The Linux CD-ROM HOWTO
Jeff Tranter, Jeff_Tranter@Mitel.COM
v1.4, 2 December 1994
This document describes how to install, configure, and use CD-ROM
drives under Linux. It lists the supported hardware and answers a num-
ber of frequently asked questions. The intent is to bring new users up
to speed quickly and reduce the amount of traffic in the usenet news
groups.
1. Introduction
This is the Linux CD-ROM HOWTO document. It is intended as a quick
reference covering everything you need to know to install and
configure CD-ROM hardware under Linux. Frequently asked questions
related to CD-ROM are answered, and references are given to other
sources of information related to CD-ROM applications and technology.
1.1. Acknowledgments
Much of this information came from the file README.sbpcd provided with
the Linux kernel source code and written by Eberhard Moenkeberg
(eberhard_moenkeberg@rollo.central.de), the internet alt.cd-rom FAQ,
and input from Linux users.
Thanks to the Linuxdoc-SGML package, this HOWTO is available in
several formats, all generated from a common source file.
1.2. Revision History
Version 1.0
first version made publicly available
Version 1.1
CDU33A is explicitly supported as of 1.1.20 kernel; notes on
Reveal FX; info on reading audio tracks; info on some alpha
drivers; added troubleshooting section; a few other minor
additions
Version 1.2
ISO9660 file systems must be mounted read-only starting with
1.1.33 kernel; clarified that SB16 SCSI is supported and newer
Aztech drives are not supported; references to photocd and xpcd
programs; note new on sbpcd autoeject feature
Version 1.3
minor change to the way SBPCD eject feature is disabled starting
with the 1.1.49 kernel; added info on XA discs and how to
identify them
Version 1.4
HOWTO now available in other languages; IBM and Longshine drives
now supported by SBPCD; alpha driver for Aztech drives; CDU-33
driver no longer auto-probes, supports PhotoCD and audio; more
than 2 SCSI drives are supported; new driver for IDE; reminder
to check drive jumpers; can now set SBPCD auto-eject with IOCTL;
list drivers with multisession support; question on flashing
light on CDU-33
1.3. New Versions Of This Document
New versions of this document will be periodically posted to
comp.os.linux.announce. They will also be uploaded to various
anonymous ftp sites that archive such information including
sunsite.unc.edu:/pub/Linux/docs/HOWTO.
Hypertext versions of this and other Linux HOWTOs are available on
many World-Wide-Web sites. You can also buy printed copies from
several vendors.
A French translation of this HOWTO, by Bruno Cornec
(cornec@stna7.stna.dgac.fr) is available at
ftp.ibp.fr:/pub2/linux/french/docs/HOWTO. A Japanese translation is
also in progress.
1.4. Feedback
I rely on you, the users, to make this HOWTO useful. If you have any
suggestions, corrections, or comments, please send them to the author
and I will try to incorporate them in the next revision.
2. CD-ROM Technology
"CD-ROM is read-only memory, and audio compact disc system is
available as package-media of digital data for those purpose. For
playing audio CD, please insert Head-phone jack."
--- from a CD-ROM instruction manual
Don't Panic! The world of CD-ROM technology is not as confusing as
your instruction manual.
CD-ROM stands for Compact Disc Read-Only Memory, a mass storage medium
utilizing an optical laser to read microscopic pits on the aluminized
layer of a polycarbonate disc. The same format is used for audio
Compact Discs. Because of its high storage capacity, reliability, and
low cost, CD-ROM has become an increasingly popular storage media.
The storage capacity of a CD-ROM disc is approximately 650 megabytes,
equivalent to over 500 high density 3.5" floppy disks or roughly
250,000 typed pages.
First generation drives (known as single speed), provide a transfer
rate of approximately 150 kilobytes per second. Double speed drives
are commonly available, and triple and quad speed drives have recently
been introduced.
Most CD-ROM drives use either the Small Computer Systems Interface
(SCSI) or a vendor proprietary interface. They also typically support
playing audio CDs via an external headphone jack or line level output.
