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.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.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.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.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.). Lacking anything else, you could use the 149cdtester program in Documentation/cdrom/sbpcd. 150 151On a few drives, you can read digital audio directly using a program 152such as cdda2wav. The only types of drive which I've heard support 153this are Sony and Toshiba drives. You will get errors if you try to 154use this function on a drive which does not support it. 155 156For supported changers, you can use the `cdchange' program (appended to 157the end of this file) to switch between changer slots. Note that the 158drive should be unmounted before attempting this. The program takes 159two arguments: the CDROM device, and the slot number to which you wish 160to change. If the slot number is -1, the drive is unloaded. 161 162 1634. Compilation options 164---------------------- 165 166There are a few additional options which can be set when compiling the 167driver. Most people should not need to mess with any of these; they 168are listed here simply for completeness. A compilation option can be 169enabled by adding a line of the form `#define <option> 1' to the top 170of ide-cd.c. All these options are disabled by default. 171 172VERBOSE_IDE_CD_ERRORS 173 If this is set, ATAPI error codes will be translated into textual 174 descriptions. In addition, a dump is made of the command which 175 provoked the error. This is off by default to save the memory used 176 by the (somewhat long) table of error descriptions. 177 178STANDARD_ATAPI 179 If this is set, the code needed to deal with certain drives which do 180 not properly implement the ATAPI spec will be disabled. If you know 181 your drive implements ATAPI properly, you can turn this on to get a 182 slightly smaller kernel. 183 184NO_DOOR_LOCKING 185 If this is set, the driver will never attempt to lock the door of 186 the drive. 187 188CDROM_NBLOCKS_BUFFER 189 This sets the size of the buffer to be used for a CDROMREADAUDIO 190 ioctl. The default is 8. 191 192TEST 193 This currently enables an additional ioctl which enables a user-mode 194 program to execute an arbitrary packet command. See the source for 195 details. This should be left off unless you know what you're doing. 196 197 1985. Common problems 199------------------ 200 201This section discusses some common problems encountered when trying to 202use the driver, and some possible solutions. Note that if you are 203experiencing problems, you should probably also review 204Documentation/ide.txt for current information about the underlying 205IDE support code. Some of these items apply only to earlier versions 206of the driver, but are mentioned here for completeness. 207 208In most cases, you should probably check with `dmesg' for any errors 209from the driver. 210 211a. Drive is not detected during booting. 212 213 - Review the configuration instructions above and in 214 Documentation/ide.txt, and check how your hardware is 215 configured. 216 217 - If your drive is the only device on an IDE interface, it should 218 be jumpered as master, if at all possible. 219 220 - If your IDE interface is not at the standard addresses of 0x170 221 or 0x1f0, you'll need to explicitly inform the driver using a 222 lilo option. See Documentation/ide.txt. (This feature was 223 added around kernel version 1.3.30.) 224 225 - If the autoprobing is not finding your drive, you can tell the 226 driver to assume that one exists by using a lilo option of the 227 form `hdX=cdrom', where X is the drive letter corresponding to 228 where your drive is installed. Note that if you do this and you 229 see a boot message like 230 231 hdX: ATAPI cdrom (?) 232 233 this does _not_ mean that the driver has successfully detected 234 the drive; rather, it means that the driver has not detected a 235 drive, but is assuming there's one there anyway because you told 236 it so. If you actually try to do I/O to a drive defined at a 237 nonexistent or nonresponding I/O address, you'll probably get 238 errors with a status value of 0xff. 239 240 - Some IDE adapters require a nonstandard initialization sequence 241 before they'll function properly. (If this is the case, there 242 will often be a separate MS-DOS driver just for the controller.) 243 IDE interfaces on sound cards often fall into this category. 244 245 Support for some interfaces needing extra initialization is 246 provided in later 1.3.x kernels. You may need to turn on 247 additional kernel configuration options to get them to work; 248 see Documentation/ide.txt. 249 250 Even if support is not available for your interface, you may be 251 able to get it to work with the following procedure. First boot 252 MS-DOS and load the appropriate drivers. Then warm-boot linux 253 (i.e., without powering off). If this works, it can be automated 254 by running loadlin from the MS-DOS autoexec. 