diff --git a/ChangeLog b/ChangeLog
index 65bd6ad03..39a658288 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,19 @@
+2010-05-23  Vladimir Serbinenko  <phcoder@gmail.com>
+
+	cmostest support.
+
+	* commands/i386/cmostest.c: New file.
+	* conf/i386-coreboot.rmk (pkglib_MODULES): Add cmostest.mod.
+	(cmostest_mod_SOURCES): New variable.
+	(cmostest_mod_CFLAGS): Likewise.
+	(cmostest_mod_LDFLAGS): Likewise.
+	* conf/i386-pc.rmk: Likewise.
+	* docs/grub.texi (Vendor power-on keys): New section.
+	* util/grub-mkconfig.in: export GRUB_DEFAULT_BUTTON,
+	GRUB_HIDDEN_TIMEOUT_BUTTON, GRUB_TIMEOUT_BUTTON
+	and GRUB_BUTTON_CMOS_ADDRESS.
+	* util/grub.d/00_header.in: Handle powering-on by separate button.
+
 2010-05-23  Vladimir Serbinenko  <phcoder@gmail.com>
 
 	* gfxmenu/gui_list.c (draw_menu): Don't add scrollbar width to padding.
diff --git a/commands/i386/cmostest.c b/commands/i386/cmostest.c
new file mode 100644
index 000000000..36c35e6c4
--- /dev/null
+++ b/commands/i386/cmostest.c
@@ -0,0 +1,59 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2009  Free Software Foundation, Inc.
+ *
+ *  GRUB 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 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB 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 GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/dl.h>
+#include <grub/command.h>
+#include <grub/misc.h>
+#include <grub/cmos.h>
+
+static grub_err_t
+grub_cmd_cmostest (struct grub_command *cmd __attribute__ ((unused)),
+		   int argc, char *argv[])
+{
+  int byte, bit;
+  char *rest;
+
+  if (argc != 1)
+    return grub_error (GRUB_ERR_BAD_ARGUMENT, "Address required.");
+
+  byte = grub_strtoul (argv[0], &rest, 0);
+  if (*rest != ':')
+    return grub_error (GRUB_ERR_BAD_ARGUMENT, "Address required.");
+
+  bit = grub_strtoul (rest + 1, 0, 0);
+
+  if (grub_cmos_read (byte) & (1 << bit))
+    return GRUB_ERR_NONE;
+
+  return grub_error (GRUB_ERR_TEST_FAILURE, "false");
+}
+
+static grub_command_t cmd;
+
+
+GRUB_MOD_INIT(cmostest)
+{
+  cmd = grub_register_command ("cmostest", grub_cmd_cmostest,
+			       "cmostest BYTE:BIT",
+			       "Test bit at BYTE:BIT in CMOS.");
+}
+
+GRUB_MOD_FINI(cmostest)
+{
+  grub_unregister_command (cmd);
+}
diff --git a/conf/i386-coreboot.rmk b/conf/i386-coreboot.rmk
index b8713a7b0..f6a375624 100644
--- a/conf/i386-coreboot.rmk
+++ b/conf/i386-coreboot.rmk
@@ -68,5 +68,11 @@ datetime_mod_SOURCES = lib/cmos_datetime.c
 datetime_mod_CFLAGS = $(COMMON_CFLAGS)
 datetime_mod_LDFLAGS = $(COMMON_LDFLAGS)
 
+# For cmostest.mod
+pkglib_MODULES += cmostest.mod
+cmostest_mod_SOURCES = commands/i386/cmostest.c
+cmostest_mod_CFLAGS = $(COMMON_CFLAGS)
+cmostest_mod_LDFLAGS = $(COMMON_LDFLAGS)
+
 include $(srcdir)/conf/i386.mk
 include $(srcdir)/conf/common.mk
diff --git a/conf/i386-pc.rmk b/conf/i386-pc.rmk
index 8e50ee889..fa8394b52 100644
--- a/conf/i386-pc.rmk
+++ b/conf/i386-pc.rmk
@@ -244,6 +244,12 @@ hdparm_mod_SOURCES = commands/hdparm.c lib/hexdump.c
 hdparm_mod_CFLAGS = $(COMMON_CFLAGS)
 hdparm_mod_LDFLAGS = $(COMMON_LDFLAGS)
 
+# For cmostest.mod
+pkglib_MODULES += cmostest.mod
+cmostest_mod_SOURCES = commands/i386/cmostest.c
+cmostest_mod_CFLAGS = $(COMMON_CFLAGS)
+cmostest_mod_LDFLAGS = $(COMMON_LDFLAGS)
+
 ifeq ($(enable_efiemu), yes)
 
 efiemu32.o: efiemu/runtime/efiemu.c $(TARGET_OBJ2ELF)
diff --git a/docs/grub.texi b/docs/grub.texi
index 704f8b2a3..bcc05c1f8 100644
--- a/docs/grub.texi
+++ b/docs/grub.texi
@@ -80,6 +80,7 @@ This edition documents version @value{VERSION}.
 * Configuration::               Writing your own configuration file
 * Network::                     Downloading OS images from a network
 * Serial terminal::             Using GRUB via a serial line
+* Vendor power-on keys::        Changing GRUB behaviour on vendor power-on keys
 * Preset Menu::                 Embedding a configuration file into GRUB
 * Images::                      GRUB image files
 * Filesystem::                  Filesystem syntax and semantics
@@ -747,6 +748,23 @@ implements few VT100 escape sequences. If you specify this option then
 GRUB provides you with an alternative menu interface, because the normal
 menu requires several fancy features of your terminal.
 
