ybin/ofpath

#! /bin/sh

###############################################################################
##
## ofpath: determine OpenFirmware path from unix device node
## Copyright (C) 2000, 2001, 2002, 2003 Ethan Benson
##
## Portions based on show_of_path.sh:
##
## Copyright (C) 2000 Olaf Hering <olh@suse.de>
## 
## This program is free software; you can redistribute it and/or
## modify it under the terms of the GNU General Public License
## as published by the Free Software Foundation; either version 2
## of the License, or (at your option) any later version.
##
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this program; if not, write to the Free Software
## Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
##
###############################################################################

PATH="/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin"
PRG="${0##*/}"
VERSION=1.0.7
DEBUG=0
export LC_COLLATE=C

## --version output.
version()
{
echo \
"$PRG $VERSION
Written by Ethan Benson
Portions based on show_of_path.sh written by Olaf Hering

Copyright (C) 2000, 2001, 2002, 2003 Ethan Benson
Portions Copyright (C) 2000 Olaf Hering
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE."
}

## --help output.
usage()
{
echo \
"Usage: $PRG [OPTION]... FILE
Find OpenFirmware device path from unix device node.

      --debug                print boring junk only useful for debugging
  -h, --help                 display this help and exit
  -V, --version              output version information and exit"
}

## a small seq replacement, seq is not present on boot/rescue floppies.
smallseq()
{
    local v="$1"
    local n=1
    echo 1
    while [ "$v" -gt 1 ] ; do
	echo "$(($n + 1))"
	local n="$(($n + 1))"
	local v="$(($v - 1))"
    done
    return 0
}

## a kludge to replace wc -l, wc is not present on boot/rescue
## floppies. max file is 145 lines, 3 hosts * 16 devs each * 3 lines
## per device, + 1 "Attached Devices:" line.
linecount()
{
    if [ $# = 0 ] ; then
	local file="$(cat)"
	local v="$file"
    else
	local file="$(cat $1)"
	local v="$file"
    fi

    if [ -z "$file" ] ; then
	echo 0
	return 0
    fi

    ## use real wc if available
    if (command -v wc > /dev/null 2>&1) ; then
	if [ -x `command -v wc` ] ; then
	    lines="$(echo "$file" | wc -l)"
	    if [ $? = 0 ] ; then
		echo $lines
		unset lines
		return 0
	    fi
	fi
    fi

    while true ; do
	for i in `smallseq 145` ; do
	    local b="$(echo "$file" | tail -n $i)"
	    if [ "$v" = "$b" ] ; then
		echo "$i"
		break 2
	    fi
	done
    done
    return 0
}

## small tr replacment which handles a specific need of this script.
smalltr()
{
    case "$1" in 
	a) echo 1 ;; b) echo 2 ;; c) echo 3 ;; d) echo 4 ;; e) echo 5 ;; f) echo 6 ;;
	g) echo 7 ;; h) echo 8 ;; i) echo 9 ;; j) echo 10 ;; k) echo 11 ;; l) echo 12 ;;
	m) echo 13 ;; n) echo 14 ;; o) echo 15 ;; p) echo 16 ;;
	1) echo a ;; 2) echo b ;; 3) echo c ;; 4) echo d ;; 5) echo e ;; 
	6) echo f ;; 7) echo g ;; 8) echo h ;; 9) echo i ;; 10) echo j ;;
	11) echo k ;; 12) echo l ;; 13) echo m ;; 14) echo n ;; 15) echo o ;;
	16) echo p ;;
    esac
    return 0
}

## replacment for grep -l which is not supported by busybox grep.
## echo $(cat..) hack needed because busybox grep barfs with `line too
## long' when fed /proc files.  the for loop is needed since busybox
## grep seems to have somewhat broken regexp support.
## usage: lgrep filename regexp regexp ...
lgrep()
{
    local f="$1"
    shift
    for i in "$@" ; do
	echo "$(cat "$f")" | grep -q "$i" && echo "$f" && break
    done
    return 0
}

## if readlink is missing use a kludge
if (command -v readlink > /dev/null 2>&1) ; then
    true
else
    readlink()
    {
        local SYMTARGET="$(v=`ls -l "$1" 2>/dev/null` ; echo ${v##*> })"
        if [ -n "$SYMTARGET" ] ; then
            echo "$SYMTARGET"
            return 0
        else
            return 1
        fi
    }
fi