255 256 257b. Timeout/IRQ errors. 258 259 - If you always get timeout errors, interrupts from the drive are 260 probably not making it to the host. 261 262 - IRQ problems may also be indicated by the message 263 `IRQ probe failed (<n>)' while booting. If <n> is zero, that 264 means that the system did not see an interrupt from the drive when 265 it was expecting one (on any feasible IRQ). If <n> is negative, 266 that means the system saw interrupts on multiple IRQ lines, when 267 it was expecting to receive just one from the CDROM drive. 268 269 - Double-check your hardware configuration to make sure that the IRQ 270 number of your IDE interface matches what the driver expects. 271 (The usual assignments are 14 for the primary (0x1f0) interface 272 and 15 for the secondary (0x170) interface.) Also be sure that 273 you don't have some other hardware which might be conflicting with 274 the IRQ you're using. Also check the BIOS setup for your system; 275 some have the ability to disable individual IRQ levels, and I've 276 had one report of a system which was shipped with IRQ 15 disabled 277 by default. 278 279 - Note that many MS-DOS CDROM drivers will still function even if 280 there are hardware problems with the interrupt setup; they 281 apparently don't use interrupts. 282 283 - If you own a Pioneer DR-A24X, you _will_ get nasty error messages 284 on boot such as "irq timeout: status=0x50 { DriveReady SeekComplete }" 285 The Pioneer DR-A24X CDROM drives are fairly popular these days. 286 Unfortunately, these drives seem to become very confused when we perform 287 the standard Linux ATA disk drive probe. If you own one of these drives, 288 you can bypass the ATA probing which confuses these CDROM drives, by 289 adding `append="hdX=noprobe hdX=cdrom"' to your lilo.conf file and running 290 lilo (again where X is the drive letter corresponding to where your drive 291 is installed.) 292 293c. System hangups. 294 295 - If the system locks up when you try to access the CDROM, the most 296 likely cause is that you have a buggy IDE adapter which doesn't 297 properly handle simultaneous transactions on multiple interfaces. 298 The most notorious of these is the CMD640B chip. This problem can 299 be worked around by specifying the `serialize' option when 300 booting. Recent kernels should be able to detect the need for 301 this automatically in most cases, but the detection is not 302 foolproof. See Documentation/ide.txt for more information 303 about the `serialize' option and the CMD640B. 304 305 - Note that many MS-DOS CDROM drivers will work with such buggy 306 hardware, apparently because they never attempt to overlap CDROM 307 operations with other disk activity. 308 309 310d. Can't mount a CDROM. 311 312 - If you get errors from mount, it may help to check `dmesg' to see 313 if there are any more specific errors from the driver or from the 314 filesystem. 315 316 - Make sure there's a CDROM loaded in the drive, and that's it's an 317 ISO 9660 disc. You can't mount an audio CD. 318 319 - With the CDROM in the drive and unmounted, try something like 320 321 cat /dev/cdrom | od | more 322 323 If you see a dump, then the drive and driver are probably working 324 OK, and the problem is at the filesystem level (i.e., the CDROM is 325 not ISO 9660 or has errors in the filesystem structure). 326 327 - If you see `not a block device' errors, check that the definitions 328 of the device special files are correct. They should be as 329 follows: 330 331 brw-rw---- 1 root disk 3, 0 Nov 11 18:48 /dev/hda 332 brw-rw---- 1 root disk 3, 64 Nov 11 18:48 /dev/hdb 333 brw-rw---- 1 root disk 22, 0 Nov 11 18:48 /dev/hdc 334 brw-rw---- 1 root disk 22, 64 Nov 11 18:48 /dev/hdd 335 336 Some early Slackware releases had these defined incorrectly. If 337 these are wrong, you can remake them by running the script 338 scripts/MAKEDEV.ide. (You may have to make it executable 339 with chmod first.) 340 341 If you have a /dev/cdrom symbolic link, check that it is pointing 342 to the correct device file. 343 344 If you hear people talking of the devices `hd1a' and `hd1b', these 345 were old names for what are now called hdc and hdd. Those names 346 should be considered obsolete. 347 348 - If mount is complaining that the iso9660 filesystem is not 349 available, but you know it is (check /proc/filesystems), you 350 probably need a newer version of mount. Early versions would not 351 always give meaningful error messages. 352 353 354e. Directory listings are unpredictably truncated, and `dmesg' shows 355 `buffer botch' error messages from the driver. 356 357 - There was a bug in the version of the driver in 1.2.x kernels 358 which could cause this. It was fixed in 1.3.0. If you can't 359 upgrade, you can probably work around the problem by specifying a 360 blocksize of 2048 when mounting. (Note that you won't be able to 361 directly execute binaries off the CDROM in that case.) 362 363 If you see this in kernels later than 1.3.0, please report it as a 364 bug. 365 366 367f. Data corruption. 