1 IDE-CD driver documentation
2 Originally by scott snyder <snyder@fnald0.fnal.gov> (19 May 1996)
3 Carrying on the torch is: Erik Andersen <andersee@debian.org>
4 New maintainers (19 Oct 1998): Jens Axboe <axboe@image.dk>
9 The ide-cd driver should work with all ATAPI ver 1.2 to ATAPI 2.6 compliant
10 CDROM drives which attach to an IDE interface. Note that some CDROM vendors
11 (including Mitsumi, Sony, Creative, Aztech, and Goldstar) have made
12 both ATAPI-compliant drives and drives which use a proprietary
13 interface. If your drive uses one of those proprietary interfaces,
14 this driver will not work with it (but one of the other CDROM drivers
15 probably will). This driver will not work with `ATAPI' drives which
16 attach to the parallel port. In addition, there is at least one drive
17 (CyCDROM CR520ie) which attaches to the IDE port but is not ATAPI;
18 this driver will not work with drives like that either (but see the
21 This driver provides the following features:
23 - Reading from data tracks, and mounting ISO 9660 filesystems.
25 - Playing audio tracks. Most of the CDROM player programs floating
26 around should work; I usually use Workman.
28 - Multisession support.
30 - On drives which support it, reading digital audio data directly
31 from audio tracks. The program cdda2wav can be used for this.
32 Note, however, that only some drives actually support this.
34 - There is now support for CDROM changers which comply with the
35 ATAPI 2.6 draft standard (such as the NEC CDR-251). This additional
36 functionality includes a function call to query which slot is the
37 currently selected slot, a function call to query which slots contain
38 CDs, etc. A sample program which demonstrates this functionality is
39 appended to the end of this file. The Sanyo 3-disc changer
40 (which does not conform to the standard) is also now supported.
41 Please note the driver refers to the first CD as slot # 0.
47 0. The ide-cd relies on the ide disk driver. See
48 Documentation/ide/ide.txt for up-to-date information on the ide
51 1. Make sure that the ide and ide-cd drivers are compiled into the
52 kernel you're using. When configuring the kernel, in the section
53 entitled "Floppy, IDE, and other block devices", say either `Y'
54 (which will compile the support directly into the kernel) or `M'
55 (to compile support as a module which can be loaded and unloaded)
58 Enhanced IDE/MFM/RLL disk/cdrom/tape/floppy support
59 Include IDE/ATAPI CDROM support
63 Use old disk-only driver on primary interface
65 Depending on what type of IDE interface you have, you may need to
66 specify additional configuration options. See
67 Documentation/ide/ide.txt.
69 2. You should also ensure that the iso9660 filesystem is either
70 compiled into the kernel or available as a loadable module. You
71 can see if a filesystem is known to the kernel by catting
74 3. The CDROM drive should be connected to the host on an IDE
75 interface. Each interface on a system is defined by an I/O port
76 address and an IRQ number, the standard assignments being
77 0x1f0 and 14 for the primary interface and 0x170 and 15 for the
78 secondary interface. Each interface can control up to two devices,
79 where each device can be a hard drive, a CDROM drive, a floppy drive,
80 or a tape drive. The two devices on an interface are called `master'
81 and `slave'; this is usually selectable via a jumper on the drive.
83 Linux names these devices as follows. The master and slave devices
84 on the primary IDE interface are called `hda' and `hdb',
85 respectively. The drives on the secondary interface are called
86 `hdc' and `hdd'. (Interfaces at other locations get other letters
87 in the third position; see Documentation/ide/ide.txt.)
89 If you want your CDROM drive to be found automatically by the
90 driver, you should make sure your IDE interface uses either the
91 primary or secondary addresses mentioned above. In addition, if
92 the CDROM drive is the only device on the IDE interface, it should
93 be jumpered as `master'. (If for some reason you cannot configure
94 your system in this manner, you can probably still use the driver.
