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Diffstat (limited to 'kernel/Documentation/cdrom/ide-cd')
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diff --git a/kernel/Documentation/cdrom/ide-cd b/kernel/Documentation/cdrom/ide-cd new file mode 100644 index 000000000..f4dc9de26 --- /dev/null +++ b/kernel/Documentation/cdrom/ide-cd @@ -0,0 +1,538 @@ +IDE-CD driver documentation +Originally by scott snyder <snyder@fnald0.fnal.gov> (19 May 1996) +Carrying on the torch is: Erik Andersen <andersee@debian.org> +New maintainers (19 Oct 1998): Jens Axboe <axboe@image.dk> + +1. Introduction +--------------- + +The ide-cd driver should work with all ATAPI ver 1.2 to ATAPI 2.6 compliant +CDROM drives which attach to an IDE interface. Note that some CDROM vendors +(including Mitsumi, Sony, Creative, Aztech, and Goldstar) have made +both ATAPI-compliant drives and drives which use a proprietary +interface. If your drive uses one of those proprietary interfaces, +this driver will not work with it (but one of the other CDROM drivers +probably will). This driver will not work with `ATAPI' drives which +attach to the parallel port. In addition, there is at least one drive +(CyCDROM CR520ie) which attaches to the IDE port but is not ATAPI; +this driver will not work with drives like that either (but see the +aztcd driver). + +This driver provides the following features: + + - Reading from data tracks, and mounting ISO 9660 filesystems. + + - Playing audio tracks. Most of the CDROM player programs floating + around should work; I usually use Workman. + + - Multisession support. + + - On drives which support it, reading digital audio data directly + from audio tracks. The program cdda2wav can be used for this. + Note, however, that only some drives actually support this. + + - There is now support for CDROM changers which comply with the + ATAPI 2.6 draft standard (such as the NEC CDR-251). This additional + functionality includes a function call to query which slot is the + currently selected slot, a function call to query which slots contain + CDs, etc. A sample program which demonstrates this functionality is + appended to the end of this file. The Sanyo 3-disc changer + (which does not conform to the standard) is also now supported. + Please note the driver refers to the first CD as slot # 0. + + +2. Installation +--------------- + +0. The ide-cd relies on the ide disk driver. See + Documentation/ide/ide.txt for up-to-date information on the ide + driver. + +1. Make sure that the ide and ide-cd drivers are compiled into the + kernel you're using. When configuring the kernel, in the section + entitled "Floppy, IDE, and other block devices", say either `Y' + (which will compile the support directly into the kernel) or `M' + (to compile support as a module which can be loaded and unloaded) + to the options: + + Enhanced IDE/MFM/RLL disk/cdrom/tape/floppy support + Include IDE/ATAPI CDROM support + + and `no' to + + Use old disk-only driver on primary interface + + Depending on what type of IDE interface you have, you may need to + specify additional configuration options. See + Documentation/ide/ide.txt. + +2. You should also ensure that the iso9660 filesystem is either + compiled into the kernel or available as a loadable module. You + can see if a filesystem is known to the kernel by catting + /proc/filesystems. + +3. The CDROM drive should be connected to the host on an IDE + interface. Each interface on a system is defined by an I/O port + address and an IRQ number, the standard assignments being + 0x1f0 and 14 for the primary interface and 0x170 and 15 for the + secondary interface. Each interface can control up to two devices, + where each device can be a hard drive, a CDROM drive, a floppy drive, + or a tape drive. The two devices on an interface are called `master' + and `slave'; this is usually selectable via a jumper on the drive. + + Linux names these devices as follows. The master and slave devices + on the primary IDE interface are called `hda' and `hdb', + respectively. The drives on the secondary interface are called + `hdc' and `hdd'. (Interfaces at other locations get other letters + in the third position; see Documentation/ide/ide.txt.) + + If you want your CDROM drive to be found automatically by the + driver, you should make sure your IDE interface uses either the + primary or secondary addresses mentioned above. In addition, if + the CDROM drive is the only device on the IDE interface, it should + be jumpered as `master'. (If for some reason you cannot configure + your system in this manner, you can probably still use the driver. + You may have to pass extra configuration information to the kernel + when you boot, however. See Documentation/ide/ide.txt for more + information.) + +4. Boot the system. If the drive is recognized, you should see a + message which looks like + + hdb: NEC CD-ROM DRIVE:260, ATAPI CDROM drive + + If you do not see this, see section 5 below. + +5. You may want to create a symbolic link /dev/cdrom pointing to the + actual device. You can do this with the command + + ln -s /dev/hdX /dev/cdrom + + where X should be replaced by the letter indicating where your + drive is installed. + +6. You should be able to see any error messages from the driver with + the `dmesg' command. + + +3. Basic usage +-------------- + +An ISO 9660 CDROM can be mounted by putting the disc in the drive and +typing (as root) + + mount -t iso9660 /dev/cdrom /mnt/cdrom + +where it is assumed that /dev/cdrom is a link pointing to the actual +device (as described in step 5 of the last section) and /mnt/cdrom is +an empty directory. You should now be able to see the contents of the +CDROM under the /mnt/cdrom directory. If you want to eject the CDROM, +you must first dismount it with a command like + + umount /mnt/cdrom + +Note that audio CDs cannot be mounted. + +Some distributions set up /etc/fstab to always try to mount a CDROM +filesystem on bootup. It is not required to mount the CDROM in this +manner, though, and it may be a nuisance if you change CDROMs often. +You should feel free to remove the cdrom line from /etc/fstab and +mount CDROMs manually if that suits you better. + +Multisession and photocd discs should work with no special handling. +The hpcdtoppm package (ftp.gwdg.de:/pub/linux/hpcdtoppm/) may be +useful for reading photocds. + +To play an audio CD, you should first unmount and remove any data +CDROM. Any of the CDROM player programs should then work (workman, +workbone, cdplayer, etc.). + +On a few drives, you can read digital audio directly using a program +such as cdda2wav. The only types of drive which I've heard support +this are Sony and Toshiba drives. You will get errors if you try to +use this function on a drive which does not support it. + +For supported changers, you can use the `cdchange' program (appended to +the end of this file) to switch between changer slots. Note that the +drive should be unmounted before attempting this. The program takes +two arguments: the CDROM device, and the slot number to which you wish +to change. If the slot number is -1, the drive is unloaded. + + +4. Common problems +------------------ + +This section discusses some common problems encountered when trying to +use the driver, and some possible solutions. Note that if you are +experiencing problems, you should probably also review +Documentation/ide/ide.txt for current information about the underlying +IDE support code. Some of these items apply only to earlier versions +of the driver, but are mentioned here for completeness. + +In most cases, you should probably check with `dmesg' for any errors +from the driver. + +a. Drive is not detected during booting. + + - Review the configuration instructions above and in + Documentation/ide/ide.txt, and check how your hardware is + configured. + + - If your drive is the only device on an IDE interface, it should + be jumpered as master, if at all possible. + + - If your IDE interface is not at the standard addresses of 0x170 + or 0x1f0, you'll need to explicitly inform the driver using a + lilo option. See Documentation/ide/ide.txt. (This feature was + added around kernel version 1.3.30.) + + - If the autoprobing is not finding your drive, you can tell the + driver to assume that one exists by using a lilo option of the + form `hdX=cdrom', where X is the drive letter corresponding to + where your drive is installed. Note that if you do this and you + see a boot message like + + hdX: ATAPI cdrom (?) + + this does _not_ mean that the driver has successfully detected + the drive; rather, it means that the driver has not detected a + drive, but is assuming there's one there anyway because you told + it so. If you actually try to do I/O to a drive defined at a + nonexistent or nonresponding I/O address, you'll probably get + errors with a status value of 0xff. + + - Some IDE adapters require a nonstandard initialization sequence + before they'll function properly. (If this is the case, there + will often be a separate MS-DOS driver just for the controller.) + IDE interfaces on sound cards often fall into this category. + + Support for some interfaces needing extra initialization is + provided in later 1.3.x kernels. You may need to turn on + additional kernel configuration options to get them to work; + see Documentation/ide/ide.txt. + + Even if support is not available for your interface, you may be + able to get it to work with the following procedure. First boot + MS-DOS and load the appropriate