Drop config_debug, not working under systemd as intended

Startup of shells during bootup under systemd doesn't work
as with file-rc and actually causes ugly error messages.
systemd has its own mechanism and we should rely on that.

With this change also drop the /proc/sys/kernel/printk related
code, this *shouldn't* be relevant anymore.

Closes grml/grml#3

autoconfig

@@ -55,7 +55,6 @@ CONFIG_BRLTTY='yes'           # automatically start brltty if a brltty option is
 CONFIG_DEBOOTSTRAP='yes'      # support automatic installation of Debian via grml-deboostrap
 CONFIG_DEBNET='yes'           # search for /etc/network/interfaces on partitions and set up network afterwards
 CONFIG_DEBS='yes'             # check for bootoption debs for installing .debs
-CONFIG_DEBUG='yes'            # activate start of shells during startup at several stages
 CONFIG_DISPLAY_SSH_FINGERPRINTS='yes' # display SSH server key fingerprints
 CONFIG_DISTRI='yes'           # support some customization via bootoption distri
 CONFIG_DMRAID='yes'           # support for dmraid

autoconfig.functions

@@ -201,36 +201,6 @@ else
 fi
 # }}}
 
-# {{{ debug
-config_debug(){
- checkbootparam 'debug'            && BOOTDEBUG="yes"
- checkbootparam "BOOT_IMAGE=debug" && BOOTDEBUG="yes"
-
- rundebugshell(){
-  if [ -n "$BOOTDEBUG" ]; then
-     einfo "Starting intermediate shell stage $stage as requested by \"debug\" option."
-     if [ grep -q "debug=noscreen" "$CMDLINE" ] ; then
-        einfo "Notice that the shell does not provide job handling: ctrl-z, bg and fg won't work!"
-        einfo "Just exit the shell to continue boot process..."
-        /bin/zsh
-     else
-        eindent
-        if [ -r /etc/grml/screenrc ] ; then
-           einfo "Starting GNU screen to be able to use a full featured shell environment."
-           einfo "Just exit the shells (and therefore screen) to continue boot process..."
-           /bin/zsh -c "screen -c /etc/grml/screenrc"
-        else
-           einfo "Notice that the shell does not provide job handling: ctrl-z, bg and fg won't work!"
-           einfo "Just exit the shell to continue boot process..."
-           /bin/zsh
-        fi
-        eoutdent
-     fi
-  fi
- }
-}
-# }}}
-
 # {{{ log
 config_log(){
 if checkbootparam 'log' || checkbootparam 'debug' ; then
@@ -1986,7 +1956,6 @@ config_distri(){
 if checkbootparam 'distri'; then
   DISTRI="$(getbootparam 'distri' 2>>$DEBUG)"
   if [ -r "${LIVECD_PATH}"/desktop/"$DISTRI".jpg ] ; then
-     [ -n "$BOOTDEBUG" ] && einfo "Debug: bootoption distri found and file ${LIVECD_PATH}/desktop/${DISTRI} present" && eend 0
      # make sure the desktop.jpg file is not a symlink, so copying does not file then
      [ -L /usr/share/grml/desktop.jpg ] && rm /usr/share/grml/desktop.jpg
      cp "${LIVECD_PATH}"/desktop/"$DISTRI".jpg /usr/share/grml/desktop.jpg

grml-autoconfig

@@ -54,25 +54,12 @@ mount_sys
 # }}}
 
 # {{{ main grml-autoconfig
-checkvalue $CONFIG_DEBUG && config_debug
-
 # make sure symlink /etc/mtab exists, this is usually handled by
 # /etc/init.d/checkroot.sh but we don't execute this script on the live system
 if [ -z "$INSTALLED" ] ; then
   ln -sf /proc/mounts /etc/mtab
 fi
 
-stage=5
-rundebugshell
-
-if [ -z "$BOOTDEBUG" ] ; then
-   einfo "Setting kernel ring buffer to level 2."
-   echo "2" > /proc/sys/kernel/printk ; eend $?
-else
-   einfo "Setting kernel ring buffer to level 6. Adjust manually via running dmesg -n \$VALUE."
-   echo "6" > /proc/sys/kernel/printk ; eend $?
-fi
-
 checkvalue $CONFIG_SYSLOG && config_syslog
 
 if checkbootparam 'forensic' ; then
@@ -100,9 +87,6 @@ checkvalue $CONFIG_DMRAID && config_dmraid
 
 checkvalue $CONFIG_LVM && config_lvm
 
-# No kernel messages while probing modules
-echo "0" > /proc/sys/kernel/printk
-
 checkvalue $CONFIG_TESTCD && config_testcd
 
 checkvalue $CONFIG_BRLTTY && config_brltty
@@ -162,21 +146,6 @@ checkvalue $CONFIG_DEBOOTSTRAP && config_debootstrap
 checkvalue $CONFIG_XSTARTUP && config_x_startup
 # }}}
 
-# {{{ debug
-stage=6
-rundebugshell
-
-if [ -n "$BOOTDEBUG" ] ; then
-   # set only if not already set
-   if [ -z "$CMDLINE" ] ; then
-     CMDLINE="$(cat /proc/cmdline)"
-     [ -d ${LIVECD_PATH}/bootparams/ ] && CMDLINE="$CMDLINE $(cat ${LIVECD_PATH}/bootparams/*)"
-   fi
-   einfo "Bootoption debug detected. Printing kernel command line:"
-   echo "$CMDLINE"
-fi
-# }}}
-
 # {{{ Re-enable signals
 trap 2 3 11
 # }}}