Difference between revisions of "Doc/isolinux"

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(Update to v.6.04-pre1, with minor modifications. Wiki formatting.)
m (Minor rewording. Wiki formatting.)
 
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[[Category:ISOLINUX]]
 
[[Category:ISOLINUX]]
 
'''This document is partially outdated. Please see [[ISOLINUX]].'''<br />
 
'''This document is partially outdated. Please see [[ISOLINUX]].'''<br />
''The content of doc/isolinux.txt (<!--release -->6.04-pre1, with minor corrections):''
+
''The content of doc/isolinux.txt (<!--release -->6.04-pre1, with minor modifications):''
  
 
<div style="color: black; background: none; font-weight: normal; margin: 0; padding-top: .5em; padding-bottom: .17em; border-bottom: 1px solid #aaa; font-size: 188%; text-align: center; "> <center> ISOLINUX </center> </div>
 
<div style="color: black; background: none; font-weight: normal; margin: 0; padding-top: .5em; padding-bottom: .17em; border-bottom: 1px solid #aaa; font-size: 188%; text-align: center; "> <center> ISOLINUX </center> </div>
  
<center>'''A bootloader for Linux using {{nowrap|ISO 9660/El Torito}} CD-ROMs'''</center>
+
<center>'''A bootloader for Linux using {{nowrap|1=ISO 9660/El Torito}} CD-ROMs'''</center>
  
 
<center>''Copyright 1994-2008 H. Peter Anvin - All Rights Reserved''</center>
 
<center>''Copyright 1994-2008 H. Peter Anvin - All Rights Reserved''</center>
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----
 
----
 
__toc__
 
__toc__
ISOLINUX is a boot loader for Linux/i386 that operates off {{nowrap|ISO 9660/El <!--
+
ISOLINUX is a boot loader for Linux/i386 that operates off {{nowrap|1=ISO 9660/El <!--
 
-->Torito}} CD-ROMs in "no emulation" mode.  This avoids the need to create  
 
-->Torito}} CD-ROMs in "no emulation" mode.  This avoids the need to create  
 
an "emulation disk image" with limited space (for "floppy emulation")  
 
an "emulation disk image" with limited space (for "floppy emulation")  
Line 25: Line 25:
 
be able to test it out:
 
be able to test it out:
  
Make sure you have a recent enough version of mkisofs.  I recommend  
+
Make sure you have a recent-enough version of mkisofs.  I recommend  
 
mkisofs 1.13 (distributed with cdrecord 1.9), but 1.12 might work as  
 
mkisofs 1.13 (distributed with cdrecord 1.9), but 1.12 might work as  
 
well (not tested).
 
well (not tested).
Line 32: Line 32:
 
prefer, "<tt>boot/isolinux</tt>") underneath the root directory of your ISO  
 
prefer, "<tt>boot/isolinux</tt>") underneath the root directory of your ISO  
 
image master file tree.  Copy isolinux.bin, a config file called  
 
image master file tree.  Copy isolinux.bin, a config file called  
"<tt>isolinux.cfg</tt>" (see [[doc/syslinux|syslinux.txt]] for details on the configuration  
+
"<tt>isolinux.cfg</tt>" &#8208; see [[doc/syslinux|syslinux.txt]] for details on the configuration  
file), and all necessary files (kernels, initrd, display files, etc.)  
+
file &#8208; and all necessary files (kernels, initrd, display files, etc.)  
into this directory, then use the following command to create your ISO  
+
into this directory. Then use the following command to create your ISO  
image (add additional options as appropriate, such as -J or -R):
+
image; add additional options as appropriate, such as {{nowrap|1="<tt>-J</tt>"}} or {{nowrap|1="<tt>-R</tt>":}}
 
{|
 
{|
 
|
 
|
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  <root-of-iso-tree>
 
  <root-of-iso-tree>
 
|}
 
|}
If you named the directory <tt>boot/isolinux</tt> that should of course be
+
If you named the directory as {{nowrap|1="<tt>boot/isolinux</tt>",}} that should of course be:
 
{|
 
{|
 
|
 
|
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--> search is from the isolinux directory (think of this as the "current <!--
 
--> search is from the isolinux directory (think of this as the "current <!--
 
--> directory").
 
--> directory").
* <s> . and .. in pathname searches are not supported.</s>
+
* <s> "." and ".." in pathname searches are not supported.</s>
 
* The maximum length of any pathname is 255 characters.
 
* The maximum length of any pathname is 255 characters.
  
