href="mailto:rodsmith@rodsbooks.com">rodsmith@rodsbooks.com</a></p>
<p>Originally written: 3/19/2012; last Web page update:
-12/16/2012, referencing rEFInd 0.6.0</p>
+2/3/2013, referencing rEFInd 0.6.7</p>
<p>I'm a technical writer and consultant specializing in Linux technologies. This Web page is provided free of charge and with no annoying outside ads; however, I did take time to prepare it, and Web hosting does cost money. If you find this Web page useful, please consider making a small donation to help keep this site up and running. Thanks!</p>
<hr />
+<div style="float:right; width:55%">
+
<p>Windows and Mac OS X both provide relatively simple EFI boot loader programs. Launch them, and if they're launched from the correct locations and have the correct files in place, they'll boot their respective OSes. This makes rEFInd's job easy; it just locates the boot loader program files and runs them.</p>
+</div>
+
+<div class="navbar">
+
+<h4 class="tight">Contents</h4>
+
+<ul>
+
+<li class="tight"><a href="#traditional">Using a Traditional Linux Boot Loader</li>
+
+<li class="tight"><a href="#quickstart">Using the EFI Stub Loader: Three Configuration Options</a>
+
+<ul>
+
+<li class="tight"><a href="#easiest">For Those With Foresight or Luck: The Easiest Method</a></li>
+
+<li class="tight"><a href="#testing">Preparing a Test Configuration</a></li>
+
+<li class="tight"><a href="#reconfigure">If You Need to Reconfigure Your Partitions....</a></li>
+
+</ul></li>
+
+<li class="tight"><a href="#efistub">EFI Stub Loader Support Technical Details</a></li>
+
+</ul>
+
+</div>
+
<p>Under Linux, by contrast, things can get complicated. As detailed on my <a href="http://www.rodsbooks.com/efi-bootloaders/index.html">Managing EFI Boot Loaders for Linux</a> page, several different EFI boot loaders for Linux exist, and all of them require configuration. If you're lucky, your distribution will have set up a Linux boot loader in a sensible way, in which case rEFInd should detect it and it will work as easily as a Windows or Mac OS X boot loader. If you're not lucky, though, you may need to configure it further. rEFInd offers options to help out with this task. Naturally, rEFInd supports <a href="#traditional">traditional Linux boot loaders.</a> It works even better with the Linux EFI stub loader, so I provide <a href="#quickstart">instructions on starting with it.</a> For those interested in manual configuration, I also provide <a href="#efistub">detailed instructions</a> on how the EFI stub support works and how to configure it.</p>
<a name="traditional">
<p>If you prefer, you can disable automatic scanning and create an entry in <tt>refind.conf</tt> for your distribution, as described on the <a href="configfile.html">Configuring the Boot Manager</a> page. This method is harder to set up but can be preferable if you want to customize your options.</p>
<a name="quickstart">
-<h2>Using the EFI Stub Loader: A Quick Setup Guide</h2>
+<h2>Using the EFI Stub Loader: Three Configuration Options</h2>
</a>
-<p>The EFI stub loader is basic and reliable, but it requires some setup to use it on some computers. I
describe three methods of using it: an <a href="#easiest">easiest method</a> for those with compatible partition and filesystem layouts, a <a href="#testing">quick test configuration</a> for those without such a layout, and <a href="#longterm">a long-term setup</a> for those without the ideal setup.</p>
+<p>The EFI stub loader is basic and reliable, but it requires some setup to use it on some computers. I
t also requires that you run a kernel with the same bit width as your EFI. In most cases, this means running a 64-bit kernel, since 32-bit EFI-based computers are so rare. I describe three methods of using the EFI stub loader: an <a href="#easiest">easiest method</a> for those with compatible partition and filesystem layouts, a <a href="#testing">quick test configuration</a> for those without such a layout, and <a href="#longterm">a long-term setup</a> for those without the ideal setup.</p>
<a name="easiest">
<h3>For Those With Foresight or Luck: The Easiest Method</h3>
<p>When you reboot, you should see rEFInd options for your Linux kernels. If they work, your job is done, although you might want to apply some of the tweaks described in the <a href="#longterm">maintenance-free setup</a> section. If you have problems, you may need to adjust the <tt>refind_linux.conf</tt> file, as described in the <a href="#efistub">detailed configuration section.</a></p>
<a name="testing">
-<h3>Testing the EFI Stub Loader</h3>
+<h3>Preparing a Test Configuration</h3>
</a>
<p>If you're not sure you want to use the EFI stub loader in the long term, you can perform a fairly quick initial test of it. This procedure assumes that you have access to a 3.3.0 or later Linux kernel with EFI stub support compiled into it. (Fedora 17, Ubuntu 12.10, and probably other distributions ship with such kernels.) Creating this configuration poses no risk to your current boot options, provided you don't accidentally delete existing files. The procedure for a quick test is:</p>
<p>You can continue to boot your computer with this type of configuration; however, the drawback is that you'll need to copy your kernel whenever it's updated. This can be a hassle. A better way is to configure you system so that the EFI, and therefore rEFInd, can read your Linux <tt>/boot</tt> directory, where most Linux distributions place their kernels.</p>
-<a name="longterm">
-<h3>Configuring a Maintenance-Free Setup</h3>
+<a name="reconfigure">
+<h3>If You Need to Reconfigure Your Partitions....</h3>