## a function to print relevant scsi host path when there is more then
## one.  this function also takes care of stripping off the trailing
## /compatible.
printhost()
{
    case "$1" in
	1)
	echo "${2%/*}"
	;;
	2)
	echo "${3%/*}"
	;;
	3)
	echo "${4%/*}"
	;;
	4)
	echo "${5%/*}"
	;;
    esac
    return 0
}

## this finds information we need on both newworld and oldworld macs.
## mainly what scsi host a disk is attached to.
scsiinfo()
{
    ## see if system has scsi at all
    if [ ! -f /proc/scsi/scsi ] ; then
	local kver="$(uname -r)"
	case "$kver" in
	    2.5.*|2.6.*)
		if [ -d /sys/bus/scsi/devices -a \
		    -n "$(ls /sys/bus/scsi/devices 2>/dev/null)" ] ; then
		    echo 1>&2 "$PRG: /proc/scsi/scsi does not exist"
		    echo 1>&2 "$PRG: Make sure you compiled your kernel with CONFIG_SCSI_PROC_FS=y"
		    return 1
		fi
		;;
	esac
	echo 1>&2 "$PRG: /dev/$DEVNODE: Device not configured"
	return 1
    fi

    ## first we have to figure out the SCSI ID, have to do that
    ## anyway [to] find the attached scsi disks = "Direct-Access" and
    ## stop at sda=1 sdb=2 or whatever count in 3 lines steps

    ## get last letter of device node, ie sda -> a
    SUBNODE=${DEVNODE##*sd}

    ## turn SUBNODE above into a number starting at 1, ie a -> 1
    SUBDEV="$(smalltr $SUBNODE)"
    [ "$DEBUG" = 1 ] && echo 1>&2 "$PRG: DEBUG: SUBNODE=$SUBNODE SUBDEV=$SUBDEV"

    DEVCOUNT=0

    ## copy scsi file into a variable removing "Attached Devices"
    ## which is the first line. this avoids a lot of
    ## [incmopatible] crap later, and improves readability.

    ## find number of lines once and recycle that number, to save
    ## some time (linecount is a bit slow). subtract one line
    ## to scrap Attached Devices:

    SCSILINES="$(($(linecount /proc/scsi/scsi) - 1))"

    if [ "$SUBDEV" -gt "$(cat /proc/scsi/scsi | grep Direct-Access | linecount)" ] ; then
	echo 1>&2 "$PRG: /dev/$DEVNODE: Device not configured"
	return 1
    fi

    PROCSCSI="$(cat /proc/scsi/scsi | tail -n $SCSILINES)"

    for i in $(smallseq $(($SCSILINES / 3))) ; do

	## put every scsi device into one single line
	DEVINFO="$(echo "$PROCSCSI" | head -n $(($i * 3)) | tail -n 3)"
	[ "$DEBUG" = 1 ] && echo 1>&2 "$PRG: DEBUG: DEVINFO=$DEVINFO"

	## cut the type field, expect "Direct-Access" later.
	DEVTYPE="$(v=$(echo ${DEVINFO##*Type: }) ; echo ${v%% *})"
	[ "$DEBUG" = 1 ] && echo 1>&2 "$PRG: DEBUG: DEVTYPE=$DEVTYPE"

	## get the device id.
	DEVID="$(v=$(echo ${DEVINFO##*Id: }) ; n=$(echo ${v%% *}) ; echo ${n#*0})"
	[ "$DEBUG" = 1 ] && echo 1>&2 "$PRG: DEBUG: DEVID=$DEVID"

	## get the scsi host id.
	DEVHOST="$(v=$(echo ${DEVINFO##*Host: scsi}) ; echo ${v%% *})"
	[ "$DEBUG" = 1 ] && echo 1>&2 "$PRG: DEBUG: DEVHOST=$DEVHOST"

	if [ "$DEVTYPE" = "Direct-Access" ] ; then
	    DEVCOUNT="$(($DEVCOUNT + 1))"
	    [ "$DEBUG" = 1 ] && echo 1>&2 "$PRG: DEBUG: DEVCOUNT=$DEVCOUNT"
	    if [ "$SUBDEV" = "$DEVCOUNT" ] ; then
		DEVICE_HOST=$DEVHOST
		DEVICE_ID=$DEVID
		[ "$DEBUG" = 1 ] && echo 1>&2 "$PRG: DEBUG: DEVICE_HOST=$DEVICE_HOST"
		break
	    fi
	fi
    done