Note that ISOLINUX only uses the "plain" ISO 9660 filenames, i.e. it  
+
<span id="note1"></span>
does not support Rock Ridge or Joliet filenames.  It can still be used  
+
Note that ISOLINUX <s>only</s> uses the "plain" ISO 9660 filenames, i.e. it  
 +
does not support <s>Rock Ridge</s><sup><small>&#91;[[#lnote1|1]]&#93;</small></sup><s> or</s> Joliet filenames.  It can still be used  
 
on a disk which uses Rock Ridge and/or Joliet extensions, of course.  
 
on a disk which uses Rock Ridge and/or Joliet extensions, of course.  
 
Under Linux, you can verify the plain filenames by mounting with the  
 
Under Linux, you can verify the plain filenames by mounting with the  
"<tt>-o norock,nojoliet</tt>" option to the mount command.  Note, however, that  
+
{{nowrap|1="<code>-o norock,nojoliet</code>"}} option to the mount command.  Note, however, that  
 
ISOLINUX does support "long" (level 2) ISO 9660 plain filenames, so if  
 
ISOLINUX does support "long" (level 2) ISO 9660 plain filenames, so if  
 
compatibility with short-names-only operating systems like MS-DOS is  
 
compatibility with short-names-only operating systems like MS-DOS is  
not an issue, you can use the "<tt>-l</tt>" or "<tt>-iso-level 2</tt>" option to mkisofs  
+
not an issue, you can use the {{nowrap|1="<tt>-l</tt>"}} or {{nowrap|1="<tt>-iso-level 2</tt>"}} option of mkisofs  
 
to generate long (up to 31 characters) plain filenames.
 
to generate long (up to 31 characters) plain filenames.
 +
 +
* <span id="lnote1"></span><sup><small>[[#note1|&#94;1]]</small></sup> <!--
 +
--> {{v|6.03+}} ISOLINUX supports Rock Ridge (too) since version 6.03.
 +
  
 
ISOLINUX does not support discontiguous files, interleaved mode, or  
 
ISOLINUX does not support discontiguous files, interleaved mode, or  
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not be a problem.
 
not be a problem.
  
ISOLINUX is by default built in two versions, one version with extra  
+
ISOLINUX is by default built in two versions; one version with extra  
 
debugging messages enabled.  If you are having problems with ISOLINUX,  
 
debugging messages enabled.  If you are having problems with ISOLINUX,  
 
I would greatly appreciate if you could try out the debugging version  
 
I would greatly appreciate if you could try out the debugging version  
(<tt>isolinux-debug.bin</tt>) and let me know what it reports.  The debugging  
+
{{nowrap|1=(<tt>isolinux-debug.bin</tt>)}} and let me know what it reports.  The debugging  
 
version does not include hybrid mode support (see below).
 
version does not include hybrid mode support (see below).
  
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these directories don't exist if you don't want ISOLINUX to use them.
 
these directories don't exist if you don't want ISOLINUX to use them.
  
<!-- -->
+
<!-- --><!--
<!-- The following paragraph is not part of the official documentation: -->
+
--><!-- The following paragraph is not part of the official documentation:  
<!-- -->
+
--><!-- -->
<small><font color=lightgray><!--
+
<small><font color="lightgray"><!--
 
-->See also [[Doc/syslinux#CONFIGURATION_FILE|Syslinux configuration file]]<!--
 
-->See also [[Doc/syslinux#CONFIGURATION_FILE|Syslinux configuration file]]<!--
 
--></font></small>
 
--></font></small>
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of the device for persistent storage by creating a second partition.
 
of the device for persistent storage by creating a second partition.
  
<!-- -->
+
<!-- --><!--
<!-- The following paragraph is not part of the official documentation: -->
+
--><!-- The following paragraph is not part of the official documentation:  
<!-- -->
+
--><!-- -->
<small><font color=lightgray><!--
+
<small><font color="lightgray"><!--
 