368 369 - Random data corruption was occasionally observed with the Hitachi 370 CDR-7730 CDROM. If you experience data corruption, using "hdx=slow" 371 as a command line parameter may work around the problem, at the 372 expense of low system performance. 373 374 3756. cdchange.c 376------------- 377 378/* 379 * cdchange.c [-v] <device> [<slot>] 380 * 381 * This loads a CDROM from a specified slot in a changer, and displays 382 * information about the changer status. The drive should be unmounted before 383 * using this program. 384 * 385 * Changer information is displayed if either the -v flag is specified 386 * or no slot was specified. 387 * 388 * Based on code originally from Gerhard Zuber <zuber@berlin.snafu.de>. 389 * Changer status information, and rewrite for the new Uniform CDROM driver 390 * interface by Erik Andersen <andersee@debian.org>. 391 */ 392 393#include <stdio.h> 394#include <stdlib.h> 395#include <errno.h> 396#include <string.h> 397#include <unistd.h> 398#include <fcntl.h> 399#include <sys/ioctl.h> 400#include <linux/cdrom.h> 401 402 403int 404main (int argc, char **argv) 405{ 406 char *program; 407 char *device; 408 int fd; /* file descriptor for CD-ROM device */ 409 int status; /* return status for system calls */ 410 int verbose = 0; 411 int slot=-1, x_slot; 412 int total_slots_available; 413 414 program = argv[0]; 415 416 ++argv; 417 --argc; 418 419 if (argc < 1 || argc > 3) { 420 fprintf (stderr, "usage: %s [-v] <device> [<slot>]\n", 421 program); 422 fprintf (stderr, " Slots are numbered 1 -- n.\n"); 423 exit (1); 424 } 425 426 if (strcmp (argv[0], "-v") == 0) { 427 verbose = 1; 428 ++argv; 429 --argc; 430 } 431 432 device = argv[0]; 433 434 if (argc == 2) 435 slot = atoi (argv[1]) - 1; 436 437 /* open device */ 438 fd = open(device, O_RDONLY | O_NONBLOCK); 439 if (fd < 0) { 440 fprintf (stderr, "%s: open failed for `%s': %s\n", 441 program, device, strerror (errno)); 442 exit (1); 443 } 444 445 /* Check CD player status */ 446 total_slots_available = ioctl (fd, CDROM_CHANGER_NSLOTS); 447 if (total_slots_available <= 1 ) { 448 fprintf (stderr, "%s: Device `%s' is not an ATAPI " 449 "compliant CD changer.\n", program, device); 450 exit (1); 451 } 452 453 if (slot >= 0) { 454 if (slot >= total_slots_available) { 455 fprintf (stderr, "Bad slot number. " 456 "Should be 1 -- %d.\n", 457 total_slots_available); 458 exit (1); 459 } 460 461 /* load */ 462 slot=ioctl (fd, CDROM_SELECT_DISC, slot); 463 if (slot<0) { 464 fflush(stdout); 465 perror ("CDROM_SELECT_DISC "); 466 exit(1); 467 } 468 } 469 470 if (slot < 0 || verbose) { 471 472 status=ioctl (fd, CDROM_SELECT_DISC, CDSL_CURRENT); 473 if (status<0) { 474 fflush(stdout); 475 perror (" CDROM_SELECT_DISC"); 476 exit(1); 477 } 478 slot=status; 479 480 printf ("Current slot: %d\n", slot+1); 481 printf ("Total slots available: %d\n", 482 total_slots_available); 483 484 printf ("Drive status: "); 485 status = ioctl (fd, CDROM_DRIVE_STATUS, CDSL_CURRENT); 486 if (status<0) { 487 perror(" CDROM_DRIVE_STATUS"); 488 } else switch(status) { 489 case CDS_DISC_OK: 490 printf ("Ready.\n"); 491 break; 492 case CDS_TRAY_OPEN: 493 printf ("Tray Open.\n"); 494 break; 495 case CDS_DRIVE_NOT_READY: 496 printf ("Drive Not Ready.\n"); 497 break; 498 default: 499 printf ("This Should not happen!\n"); 500 break; 501 } 502 503 for (x_slot=0; x_slot<total_slots_available; x_slot++) { 504 printf ("Slot %2d: ", x_slot+1); 505 status = ioctl (fd, CDROM_DRIVE_STATUS, x_slot); 506 if (status<0) { 507 perror(" CDROM_DRIVE_STATUS"); 508 } else switch(status) { 509 case CDS_DISC_OK: 510 printf ("Disc present."); 511 break; 512 case CDS_NO_DISC: 513 printf ("Empty slot."); 514 break; 515 case CDS_TRAY_OPEN: 516 printf ("CD-ROM tray open.\n"); 517 break; 518 case CDS_DRIVE_NOT_READY: 519 printf ("CD-ROM drive not ready.\n"); 520 break; 521 case CDS_NO_INFO: 522 printf ("No Information available."); 523 break; 524 default: 525 printf ("This Should not happen!\n"); 526 break; 527 } 528 if (slot == x_slot) { 529 status = ioctl (fd, CDROM_DISC_STATUS); 530 if (status<0) { 531 perror(" CDROM_DISC_STATUS"); 532 } 533 switch (status) { 534 case CDS_AUDIO: 535 printf ("\tAudio disc.\t"); 536 break; 537 case CDS_DATA_1: 538 case CDS_DATA_2: 539 printf ("\tData disc type %d.\t", status-CDS_DATA_1+1); 540 break; 541 case CDS_XA_2_1: 542 case CDS_XA_2_2: 543 printf ("\tXA data disc type %d.\t", status-CDS_XA_2_1+1); 544 break; 545 default: 546 printf ("\tUnknown disc type 0x%x!\t", status); 547 break; 548 } 549 } 550 status = ioctl (fd, CDROM_MEDIA_CHANGED, x_slot); 551 if (status<0) { 552 perror(" CDROM_MEDIA_CHANGED"); 553 } 554 switch (status) { 555 case 1: 556 printf ("Changed.\n"); 557 break; 558 default: 559 printf ("\n"); 560 break; 561 } 562 } 563 } 564 565 /* close device */ 566 status = close (fd); 567 if (status != 0) { 568 fprintf (stderr, "%s: close failed for `%s': %s\n", 569 program, device, strerror (errno)); 570 exit (1); 571 } 572 573 exit (0); 574} 575