95 You may have to pass extra configuration information to the kernel
96 when you boot, however. See Documentation/ide/ide.txt for more
99 4. Boot the system. If the drive is recognized, you should see a
100 message which looks like
102 hdb: NEC CD-ROM DRIVE:260, ATAPI CDROM drive
104 If you do not see this, see section 5 below.
106 5. You may want to create a symbolic link /dev/cdrom pointing to the
107 actual device. You can do this with the command
109 ln -s /dev/hdX /dev/cdrom
111 where X should be replaced by the letter indicating where your
114 6. You should be able to see any error messages from the driver with
121 An ISO 9660 CDROM can be mounted by putting the disc in the drive and
124 mount -t iso9660 /dev/cdrom /mnt/cdrom
126 where it is assumed that /dev/cdrom is a link pointing to the actual
127 device (as described in step 5 of the last section) and /mnt/cdrom is
128 an empty directory. You should now be able to see the contents of the
129 CDROM under the /mnt/cdrom directory. If you want to eject the CDROM,
130 you must first dismount it with a command like
134 Note that audio CDs cannot be mounted.
136 Some distributions set up /etc/fstab to always try to mount a CDROM
137 filesystem on bootup. It is not required to mount the CDROM in this
138 manner, though, and it may be a nuisance if you change CDROMs often.
139 You should feel free to remove the cdrom line from /etc/fstab and
140 mount CDROMs manually if that suits you better.
142 Multisession and photocd discs should work with no special handling.
143 The hpcdtoppm package (ftp.gwdg.de:/pub/linux/hpcdtoppm/) may be
144 useful for reading photocds.
146 To play an audio CD, you should first unmount and remove any data
147 CDROM. Any of the CDROM player programs should then work (workman,
148 workbone, cdplayer, etc.).
150 On a few drives, you can read digital audio directly using a program
151 such as cdda2wav. The only types of drive which I've heard support
152 this are Sony and Toshiba drives. You will get errors if you try to
153 use this function on a drive which does not support it.
155 For supported changers, you can use the `cdchange' program (appended to
156 the end of this file) to switch between changer slots. Note that the
157 drive should be unmounted before attempting this. The program takes
158 two arguments: the CDROM device, and the slot number to which you wish
159 to change. If the slot number is -1, the drive is unloaded.
162 4. Compilation options
163 ----------------------
165 There are a few additional options which can be set when compiling the
166 driver. Most people should not need to mess with any of these; they
167 are listed here simply for completeness. A compilation option can be
168 enabled by adding a line of the form `#define <option> 1' to the top
169 of ide-cd.c. All these options are disabled by default.
171 VERBOSE_IDE_CD_ERRORS
172 If this is set, ATAPI error codes will be translated into textual
173 descriptions. In addition, a dump is made of the command which
174 provoked the error. This is off by default to save the memory used
175 by the (somewhat long) table of error descriptions.
178 If this is set, the code needed to deal with certain drives which do
179 not properly implement the ATAPI spec will be disabled. If you know
180 your drive implements ATAPI properly, you can turn this on to get a
181 slightly smaller kernel.
184 If this is set, the driver will never attempt to lock the door of
188 This sets the size of the buffer to be used for a CDROMREADAUDIO
189 ioctl. The default is 8.
192 This currently enables an additional ioctl which enables a user-mode
193 program to execute an arbitrary packet command. See the source for
194 details. This should be left off unless you know what you're doing.
200 This section discusses some common problems encountered when trying to
201 use the driver, and some possible solutions. Note that if you are
202 experiencing problems, you should probably also review
203 Documentation/ide/ide.txt for current information about the underlying
204 IDE support code. Some of these items apply only to earlier versions
205 of the driver, but are mentioned here for completeness.
207 In most cases, you should probably check with `dmesg' for any errors
210 a. Drive is not detected during booting.
212 - Review the configuration instructions above and in
213 Documentation/ide/ide.txt, and check how your hardware is
216 - If your drive is the only device on an IDE interface, it should
217 be jumpered as master, if at all possible.
219 - If your IDE interface is not at the standard addresses of 0x170
220 or 0x1f0, you'll need to explicitly inform the driver using a
221 lilo option. See Documentation/ide/ide.txt. (This feature was
222 added around kernel version 1.3.30.)
224 - If the autoprobing is not finding your drive, you can tell the
225 driver to assume that one exists by using a lilo option of the
226 form `hdX=cdrom', where X is the drive letter corresponding to
227 where your drive is installed. Note that if you do this and you
228 see a boot message like
232 this does _not_ mean that the driver has successfully detected
233 the drive; rather, it means that the driver has not detected a
234 drive, but is assuming there's one there anyway because you told
235 it so. If you actually try to do I/O to a drive defined at a
236 nonexistent or nonresponding I/O address, you'll probably get
237 errors with a status value of 0xff.
239 - Some IDE adapters require a nonstandard initialization sequence
240 before they'll function properly. (If this is the case, there
241 will often be a separate MS-DOS driver just for the controller.)
242 IDE interfaces on sound cards often fall into this category.
244 Support for some interfaces needing extra initialization is
245 provided in later 1.3.x kernels. You may need to turn on
246 additional kernel configuration options to get them to work;
247 see Documentation/ide/ide.txt.