CD-ROMs are usually formatted with an ISO-9660 (formerly called High
Sierra) file system. This format restricts filenames to the MS-DOS
style (8+3 characters). The Rock Ridge Extensions use undefined fields
in the ISO-9660 standard to support longer filenames and additional
Unix style information (e.g. file ownership, symbolic links, etc.).
PhotoCD is a standard developed by Kodak for storing photographic
images as digital data on a CD-ROM. With appropriate software, you can
view the images on a computer, manipulate them, or send them to a
printer.
CD recorders (CD-R) have recently become available. They use a
different media and specialized equipment for recording, but the
resulting disc can be read by any CD-ROM drive.
3. Supported Hardware
This section lists the CD-ROM drivers and interfaces that are
currently supported under Linux. The information here is based on the
latest Linux kernel, which at time of writing was version 1.1.69.
3.1. SCSI CD-ROM Drives
SCSI (Small Computer Systems Interface) is a popular format for CD-ROM
drives. Its chief advantages are a reasonably fast transfer rate,
multi-device capability, and support on a variety of computer
platforms.
Any SCSI CD-ROM drive with a block size of 512 or 2048 bytes should
work under Linux; this includes the vast majority of CD-ROM drives on
the market.
You will also need a supported SCSI controller card; see the SCSI
HOWTO for more information on interface hardware.
Note that some CD-ROMs include a controller with a modified interface
that is not fully SCSI compatible (e.g. it may not support adding
other SCSI devices on the bus).
3.2. Proprietary CD-ROM Drives
Several CD-ROM drives using proprietary interfaces are available; the
interface is often provided on a sound card. Simple interface cards
equivalent to that provided on the sound card are also available.
These drives generally tend to be lower in cost and smaller than SCSI
drives.
The following proprietary CD-ROM drives are supported by the Linux
kernel (drives listed together are compatible):
o Matsushita/Kotobuki/Panasonic/Creative Labs models CR-521, CR-522,
CR-523, CR-562, CR-563, Longshine LCS-7260, IBM
o Mitsumi/Radio Shack
o Sony CDU31A and CDU33A
o Sony CDU535 and CDU531 (driver is available as a kernel patch)
o LMS/Philips CD205/225/202 (driver is available as a kernel patch)
o NEC CDR-260 (driver is available as a kernel patch)
o Aztech CD268A (driver is available as a kernel patch)
The following sound card interfaces are supported:
o SoundBlaster/Pro
o SoundBlaster/16 (both the proprietary interface and SCSI versions)
o Galaxy
o SoundFX
o Spea Media FX sound card (Sequoia S-1000)
The following interface cards are also supported:
o Panasonic CI-101P
o LaserMate
o Aztech (see below)
o WDH-7001C
IBM sells an external CD-ROM drive and interface card that is
compatible with the Panasonic CR-562 driver.
Only the older Aztech drives compatible with the Matsushita/Panasonic
driver. There is an ALPHA driver available separately for the CD268A
drive. You can find it at ftp.gwdg.de in the directory
pub/linux/cdrom/drivers/aztech.
Drivers for some additional devices are in development and may be
available as kernel patches. They can most likely be found on
sunsite.unc.edu in the directory /pub/Linux/kernel/patches/cdrom.
Check the Linux Software Map for availability.
3.3. IDE CD-ROM Drives
CD-ROM drives based on a modified version the IDE hard disk (ATAPI)
standard have recently been introduced. One such drive is the NEC
CDR-260. An alpha release of a Linux kernel driver for IDE hard disks
and CD-ROM drives is available on sunsite.unc.edu. It works with the
NEC CDR-260 and possibly others.
Note that the proprietary interfaces are sometimes erroneously
referred to as IDE interfaces, because like IDE, they use a simple
interface based on the PC/AT bus.
4. Installation
Installation of CD-ROM under Linux consists of these steps:
1. Installing the hardware.
2. Configuring and building the Linux kernel.
3. Creating the necessary device files.
4. Mounting the media.
4.1. Installing Hardware
Follow the manufacturer's instructions for installing the hardware or
have your dealer perform the installation. The details will vary
depending on whether the drive is internal or external and on the type
of interface used. There are no special installation requirements for
Linux. You may need to set jumpers on the drive and/or interface card
for correct operation.
