diff --git a/linbofs/init.sh b/linbofs/init.sh
index 6228bf0..ada6f71 100755
--- a/linbofs/init.sh
+++ b/linbofs/init.sh
@@ -5,7 +5,7 @@
 # License: GPL V2
 #
 # thomas@linuxmuster.net
-# 20211122
+# 20211129
 #
 
 # If you don't have a "standalone shell" busybox, enable this:
@@ -489,13 +489,15 @@ do_housekeeping(){
 do_linbo_update(){
   local server="$1"
   local rebootflag="/tmp/.linbo.reboot"
+  local cfg="/cache/boot/grub/custom.cfg"
   local cachedev="$(printcache)"
+  linbo_cmd mount "$cachedev" /cache
+  [ -e "${cfg}.reboot" ] && mv "${cfg}.reboot" "$cfg"
   # start linbo update
   linbo_cmd update "$server" "$cachedev" 2>&1 | tee /cache/update.log
   # initiate warm start
-  if [ -e "$rebootflag" -a "$warmstart" != "no" ]; then
+  if [ -e "$rebootflag" ]; then
     echo -n "Local LINBO/GRUB configuration was updated. Initiating linbo warmstart ..."
-    cd /
     /usr/bin/linbo_warmstart
   fi
 }
diff --git a/linbofs/usr/bin/linbo_cmd b/linbofs/usr/bin/linbo_cmd
index 44238ed..1e01482 100755
--- a/linbofs/usr/bin/linbo_cmd
+++ b/linbofs/usr/bin/linbo_cmd
@@ -1468,15 +1468,18 @@ start(){
   local INITRD
   local APPEND
   local KERNEL="${3#/}"
-  local warmstart
+  local warmstart="no"
   local i
   local partition="$2"
   local label="$(print_partlabel "$partition")"
   local cachedev="$6"
+  local mntpnt="/mnt"
+  [ "$partition" = "$cachedev" ] && mntpnt="/cache"
+  [ -d /sys/firmware/efi/efivars ] && local efi="true"
   local startflag="/tmp/.start"
   touch "$startflag"
-  if mountpart "$partition" /mnt -w 2>> /tmp/linbo.log; then
-    if [ -e "/mnt/$KERNEL" ]; then
+  if mountpart "$partition" "$mntpnt" 2>> /tmp/linbo.log; then
+    if [ -e "$mntpnt/$KERNEL" ]; then
       echo "Found kernel $KERNEL on partition $partition."
       INITRD="${4#/}"
       APPEND="$5"
@@ -1486,8 +1489,11 @@ start(){
       else
         APPEND="root=$partition $APPEND"
       fi
-      # test for warmstart boot parameter
-      for i in `cat /proc/cmdline`; do case "$i" in warmstart=*) eval $i ;; esac; done
+      # test for warmstart boot parameter, if not linbo reboot and not efi
+      if [ "$partition" != "$cachedev" -a -z "$efi" ]; then
+        warmstart="yes"
+        for i in `cat /proc/cmdline`; do case "$i" in warmstart=*) eval $i ;; esac; done
+      fi
       # load kernel for later warmstart
       if [ "$warmstart" != "no" ]; then
         kexec --type="bzImage" --append="$APPEND" --initrd="/mnt/$INITRD" --load "/mnt/$KERNEL" && warmstart="yes"
@@ -1499,7 +1505,7 @@ start(){
     # install/update grub/efi stuff if cache is mounted
     if mountcache "$cachedev"; then
       # prepare reboot if no warmstart
-      [ "$warmstart" != "yes" ] && mk_boot "$partition" "$KERNEL" "$INITRD" "$APPEND" | tee -a /tmp/linbo.log
+      [ "$warmstart" = "no" ] && mk_boot "$partition" "$KERNEL" "$INITRD" "$APPEND" | tee -a /tmp/linbo.log
       # update linuxmuster-win scripts and install start tasks
       [ "$(fstype "$partition")" = "ntfs" -a -d /cache/linuxmuster-win ] && update_win "$partition" | tee -a /tmp/linbo.log
     fi
@@ -1532,7 +1538,7 @@ start(){
   umount /mnt 2>> /tmp/linbo.log
   sendlog
   # start os directly or reboot into it
-  if [ "$warmstart" = "yes" ]; then
+  if [ "$warmstart" != "no" ]; then
     kexec -e
   else
     reboot -f
diff --git a/linbofs/usr/bin/linbo_warmstart b/linbofs/usr/bin/linbo_warmstart
index 7070ecc..c86e109 100755
--- a/linbofs/usr/bin/linbo_warmstart
+++ b/linbofs/usr/bin/linbo_warmstart
@@ -1,47 +1,57 @@
 #!/bin/sh
 #
-# linbo_warmstart <kernel> <initrd>
+# linbo_warmstart <device>
 # thomas@linuxmuster.net
-# 20211122
+# 20211129
 #
 
