Oh, to hell with all this screwy business with savedefault in Grub 2. Let’s just set the default in userspace.
$ cat /etc/rc.local
#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.
/usr/bin/perl <<'END'
# Set grub default menu entry by inspecting /proc/cmdline and
# looking for its contents in /boot/grub/grub/cfg
# [ccshan 2010年06月21日]
use strict;
my $cmdline;
{
open my $fh, '<', '/proc/cmdline' or die $!;
local $/;
$cmdline = <$fh>;
close $fh;
}
$cmdline =~ s/\A\s*BOOT_IMAGE=//;
$cmdline =~ s/\s+\z//;
open my $fh, '<', '/boot/grub/grub.cfg' or die $!;
my $title;
while (<$fh>)
{
if (/^\s*menuentry\s+'([^']*)'/)
{ $title = 1ドル }
elsif (defined $title and /^\s*linux\s+(.*\S)/ and 1ドル eq $cmdline)
{ exec "/usr/sbin/grub-set-default", $title }
}
close $fh;
print STDERR "Cannot find menu entry to set default\n";
END
exit 0$ cat /etc/default/grub
# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
GRUB_DEFAULT=saved
...