Root/Documentation/cdrom/ide-cd

1IDE-CD driver documentation
2Originally by scott snyder <snyder@fnald0.fnal.gov> (19 May 1996)
3Carrying on the torch is: Erik Andersen <andersee@debian.org>
4New maintainers (19 Oct 1998): Jens Axboe <axboe@image.dk>
5
61. Introduction
7---------------
8
9The ide-cd driver should work with all ATAPI ver 1.2 to ATAPI 2.6 compliant
10CDROM drives which attach to an IDE interface. Note that some CDROM vendors
11(including Mitsumi, Sony, Creative, Aztech, and Goldstar) have made
12both ATAPI-compliant drives and drives which use a proprietary
13interface. If your drive uses one of those proprietary interfaces,
14this driver will not work with it (but one of the other CDROM drivers
15probably will). This driver will not work with `ATAPI' drives which
16attach 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;
18this driver will not work with drives like that either (but see the
19aztcd driver).
20
21This driver provides the following features:
22
23 - Reading from data tracks, and mounting ISO 9660 filesystems.
24
25 - Playing audio tracks. Most of the CDROM player programs floating
26   around should work; I usually use Workman.
27
28 - Multisession support.
29
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.
33
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.
42
43
442. Installation
45---------------
46
470. The ide-cd relies on the ide disk driver. See
48   Documentation/ide/ide.txt for up-to-date information on the ide
49   driver.
50
511. 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)
56   to the options:
57
58      Enhanced IDE/MFM/RLL disk/cdrom/tape/floppy support
59      Include IDE/ATAPI CDROM support
60
61   and `no' to
62
63      Use old disk-only driver on primary interface
64
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.
68
692. 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
72   /proc/filesystems.
73
743. 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.
82
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.)
88
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
97   information.)
98
994. Boot the system. If the drive is recognized, you should see a
100   message which looks like
101
102     hdb: NEC CD-ROM DRIVE:260, ATAPI CDROM drive
103
104   If you do not see this, see section 5 below.
105
1065. You may want to create a symbolic link /dev/cdrom pointing to the
107   actual device. You can do this with the command
108
109     ln -s /dev/hdX /dev/cdrom
110
111   where X should be replaced by the letter indicating where your
112   drive is installed.
113
1146. You should be able to see any error messages from the driver with
115   the `dmesg' command.
116
117
1183. Basic usage
119--------------
120
121An ISO 9660 CDROM can be mounted by putting the disc in the drive and
122typing (as root)
123
124  mount -t iso9660 /dev/cdrom /mnt/cdrom
125
126where it is assumed that /dev/cdrom is a link pointing to the actual
127device (as described in step 5 of the last section) and /mnt/cdrom is
128an empty directory. You should now be able to see the contents of the
129CDROM under the /mnt/cdrom directory. If you want to eject the CDROM,
130you must first dismount it with a command like
131
132  umount /mnt/cdrom
133
134Note that audio CDs cannot be mounted.
135
136Some distributions set up /etc/fstab to always try to mount a CDROM
137filesystem on bootup. It is not required to mount the CDROM in this
138manner, though, and it may be a nuisance if you change CDROMs often.
139You should feel free to remove the cdrom line from /etc/fstab and
140mount CDROMs manually if that suits you better.
141
142Multisession and photocd discs should work with no special handling.
143The hpcdtoppm package (ftp.gwdg.de:/pub/linux/hpcdtoppm/) may be
144useful for reading photocds.
145
146To play an audio CD, you should first unmount and remove any data
147CDROM. Any of the CDROM player programs should then work (workman,
148workbone, cdplayer, etc.).
149
150On a few drives, you can read digital audio directly using a program
151such as cdda2wav. The only types of drive which I've heard support
152this are Sony and Toshiba drives. You will get errors if you try to
153use this function on a drive which does not support it.
154
155For supported changers, you can use the `cdchange' program (appended to
156the end of this file) to switch between changer slots. Note that the
157drive should be unmounted before attempting this. The program takes
158two arguments: the CDROM device, and the slot number to which you wish
159to change. If the slot number is -1, the drive is unloaded.
160
161
1624. Common problems
163------------------
164
165This section discusses some common problems encountered when trying to
166use the driver, and some possible solutions. Note that if you are
167experiencing problems, you should probably also review
168Documentation/ide/ide.txt for current information about the underlying
169IDE support code. Some of these items apply only to earlier versions
170of the driver, but are mentioned here for completeness.