4.2. Configuring and Building the Kernel
In order to use a CD-ROM you need the appropriate device drivers. To
mount most CD-ROM discs you also need the ISO-9660 file system support
in the kernel. Follow your usual procedure for building the kernel: do
a "make config" and select the appropriate drivers when prompted.
For SCSI CD-ROMs you need to answer "yes" to "SCSI support?", and then
enable "Scsi CDROM support" and the driver for the appropriate SCSI
interface (e.g. "Adaptec AHA1542 support").
For the proprietary interface drives, select "Sony CDU31A/CDU33A CDROM
driver support", "Mitsumi CDROM driver support", or
"Matsushita/Panasonic CDROM driver support", according to your drive
type. The Matsushita driver also supports up to 4 controllers.
For other drive types you must obtain the driver separately and apply
it as a kernel patch.
If you are using the Matsushita/Panasonic drive, you have the choice
of letting the kernel auto-probe for the drive, passing it on the
kernel command line, or explicitly setting it in the file
/usr/src/linux/include/linux/sbpcd.h. It is recommended that you
initially set it to auto-probe. Later you can set the type and save
some time during bootup.
As of the 1.1.64 kernel, autoprobing for the CDU-31A drives has been
removed. You now need to either add your drive to the configuration
table in the driver or use a LILO boot-line configuration. The format
of the LILO command line is:
______________________________________________________________________
cdu31a=<I/O address>,<interrupt>[,PAS]
______________________________________________________________________
Setting the interrupt to 0 will disable the interrupts and use polled
I/O. The PAS option is for ProAudioSpectum16 sound card users that
are not using the sound driver. A typical card would have a
configuration like one of the following:
______________________________________________________________________
cdu31a=0x340,0
cdu31a=0x340,5
______________________________________________________________________
The easiest way to set this up is to add a line such as the following
to your LILO configuration file:
______________________________________________________________________
append="cdu31a=0x1f88,0,PAS"
______________________________________________________________________
Again, remember to compile in the ISO-9660 file system support. The
Rock Ridge extensions are fully supported by the kernel driver.
If you have a sound card that is supported under Linux, you should
enable and configure the kernel sound driver at this time as well.
After selecting the device drivers, compile the kernel and install it
following your usual procedure.
4.3. Creating the Device Files
If you are running a standard Linux distribution you may have created
the necessary device files during installation. Under Slackware
Linux, for example, there is a menu-based setup tool that includes CD-
ROM setup, and most systems have a /dev/MAKEDEV script. It is
recommended that you at least verify the device files against the
information in this section.
Create the device file by running the shell commands indicated for
your drive type. This should be done as user root. Note that some
Linux distributions may use slightly different CD-ROM device names
from those listed here.
It is recommended that you also create a symbolic link to the CD-ROM
device to make it easier to remember. For example, for a Panasonic CD-
ROM drive, the link would be created using
______________________________________________________________________
% ln -s /dev/sbpcd /dev/cdrom
______________________________________________________________________
If you want to play audio CDs, you will need to set the protection on
the device files to allow users to read and write, e.g.
______________________________________________________________________
% chmod 666 /dev/sbpcd
______________________________________________________________________
4.3.1. Matsushita/Kotobuki/Panasonic/Creative Labs/IBM
Up to four drives per controller are supported. Only the first device
is needed if you have only one drive. If you have more than one
controller, create devices with major numbers 26, 27, and 28, up to a
maximum of 4 controllers (this is 16 CD-ROM drives in total; hopefully
enough for most users :-).
______________________________________________________________________
% mknod /dev/sbpcd b 25 0
% mknod /dev/sbpcd0 b 25 0
% mknod /dev/sbpcd1 b 25 1
% mknod /dev/sbpcd2 b 25 2
% mknod /dev/sbpcd3 b 25 3
______________________________________________________________________
4.3.2. Sony CDU31A/CDU33A
Only one drive is supported by this kernel driver. See the comments in
the file /usr/src/linux/drivers/block/cdu31a.c for information on
configuring the interface card. As of the 1.1.60 kernel, the driver
supports playing audio CDs and PhotoCD (but not multisession yet).
