#!/bin/bash
# $Id:$
#
# This provides a stripped down 'failsafe' mode for situations
# where X is failing to start up.
# Author: Bryce W. Harrington <bryce@canonical.com>
# Copyright 2007 Canonical, Ltd
#
# This is free software; you may 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,
# or (at your option) any later version.
#
# This 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 with
# the Debian operating system, in /usr/share/common-licenses/GPL; if
# not, write to the Free Software Foundation, Inc., 59 Temple Place,
# Suite 330, Boston, MA 02111-1307 USA
xorg_conf_failsafe=${BPX_XORG_CONF_FAILSAFE:-"/etc/X11/xorg.conf.failsafe"}
xorg_conf=${BPX_XORG_CONF:-"/etc/X11/xorg.conf"}
run_dexconf=${BPX_RUN_DEXCONF:-"yes"}
# TODO: This should be set to "vga", however I have been unable to
# succeed in getting the vga driver running in anything over
# 320x200, which is unusable. So fallback is disabled for now.
#fallback_driver="vga"
fallback_driver=${BPX_FALLBACK_DRIVER:-"vesa"}
client=${BPX_CLIENT:-"/etc/gdm/failsafeXinit"}
clientargs=${BPX_CLIENTARGS:-$xorg_conf_failsafe}
blacklist=${BPX_BLACKLIST:-"/etc/gdm/failsafeBlacklist"}
main_driver=${BPX_DRIVER:-"vesa"}
checkduration=${BPX_CHECK_DURATION:-30}
failsafe_log=${BPX_LOG:-"/var/log/gdm/failsafe.log"}
server=${BPX_SERVER:-/usr/bin/X}
serverargs=${BPX_SERVERARGS:-"$*"}
if [ -z $serverargs ]; then
# Use :10 to avoid overwriting the (failed) Xorg.0.log
serverargs=":10"
fi
serverargs="${serverargs} -br -once -config $xorg_conf_failsafe"
# -br: Black background
# -once: Terminate server after one session
# -config: Specify location of xorg.conf file to use
# Note: Only root can specify absolute paths
warn() {
echo "Warning: $1" 1>&2
}
is_installed() {
prog=$1
need=$2
/usr/bin/which $prog > /dev/null 2>&1
err=$?
if [ ! $err = 0 ]; then
warn "Could not $need because $prog is not installed ($err)"
return $err
fi
return 0
}
# Tests if the given pciids are in numerical order from least to greatest
# (e.g., $a <= $b <= $c <= ...)
pciids_in_order() {
lastid=0
for pciid in $* ; do
# Strip embedded : and convert hex to dec
id=$((0x${pciid/:/}))
if [ $id -lt $lastid ]; then
return 1
fi
lastid=$id
done
return 0
}
get_edid() {
# Retrieve EDID (if get-edid is installed)
is_installed get-edid "retrieve EDID" || return 1
# Discard stderr, which is text data about the card
get-edid 2>/dev/null
}
get_pciids() {
# Retrieve PCI IDs from discover
is_installed discover "retreive PCI IDs" || return 1
discover --enable-all video --format="%i\n"
}
get_driver() {
EDID=$(get_edid)
PCIIDS=$(get_pciids)
if [ "x$EDID" = "x" ]; then
echo $fallback_driver
return 1
elif [ "x$PCIIDS" = "x" ]; then
echo $fallback_driver
return 2
fi
# TODO: What if we have multiple pciids? Assume first for now.
pciid=$(echo $PCIIDS | head -n 1)
EDID_MD5=$(echo $EDID | md5sum | head -n1 | cut -d" " -f1)
matches=$(egrep "^$EDID_MD5|^ANY" $blacklist)
found="no"
for line in "$matches"; do
line=$(echo $line | sed -e "s/ \+/ /")
range=$(echo $line | cut -d' ' -f 2)
driver=$(echo $line | cut -d' ' -f 3)
pciid1=$(echo $range | cut -d- -f 1)
pciid2=$(echo $range | cut -d- -f 2)
if [ "x$pciid1" = "x" ]; then
continue
elif [ "x$pciid1" = "xANY" ]; then
found="yes"
break
elif [ "$pciid1" = "$pciid" ]; then
found="yes"
break
elif [ "x$pciid2" = "x" ]; then
continue
elif pciids_in_order $pciid1 $pciid $pciid2 ; then
found="yes"
break
fi
done
if [ $found = "no" ]; then
echo $main_driver
else
# No driver was specified - assume vga
if [ "x$driver" = "x" ]; then
warn "System is blacklisted, but no driver specified; assuming fallback"
driver=$fallback_driver
fi
echo $driver
fi
return 0
}
# Check if we've already attempted a failsafe session without success
if [ -e "$failsafe_log" ]; then
cur_time=$(date +"%s")
last_run=$(tail -n 1 $failsafe_log | cut -d' ' -f1)
time_diff=$(expr $cur_time - $last_run)
if [ $time_diff -lt $checkduration ]; then
warn "Failsafe mode was already attempted within $checkduration seconds."
warn "Falling back to gdm to report the issue."
exit 1
fi
fi
# When failsafe mode is activated, check the blacklist for systems we
# know do not support VESA 800x600/256
# Use EDID + PCI IDs as key to lookup (Can get PCI IDs from discover)
# If the display does not give EDID info, then use VGA 640x480/16 mode
# If a matching entry is found, then use VGA 640x480/16 mode
driver=$(get_driver)
if [ "x${run_dexconf}" = "xyes" ]; then
# Generate an appropriate xorg.conf
/etc/gdm/failsafeDexconf $driver $xorg_conf_failsafe
if [ ! -s $xorg_conf_failsafe ]; then
warn "Could not generate $xorg_conf_failsafe for $driver driver"
exit 1
fi
elif [ ! -s $xorg_conf_failsafe ]; then
warn "Requested to use $xorg_conf_failsafe for $driver driver, but it does not exist"
exit 1
fi
md5xorg=$(md5sum $xorg_conf)
date +"%s $md5xorg" >> $failsafe_log
if [ $? -ne 0 ]; then
warn "Cannot write to $failsafe_log"
fi
# TODO: Start up the failsafe X session using their regular user account
if pidof /usr/sbin/gdm ; then
clientargs="${clientargs} with-gdm"
fi
echo "xinit $client $clientargs -- $server $serverargs"
xinit $client $clientargs -- $server $serverargs &
sleep 3
# Stop gdm if it's running, otherwise it will attempt to manage the display
# out from under us
if pidof /usr/sbin/gdm ; then
exec kill -STOP $PPID
fi
# This seems to cause gdm to attempt to start a new x session
#exec kill -USR1 `cat /var/run/gdm.pid`