249 Even if support is not available for your interface, you may be
250 able to get it to work with the following procedure. First boot
251 MS-DOS and load the appropriate drivers. Then warm-boot linux
252 (i.e., without powering off). If this works, it can be automated
253 by running loadlin from the MS-DOS autoexec.
256 b. Timeout/IRQ errors.
258 - If you always get timeout errors, interrupts from the drive are
259 probably not making it to the host.
261 - IRQ problems may also be indicated by the message
262 `IRQ probe failed (<n>)' while booting. If <n> is zero, that
263 means that the system did not see an interrupt from the drive when
264 it was expecting one (on any feasible IRQ). If <n> is negative,
265 that means the system saw interrupts on multiple IRQ lines, when
266 it was expecting to receive just one from the CDROM drive.
268 - Double-check your hardware configuration to make sure that the IRQ
269 number of your IDE interface matches what the driver expects.
270 (The usual assignments are 14 for the primary (0x1f0) interface
271 and 15 for the secondary (0x170) interface.) Also be sure that
272 you don't have some other hardware which might be conflicting with
273 the IRQ you're using. Also check the BIOS setup for your system;
274 some have the ability to disable individual IRQ levels, and I've
275 had one report of a system which was shipped with IRQ 15 disabled
278 - Note that many MS-DOS CDROM drivers will still function even if
279 there are hardware problems with the interrupt setup; they
280 apparently don't use interrupts.
282 - If you own a Pioneer DR-A24X, you _will_ get nasty error messages
283 on boot such as "irq timeout: status=0x50 { DriveReady SeekComplete }"
284 The Pioneer DR-A24X CDROM drives are fairly popular these days.
285 Unfortunately, these drives seem to become very confused when we perform
286 the standard Linux ATA disk drive probe. If you own one of these drives,
287 you can bypass the ATA probing which confuses these CDROM drives, by
288 adding `append="hdX=noprobe hdX=cdrom"' to your lilo.conf file and running
289 lilo (again where X is the drive letter corresponding to where your drive
294 - If the system locks up when you try to access the CDROM, the most
295 likely cause is that you have a buggy IDE adapter which doesn't
296 properly handle simultaneous transactions on multiple interfaces.
297 The most notorious of these is the CMD640B chip. This problem can
298 be worked around by specifying the `serialize' option when
299 booting. Recent kernels should be able to detect the need for
300 this automatically in most cases, but the detection is not
301 foolproof. See Documentation/ide/ide.txt for more information
302 about the `serialize' option and the CMD640B.
304 - Note that many MS-DOS CDROM drivers will work with such buggy
305 hardware, apparently because they never attempt to overlap CDROM
306 operations with other disk activity.
309 d. Can't mount a CDROM.
311 - If you get errors from mount, it may help to check `dmesg' to see
312 if there are any more specific errors from the driver or from the
315 - Make sure there's a CDROM loaded in the drive, and that's it's an
316 ISO 9660 disc. You can't mount an audio CD.
318 - With the CDROM in the drive and unmounted, try something like
320 cat /dev/cdrom | od | more
322 If you see a dump, then the drive and driver are probably working
323 OK, and the problem is at the filesystem level (i.e., the CDROM is
324 not ISO 9660 or has errors in the filesystem structure).
326 - If you see `not a block device' errors, check that the definitions
327 of the device special files are correct. They should be as
330 brw-rw---- 1 root disk 3, 0 Nov 11 18:48 /dev/hda
331 brw-rw---- 1 root disk 3, 64 Nov 11 18:48 /dev/hdb
332 brw-rw---- 1 root disk 22, 0 Nov 11 18:48 /dev/hdc
333 brw-rw---- 1 root disk 22, 64 Nov 11 18:48 /dev/hdd
335 Some early Slackware releases had these defined incorrectly. If
336 these are wrong, you can remake them by running the script
337 scripts/MAKEDEV.ide. (You may have to make it executable
340 If you have a /dev/cdrom symbolic link, check that it is pointing
341 to the correct device file.
343 If you hear people talking of the devices `hd1a' and `hd1b', these
344 were old names for what are now called hdc and hdd. Those names
345 should be considered obsolete.
347 - If mount is complaining that the iso9660 filesystem is not
348 available, but you know it is (check /proc/filesystems), you
349 probably need a newer version of mount. Early versions would not
350 always give meaningful error messages.
353 e. Directory listings are unpredictably truncated, and `dmesg' shows
354 `buffer botch' error messages from the driver.