______________________________________________________________________
% mknod /dev/cdu31a b 15 0
______________________________________________________________________
See the kernel source file cdu31a.c for information on configuring the
drive interface card. Also see the notes given previously about
specifying the configuration on the LILO command line.
4.3.3. Sony CDU535/CDU531
Note again that the driver is currently only available as a kernel
patch.
______________________________________________________________________
% mknod /dev/cdu535 b 24 0
______________________________________________________________________
Some Linux distributions use /dev/sonycd for this device. Older
versions of the driver used major device number 21; make sure your
device file is correct.
4.3.4. Mitsumi
The kernel supports one Mitsumi drive. Recent kernels (1.1.25)
incorporate changes to improve performance.
______________________________________________________________________
% mknod /dev/mcd b 23 0
______________________________________________________________________
4.3.5. LMS/Philips
Note again that this driver is currently only available as a kernel
patch. See the README file included with the patches for more
information.
______________________________________________________________________
% mknod /dev/lmscd b 24 0
______________________________________________________________________
4.3.6. SCSI
Multiple drives are supported (up to the limit of the number of
devices on the SCSI bus). Create device files with major number 11
and minor numbers starting at zero:
______________________________________________________________________
% mknod /dev/scd0 b 11 0
% mknod /dev/scd1 b 11 1
______________________________________________________________________
4.3.7. IDE Drives
Information on creating the devices files are included with the kernel
patch for these drives.
4.4. Mounting/Unmounting/Ejecting Devices
You can now reboot with the new kernel. Watch for a message such as
the following indicating that the CD-ROM has been found by the device
driver (the message will vary depending on the drive type):
______________________________________________________________________
SBPCD version 2.5 Eberhard Moenkeberg <emoenke@gwdg.de>
SBPCD: Looking for a SoundBlaster/Matsushita CD-ROM drive
SBPCD:
SBPCD: = = = = = = = = = = W A R N I N G = = = = = = = = = =
SBPCD: Auto-Probing can cause a hang (f.e. touching an ethernet card).
SBPCD: If that happens, you have to reboot and use the
SBPCD: LILO (kernel) command line feature like:
SBPCD:
SBPCD: LILO boot: linux sbpcd=0x230,SoundBlaster
SBPCD: or like:
SBPCD: LILO boot: linux sbpcd=0x300,LaserMate
SBPCD: or like:
SBPCD: LILO boot: linux sbpcd=0x330,SPEA
SBPCD:
SBPCD: with your REAL address.
SBPCD: = = = = = = = = = = END of WARNING = = = = = = = = = =
SBPCD:
SBPCD: Trying to detect a SoundBlaster CD-ROM drive at 0x230.
SBPCD: - Drive 0: CR-562-x (0.76)
SBPCD: 1 SoundBlaster CD-ROM drive(s) at 0x0230.
SBPCD: init done.
______________________________________________________________________
(If the bootup messages scroll by too quickly to read, you should be
able to retrieve them with the dmesg command)
To mount a CD-ROM, insert a disc in the drive, and run the mount
command as root (this assumes you created a symbolic link to your
device file as recommended above):
______________________________________________________________________
% mount -t iso9660 -r /dev/cdrom /mnt
______________________________________________________________________
The CD can now be accessed under the directory /mnt. Note that /mnt
is commonly used as a temporary mount point; a more suitable name for
a permanent installation might be something like /cdrom. There are
other options to the mount command that you may wish to use; see the
mount(8) man page for details.
You can add an entry to /etc/fstab to automatically mount a CD-ROM
when Linux boots or to specify parameters to use when it is mounted;
see the fstab(5) man page.
Note that to play audio CDs you should not try to mount them.
To unmount a CD-ROM, use the umount command as root:
______________________________________________________________________
% umount /mnt
______________________________________________________________________
The disc can only be unmounted if no processes are currently accessing
the drive (including having their default directory set to the mounted
drive). You can then eject the disc. Most drives have an eject button;
there is also a standalone eject program that allows ejecting CD-ROMs
under software control.