    ## figure out what the scsi driver is, it is /proc/scsi/dirname.
    [ "$DEBUG" = 1 ] && echo 1>&2 "$PRG: DEBUG: DEVICE_HOST=$DEVICE_HOST"
    SCSI_DRIVER="$(x=`ls /proc/scsi/*/$DEVICE_HOST 2>/dev/null | cat` ; y=`echo ${x##*proc/scsi/}` ; echo ${y%%/*})"
    [ "$DEBUG" = 1 ] && echo 1>&2 "$PRG: DEBUG: SCSI_DRIVER=$SCSI_DRIVER"

    ## figure out which host we found.
    SCSI_HOSTNUMBER="$(v=`ls /proc/scsi/$SCSI_DRIVER/* 2>/dev/null | cat | grep -n "$DEVICE_HOST\>"` ; echo ${v%%:*})"
    [ "$DEBUG" = 1 ] && echo 1>&2 "$PRG: DEBUG: SCSI_HOSTNUMBER=$SCSI_HOSTNUMBER"

    return 0
}

## generic function that can find OF device paths for scsi devices,
## must be run after scsiinfo().
scsi_ofpath()
{
    case "$SCSI_DRIVER" in
	aic7xxx)
	    HOST_LIST="$(for i in `find /proc/device-tree -name compatible` ; do
			lgrep "$i" "^ADPT" "^pci900[45]" "^pciclass,01000" ; done)"
	    DEVICE_PATH="$(printhost $SCSI_HOSTNUMBER $HOST_LIST)"
	    echo "${DEVICE_PATH##*device-tree}/@$DEVICE_ID:$PARTITION"
	    ;;
	sym53c8xx)
	    HOST_LIST="$(for i in `find /proc/device-tree -name compatible` ; do
			lgrep "$i" "^Symbios" "^pci1000" "^pciclass,01000" ; done)"
	    DEVICE_PATH="$(printhost $SCSI_HOSTNUMBER $HOST_LIST)"
	    echo "${DEVICE_PATH##*device-tree}/@$DEVICE_ID:$PARTITION"
	    ;;
	mesh)
	    HOST_LIST="$(for i in `find /proc/device-tree -name compatible` ; do
			lgrep "$i" "mesh" ; done)"
	    DEVICE_PATH="$(printhost $SCSI_HOSTNUMBER $HOST_LIST)"
	    echo "${DEVICE_PATH##*device-tree}/@$DEVICE_ID:$PARTITION"
	    ;;
	ata_k2|sata_svw)
	    HOST_LIST="$(for i in `find /proc/device-tree -name compatible` ; do
			lgrep "$i" "k2-s-ata" ; done)"
	    DEVICE_PATH="$(printhost $SCSI_HOSTNUMBER $HOST_LIST)"
	    echo "${DEVICE_PATH##*device-tree}/k2-sata@$DEVICE_ID/disk@0:$PARTITION"
	    ;;
	*)
	    echo 1>&2 "$PRG: Driver: $SCSI_DRIVER is not supported"
	    return 1
	    ;;
    esac
    return 0
}

ide_ofpath()
{
    if [ ! -L "/proc/ide/$DEVNODE" ] ; then
	echo 1>&2 "$PRG: /dev/$DEVNODE: Device not configured"
	return 1
    fi

    local IDEBUS="$(v=`readlink /proc/ide/$DEVNODE` ; echo ${v%%/*} )"
    if [ -z "$IDEBUS" ] ; then
	echo 1>&2 "$PRG: BUG: IDEBUS == NULL"
	return 1
    fi

    case "$(uname -r)" in
	2.5.*|2.6.0*|2.6.1|2.6.1-*|2.6.2|2.6.2-*)
	    echo 1>&2 "$PRG: Linux kernel `uname -r` is not supported"
	    return 1
	    ;;
	2.6.*|2.7.*)
	    if ! (grep -q '.* .* sysfs ' /proc/mounts 2> /dev/null) ; then
		echo 1>&2 "$PRG: sysfs must be mounted for ofpath to support this system"
		return 1
	    fi
	    local SYS="$(m=`grep '.* .* sysfs ' /proc/mounts | head -n 1` ; echo `d=${m#* };echo ${d%% *}`)"
	    if [ -z "$SYS" -o ! -d "$SYS" ] ; then
		echo 1>&2 "$PRG: Unable to determine sysfs mountpoint"
		return 1
	    fi
	    local OF1275IDE="${SYS}/block/${DEVNODE}/device/../../devspec"
	    ;;
	*)
	    local OF1275IDE="/proc/ide/$IDEBUS/devspec"
	    ;;
    esac