356 - There was a bug in the version of the driver in 1.2.x kernels
357 which could cause this. It was fixed in 1.3.0. If you can't
358 upgrade, you can probably work around the problem by specifying a
359 blocksize of 2048 when mounting. (Note that you won't be able to
360 directly execute binaries off the CDROM in that case.)
362 If you see this in kernels later than 1.3.0, please report it as a
368 - Random data corruption was occasionally observed with the Hitachi
369 CDR-7730 CDROM. If you experience data corruption, using "hdx=slow"
370 as a command line parameter may work around the problem, at the
371 expense of low system performance.
378 * cdchange.c [-v] <device> [<slot>]
380 * This loads a CDROM from a specified slot in a changer, and displays
381 * information about the changer status. The drive should be unmounted before
382 * using this program.
384 * Changer information is displayed if either the -v flag is specified
385 * or no slot was specified.
387 * Based on code originally from Gerhard Zuber <zuber@berlin.snafu.de>.
388 * Changer status information, and rewrite for the new Uniform CDROM driver
389 * interface by Erik Andersen <andersee@debian.org>.
398 #include <sys/ioctl.h>
399 #include <linux/cdrom.h>
403 main (int argc, char **argv)
407 int fd; /* file descriptor for CD-ROM device */
408 int status; /* return status for system calls */
411 int total_slots_available;
418 if (argc < 1 || argc > 3) {
419 fprintf (stderr, "usage: %s [-v] <device> [<slot>]\n",
421 fprintf (stderr, " Slots are numbered 1 -- n.\n");
425 if (strcmp (argv[0], "-v") == 0) {
434 slot = atoi (argv[1]) - 1;
437 fd = open(device, O_RDONLY | O_NONBLOCK);
439 fprintf (stderr, "%s: open failed for `%s': %s\n",
440 program, device, strerror (errno));
444 /* Check CD player status */
445 total_slots_available = ioctl (fd, CDROM_CHANGER_NSLOTS);
446 if (total_slots_available <= 1 ) {
447 fprintf (stderr, "%s: Device `%s' is not an ATAPI "
448 "compliant CD changer.\n", program, device);
453 if (slot >= total_slots_available) {
454 fprintf (stderr, "Bad slot number. "
455 "Should be 1 -- %d.\n",
456 total_slots_available);
461 slot=ioctl (fd, CDROM_SELECT_DISC, slot);
464 perror ("CDROM_SELECT_DISC ");
469 if (slot < 0 || verbose) {
471 status=ioctl (fd, CDROM_SELECT_DISC, CDSL_CURRENT);
474 perror (" CDROM_SELECT_DISC");
479 printf ("Current slot: %d\n", slot+1);
480 printf ("Total slots available: %d\n",
481 total_slots_available);
483 printf ("Drive status: ");
484 status = ioctl (fd, CDROM_DRIVE_STATUS, CDSL_CURRENT);
486 perror(" CDROM_DRIVE_STATUS");
487 } else switch(status) {
492 printf ("Tray Open.\n");
494 case CDS_DRIVE_NOT_READY:
495 printf ("Drive Not Ready.\n");
498 printf ("This Should not happen!\n");
502 for (x_slot=0; x_slot<total_slots_available; x_slot++) {
503 printf ("Slot %2d: ", x_slot+1);
504 status = ioctl (fd, CDROM_DRIVE_STATUS, x_slot);
506 perror(" CDROM_DRIVE_STATUS");
507 } else switch(status) {
509 printf ("Disc present.");
512 printf ("Empty slot.");
515 printf ("CD-ROM tray open.\n");
517 case CDS_DRIVE_NOT_READY:
518 printf ("CD-ROM drive not ready.\n");
521 printf ("No Information available.");
524 printf ("This Should not happen!\n");
527 if (slot == x_slot) {
528 status = ioctl (fd, CDROM_DISC_STATUS);
530 perror(" CDROM_DISC_STATUS");
534 printf ("\tAudio disc.\t");
538 printf ("\tData disc type %d.\t", status-CDS_DATA_1+1);
542 printf ("\tXA data disc type %d.\t", status-CDS_XA_2_1+1);
545 printf ("\tUnknown disc type 0x%x!\t", status);
549 status = ioctl (fd, CDROM_MEDIA_CHANGED, x_slot);
551 perror(" CDROM_MEDIA_CHANGED");
555 printf ("Changed.\n");
567 fprintf (stderr, "%s: close failed for `%s': %s\n",
568 program, device, strerror (errno));