Note that you should not eject a disc while it is mounted (this may or
may not be possible depending on the type of drive). The sbpcd driver
will automatically eject a CD-ROM when it is unmounted and insert the
CD tray when a disc is mounted (you can turn this feature off when
compiling the kernel or by using a software command).
4.5. Troubleshooting
If you still encounter problems, here are some things to check.
If you recompiled the kernel yourself, verify that you are running the
new kernel by looking at the timestamp:
______________________________________________________________________
% uname -a
Linux fizzbin 1.1.31 #1 Wed Jul 20 16:53:35 EDT 1994 i386
______________________________________________________________________
With recent 1.1.x kernels, you can see what drivers are compiled in by
looking at /proc/devices:
______________________________________________________________________
% cat /proc/devices
Character devices:
1 mem
4 tty
5 cua
6 lp
14 sound
15 Joystick
Block devices:
2 fd
3 hd
25 sbpcd
______________________________________________________________________
If your drive has hardware jumpers for addressing, check that they are
set correctly (e.g. drive 0 if you have only one drive).
Try reading from the CD-ROM drive. Typing the following command should
cause the drive activity light come on and no errors should be
reported. Use whatever device file is appropriate for your drive and
make sure a CD-ROM is inserted; use Control-C to exit.
______________________________________________________________________
dd if=/dev/cdrom of=/dev/null bs=2048
^C
124+0 records in
124+0 records out
______________________________________________________________________
If you can read from the drive but cannot mount it, verify that you
compiled in ISO9660 file system support. With the 1.1.x kernels this
can be done as follows:
______________________________________________________________________
% cat /proc/filesystems
ext2
msdos
nodev proc
iso9660
______________________________________________________________________
Make sure you are mounting the drive with the "-t iso9660" and "-r"
options and that a known good CD-ROM (not Audio CD) is inserted in the
drive.
Make sure that the CD-ROM device files are correct, according to the
information in the previous section.
If you are running the syslog daemon, there may be error messages from
the kernel that you are not seeing. Try using the "dmesg" command:
______________________________________________________________________
% dmesg
SBPCD: sbpcd_open: no disk in drive
______________________________________________________________________
There may also be errors logged to files in /var/adm, depending on how
you system is configured.
5. Applications
This section briefly lists some of the key applications related to CD-
ROM that are available under Linux. Check the Linux Software Map for
the latest versions and archive sites.
5.1. Audio CD players
Several programs are available for playing audio CDs, either through a
headphone jack or an attached sound card.
Workman
a graphical player running under X11 and supporting a CD
database and many other features
WorkBone
an interactive text-mode player
xcdplayer
a simple X11 based player
cdplayer
a very simple command line based player
Xmcd
an X11/Motif based player
xmitsumi
another X11 based player for Mitsumi drives
xplaycd
another X11 based player, bundled with sound mixer and VU meter
programs
cdtool
command line tools for playing audio CDs
Some of these programs are coded to use a specific device file for the
CD-ROM (e.g. /dev/cdrom). You may be able to pass the correct device
name as a parameter, or you can create a symbolic link in the /dev
directory. If sending the CD output to a sound card, you may wish to
use a mixer program to set volume settings or select the CD-ROM input
for recording.
5.2. Inheriting File System
The Inheriting File System (IFS) is a kernel driver that allows
mounting multiple file systems at the same point. It is similar to the
Translucent File System provided under SunOS. By mounting a hard disk
directory over a CD-ROM file system, you can effectively obtain a
writable CD-ROM file system.
The current version is experimental and was written for the 0.99pl11
and pl12 kernels; it may or may not work with more recent revisions.
The author is Werner Almesberger (almesber@bernina.ethz.ch).
5.3. PhotoCD
PhotoCDs use an ISO-9660 file system containing image files in a
proprietary format. Not all CD-ROM drives support reading PhotoCDs.
The hpcdtoppm program by Hadmut Danisch converts PhotoCD files to the
portable pixmap format. It can be obtained from
ftp.gwdg.de:/pub/linux/hpcdtoppm or as part of the PBM (portable bit
map) utilities, available on many archive sites (look for "pbm" or
"netpbm").