-->See also [[Isohybrid]]<!--
 
-->See also [[Isohybrid]]<!--
 
--></font></small>
 
--></font></small>
<!-- -->
 
  
<!-- The following section was included in the Syslinux wiki as of v.3.72. -->
+
<!--
<!-- The feature is no longer supported since 2011Apr. before v.4.05 was released. -->
+
--><!-- The following section was included in the Syslinux wiki as of v.3.72.  
<!-- commit: "isolinux: remove .img file support" -->
+
--><!-- The feature is no longer supported since 2011Apr. before v.4.05 was released.  
<!-- https://git.zytor.com/syslinux/syslinux.git/commit/?h=syslinux-4.05&id=b9f526b27b445b5a9b0845a598cc8babefed5f6d -->
+
--><!-- commit: "isolinux: remove .img file support"  
<!-- https://git.kernel.org/pub/scm/boot/syslinux/syslinux.git/commit/?h=syslinux-4.05&id=b9f526b27b445b5a9b0845a598cc8babefed5f6d -->
+
--><!-- https://git.zytor.com/syslinux/syslinux.git/commit/?h=syslinux-4.05&id=b9f526b27b445b5a9b0845a598cc8babefed5f6d  
<!-- https://repo.or.cz/syslinux.git/commit/b9f526b27b445b5a9b0845a598cc8babefed5f6d -->
+
--><!-- https://git.kernel.org/pub/scm/boot/syslinux/syslinux.git/commit/?h=syslinux-4.05&id=b9f526b27b445b5a9b0845a598cc8babefed5f6d  
<!-- -->
+
--><!-- https://repo.or.cz/syslinux.git/commit/b9f526b27b445b5a9b0845a598cc8babefed5f6d  
<!-- == BOOTING DOS (OR OTHER SIMILAR OPERATING SYSTEMS) == -->
+
--><!-- --><!--
<!-- -->
+
--><!-- == BOOTING DOS (OR OTHER SIMILAR OPERATING SYSTEMS) == --><!--
<!-- '''WARNING:''' This feature depends on BIOS functionality which is -->
+
--><!--
<!-- apparently broken in a very large number of BIOSes.  Therefore, this -->
+
--><!-- '''WARNING:''' This feature depends on BIOS functionality which is  
<!-- may not work on any particular system.  No workaround is possible; if -->
+
--><!-- apparently broken in a very large number of BIOSes.  Therefore, this  
<!-- you find that it doesn't work please complain to your vendor and -->
+
--><!-- may not work on any particular system.  No workaround is possible; if  
<!-- indicate that "<tt>{{nowrap|1=BIOS INT 13h AX=4C00h}}</tt> fails". -->
+
--><!-- you find that it doesn't work please complain to your vendor and  
<!-- -->
+
--><!-- indicate that "<tt>{{nowrap|1=BIOS INT 13h AX=4C00h}}</tt> fails".
<!-- To boot DOS, or other real-mode operating systems (protected-mode -->
+
--><!--  
<!-- operating systems may or may not work correctly), using ISOLINUX, you -->
+
--><!-- To boot DOS, or other real-mode operating systems (protected-mode  
<!-- need to prepare a disk image (usually a floppy image, but a hard disk -->
+
--><!-- operating systems may or may not work correctly), using ISOLINUX, you  
<!-- image can be used on *most* systems) with the relevant operating -->
+
--><!-- need to prepare a disk image (usually a floppy image, but a hard disk  
<!-- system.  This file should be included on the CD-ROM in the <tt>/isolinux</tt> -->
+
--><!-- image can be used on *most* systems) with the relevant operating  
<!-- directory, and have a <tt>.img</tt> extension.  The "<tt>.img</tt>" extension does not -->
+
--><!-- system.  This file should be included on the CD-ROM in the <tt>/isolinux</tt>  
<!-- have to be specified on the command line, but has to be explicitly -->
+
--><!-- directory, and have a <tt>.img</tt> extension.  The "<tt>.img</tt>" extension does not  
<!-- specified if used in a "<tt>kernel</tt>" statement in <tt>isolinux.cfg</tt>. -->
+
--><!-- have to be specified on the command line, but has to be explicitly  
<!-- -->
+
--><!-- specified if used in a "<tt>kernel</tt>" statement in <tt>isolinux.cfg</tt>.
<!-- For a floppy image, the size of the image should be exactly one of the -->
+
--><!--  
<!-- following: -->
+
--><!-- For a floppy image, the size of the image should be exactly one of the  
<!-- -->
+
--><!-- following:  
<!-- :::1,228,800 bytes        - For a 1200K floppy image -->
+
--><!--  
<!-- :::1,474,560 bytes        - For a 1440K floppy image -->
+
--><!-- :::1,228,800 bytes        - For a 1200K floppy image  
<!-- :::2,949,120 bytes        - For a 2880K floppy image -->
+
--><!-- :::1,474,560 bytes        - For a 1440K floppy image  
<!-- -->
+
--><!-- :::2,949,120 bytes        - For a 2880K floppy image  
<!-- Any other size is assumed to be a hard disk image.  In order to work -->
+
--><!--  
<!-- on as many systems as possible, a hard disk image should have exactly -->
+
--><!-- Any other size is assumed to be a hard disk image.  In order to work  
<!-- one partition, marked active, that covers the entire size of the disk -->
+
--><!-- on as many systems as possible, a hard disk image should have exactly  
<!-- image file.  Even so, hard disk images are not supported on all -->
+
--><!-- one partition, marked active, that covers the entire size of the disk  
<!-- BIOSes. -->
+
--><!-- image file.  Even so, hard disk images are not supported on all  
 +
--><!-- BIOSes. -->