171
172In most cases, you should probably check with `dmesg' for any errors
173from the driver.
174
175a. Drive is not detected during booting.
176
177   - Review the configuration instructions above and in
178     Documentation/ide/ide.txt, and check how your hardware is
179     configured.
180
181   - If your drive is the only device on an IDE interface, it should
182     be jumpered as master, if at all possible.
183
184   - If your IDE interface is not at the standard addresses of 0x170
185     or 0x1f0, you'll need to explicitly inform the driver using a
186     lilo option. See Documentation/ide/ide.txt. (This feature was
187     added around kernel version 1.3.30.)
188
189   - If the autoprobing is not finding your drive, you can tell the
190     driver to assume that one exists by using a lilo option of the
191     form `hdX=cdrom', where X is the drive letter corresponding to
192     where your drive is installed. Note that if you do this and you
193     see a boot message like
194
195       hdX: ATAPI cdrom (?)
196
197     this does _not_ mean that the driver has successfully detected
198     the drive; rather, it means that the driver has not detected a
199     drive, but is assuming there's one there anyway because you told
200     it so. If you actually try to do I/O to a drive defined at a
201     nonexistent or nonresponding I/O address, you'll probably get
202     errors with a status value of 0xff.
203
204   - Some IDE adapters require a nonstandard initialization sequence
205     before they'll function properly. (If this is the case, there
206     will often be a separate MS-DOS driver just for the controller.)
207     IDE interfaces on sound cards often fall into this category.
208
209     Support for some interfaces needing extra initialization is
210     provided in later 1.3.x kernels. You may need to turn on
211     additional kernel configuration options to get them to work;
212     see Documentation/ide/ide.txt.
213
214     Even if support is not available for your interface, you may be
215     able to get it to work with the following procedure. First boot
216     MS-DOS and load the appropriate drivers. Then warm-boot linux
217     (i.e., without powering off). If this works, it can be automated
218     by running loadlin from the MS-DOS autoexec.
219
220
221b. Timeout/IRQ errors.
222
223  - If you always get timeout errors, interrupts from the drive are
224    probably not making it to the host.
225
226  - IRQ problems may also be indicated by the message
227    `IRQ probe failed (<n>)' while booting. If <n> is zero, that
228    means that the system did not see an interrupt from the drive when
229    it was expecting one (on any feasible IRQ). If <n> is negative,
230    that means the system saw interrupts on multiple IRQ lines, when
231    it was expecting to receive just one from the CDROM drive.
232
233  - Double-check your hardware configuration to make sure that the IRQ
234    number of your IDE interface matches what the driver expects.
235    (The usual assignments are 14 for the primary (0x1f0) interface
236    and 15 for the secondary (0x170) interface.) Also be sure that
237    you don't have some other hardware which might be conflicting with
238    the IRQ you're using. Also check the BIOS setup for your system;
239    some have the ability to disable individual IRQ levels, and I've
240    had one report of a system which was shipped with IRQ 15 disabled
241    by default.
242
243  - Note that many MS-DOS CDROM drivers will still function even if
244    there are hardware problems with the interrupt setup; they
245    apparently don't use interrupts.
246
247  - If you own a Pioneer DR-A24X, you _will_ get nasty error messages
248    on boot such as "irq timeout: status=0x50 { DriveReady SeekComplete }"
249    The Pioneer DR-A24X CDROM drives are fairly popular these days.
250    Unfortunately, these drives seem to become very confused when we perform
251    the standard Linux ATA disk drive probe. If you own one of these drives,
252    you can bypass the ATA probing which confuses these CDROM drives, by
253    adding `append="hdX=noprobe hdX=cdrom"' to your lilo.conf file and running
254    lilo (again where X is the drive letter corresponding to where your drive
255    is installed.)
256    
257c. System hangups.
258
259  - If the system locks up when you try to access the CDROM, the most
260    likely cause is that you have a buggy IDE adapter which doesn't
261    properly handle simultaneous transactions on multiple interfaces.
262    The most notorious of these is the CMD640B chip. This problem can
263    be worked around by specifying the `serialize' option when
264    booting. Recent kernels should be able to detect the need for
265    this automatically in most cases, but the detection is not
266    foolproof. See Documentation/ide/ide.txt for more information
267    about the `serialize' option and the CMD640B.
268
269  - Note that many MS-DOS CDROM drivers will work with such buggy
270    hardware, apparently because they never attempt to overlap CDROM
271    operations with other disk activity.