drivers. Then warm-boot linux + (i.e., without powering off). If this works, it can be automated + by running loadlin from the MS-DOS autoexec. + + +b. Timeout/IRQ errors. + + - If you always get timeout errors, interrupts from the drive are + probably not making it to the host. + + - IRQ problems may also be indicated by the message + `IRQ probe failed (<n>)' while booting. If <n> is zero, that + means that the system did not see an interrupt from the drive when + it was expecting one (on any feasible IRQ). If <n> is negative, + that means the system saw interrupts on multiple IRQ lines, when + it was expecting to receive just one from the CDROM drive. + + - Double-check your hardware configuration to make sure that the IRQ + number of your IDE interface matches what the driver expects. + (The usual assignments are 14 for the primary (0x1f0) interface + and 15 for the secondary (0x170) interface.) Also be sure that + you don't have some other hardware which might be conflicting with + the IRQ you're using. Also check the BIOS setup for your system; + some have the ability to disable individual IRQ levels, and I've + had one report of a system which was shipped with IRQ 15 disabled + by default. + + - Note that many MS-DOS CDROM drivers will still function even if + there are hardware problems with the interrupt setup; they + apparently don't use interrupts. + + - If you own a Pioneer DR-A24X, you _will_ get nasty error messages + on boot such as "irq timeout: status=0x50 { DriveReady SeekComplete }" + The Pioneer DR-A24X CDROM drives are fairly popular these days. + Unfortunately, these drives seem to become very confused when we perform + the standard Linux ATA disk drive probe. If you own one of these drives, + you can bypass the ATA probing which confuses these CDROM drives, by + adding `append="hdX=noprobe hdX=cdrom"' to your lilo.conf file and running + lilo (again where X is the drive letter corresponding to where your drive + is installed.) + +c. System hangups. + + - If the system locks up when you try to access the CDROM, the most + likely cause is that you have a buggy IDE adapter which doesn't + properly handle simultaneous transactions on multiple interfaces. + The most notorious of these is the CMD640B chip. This problem can + be worked around by specifying the `serialize' option when + booting. Recent kernels should be able to detect the need for + this automatically in most cases, but the detection is not + foolproof. See Documentation/ide/ide.txt for more information + about the `serialize' option and the CMD640B. + + - Note that many MS-DOS CDROM drivers will work with such buggy + hardware, apparently because they never attempt to overlap CDROM + operations with other disk activity. + + +d. Can't mount a CDROM. + + - If you get errors from mount, it may help to check `dmesg' to see + if there are any more specific errors from the driver or from the + filesystem. + + - Make sure there's a CDROM loaded in the drive, and that's it's an + ISO 9660 disc. You can't mount an audio CD. + + - With the CDROM in the drive and unmounted, try something like + + cat /dev/cdrom | od | more + + If you see a dump, then the drive and driver are probably working + OK, and the problem is at the filesystem level (i.e., the CDROM is + not ISO 9660 or has errors in the filesystem structure). + + - If you see `not a block device' errors, check that the definitions + of the device special files are correct. They should be as + follows: + + brw-rw---- 1 root disk 3, 0 Nov 11 18:48 /dev/hda + brw-rw---- 1 root disk 3, 64 Nov 11 18:48 /dev/hdb + brw-rw---- 1 root disk 22, 0 Nov 11 18:48 /dev/hdc + brw-rw---- 1 root disk 22, 64 Nov 11 18:48 /dev/hdd + + Some early Slackware releases had these defined incorrectly. If + these are wrong, you can remake them by running the script + scripts/MAKEDEV.ide. (You may have to make it executable + with chmod first.) + + If you have a /dev/cdrom symbolic link, check that it is pointing + to the correct device file. + + If you hear people talking of the devices `hd1a' and `hd1b', these + were old names for what are now called hdc and hdd. Those names + should be considered obsolete. + + - If mount is complaining that the iso9660 filesystem is not + available, but you know it is (check /proc/filesystems), you + probably need a newer version of mount. Early versions would not + always give meaningful error messages. + + +e. Directory listings are unpredictably truncated, and `dmesg' shows + `buffer botch' error messages from the driver. + + - There was a bug in the version of the driver in 1.2.x kernels + which could cause this. It was fixed in 1.3.0. If you can't + upgrade, you can probably work around the problem by specifying a + blocksize of 2048 when