    if [ ! -f "$OF1275IDE" ] ; then
	case "$(cat /proc/device-tree/model)" in
	    PowerMac3*|PowerMac4*|PowerMac5*|PowerMac6*|PowerMac7*|RackMac*)
		local CDROM="$(grep "^drive name:" /proc/sys/dev/cdrom/info 2> /dev/null | grep $DEVNODE)"
		if [ -z "$CDROM" ] ; then
		    echo 1>&2 "$PRG: WARNING: Your kernel is too old for proper support, device may be innaccurate."
		    echo "ultra2:$PARTITION"
		else
		    echo "cd:$PARTITION"
		fi
		;;
	    *)
		local CDROM="$(grep "^drive name:" /proc/sys/dev/cdrom/info 2> /dev/null | grep $DEVNODE)"
		if [ -z "$CDROM" ] ; then
		    if [ "$DEVNODE" = hda ] ; then
			echo "hd:$PARTITION"
		    else
			echo "ultra1:$PARTITION"
		    fi
		else
		    echo "cd:$PARTITION"
		fi
		;;
	esac
    else
	local DEVSPEC="$(cat $OF1275IDE)"
	[ "$DEBUG" = 1 ] && echo 1>&2 "$PRG: DEBUG: DEVSPEC=$DEVSPEC"
	if [ -z "$DEVSPEC" ] ; then
	    echo 1>&2 "$PRG: KERNEL BUG: $OF1275IDE exists, but is empty"
	    return 1
	fi

	if [ ! -f "/proc/ide/${IDEBUS}/channel" ] ; then
	    echo 1>&2 "$PRG: KERNEL BUG: /proc/ide/${IDEBUS}/channel does not exist"
	    return 1
	fi

	case "$(cat /proc/device-tree${DEVSPEC}/device_type 2> /dev/null)" in
	    ide|ata)
		local MASTER="/disk@0"
		local SLAVE="/disk@1"
		;;
	    pci-ide|pci-ata)
		local MASTER="/@$(cat /proc/ide/${IDEBUS}/channel)/disk@0"
		local SLAVE="/@$(cat /proc/ide/${IDEBUS}/channel)/disk@1"
		;;
	    scsi) ## some lame controllers pretend they are scsi, hopefully all kludges are created equal.
		local MASTER="/@$(($(cat /proc/ide/${IDEBUS}/channel) * 2 + 0))"
		local SLAVE="/@$(($(cat /proc/ide/${IDEBUS}/channel) * 2 + 1))"
		;;
	    *)
		echo 1>&2 "$PRG: Unsupported IDE device type: \"$(cat /proc/device-tree${DEVSPEC}/device_type 2> /dev/null)\""
		return 1
		;;
	esac

	case "$DEVNODE" in
	    hda|hdc|hde|hdg|hdi|hdk|hdm|hdo)
		echo "${DEVSPEC}${MASTER}:$PARTITION"
		return 0
		;;
	    hdb|hdd|hdf|hdh|hdj|hdl|hdn|hdp)
		echo "${DEVSPEC}${SLAVE}:$PARTITION"
		return 0
		;;
	    *)
		echo 1>&2 "$PRG: /dev/$DEVNODE is not supported"
		return 1
		;;
	esac
    fi
}

## figure out the OpenFirmware device path for newworld macs.
## sd* scsi disks , hd* ide disks.
newworld()
{
    case "$DEVNODE" in
	sd*)
	    ## use common scsiinfo function to get info we need.
	    scsiinfo || return 1

	    ## now we have the data for /@$DEVID:$PARTITION
	    ## find the actual OF path.	
	    scsi_ofpath || return 1
	    ;;
	hd*)
	    ide_ofpath || return 1
	    ;;
	*)
	    echo 1>&2 "$PRG: Device: /dev/$DEVNODE is not supported"
	    return 1
	    ;;
    esac
    return 0
}

oldworld()
{
    ## for some reason 2.4 kernels put OF aliases in aliases@0/ instead of plain aliases/
    if [ -d "/proc/device-tree/aliases" ] ; then
	local ALIASES="aliases"
    elif [ -d "/proc/device-tree/aliases@0" ] ; then
	local ALIASES="aliases@0"
    else
	echo 1>&2 "$PRG: Cannot find OpenFirmware aliases directory in /proc/device-tree/"
	return 1
    fi