-KEXEC="/sbin/kexec"
-LINBO="/cache/linbo64"
-LINBOFS="/cache/linbofs64.lz"
-
-KERNEL="$1"
-[ -z "$KERNEL" ] && KERNEL="$LINBO"
-if [ ! -s "$KERNEL" ]; then
-  echo "Kernel $KERNEL not found!"
-  exit 1
+if [ -n "$1" ]; then
+  CACHE="$1"
+else
+  CACHE="$(grep -iw ^cache /start.conf | tail -1 | awk -F\= '{print $2}' | awk '{print $1}' | awk -F\# '{print $1}' | awk '{print $1}')"
 fi
 
-INITRD="$2"
-[ -z "$INITRD" ] && INITRD="$LINBOFS"
-if [ ! -s "$INITRD" ]; then
-  echo "Initrd $INITRD not found!"
+if [ ! -b "$CACHE" ]; then
+  [ -z "$CACHE" ] && CACHE="<None>"
+  echo "Cache $CACHE is not a blockdevice!"
   exit 1
 fi
 
-APPEND="$3"
-if [ -z "$APPEND" -a "$KERNEL" = "$LINBO" -a "$INITRD" = "$LINBOFS" ]; then
-  APPEND="$(cat /proc/cmdline)"
-fi
-if [ -z "$APPEND" ]; then
-  echo "Kernel append string is empty. Check your parameters!"
-  exit 1
-fi
+KEXEC="/sbin/kexec"
+KERNEL="linbo64"
+INITRD="linbofs64.lz"
+APPEND="$(cat /proc/cmdline)"
+CFG="/cache/boot/grub/custom.cfg"
+TPL="/usr/share/linbo/warmstart.cfg"
+[ -d /sys/firmware/efi/efivars ] && EFI="true"
 
-# load linbo kernel
-if ! $KEXEC --type="bzImage" --append="$APPEND" --initrd="$INITRD" --load "$KERNEL"; then
-  echo "Failed to load kernel!"
-  exit 1
+# test for warmstart boot parameter
+warmstart="yes"
+for i in $APPEND; do case "$i" in warmstart=*) eval $i ;; esac; done
+if [ "$warmstart" = "no" ]; then
+  echo "Skipping kexec'd linbo warmstart, rebooting instead."
 fi
 
-# execute linbo kernel
-if ! $KEXEC -e; then
-  echo "Failed to execute kernel!"
-  exit 1
+cd /
+linbo_cmd mount "$CACHE" /cache
+
+# cold reboot
+if [ -n "$EFI" -o "$warmstart" = "no" ]; then
+  mv "$CFG" "$CFG".reboot || exit 1
+  sed -e "s|@@kopts@@|$APPEND|" "$TPL" > "$CFG" || exit 1
+  linbo_cmd start "" "$CACHE" "$KERNEL" "$INITRD" "$APPEND" "$CACHE"
+# kexec boot
+else
+  # load linbo kernel
+  if ! $KEXEC --type="bzImage" --append="$APPEND" --initrd="/cache/$INITRD" --load "/cache/$KERNEL"; then
+    echo "Failed to load kernel!"
+    exit 1
+  fi
+  # execute linbo kernel
+  if ! $KEXEC -e; then
+    echo "Failed to execute kernel!"
+    exit 1
+  fi
 fi
 
 exit 0
diff --git a/linbofs/usr/share/linbo/warmstart.cfg b/linbofs/usr/share/linbo/warmstart.cfg
new file mode 100644
index 0000000..0da7ccc
--- /dev/null
+++ b/linbofs/usr/share/linbo/warmstart.cfg
@@ -0,0 +1,42 @@
+# temporary grub.cfg template for linbo reboot
+# thomas@linuxmuster.net
+# 20211129
+#
+
+set default=0
+set timeout=0
+
+set gfxmode=auto
+set gfxpayload=keep
+
+insmod all_video
+insmod png
+insmod gfxterm
+insmod gfxmenu
+insmod minicmd
+insmod progress
+
+terminal_output gfxterm
+
+background_color 42,68,87
+
+set linbo_kernel=/linbo64
+set linbo_initrd=/linbofs64.lz
+
+# theme settings (modify for custom theme)
+set theme=/boot/grub/themes/linbo/theme.txt
+export theme
+
+clear
+
+# find linbo cache partition
+search --file "$linbo_initrd" --set root
+
+menuentry 'LINBO' --class linbo {
+  echo -n "Loading $linbo_kernel ..."
+  linux $linbo_kernel @@kopts@@
+  echo
+  echo -n "Loading $linbo_initrd ..."
+  initrd $linbo_initrd
+  boot
+}