272
273
274d. Can't mount a CDROM.
275
276  - If you get errors from mount, it may help to check `dmesg' to see
277    if there are any more specific errors from the driver or from the
278    filesystem.
279
280  - Make sure there's a CDROM loaded in the drive, and that's it's an
281    ISO 9660 disc. You can't mount an audio CD.
282
283  - With the CDROM in the drive and unmounted, try something like
284
285      cat /dev/cdrom | od | more
286
287    If you see a dump, then the drive and driver are probably working
288    OK, and the problem is at the filesystem level (i.e., the CDROM is
289    not ISO 9660 or has errors in the filesystem structure).
290
291  - If you see `not a block device' errors, check that the definitions
292    of the device special files are correct. They should be as
293    follows:
294
295      brw-rw---- 1 root disk 3, 0 Nov 11 18:48 /dev/hda
296      brw-rw---- 1 root disk 3, 64 Nov 11 18:48 /dev/hdb
297      brw-rw---- 1 root disk 22, 0 Nov 11 18:48 /dev/hdc
298      brw-rw---- 1 root disk 22, 64 Nov 11 18:48 /dev/hdd
299
300    Some early Slackware releases had these defined incorrectly. If
301    these are wrong, you can remake them by running the script
302    scripts/MAKEDEV.ide. (You may have to make it executable
303    with chmod first.)
304
305    If you have a /dev/cdrom symbolic link, check that it is pointing
306    to the correct device file.
307
308    If you hear people talking of the devices `hd1a' and `hd1b', these
309    were old names for what are now called hdc and hdd. Those names
310    should be considered obsolete.
311
312  - If mount is complaining that the iso9660 filesystem is not
313    available, but you know it is (check /proc/filesystems), you
314    probably need a newer version of mount. Early versions would not
315    always give meaningful error messages.
316
317
318e. Directory listings are unpredictably truncated, and `dmesg' shows
319   `buffer botch' error messages from the driver.
320
321  - There was a bug in the version of the driver in 1.2.x kernels
322    which could cause this. It was fixed in 1.3.0. If you can't
323    upgrade, you can probably work around the problem by specifying a
324    blocksize of 2048 when mounting. (Note that you won't be able to
325    directly execute binaries off the CDROM in that case.)
326
327    If you see this in kernels later than 1.3.0, please report it as a
328    bug.
329
330
331f. Data corruption.
332
333  - Random data corruption was occasionally observed with the Hitachi
334    CDR-7730 CDROM. If you experience data corruption, using "hdx=slow"
335    as a command line parameter may work around the problem, at the
336    expense of low system performance.
337
338
3395. cdchange.c
340-------------
341
342/*
343 * cdchange.c [-v] <device> [<slot>]
344 *
345 * This loads a CDROM from a specified slot in a changer, and displays
346 * information about the changer status. The drive should be unmounted before
347 * using this program.
348 *
349 * Changer information is displayed if either the -v flag is specified
350 * or no slot was specified.
351 *
352 * Based on code originally from Gerhard Zuber <zuber@berlin.snafu.de>.
353 * Changer status information, and rewrite for the new Uniform CDROM driver
354 * interface by Erik Andersen <andersee@debian.org>.