    local MODEL="$(cat /proc/device-tree/compatible)"
    [ "$DEBUG" = 1 ] && echo 1>&2 "$PRG: DEBUG: Oldworld subarch: $MODEL"

    case "$MODEL" in
	AAPL,7300*|AAPL,7500*|AAPL,8500*|AAPL,9500*|AAPL,\?\?\?\?*)
	    case "$DEVNODE" in
		sd*)
		scsiinfo || return 1
		case "$SCSI_DRIVER" in
		    mesh)
		    echo $(cat /proc/device-tree/$ALIASES/scsi-int)/sd\@$DEVICE_ID:$PARTITION
		    ;;
		    53c94)
		    echo $(cat /proc/device-tree/$ALIASES/scsi)/sd\@$DEVICE_ID:$PARTITION
		    ;;
		    *)
		    echo 1>&2 "$PRG: Driver $SCSI_DRIVER is not supported"
		    return 1
		    ;;
		esac
		;;
		*)
		echo 1>&2 "$PRG: Unsupported device: /dev/$DEVNODE"
		return 1
		;;
	    esac
	    ;;
	AAPL,e407*)
	    case "$DEVNODE" in
		sd*)
		scsiinfo || return 1
		case "$SCSI_DRIVER" in
		    mesh)
		    echo $(cat /proc/device-tree/$ALIASES/scsi)/sd\@$DEVICE_ID:$PARTITION
		    ;;
		    *)
		    echo 1>&2 "$PRG: Driver $SCSI_DRIVER is not supported"
		    return 1
		    ;;
		esac
		;;
		hda*)
		echo $(cat /proc/device-tree/$ALIASES/ata)/ATA-Disk\@0:$PARTITION
		;;
		hdb*)
		echo $(cat /proc/device-tree/$ALIASES/ata)/ATA-Disk\@1:$PARTITION
		;;
		hd*)
		echo 1>&2 "$PRG: Device: /dev/$DEVNODE is not supported"
		;;
	    esac
	    ;;
	AAPL,e826*)
	    case "$DEVNODE" in
		sd*)
		scsiinfo || return 1
		case "$SCSI_DRIVER" in
		    mesh)
		    echo $(cat /proc/device-tree/$ALIASES/scsi)/sd\@$DEVICE_ID:$PARTITION
		    ;;
		    *)
		    echo 1>&2 "$PRG: Driver $SCSI_DRIVER is not supported"
		    return 1
		    ;;
		esac
		;;
		hda*)
		echo $(cat /proc/device-tree/$ALIASES/ata)/ata-disk\@0:$PARTITION
		;;
		hdb*)
		echo $(cat /proc/device-tree/$ALIASES/ata)/ata-disk\@1:$PARTITION
		;;
		hd*)
		echo 1>&2 "$PRG: Device: /dev/$DEVNODE is not supported"
		;;
	    esac
	    ;;
	AAPL,Gossamer*|AAPL,PowerMac\ G3*)
	    case "$DEVNODE" in
		sd*)
		scsiinfo || return 1
		case "$SCSI_DRIVER" in
		    mesh)
		    echo $(cat /proc/device-tree/$ALIASES/scsi)/sd\@$DEVICE_ID:$PARTITION
		    ;;
		    *)
		    echo 1>&2 "$PRG: Driver $SCSI_DRIVER is not supported"
		    return 1
		    ;;
		esac
		;;
		hda*)
		echo $(cat /proc/device-tree/$ALIASES/ide0)/ata-disk\@0:$PARTITION
		;;
		hdb*)
		echo $(cat /proc/device-tree/$ALIASES/ide0)/ata-disk\@1:$PARTITION
		;;
		hdc*)
