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