355 */
356
357#include <stdio.h>
358#include <stdlib.h>
359#include <errno.h>
360#include <string.h>
361#include <unistd.h>
362#include <fcntl.h>
363#include <sys/ioctl.h>
364#include <linux/cdrom.h>
365
366
367int
368main (int argc, char **argv)
369{
370    char *program;
371    char *device;
372    int fd; /* file descriptor for CD-ROM device */
373    int status; /* return status for system calls */
374    int verbose = 0;
375    int slot=-1, x_slot;
376    int total_slots_available;
377
378    program = argv[0];
379
380    ++argv;
381    --argc;
382
383    if (argc < 1 || argc > 3) {
384        fprintf (stderr, "usage: %s [-v] <device> [<slot>]\n",
385             program);
386        fprintf (stderr, " Slots are numbered 1 -- n.\n");
387        exit (1);
388    }
389 
390       if (strcmp (argv[0], "-v") == 0) {
391                verbose = 1;
392                ++argv;
393                --argc;
394        }
395 
396    device = argv[0];
397 
398    if (argc == 2)
399        slot = atoi (argv[1]) - 1;
400
401    /* open device */
402    fd = open(device, O_RDONLY | O_NONBLOCK);
403    if (fd < 0) {
404        fprintf (stderr, "%s: open failed for `%s': %s\n",
405             program, device, strerror (errno));
406        exit (1);
407    }
408
409    /* Check CD player status */
410    total_slots_available = ioctl (fd, CDROM_CHANGER_NSLOTS);
411    if (total_slots_available <= 1 ) {
412        fprintf (stderr, "%s: Device `%s' is not an ATAPI "
413            "compliant CD changer.\n", program, device);
414        exit (1);
415    }
416
417    if (slot >= 0) {
418        if (slot >= total_slots_available) {
419            fprintf (stderr, "Bad slot number. "
420                 "Should be 1 -- %d.\n",
421                 total_slots_available);
422            exit (1);
423        }
424
425        /* load */
426        slot=ioctl (fd, CDROM_SELECT_DISC, slot);
427        if (slot<0) {
428            fflush(stdout);
429                perror ("CDROM_SELECT_DISC ");
430            exit(1);
431        }
432    }
433
434    if (slot < 0 || verbose) {
435
436        status=ioctl (fd, CDROM_SELECT_DISC, CDSL_CURRENT);
437        if (status<0) {
438            fflush(stdout);
439            perror (" CDROM_SELECT_DISC");
440            exit(1);
441        }
442        slot=status;
443
444        printf ("Current slot: %d\n", slot+1);
445        printf ("Total slots available: %d\n",
446            total_slots_available);
447
448        printf ("Drive status: ");
449                status = ioctl (fd, CDROM_DRIVE_STATUS, CDSL_CURRENT);
450                if (status<0) {
451                  perror(" CDROM_DRIVE_STATUS");
452                } else switch(status) {
453        case CDS_DISC_OK:
454            printf ("Ready.\n");
455            break;
456        case CDS_TRAY_OPEN:
457            printf ("Tray Open.\n");
458            break;
459        case CDS_DRIVE_NOT_READY:
460            printf ("Drive Not Ready.\n");
461            break;
462        default:
463            printf ("This Should not happen!\n");
464            break;
465        }
466
467        for (x_slot=0; x_slot<total_slots_available; x_slot++) {
468            printf ("Slot %2d: ", x_slot+1);
469                     status = ioctl (fd, CDROM_DRIVE_STATUS, x_slot);
470                     if (status<0) {
471                          perror(" CDROM_DRIVE_STATUS");
472                     } else switch(status) {
473            case CDS_DISC_OK:
474                printf ("Disc present.");
475                break;
476            case CDS_NO_DISC:
477                printf ("Empty slot.");
478                break;
479            case CDS_TRAY_OPEN:
480                printf ("CD-ROM tray open.\n");
481                break;
482            case CDS_DRIVE_NOT_READY:
483                printf ("CD-ROM drive not ready.\n");
484                break;
485            case CDS_NO_INFO:
486                printf ("No Information available.");
487                break;
488            default:
489                printf ("This Should not happen!\n");
490                break;
491            }
492          if (slot == x_slot) {
493                  status = ioctl (fd, CDROM_DISC_STATUS);
494                  if (status<0) {
495            perror(" CDROM_DISC_STATUS");
496                  }
497          switch (status) {
498            case CDS_AUDIO:
499                printf ("\tAudio disc.\t");
500                break;
501            case CDS_DATA_1:
502            case CDS_DATA_2:
503                printf ("\tData disc type %d.\t", status-CDS_DATA_1+1);
504                break;
505            case CDS_XA_2_1:
506            case CDS_XA_2_2:
507                printf ("\tXA data disc type %d.\t", status-CDS_XA_2_1+1);
508                break;
509            default:
510                printf ("\tUnknown disc type 0x%x!\t", status);
511                break;
512            }
513            }
514                      status = ioctl (fd, CDROM_MEDIA_CHANGED, x_slot);
515                      if (status<0) {
516                perror(" CDROM_MEDIA_CHANGED");
517                      }
518              switch (status) {
519            case 1:
520                printf ("Changed.\n");
521                break;
522            default:
523                printf ("\n");
524                break;
525            }
526        }
527    }
528
529    /* close device */
530    status = close (fd);
531    if (status != 0) {
532        fprintf (stderr, "%s: close failed for `%s': %s\n",
533             program, device, strerror (errno));
534        exit (1);
535    }
536 
537    exit (0);
538}
539

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