The photocd program by Gerd Knorr kraxel@cs.tu-berlin.de can convert
PhotoCD images into targa or Windows and OS/2 bitmap files.
The same author has written the program xpcd, an X11-based program for
handling PhotoCD images. You can select the images with a mouse,
preview the image in a small window, and load the image with any of
the five possible resolutions. You can also mark a part of the Image
and load only the selected part. Look for these packages at ftp.cs.tu-
berlin.de:/pub/linux/Local/misc.
(I've actually tried a PhotoCD! If anyone wants more detail on how to
view files, etc... let me know and I can expand this section).
5.4. Mkisofs
Eric Youngdale's mkisofs package allows creating an ISO-9660 file
system on a hard disk partition. This can then be used to assist in
creating and testing CD-ROM file systems before mastering discs.
The tools for actually writing data to writable CD-ROM drives tend to
be vendor specific. They also require writing the data with no
interruptions, so a multitasking operating system like Linux is not
particularly well suited.
5.5. 9660_u
These are some utilities for verifying the format of ISO-9660
formatted discs; you may find them useful for testing suspect CDs. The
package can be found on ftp.cdrom.com in the /pub/ptf directory. They
were written by Bill Siegmund and Rich Morin.
6. Answers to Frequently Asked Questions
6.1. How can a non-root user mount and unmount discs?
Some mount commands support the user option. If you make an entry such
as the following in /etc/fstab:
______________________________________________________________________
/dev/sbpcd /cdrom iso9660 user,noauto,ro
______________________________________________________________________
then an ordinary user will be allowed to mount and unmount the drive
using these commands:
______________________________________________________________________
% mount /cdrom
% umount /cdrom
______________________________________________________________________
The disc will be mounted with some options that ensure security (e.g.
programs cannot executed, device files are ignored); in some cases
this may be too restrictive.
Another method is to get the usermount package which allows non-root
users to mount and unmount removable devices such as floppies and CD-
ROMs, but restricts access to other devices (such as hard disk
partitions). It is available on major archive sites.
The archive site ftp.cdrom.com has the source file mount.c which
allows mounting an unmounting of CD-ROMs (only) by normal users. It
runs as a setuid executable.
6.2. Why do I get device is busy when unmounting a CD-ROM?
The disc cannot be unmounted if any processes are accessing the drive,
including having their default directory set to the mounted
filesystem. If you cannot identify the processes using the disc, you
can use the fuser command, as shown in the following example.
______________________________________________________________________
% umount /cdrom
umount: /dev/sbpcd: device is busy
% fuser -v /cdrom
/cdrom: USER PID ACCESS COMMAND
tranter 50 ..c.. bash
______________________________________________________________________
6.3. How do I export a CD-ROM to other hosts over NFS?
You need to add an entry to the /etc/exports file; see the exports(5)
man page for details.
6.4. Can I boot Linux from a CD-ROM?
The easiest way to boot from CD-ROM is to use a boot floppy. Several
of the Linux CD-ROM distributions (e.g. Yggdrasil) include one, or you
can use the boot disk(s) from one of the Linux distributions (e.g.
Slackware) that includes the necessary CD-ROM drivers for your system.
In the future it may be possible to boot from IDE CD-ROM drives which
have the appropriate ROM BIOS functions.
6.5. Why doesn't the kernel recognize my CD-ROM drive?
If you have a proprietary interface at a non-standard address, you may
need to set the i/o port location in the appropriate kernel header
file. Similarly, auto-probing by the kernel driver may conflict with
another device (e.g. network card) and cause your system to hang.
For the Matsushita/Kotubuki/Panasonic/Creative Labs drives, you need
to edit the file sbpcd.h. For the Mitsumi drives it is mcd.h and for
Sony drives it is cdu31a.h. All of these files are normally installed
in /usr/include/linux. Alternatively you can set the drive parameters
on the LILO command line.
6.6. How can I read digital data from audio CDs?
Only a few CD-ROM drives support this. Heiko Eissfeldt
(heiko@colossus.escape.de) and Olaf Kindel have written a utility that
reads audio data and saves it as .wav format sound files. It only
works with the Toshiba XM3401 and XM4101 SCSI drives. The package is
called cdda2wav.tar.gz and can be found on sunsite.unc.edu.