mounting. (Note that you won't be able to + directly execute binaries off the CDROM in that case.) + + If you see this in kernels later than 1.3.0, please report it as a + bug. + + +f. Data corruption. + + - Random data corruption was occasionally observed with the Hitachi + CDR-7730 CDROM. If you experience data corruption, using "hdx=slow" + as a command line parameter may work around the problem, at the + expense of low system performance. + + +5. cdchange.c +------------- + +/* + * cdchange.c [-v] <device> [<slot>] + * + * This loads a CDROM from a specified slot in a changer, and displays + * information about the changer status. The drive should be unmounted before + * using this program. + * + * Changer information is displayed if either the -v flag is specified + * or no slot was specified. + * + * Based on code originally from Gerhard Zuber <zuber@berlin.snafu.de>. + * Changer status information, and rewrite for the new Uniform CDROM driver + * interface by Erik Andersen <andersee@debian.org>. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <errno.h> +#include <string.h> +#include <unistd.h> +#include <fcntl.h> +#include <sys/ioctl.h> +#include <linux/cdrom.h> + + +int +main (int argc, char **argv) +{ + char *program; + char *device; + int fd; /* file descriptor for CD-ROM device */ + int status; /* return status for system calls */ + int verbose = 0; + int slot=-1, x_slot; + int total_slots_available; + + program = argv[0]; + + ++argv; + --argc; + + if (argc < 1 || argc > 3) { + fprintf (stderr, "usage: %s [-v] <device> [<slot>]\n", + program); + fprintf (stderr, " Slots are numbered 1 -- n.\n"); + exit (1); + } + + if (strcmp (argv[0], "-v") == 0) { + verbose = 1; + ++argv; + --argc; + } + + device = argv[0]; + + if (argc == 2) + slot = atoi (argv[1]) - 1; + + /* open device */ + fd = open(device, O_RDONLY | O_NONBLOCK); + if (fd < 0) { + fprintf (stderr, "%s: open failed for `%s': %s\n", + program, device, strerror (errno)); + exit (1); + } + + /* Check CD player status */ + total_slots_available = ioctl (fd, CDROM_CHANGER_NSLOTS); + if (total_slots_available <= 1 ) { + fprintf (stderr, "%s: Device `%s' is not an ATAPI " + "compliant CD changer.\n", program, device); + exit (1); + } + + if (slot >= 0) { + if (slot >= total_slots_available) { + fprintf (stderr, "Bad slot number. " + "Should be 1 -- %d.\n", + total_slots_available); + exit (1); + } + + /* load */ + slot=ioctl (fd, CDROM_SELECT_DISC, slot); + if (slot<0) { + fflush(stdout); + perror ("CDROM_SELECT_DISC "); + exit(1); + } + } + + if (slot < 0 || verbose) { + + status=ioctl (fd, CDROM_SELECT_DISC, CDSL_CURRENT); + if (status<0) { + fflush(stdout); + perror (" CDROM_SELECT_DISC"); + exit(1); + } + slot=status; + + printf ("Current slot: %d\n", slot+1); + printf ("Total slots available: %d\n", + total_slots_available); + + printf ("Drive status: "); + status = ioctl (fd, CDROM_DRIVE_STATUS, CDSL_CURRENT); + if (status<0) { + perror(" CDROM_DRIVE_STATUS"); + } else switch(status) { + case CDS_DISC_OK: + printf ("Ready.\n"); + break; + case CDS_TRAY_OPEN: + printf ("Tray Open.\n"); + break; + case CDS_DRIVE_NOT_READY: + printf ("Drive Not Ready.\n"); + break; + default: + printf ("This Should not happen!\n"); + break; + } + + for (x_slot=0; x_slot<total_slots_available; x_slot++) { + printf ("Slot %2d: ", x_slot+1); + status = ioctl (fd, CDROM_DRIVE_STATUS, x_slot); + if (status<0) { + perror(" CDROM_DRIVE_STATUS"); + } else switch(status) { + case CDS_DISC_OK: + printf ("Disc present."); + break; + case CDS_NO_DISC: + printf ("Empty slot."); + break; + case CDS_TRAY_OPEN: + printf ("CD-ROM tray open.\n"); + break; + case CDS_DRIVE_NOT_READY: + printf ("CD-ROM drive not ready.\n"); + break; + case CDS_NO_INFO: + printf ("No Information available."); + break; + default: + printf ("This Should not happen!\n"); + break; + } + if (slot == x_slot) { + status = ioctl (fd, CDROM_DISC_STATUS); + if (status<0) { + perror(" CDROM_DISC_STATUS"); + } + switch (status) { + case CDS_AUDIO: + printf ("\tAudio disc.\t"); + break; + case CDS_DATA_1: + case CDS_DATA_2: + printf ("\tData disc type %d.\t", status-CDS_DATA_1+1); + break; + case CDS_XA_2_1: + case CDS_XA_2_2: + printf ("\tXA data disc type %d.\t", status-CDS_XA_2_1+1); + break; + default: + printf ("\tUnknown disc type 0x%x!\t", status); + break; + } + } + status = ioctl (fd, CDROM_MEDIA_CHANGED, x_slot); + if (status<0) { + perror(" CDROM_MEDIA_CHANGED"); + } + switch (status) { + case 1: + printf ("Changed.\n"); + break; + default: + printf ("\n"); + break; + } + } + } + + /* close device */ + status = close (fd); + if (status != 0) { + fprintf (stderr, "%s: close failed for `%s': %s\n", + program, device, strerror (errno)); + exit (1); + } + + exit (0); +} |