+@node Vendor power-on keys
+@chapter Using GRUB with vendor power-on keys
+Some laptop vendor provide an additional power-on button which boots another OS.
+GRUB supports such buttons with GRUB_TIMEOUT_BUTTON, GRUB_DEFAULT_BUTTON,
+GRUB_HIDDEN_TIMEOUT_BUTTON and GRUB_BUTTON_CMOS_ADDRESS variables in
+default/grub. GRUB_TIMEOUT_BUTTON, GRUB_DEFAULT_BUTTON and 
+GRUB_HIDDEN_TIMEOUT_BUTTON are used instead of corresponding variables without
+_BUTTON suffix when powered using special button.
+GRUB_BUTTON_CMOS_ADDRESS is vendor specific and partially model-specific.
+Values known to GRUB team are:
+
+@table @key
+@item Dell XPS M1530
+85:3
+@end table
+
+To take full advantage of this function install GRUB into MBR.
 
 @node Filesystem
 @chapter Filesystem syntax and semantics
diff --git a/util/grub-mkconfig.in b/util/grub-mkconfig.in
index d1abfa36a..0095e1ce8 100644
--- a/util/grub-mkconfig.in
+++ b/util/grub-mkconfig.in
@@ -246,6 +246,10 @@ export GRUB_DEFAULT \
   GRUB_HIDDEN_TIMEOUT \
   GRUB_HIDDEN_TIMEOUT_QUIET \
   GRUB_TIMEOUT \
+  GRUB_DEFAULT_BUTTON \
+  GRUB_HIDDEN_TIMEOUT_BUTTON \
+  GRUB_TIMEOUT_BUTTON \
+  GRUB_BUTTON_CMOS_ADDRESS \
   GRUB_DISTRIBUTOR \
   GRUB_CMDLINE_LINUX \
   GRUB_CMDLINE_LINUX_DEFAULT \
diff --git a/util/grub.d/00_header.in b/util/grub.d/00_header.in
index d181fdffc..df8f5dfaa 100644
--- a/util/grub.d/00_header.in
+++ b/util/grub.d/00_header.in
@@ -38,11 +38,29 @@ if [ "x${GRUB_DEFAULT}" = "xsaved" ] ; then GRUB_DEFAULT='${saved_entry}' ; fi
 if [ "x${GRUB_TIMEOUT}" = "x" ] ; then GRUB_TIMEOUT=5 ; fi
 if [ "x${GRUB_GFXMODE}" = "x" ] ; then GRUB_GFXMODE=640x480 ; fi
 
+if [ "x${GRUB_DEFAULT_BUTTON}" = "x" ] ; then GRUB_DEFAULT_BUTTON="$GRUB_DEFAULT" ; fi
+if [ "x${GRUB_DEFAULT_BUTTON}" = "xsaved" ] ; then GRUB_DEFAULT_BUTTON='${saved_entry}' ; fi
+if [ "x${GRUB_TIMEOUT_BUTTON}" = "x" ] ; then GRUB_TIMEOUT_BUTTON="$GRUB_TIMEOUT" ; fi
+
 cat << EOF
 if [ -s \$prefix/grubenv ]; then
   load_env
 fi
+EOF
+if [ "x$GRUB_BUTTON_CMOS_ADDRESS" != "x" ]; then
+    cat <<EOF
+if cmostest $GRUB_BUTTON_CMOS_ADDRESS ; then
+   set default="${GRUB_DEFAULT_BUTTON}"
+else
+   set default="${GRUB_DEFAULT}"
+fi
+EOF
+else
+    cat <<EOF
 set default="${GRUB_DEFAULT}"
+EOF
+fi
+cat <<EOF
 if [ \${prev_saved_entry} ]; then
   set saved_entry=\${prev_saved_entry}
   save_env saved_entry
@@ -186,21 +204,36 @@ insmod gettext
 EOF
 fi
 
-if [ "x${GRUB_HIDDEN_TIMEOUT}" != "x" ] ; then
-  if [ "x${GRUB_HIDDEN_TIMEOUT_QUIET}" = "xtrue" ] ; then
-    verbose=
-  else
-    verbose=" --verbose"
-  fi
-  cat << EOF
-if sleep$verbose --interruptible ${GRUB_HIDDEN_TIMEOUT} ; then
-  set timeout=${GRUB_TIMEOUT}
+make_timeout ()
+{
+    if [ "x${1}" != "x" ] ; then
+	if [ "x${GRUB_HIDDEN_TIMEOUT_QUIET}" = "xtrue" ] ; then
+	    verbose=
+	else
+	    verbose=" --verbose"
+	fi
+	cat << EOF
+if sleep$verbose --interruptible ${1} ; then
+  set timeout=${2}
 fi
 EOF
-else
-  cat << EOF
-set timeout=${GRUB_TIMEOUT}
+    else
+	cat << EOF
+set timeout=${2}
 EOF
+    fi
+}
+
+if [ "x$GRUB_BUTTON_CMOS_ADDRESS" != "x" ]; then
+    cat <<EOF
+if cmostest $GRUB_BUTTON_CMOS_ADDRESS ; then
+EOF
+make_timeout "${GRUB_HIDDEN_TIMEOUT_BUTTON}" "${GRUB_TIMEOUT_BUTTON}"
+echo else
+make_timeout "${GRUB_HIDDEN_TIMEOUT}" "${GRUB_TIMEOUT}"
+echo fi
+else
+make_timeout "${GRUB_HIDDEN_TIMEOUT}" "${GRUB_TIMEOUT}"
 fi
 
 # Play an initial tune