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Based on kernel version 3.15.4. Page generated on 2014-07-07 09:00 EST.

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>
5	
6	1. Introduction
7	---------------
8	
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
19	aztcd driver).
20	
21	This 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	
44	2. Installation
45	---------------
46	
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
49	   driver.
50	
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)
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	
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
72	   /proc/filesystems.
73	
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.
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	
99	4. 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	
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
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	
114	6. You should be able to see any error messages from the driver with
115	   the `dmesg' command.
116	
117	
118	3. Basic usage
119	--------------
120	
121	An ISO 9660 CDROM can be mounted by putting the disc in the drive and 
122	typing (as root)
123	
124	  mount -t iso9660 /dev/cdrom /mnt/cdrom
125	
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
131	
132	  umount /mnt/cdrom
133	
134	Note that audio CDs cannot be mounted.
135	
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.
141	
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.
145	
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.).
149	
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.
154	
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.
160	
161	
162	4. Common problems
163	------------------
164	
165	This section discusses some common problems encountered when trying to
166	use the driver, and some possible solutions.  Note that if you are
167	experiencing problems, you should probably also review
168	Documentation/ide/ide.txt for current information about the underlying
169	IDE support code.  Some of these items apply only to earlier versions
170	of the driver, but are mentioned here for completeness.
171	
172	In most cases, you should probably check with `dmesg' for any errors
173	from the driver.
174	
175	a. 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	
221	b. 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	    
257	c. 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	
274	d. 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	
318	e. 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	
331	f. 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	
339	5. 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	
367	int
368	main (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	}
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