device2grub

[Michael Goetze]

Hi,

as some of you have may have heard I'm working on CentOS support for FAI 
4.0. One of the problems I have is the following: during the 
installation, I have a Squeeze kernel with a Squeeze udev. After the 
installation, I will have a much older CentOS kernel with a much older 
CentOS udev, and devices may have different names (hda vs. sda and so 
on). However, device2grub depends on $target/boot/grub/device.map. I 
would have to generate this file, even though the contents would 
possibly be wrong after the installation.

Therefore, I propose to make device2grub independent of $target. An 
example implementation can be found below. However, this may have 
unforeseen consequences, so I would like to ask whether anyone sees a 
problem with this change for FAI 4.0.

--- device2grub.orig    2011-02-10 21:29:03.394046849 +0100
+++ device2grub    2011-02-10 21:51:43.217071970 +0100
@@ -2,6 +2,7 @@

  # $Id: device2grub 5910 2010-07-29 23:50:20Z lange $
  # copyright Thomas Lange 2001-2010, lange at debian.org
+# copyright Michael Goetze 2011, mgoetze at mgoetze.net
  # map "normal" device notation to grub notation

  # TODO: read from stdin if no parameter given
@@ -14,10 +15,13 @@
  my %map;

  my $device=shift;
-my $devicemap="$ENV{target}/boot/grub/device.map";
+my $devicemap = `mktemp`;
+chomp $devicemap;
  my $devbyid = "/dev/disk/by-id";

-open (DEVICEMAP,"<$devicemap") || die "Can't open $devicemap\n";
+system("/usr/sbin/grub-mkdevicemap", "-m", "$devicemap") == 0 or die 
"Could not run grub-mkdevicemap\n";
+
+open (DEVICEMAP,"<$devicemap") || die "Can't open device map $devicemap\n";
  while (<DEVICEMAP>) {
    my ($grubdevice,$olddevice) = split;
    $map{$olddevice} = $grubdevice;
@@ -53,4 +57,5 @@
  }

  print "$grubdevice\n";
+unlink("$devicemap");
  exit 0;


Regards,
Michael