</a>
<p>If your <tt>/boot</tt> directory happens to be on an XFS, JFS, or Btrfs partition that the EFI can't read, or it's tucked away in an LVM or RAID configuration that the EFI can't read, you won't be able to use the <a href="#easiest">easiest solution.</a> Fortunately, this problem can be overcome with relatively little fuss. Several variant procedures are possible, but I begin by describing one that will almost always work, although it's got some important caveats (described at the end). You should perform the following steps as <tt>root</tt>, or precede each of these commands with <tt>sudo</tt>:</p>
<a name="refind_linux">
<pre class="listing">
-"Boot using default options" "root=/dev/sda3 ro quiet splash vt.handoff=7"
-"Boot into single-user mode" "root=UUID=1cd95082-bce0-494c-a290-d2e642dd82b7 ro single"
-"Boot without graphics" "root=UUID=1cd95082-bce0-494c-a290-d2e642dd82b7 ro"
-# "Boot alternate install" "root=/dev/sdb9 ro quiet splash vt.handoff=7"
+"Boot with standard options" "root=/dev/sda3 ro quiet splash vt.handoff=7"
+"Boot to single-user mode" "root=UUID=1cd95082-bce0-494c-a290-d2e642dd82b7 ro single"
+"Boot with minimal options" "root=UUID=1cd95082-bce0-494c-a290-d2e642dd82b7 ro"
+# "Boot alternate install" "root=/dev/sdb9 ro quiet splash vt.handoff=7"
</pre>
</a>
<p>In the preceding example, the first line sets the options that rEFInd passes to the kernel by default (along with the name of the <tt>initrd.img-3.3.0</tt> file, since its version string matches that of the kernel). The next two lines set options that you can obtain by pressing Insert, F2, or + on the main menu, as shown here:</p>
<br /><center><img src="automatic-submenu.png" align="center"
- width="376" height="279" alt="rEFInd can load Linux boot options from
+ width="471" height="189" alt="rEFInd can load Linux boot options from
a refind_linux.conf file in the Linux kernel's directory."
border=2></center><br />
<p>Ordinarily, a kernel booted in this way must reside on the ESP, or at least on another FAT partition. On a Macintosh, though, you can use HFS+ to house your kernel files. In fact, that may be necessary; my Mac Mini hangs when I try to boot a Linux kernel via an EFI stub loader from the computer's ESP, but it works fine when booting from an HFS+ partition. If you use <a href="drivers.html">EFI drivers,</a> though, you can place your kernel on any filesystem for which an EFI driver exists. This list is currently rather limited (ext2fs/ext3fs, ReiserFS, ISO-9660, and HFS+), but even just one or two options might help a lot if you've got an undersized ESP or if copying your kernel file to the ESP is a hassle you'd rather avoid.</p>
-<p>
Beginning with version 0.3.1, rEFInd sorts boot loader entries <i>within each directory</i> by time stamp, so that the most recent entry comes first. Thus, if you specify a directory name (or a volume label, for loaders stored in a volume's root directory) as the <tt>default_selection</tt>, rEFInd will make the most recent loader in the directory the default. This can obviate the need to adjust this configuration parameter when you add a new kernel; chances are you want the most recently-added kernel to be the default, and rEFInd makes it so when you set the <tt>default_selection</tt> in this way. If you <i>don't</i> want the latest kernel to become the default, you can use <tt>touch</tt> to give the desired kernel (or other boot loader) in the directory a more recent time stamp, or you can set <tt>default_selection</tt> to a value that uniquely identifies your desired default loader. One caveat you should keep in mind is that the EFI and Windows interpret the hardware clock as local time, whereas Mac OS X uses <a href="http://en.wikipedia.org/wiki/Coordinated_Universal_Time">Coordinated Universal Time (UTC)</a>. Linux can work either way. Thus, time stamps for boot loaders can be skewed by several hours depending on the environment in which they were created or last modified.</p>
+<p>rEFInd sorts boot loader entries <i>within each directory</i> by time stamp, so that the most recent entry comes first. Thus, if you specify a directory name (or a volume label, for loaders stored in a volume's root directory) as the <tt>default_selection</tt>, rEFInd will make the most recent loader in the directory the default. This can obviate the need to adjust this configuration parameter when you add a new kernel; chances are you want the most recently-added kernel to be the default, and rEFInd makes it so when you set the <tt>default_selection</tt> in this way. If you <i>don't</i> want the latest kernel to become the default, you can use <tt>touch</tt> to give the desired kernel (or other boot loader) in the directory a more recent time stamp, or you can set <tt>default_selection</tt> to a value that uniquely identifies your desired default loader. One caveat you should keep in mind is that the EFI and Windows interpret the hardware clock as local time, whereas Mac OS X uses <a href="http://en.wikipedia.org/wiki/Coordinated_Universal_Time">Coordinated Universal Time (UTC)</a>. Linux can work either way. Thus, time stamps for boot loaders can be skewed by several hours depending on the environment in which they were created or last modified.</p>
<p class="sidebar"><b>Tip for distribution maintainers:</b> If you maintain an <tt>EFI/<tt class="variable">distname</tt></tt> directory for your kernels, you can place your version of rEFInd in a directory called <tt>EFI/<tt class="variable">distname</tt>/refind</tt>. This will avoid collisions with duplicate rEFInd installations from other distributions.</p>