITLE"
						then
							let cnt=$cnt+1
							# Keep a list of existing "modules" together with an index number
							# This sure is ugly, but Busybox sh doesn't do arrays....
							#m_entry="`echo -e "$m_entry\n$cnt:$dir/$file\n"`"
							
							set_pref "menu_filelist" "$cnt" "$dir/$file"
							#echo -e "\t\t[$cnt] $M_TITLE"					
						fi
						M_TITLE=""
					fi
				done
				cd "$OLD_PWD"

			fi
			M_TITLE=""
		fi
	done

	#echo_pref "menu_filelist"
	echo ""
	
}

# This function is used to display the content of directories below
# /etc/altboot-menu as menu-items
show_sub_menu() {
	dirname="`basename "$1"`"
		
	d_entries="`dump_pref "menu_filelist" | grep "$dirname/"`"
	
	#echo "[$d_entries]"
	
	echo -e "\naltboot v$VERSION: $dirname menu\n" 
	
	
	for d_entry in $d_entries
	do
		d_entry_number="`echo "$d_entry"| sed -n "s/\(.*\)\#\#\(.*\)\#\#\#/\1/p"`"
		d_entry_file="`echo "$d_entry"| sed -n "s/\(.*\)\#\#\(.*\)\#\#\#/\2/p"`"
		d_entry_title="`$d_entry_file title`"
		
#		echo "number: [$d_entry_number]"
#		echo "file: [$d_entry_file]"
#		echo "title: [$d_entry_title]"
		
		echo -e "\t\t[$d_entry_number] $d_entry_title"
	done
		
	echo ""
	
}

# Shows the timer and sets $launch_altboot to yes if a keypress was detected
run_timer() {
	if test "$TIMEOUT" != 0
	then			
			
		mount -t proc proc /proc >/dev/null 2>&1
		
		case "`uname -r`" in
		2.4*)	key_ints="`cat /proc/interrupts | grep keyboard | awk '{print $2}'`";;
		2.6*)	key_ints="`cat /proc/interrupts | grep Spitzkbd`"
			test -z "$key_ints" && key_ints="`cat /proc/interrupts | grep -i corgikbd`";;	
		esac		
	
		stty -echo  </dev/tty0 >/dev/tty0 2>&1
		echo -en "\n\nPlease press any key to launch altboot." > /dev/tty1
		
		test -z "$TIMEOUT" && TIMEOUT="3"

		cnt=0
		while test "$cnt" != "$TIMEOUT"
		do		
			sleep 1
			case "`uname -r`" in
			2.4*)	key_ints_now="`cat /proc/interrupts | grep keyboard | awk '{print $2}'`";;
			2.6*)	key_ints_now="`cat /proc/interrupts | grep Spitzkbd`"
				test -z "$key_ints_now" && key_ints_now="`cat /proc/interrupts | grep -i corgikbd`";;	
			esac		
			
			if test "$key_ints_now" != "$key_ints" -o -z "$key_ints_now"
			then				
				launch_altboot=yes				
				stty echo </dev/tty0 >/dev/tty0 2>&1
				break
			fi
			echo -n "." >/dev/tty1
			let cnt=$cnt+1
		done
		
		if test "$launch_altboot" != "yes"
		then
			AUTOBOOT=yes
		else
			rm -f /etc/.altboot*.last
		fi
				
	else
		launch_altboot=yes
	fi
} 

# This function launches the selected menu item / script
# $1: Directory containing the scripts for the menu-items
launch_selection() {
	test -z "$1" && die "Parameter 1 of launch_selection is empty!"
	
	case "$junk" in
	*)	#file="`echo "$m_entry"| sed -n "/$junk\:/s/^.*\:\(.*\)/\1/p"`"
		
		get_pref "menu_filelist" "$junk" file_
		type="`echo "$file_" | sed -n "s/\(.*\)\:\(.*\)/\2/p"`"
		file="`echo "$file_" | sed -n "s/\(.*\)\:\(.*\)/\1/p"`"
		test -z "$file" && file="$file_"
		
		#echo "[$file_]: [$type] / [$file] ($junk)"
		
		# The selected menu-item points to a directory
		if test "$type" = DIR
		then
			show_sub_menu /etc/altboot-menu/$file >/dev/tty0
			wait_for_input >/dev/tty0			
			launch_selection /etc/altboot-menu >/dev/tty0						
		fi
		
		if test "$type" = MAIN
		then
			show_sub_menu /etc/altboot-menu >/dev/tty0
			wait_for_input >/dev/tty0			
			launch_selection /etc/altboot-menu >/dev/tty0						
		fi	
		
		
				
		. $1/$file run "$file" >/dev/tty0	
		die "WARNING: Using failsafe shell" >/dev/tty0			
		
		;;	
	esac
}


wait_for_input() {
	while true
	do
		
		
		# Do _not_ change the next few lines!
		# 	
		# This is required to work around an annoying busybox bug.
		# Every key you press while this script runs will be
		# picked up by the next "read $junk".	
		# So the next read would pick up the "any" key the user pressed
		# above to launch the altboot menu.		
				