The Panasonic SBPCD driver also has support for reading sound data
beginning with the 2.0 driver included in the 1.1.22 kernel. A
modified version of the cdda2wav program that works with this can be
found at ftp.gwdg.de in /pub/linux/misc/cdda2wav-sbpcd.2.tar.gz
Even though the standard cdda2wav program claims to support the
Panasonic drives, it does not yet work properly, because of the need
to handle "overlap" of the data.
The CDU-33 driver now supports reading audio data. It is said to work
with the cdda2wav program.
For more information on this subject, see the alt.cd-rom FAQ listed in
the references section.
6.7. How do I turn off the autoprobing messages on boot?
The SBPCD driver displays a lot of information during bootup. If you
want to suppress this, set the variable sbpcd_debug in the file
sbpcd.c. The comments in the file explain the various values that this
can be set to.
6.8. Why doesn't the find command work properly?
On ISO-9660 formatted discs without the Rock Ridge Extensions, you
need to add the -noleaf option to the find command.
The reason for this is that the number of links for each directory
file is not easily obtainable, so it is set to 2. The default behavior
for the find program is to look for (i_links - 2) subdirectories in
each directory, and it then assumes that the rest are regular files.
The -noleaf switch disables this optimization.
6.9. Is the Reveal Multimedia Effects kit CD-ROM supported?
(the following was provided by Horne@leader.pfc.mit.edu)
Here's what I discovered about the Reveal Multimedia kits that are
available fairly cheap ($300 or so) from department stores. After some
thrashing I discovered how to make the following CD work under linux.
This is a Reveal Multimedia FX kit, which includes a Sound FX SC400
sound card, which has interfaces for Sony CDU33A, Panasonic CR-563,
and Mitsumi LU005s. My kit includes a Sony.
The tricks to making the Sony CD work are as follows:
o Decide which kernel to patch. I pulled the 1.0 kernel off the
Trans-Ameritech CD-ROM via DOS (My system started out as SLS a long
time ago)
o Add addresses 0x634, 0x654 to the table at the top of the cdu31a
driver:
______________________________________________________________________
static unsigned short cdu31a_addresses[] =
{
0x340, /* Standard configuration Sony Interface */
0x1f88, /* Fusion CD-16 */
0x230, /* SoundBlaster 16 card */
0x360, /* Secondary standard Sony Interface */
0x320, /* Secondary standard Sony Interface */
0x330, /* Secondary standard Sony Interface */
0x634,
0x654,
0
};
______________________________________________________________________
o Recompile your kernel, specifying Sony CDU31A and ISO9960 support
o Create the device file (use major number 15, not 21 as in the
Transameritech doc)
______________________________________________________________________
% mknod /dev/cd b 15 0
______________________________________________________________________
o Mount the drive
______________________________________________________________________
% mount -t iso9660 -r /dev/cd /cdrom
______________________________________________________________________
I'm still working on the actual sound support (I don't really need it
yet) but that should be much easier.
Thanks to Reveal tech support for the info that the CD interface is at
0x414 off of the soundcard base address, Roman at Trans-Ameritech
(roman@btr.btr.com) who suggested patching the CDU31A driver, and Dale
Elrod (dale@post.dungeon.com) who provided an existence proof (Dale,
your zImage didn't recognize the drive - I expect you actually have
slightly different hardware. I'd have returned this thing a week ago,
though, if I hadn't thought you had it working.)
The original driver is due to minyard@wf-rch.cirr.com, and Linus made
it all possible.
6.10. Does Linux support any recordable CD-ROM drives?
According to Adam J. Richter, adam@yggdrasil.com:
The Yggdrasil distribution can drive a Philips CD writer with an
Adaptec 154x SCSI controller. I'm not sure which other SCSI
controllers, if any, will work. You can use mkisofs to make an
ISO-9660 filesystem and cdwrite to write it to the CD. If you want us
to help you set this up, you can call us on our 900 technical support
number: 1-900-446-6075 extension 835 (US$2.95/minute, U.S. only).