		echo $(cat /proc/device-tree/$ALIASES/ide1)/ata-disk\@0:$PARTITION
		;;
		hdd*)
		echo $(cat /proc/device-tree/$ALIASES/ide1)/ata-disk\@1:$PARTITION
		;;
		hd*)
		echo 1>&2 "$PRG: Device: /dev/$DEVNODE is not supported"
		;;
	    esac
	    ;;
	AAPL,PowerBook1998*)
	    if [ -f  /proc/device-tree/$ALIASES/ata0 ] ; then
		local ATA0=ata0
	    else
		local ATA0=ide0
	    fi
	    if [ -f  /proc/device-tree/$ALIASES/ata1 ] ; then
		local ATA1=ata1
	    else
		local ATA1=bay-ata1
	    fi
	    case "$DEVNODE" in
		sd*)
		scsiinfo || return 1
		case "$SCSI_DRIVER" in
		    mesh)
		    echo $(cat /proc/device-tree/$ALIASES/scsi)/sd\@$DEVICE_ID:$PARTITON
		    ;;
		    *)
		    echo 1>&2 "$PRG: Driver $SCSI_DRIVER is not supported"
		    return 1
		    ;;
		esac
		;;
		hda*)
		echo $(cat /proc/device-tree/$ALIASES/$ATA0)/ata-disk\@0:$PARTITION
		;;
		hdb*)
		echo $(cat /proc/device-tree/$ALIASES/$ATA0)/ata-disk\@1:$PARTITION
		;;
		hdc*)
		echo $(cat /proc/device-tree/$ALIASES/$ATA1)/atapi-disk\@0:$PARTITION
		;;
		hdd*)
		echo $(cat /proc/device-tree/$ALIASES/$ATA1)/atapi-disk\@1:$PARTITION
		;;
		*)
		echo 1>&2 "$PRG: Unsupported device: /dev/$DEVNODE"
		return 1
		;;
	    esac
	    ;;
	AAPL,3400/2400*)
	    case "$DEVNODE" in
		sd*)
		scsiinfo || return 1
		case "$SCSI_DRIVER" in
		    mesh)
		    echo $(cat /proc/device-tree/$ALIASES/scsi-int)/sd\@$DEVICE_ID:$PARTITON
		    ;;
		    53c94)
		    echo $(cat /proc/device-tree/$ALIASES/scsi)/sd\@$DEVICE_ID:$PARTITON
		    ;;
		    *)
		    echo 1>&2 "$PRG: Driver $SCSI_DRIVER is not supported"
		    return 1
		    ;;
		esac
		;;
		hda*)
		echo $(cat /proc/device-tree/$ALIASES/ata0)/ata-disk\@0:$PARTITION
		;;
		hdb*)
		echo $(cat /proc/device-tree/$ALIASES/ata0)/ata-disk\@1:$PARTITION
		;;
		hdc*)
		echo $(cat /proc/device-tree/$ALIASES/ata1)/atapi-disk\@0:$PARTITION
		;;
		hdd*)
		echo $(cat /proc/device-tree/$ALIASES/ata1)/atapi-disk\@1:$PARTITION
		;;
		hde*)
		echo $(cat /proc/device-tree/$ALIASES/ata2):$PARTITION
		;;
		hdf*)
		echo $(cat /proc/device-tree/$ALIASES/ata3):$PARTITION
		;;
		*)
		echo 1>&2 "$PRG: Unsupported device: /dev/$DEVNODE"
		return 1
		;;
	    esac
	    ;;
	*)
	    echo 1>&2 "$PRG: This machine is not supported: $MODEL"
	    return 1
	    ;;
    esac
    return 0
}