 		
		# Bash throws an ugly error on kill
		if ! (readlink /bin/sh | grep -q bash)
		then
			# This filters an "<ENTER>" from the user as "any key"
			( while :; do read x< /dev/tty0 2>&1; done; ) > /dev/null 2>&1 &
			sleep 1; kill $! >/dev/null 2>&1
		fi
								
		echo -n "Please choose one of the above [$last_selection]: " </dev/tty0 > /dev/tty0 2>&1
		stty echo </dev/tty0 >/dev/tty0 2>&1
		read junk< /dev/tty0 2>&1
		
		# This filters other chars the user may have used
		
		#echo "junk: [$junk]"
		junk="`echo "$junk" | sed "s/[a-zA-Z]//g"`"
		#echo "junk: [$junk]"
				
		if test "$junk" -lt "$cnt" -o "$junk" -eq "$cnt" 
		then
			if test ! -z "$junk"
			then
				# Don't remount rw if the drive is already mounted rw
				# Only helpful for testing / debugging
				if test "`mount|sed -n "/\/dev\/root/s/.*(\(.*\))/\1/p"`" != "rw"
				then					
					mount -o remount,rw / >/dev/null 2>&1
					echo "$junk" > /etc/altboot.conf
					mount -o remount,ro / >/dev/null 2>&1	
				else
					echo "$junk" > /etc/altboot.conf
				fi
			else
				junk="$last_selection"
				break
			fi
			break
		fi
	done
}

# * * * * * * This is the main function * * * * * *
# Note: this is positively ugly. If someone knows a better way to detect wheter
# we are already booted into a runlevel _without_ reading /var and / or using `runlevel`
# PLEASE let me know.

if ( echo "$VERSION" |  egrep -iq "(snapshot|-rc)" )
then
	ENABLE_DEBUG="yes"
	debug_shell 4 >/dev/null 2>&1 &
fi

if test -f /proc/cmdline -a "`ps ax|wc -l|tr -d " "`" -gt 30 -a "$1" != "-force"
then
	echo "altboot: Using real init [$REAL_INIT] [$*] [`ps ax|wc -l|tr -d " "`] *" >/dev/tty1
	exec $REAL_INIT $*
#	exec $SH_SHELL </dev/tty0 >/dev/tty0 2>&1
	exit 0
else	
	# Boot original init if altboot is turned off
	if test "$ENABLE_ALTBOOT" != "yes" 
	then	
		echo "altboot: Using real init [$REAL_INIT] **" >/dev/tty1
		exec $REAL_INIT $INIT_RUNLEVEL
		exit 0
	fi

	# Execute scripts in /etc/altboot.rc before doing anything else.
	# Required in special situations, like booting spitz
	RC_FILES=`ls /etc/altboot.rc | grep \.sh$`

	for file in $RC_FILES
	do
		 . /etc/altboot.rc/$file >/dev/tty1 2>&1 || echo "/etc/altboot.rc/$file failed!"
	done
			
	# Make sure altboots master password is set
	set_password >/dev/tty0 
	
	test "$ASK_PW_ON_BOOT" = "yes" && verify_master_pw >/dev/tty0 

	# When started with -force, always print the menu
	echo "$*" | grep -q -- "-force" && TIMEOUT=0
	
	# This timeout works by reading /proc/interrupts to see if the keyboard interrupt
	# increases while the timer is running. A TIMEOUT of 0 will always launch altboot.	
	run_timer >/dev/tty1 
		
	echo "" >/dev/tty0
	
	
	if test "$launch_altboot" != yes
	then
		# last_selection is the previously selected menu item by the user
		last_selection="`cat /etc/altboot.conf`" >/dev/null 2>&1
		test -z "$last_selection" && last_selection="1"	
		
		echo "Booting last selection: [$last_selection]" >/dev/tty0
		
		# Set up the wanna-be array of available menu entries and their numbers
		show_menu /etc/altboot-menu >/dev/null
		junk="$last_selection"
		launch_selection /etc/altboot-menu >/dev/tty0

	fi

	# Anything after this point will never be reached if $launch_altboot != yes	
	
	# Show the altboot menu
	stty -echo </dev/tty0 >/dev/tty0 2>&1
	show_menu /etc/altboot-menu >/dev/tty0

	# Load last selection for use as default if <ENTER> is pressed at the prompt
	last_selection="`cat /etc/altboot.conf`" >/dev/null 2>&1
	test -z "$last_selection" && last_selection="1"	

	# Ask the user which menu-item to use
	wait_for_input >/dev/tty0 
	
	# This should _never_ happen.
	if test -z "$junk"
	then
		echo "WARNING: Trying failsafe mode" >/dev/tty0
		mount -o remount,rw / >/dev/tty0 2>&1
		echo "Dumping environment to /altboot.env"
		echo "$CURRENT_ENV" > /altboot.env
		mount -o remount,ro / >/dev/tty0 2>&1
		junk=1
	fi

	launch_selection /etc/altboot-menu >/dev/tty0	
	
	# Uhoh, something went terribly wrong if we reach this point!
	die "WARNING: Failsafe fall-through activated. Spawning emergency shell"	

fi