Latest revision as of 13:45, 20 March 2020

This document is partially outdated. Please see ISOLINUX.
The content of doc/isolinux.txt (6.04-pre1, with minor modifications):

ISOLINUX
A bootloader for Linux using ISO 9660/El Torito CD-ROMs
Copyright 1994-2008 H. Peter Anvin - All Rights Reserved

This program is provided under the terms of the GNU General Public License, version 2 or, at your option, any later version. There is no warranty, neither expressed nor implied, to the function of this program. Please see the included file COPYING for details.


ISOLINUX is a boot loader for Linux/i386 that operates off ISO 9660/El Torito CD-ROMs in "no emulation" mode. This avoids the need to create an "emulation disk image" with limited space (for "floppy emulation") or compatibility problems (for "hard disk emulation").

This documentation isn't here yet, but here is enough that you should be able to test it out:

Make sure you have a recent-enough version of mkisofs. I recommend mkisofs 1.13 (distributed with cdrecord 1.9), but 1.12 might work as well (not tested).

To create an image, create a directory called "isolinux" (or, if you prefer, "boot/isolinux") underneath the root directory of your ISO image master file tree. Copy isolinux.bin, a config file called "isolinux.cfg" ‐ see syslinux.txt for details on the configuration file ‐ and all necessary files (kernels, initrd, display files, etc.) into this directory. Then use the following command to create your ISO image; add additional options as appropriate, such as "-J" or "-R":

mkisofs -o <isoimage> \
	-b isolinux/isolinux.bin -c isolinux/boot.cat \
	-no-emul-boot -boot-load-size 4 -boot-info-table \
	<root-of-iso-tree>

If you named the directory as "boot/isolinux", that should of course be:

	-b boot/isolinux/isolinux.bin -c boot/isolinux/boot.cat

ISOLINUX resolves pathnames the following way:

  • A pathname consists of names separated by slashes, Unix-style.
  • A leading "/" means it searches from the root directory[of the ISO 9660 filesystem]; otherwise the search is from the isolinux directory (think of this as the "current directory").
  • "." and ".." in pathname searches are not supported.
  • The maximum length of any pathname is 255 characters.

Note that ISOLINUX only uses the "plain" ISO 9660 filenames, i.e. it does not support Rock Ridge[1] or Joliet filenames. It can still be used on a disk which uses Rock Ridge and/or Joliet extensions, of course. Under Linux, you can verify the plain filenames by mounting with the "-o norock,nojoliet" option to the mount command. Note, however, that ISOLINUX does support "long" (level 2) ISO 9660 plain filenames, so if compatibility with short-names-only operating systems like MS-DOS is not an issue, you can use the "-l" or "-iso-level 2" option of mkisofs to generate long (up to 31 characters) plain filenames.

  • ^1 [6.03+] ISOLINUX supports Rock Ridge (too) since version 6.03.


ISOLINUX does not support discontiguous files, interleaved mode, or logical block and sector sizes other than 2048. This should normally not be a problem.

ISOLINUX is by default built in two versions; one version with extra debugging messages enabled. If you are having problems with ISOLINUX, I would greatly appreciate if you could try out the debugging version (isolinux-debug.bin) and let me know what it reports. The debugging version does not include hybrid mode support (see below).


NOTE ON THE CONFIG FILE DIRECTORY

ISOLINUX will search for the config file directory in the order

  1. /boot/isolinux
  2. /isolinux
  3. /

The first directory that exists is used, even if it contains no files. Therefore, please make sure that these directories don't exist if you don't want ISOLINUX to use them.

See also Syslinux configuration file


HYBRID CD-ROM/HARD DISK MODE

Starting in version 3.72, ISOLINUX supports a "hybrid mode" which can be booted from either CD-ROM or from a device which BIOS considers a hard disk or ZIP disk, e.g. a USB key or similar.

To enable this mode, the .iso image should be post-processed with the "isohybrid" script from the utils directory:

isohybrid filename.iso

This script creates the necessary additional information to be able to boot in hybrid mode. It also pads out the image to an even multiple of 1 MB.

This image can then be copied using any raw disk writing tool (on Unix systems, typically "dd" or "cat") to a USB disk, or written to a CD-ROM using standard CD burning tools.

The ISO 9660 filesystem is encapsulated in a partition (which starts at offset zero, which may confuse some systems). This makes it possible for the operating system, once booted, to use the remainder of the device for persistent storage by creating a second partition.

See also Isohybrid