## find OpenFirmware device path for IBM CHRP hardware (scsi only)
chrp()
{
    case "$DEVNODE" in
	sd*)
	    if ls -l /proc/device-tree | grep -q ^lr ; then
		true
	    else
		echo 1>&2 "$PRG: /proc/device-tree is broken."
		return 1
	    fi

	    ## use common scsiinfo function to get info we need.
	    scsiinfo || return 1

	    ## now we have the data for /@$DEVID:$PARTITION
	    ## find the actual OF path.	
	    scsi_ofpath || return 1
	    ;;
	*)
	    echo 1>&2 "$PRG: Device: /dev/$DEVNODE is not supported"
	    return 1
	    ;;
    esac
    return 0
}

## If we get lame devfs name, we need to make it foad
ckdevfs()
{
    case "$1" in
	/dev/ide/*|/dev/scsi/*|/dev/discs/*)
	return 0
	;;
	*)
	return 1
	;;
    esac
}

## convert devfs names into normal short ones, written by Tom Rini.
fixdevfs()
{
    ## get partition number, if any
    local PARTNUM="${1##*[a-z]}"
    ## Find the bus type.
    local TYPE="$(v=${1#/dev/} ; echo ${v%/host*})"
    ## Find the host number.
    local HOST="$(v=${1#/dev/*/host} ; echo ${v%/bus*})"
    ## Find the bus number.
    local BUS="$(v=${1#/dev/*/bus} ; echo ${v%/tar*})"
    ## Find the target.
    local TARGET="$(v=${1#/dev/*/target} ; echo ${v%/lun*})"

    case "$TYPE" in
	ide)
	case "$HOST" in
	    0)
	    case "$TARGET" in
		0)
		local DEV=hda
		;;
		1)
		local DEV=hdb
		;;
	    esac
	    ;;
	    1)
	    case "$TARGET" in
		0)
	        local DEV=hdc
	        ;;
		1)
		local DEV=hdd
		;;
	    esac
	    ;;
	    *)
		echo 1>&2 "$PRG: $1: Unable to translate this device, try again without devfs."
		return 1
	esac
	local DEV="${DEV}${PARTNUM}"
	echo "/dev/$DEV"
	return 0
	;;
	scsi)
	local LUN="$(v=${1#/dev/*/lun} ; echo ${v%/*})"

	## In this case, we need to figure out what number our device is
	local DEVCOUNT=0

	## copy scsi file into a variable removing "Attached Devices"
	## which is the first line. this avoids a lot of
	## [incmopatible] crap later, and improves readability.

	## find number of lines once and recycle that number, to save
	## some time (linecount is a bit slow). subtract one line
	## to scrap Attached Devices:

	local SCSILINES="$(($(linecount /proc/scsi/scsi) - 1))"
	local PROCSCSI="$(cat /proc/scsi/scsi | tail -n $SCSILINES)"

	for i in $(smallseq $(($SCSILINES / 3))) ; do

	    ## put every scsi device into one single line
	    local DEVINFO="$(echo "$PROCSCSI" | head -n $(($i * 3)) | tail -n 3)"
	    [ "$DEBUG" = 1 ] && echo 1>&2 "$PRG: DEBUG: fixdevfs: DEVINFO=$DEVINFO"

	    ## cut the type field, expect "Direct-Access" later.
	    local DEVTYPE="$(v=$(echo ${DEVINFO##*Type: }) ; echo ${v%% *})"
	    [ "$DEBUG" = 1 ] && echo 1>&2 "$PRG: DEBUG: fixdevfs: DEVTYPE=$DEVTYPE"

	    if [ "$DEVTYPE" = "Direct-Access" ] ; then
		## Lets find out some more information
		## get the device id.
		local DEVID="$(v=$(echo ${DEVINFO##*Id: }) ; n=$(echo ${v%% *}) ; echo ${n#*0})"
		[ "$DEBUG" = 1 ] && echo 1>&2 "$PRG: DEBUG: fixdevfs: DEVID=$DEVID"

		## get the device lun.
		local DEVLUN="$(v=$(echo ${DEVINFO##*Lun: }) ; n=$(echo ${v%% *}) ; echo ${n#*0})"
		[ "$DEBUG" = 1 ] && echo 1>&2 "$PRG: DEBUG: fixdevfs: DEVLUN=$DEVLUN"

		## get the device channel.
		local DEVCHAN="$(v=$(echo ${DEVINFO##*Channel: }) ; n=$(echo ${v%% *}) ; echo ${n#*0})"
		[ "$DEBUG" = 1 ] && echo 1>&2 "$PRG: DEBUG: fixdevfs: DEVCHAN=$DEVCHAN"

		## get the scsi host id.
		local DEVHOST="$(v=$(echo ${DEVINFO##*Host: scsi}) ; echo ${v%% *})"
		[ "$DEBUG" = 1 ] && echo 1>&2 "$PRG: DEBUG: fixdevfs: DEVHOST=$DEVHOST"

		local DEVCOUNT="$(($DEVCOUNT + 1))"
		[ "$DEBUG" = 1 ] && echo 1>&2 "$PRG: DEBUG: fixdevfs: DEVCOUNT=$DEVCOUNT"
		if [ "$DEVHOST" = "$HOST" -a "$DEVCHAN" = "$BUS" -a \
		    "$DEVID" = "$TARGET" -a "$DEVLUN" = "$LUN" ] ; then
		    local DEV="sd$(smalltr $DEVCOUNT)${PARTNUM}"
		    echo "/dev/$DEV"
		    return 0
		fi
	    fi
	done
	echo 1>&2 "$PRG: $1: Unable to translate this device, try again without devfs."
	return 1
	;;
	*)
	echo 1>&2 "$PRG: Unknown bus $TYPE"
	return 1
	;;
    esac
    ## we should never get here
    return 1
}