6.11. The eject function (e.g. from Workman) does not work!
The SBPCD driver had a problem where the drive could be locked and the
eject ioctl() would fail. This appears to be corrected starting with
the 1.1.29 kernel.
6.12. You say I need to configure and build a kernel - how do I do
that?
This is not the kernel HOWTO (any volunteers?). Until one is written,
try reading the file /usr/src/linux/README; it is reasonably complete.
If you really don't want to compile a kernel, you may be able to find
a precompiled kernel that has the drivers you need as part of a Linux
distribution (e.g. the Slackware "q" series of disks).
6.13. Why do I get mount: Read-only file system when mounting a CD-
ROM?
With older kernels you could mount a CD-ROM for read/write; attempts
to write data to the CD would not generate any errors. As of kernel
version 1.1.33 this was corrected so that CD-ROMs must be mounted read
only (e.g. using the -r option to mount).
6.14. Why does the disc tray open when I shut down the system?
As of the 1.1.38 kernel, the sbpcd driver ejects the CD when it is
unmounted or closed. If you shut down the system, a mounted CD will be
unmounted.
This feature is for convenience when changing discs. If the tray is
open when you mount or read a CD, it will also automatically be
closed.
I found that this caused problems with a few programs (e.g. cdplay and
workbone). As of the 1.1.60 kernel you can control this feature under
software control. A sample program is included in the README.sbpcd
file (or use the "eject" program).
6.15. I have a "special" CD that can't be mounted
The "special" CD is likely an XA disc (like all Photo CDs or "one-
offs" created using CD-R drives). Most of the Linux kernel CD-ROM
drivers do not support XA discs, although you may be able to find a
patch to add support on one of the archive sites.
The sbpcd driver does support XA. If you are using this driver you can
determine if the disc is XA using the following procedure: go into the
file sbpcd.c and enable the display of the "Table of Contents"
(DBG_TOC). Build and install the new kernel and boot from it. During
each mount the TOC info will be written (either to the console or to a
log file). If the first displayed value in the TOC header line is
"20", then it is an XA disc. That byte is "00" with normal disks. If
the TOC display shows different tracks, that is also a sign that it is
an XA disc.
(thanks to Eberhard Moenkeberg for the above information)
6.16. Which kernel drivers support multisession?
The SBPCD driver supports multisession.
The SCSI CD-ROM driver supports multisession with NEC and TOSHIBA
drives.
The CDU-31A driver has some multi-session support written but it does
not yet work.
Some drivers available as kernel patches may support multisession for
other drives.
6.17. Why does the drive light flash on my CDU-33 drive?
This is normal and was added in a recent revision of the driver. It
flashes the drive light when a CD is mounted (it's not a bug, it's a
feature...).
7. References
Information on the Panasonic CD-ROM driver can be found in the file
/usr/src/linux/drivers/block/README.sbpcd.
The following usenet FAQs are posted periodically to news.answers and
archived at internet FTP sites such as rtfm.mit.edu:
o alt.cd-rom FAQ
o comp.periphs.scsi FAQ
Several other Linux HOWTOs have useful information relevant to CD-ROM:
o SCSI HOWTO
o Hardware Compatibility HOWTO
o Sound HOWTO
o Distribution HOWTO
At least 10 companies sell Linux distributions on CD-ROM; most of them
are listed in the Distribution HOWTO.
The following Usenet news groups cover CD-ROM related topics:
o comp.publish.cdrom.hardware
o comp.publish.cdrom.multimedia
o comp.publish.cdrom.software
o comp.sys.ibm.pc.hardware.cd-rom
o alt.cd-rom
o alt.cd-rom.reviews
The internet site ftp.cdrom.com has a large archive of CD-ROM
information and software; look in the directory /pub/cdrom.
The Linux Documentation Project has produced several books on Linux,
including Linux Installation and Getting Started. These are freely
available by anonymous FTP from major Linux archive sites or can be
purchased in hardcopy format.
The Linux Software Map (LSM) is an invaluable reference for locating
Linux software. The LSM can be found on various anonymous FTP sites,
including sunsite.unc.edu:/pub/Linux/docs/LSM.gz.