## make sure that find, head and tail can be found.  otherwise the
## script will silently give bogus paths.  these are the only /usr/*
## utilities this script depends on.
checkutils()
{
    if command -v find > /dev/null 2>&1 ; then
        [ -x `command -v find` ] || FAIL=1 ; else FAIL=1 ; fi
    if command -v head > /dev/null 2>&1 ; then
        [ -x `command -v head` ] || FAIL=1 ; else FAIL=1 ; fi
    if command -v tail > /dev/null 2>&1 ; then
        [ -x `command -v tail` ] || FAIL=1 ; else FAIL=1 ; fi

    if [ "$FAIL" = 1 ] ; then
	echo 1>&2 "$PRG: \`find', \`head', or \`tail' could not be found, aborting."
	return 1
    else
	return 0
    fi
}

## parse command line switches.
if [ $# != 0 ] ; then
    while true ; do
	case "$1" in
	    -V|--version)
		version
		exit 0
		;;
	    -h|--help)
		usage
		exit 0
		;;
	    --debug)
		DEBUG=1
		shift
		;;
	    -*)
		echo 1>&2 "$PRG: unrecognized option \`$1'"
		echo 1>&2 "$PRG: Try \`$PRG --help' for more information."
		exit 1
		;;
	    "")
		echo 1>&2 "$PRG: You must specify a filename"
		echo 1>&2 "Try \`$PRG --help' for more information."
		exit 1
		;;
	    *)
		device="$1"
		break
		;;
	esac
    done
else
    echo 1>&2 "$PRG: You must specify a /dev device"
    echo 1>&2 "Try \`$PRG --help' for more information."
    exit 1
fi

## check that FILE is a block device and exists.
if [ ! -e "$device" ] ; then
    echo 1>&2 "$PRG: $device: No such file or directory"
    exit 1
elif [ ! -b "$device" ] ; then
    echo 1>&2 "$PRG: $device is not a block device"
    exit 1
fi

## check that we are running on a GNU/Linux system, OSX/BSD does not
## have the same /proc stuff
if [ `uname -s` != Linux ] ; then
    echo 1>&2 "$PRG: This utility will only work with GNU/Linux"
    exit 1
fi

## check for ppc, i think uname -m is safe for this...
if [ `uname -m` != ppc -a `uname -m` != ppc64 ] ; then
    echo 1>&2 "$PRG: This utility will only work on PowerPC hardware"
    exit 1
fi

## ofpath cannot live without procfs
if [ ! -f /proc/uptime ] ; then
    echo 1>&2 "$PRG: This utility requires the /proc filesystem"
    exit 1
fi

## check for retarded devfs names and tell them to foad.
if ckdevfs "$device" ; then
    device="$(fixdevfs $device)" || exit 1
fi

## check for newworld mac. use cat hack due to /proc wierdness.
if [ "$(v=`cat /proc/cpuinfo 2>/dev/null | grep pmac-generation` ; echo ${v##*:[ ]})" = NewWorld ] ; then
    SUBARCH=NewWorld
elif [ "$(v=`cat /proc/cpuinfo 2>/dev/null | grep pmac-generation` ; echo ${v##*:[ ]})" = OldWorld ] ; then
    SUBARCH=OldWorld
elif (cat /proc/cpuinfo 2>/dev/null | grep ^motherboard | grep -q AAPL) ; then
    SUBARCH=OldWorld
elif (cat /proc/cpuinfo 2> /dev/null | grep ^machine | grep -q 'CHRP IBM') ; then
    SUBARCH=CHRP
else
    echo 1>&2 "$PRG: This machine is not yet supported"
    exit 1
fi

## make sure /proc/device-tree exists
if [ ! -d /proc/device-tree ] ; then
    echo 1>&2 "$PRG: /proc/device-tree does not exist"
    echo 1>&2 "$PRG: Make sure you compiled your kernel with CONFIG_PROC_DEVICETREE=y"
    exit 1
fi

## make sure we have what we need.
checkutils || exit 1

## get the base device node and scrap /dev/ ie /dev/hda2 -> hda
DEVICE="${device##*/}"
DEVNODE="${DEVICE%%[0-9]*}"
PARTITION="${DEVICE##*[a-z]}"

## use appropriate search for right sub arch.
case "$SUBARCH" in
    NewWorld)
	newworld || exit 1
	;;
    OldWorld)
	oldworld || exit 1
	;;
    CHRP)
	chrp || exit 1
	;;
esac

exit 0