+=================================
(How to avoid) Botching up ioctls
=================================
--- /dev/null
+============================
+Summary of CDROM ioctl calls
+============================
+
+- Edward A. Falk <efalk@google.com>
+
+November, 2004
+
+This document attempts to describe the ioctl(2) calls supported by
+the CDROM layer. These are by-and-large implemented (as of Linux 2.6)
+in drivers/cdrom/cdrom.c and drivers/block/scsi_ioctl.c
+
+ioctl values are listed in <linux/cdrom.h>. As of this writing, they
+are as follows:
+
+ ====================== ===============================================
+ CDROMPAUSE Pause Audio Operation
+ CDROMRESUME Resume paused Audio Operation
+ CDROMPLAYMSF Play Audio MSF (struct cdrom_msf)
+ CDROMPLAYTRKIND Play Audio Track/index (struct cdrom_ti)
+ CDROMREADTOCHDR Read TOC header (struct cdrom_tochdr)
+ CDROMREADTOCENTRY Read TOC entry (struct cdrom_tocentry)
+ CDROMSTOP Stop the cdrom drive
+ CDROMSTART Start the cdrom drive
+ CDROMEJECT Ejects the cdrom media
+ CDROMVOLCTRL Control output volume (struct cdrom_volctrl)
+ CDROMSUBCHNL Read subchannel data (struct cdrom_subchnl)
+ CDROMREADMODE2 Read CDROM mode 2 data (2336 Bytes)
+ (struct cdrom_read)
+ CDROMREADMODE1 Read CDROM mode 1 data (2048 Bytes)
+ (struct cdrom_read)
+ CDROMREADAUDIO (struct cdrom_read_audio)
+ CDROMEJECT_SW enable(1)/disable(0) auto-ejecting
+ CDROMMULTISESSION Obtain the start-of-last-session
+ address of multi session disks
+ (struct cdrom_multisession)
+ CDROM_GET_MCN Obtain the "Universal Product Code"
+ if available (struct cdrom_mcn)
+ CDROM_GET_UPC Deprecated, use CDROM_GET_MCN instead.
+ CDROMRESET hard-reset the drive
+ CDROMVOLREAD Get the drive's volume setting
+ (struct cdrom_volctrl)
+ CDROMREADRAW read data in raw mode (2352 Bytes)
+ (struct cdrom_read)
+ CDROMREADCOOKED read data in cooked mode
+ CDROMSEEK seek msf address
+ CDROMPLAYBLK scsi-cd only, (struct cdrom_blk)
+ CDROMREADALL read all 2646 bytes
+ CDROMGETSPINDOWN return 4-bit spindown value
+ CDROMSETSPINDOWN set 4-bit spindown value
+ CDROMCLOSETRAY pendant of CDROMEJECT
+ CDROM_SET_OPTIONS Set behavior options
+ CDROM_CLEAR_OPTIONS Clear behavior options
+ CDROM_SELECT_SPEED Set the CD-ROM speed
+ CDROM_SELECT_DISC Select disc (for juke-boxes)
+ CDROM_MEDIA_CHANGED Check is media changed
+ CDROM_DRIVE_STATUS Get tray position, etc.
+ CDROM_DISC_STATUS Get disc type, etc.
+ CDROM_CHANGER_NSLOTS Get number of slots
+ CDROM_LOCKDOOR lock or unlock door
+ CDROM_DEBUG Turn debug messages on/off
+ CDROM_GET_CAPABILITY get capabilities
+ CDROMAUDIOBUFSIZ set the audio buffer size
+ DVD_READ_STRUCT Read structure
+ DVD_WRITE_STRUCT Write structure
+ DVD_AUTH Authentication
+ CDROM_SEND_PACKET send a packet to the drive
+ CDROM_NEXT_WRITABLE get next writable block
+ CDROM_LAST_WRITTEN get last block written on disc
+ ====================== ===============================================
+
+
+The information that follows was determined from reading kernel source
+code. It is likely that some corrections will be made over time.
+
+------------------------------------------------------------------------------
+
+General:
+
+ Unless otherwise specified, all ioctl calls return 0 on success
+ and -1 with errno set to an appropriate value on error. (Some
+ ioctls return non-negative data values.)
+
+ Unless otherwise specified, all ioctl calls return -1 and set
+ errno to EFAULT on a failed attempt to copy data to or from user
+ address space.
+
+ Individual drivers may return error codes not listed here.
+
+ Unless otherwise specified, all data structures and constants
+ are defined in <linux/cdrom.h>
+
+------------------------------------------------------------------------------
+
+
+CDROMPAUSE
+ Pause Audio Operation
+
+
+ usage::
+
+ ioctl(fd, CDROMPAUSE, 0);
+
+
+ inputs:
+ none
+
+
+ outputs:
+ none
+
+
+ error return:
+ - ENOSYS cd drive not audio-capable.
+
+
+CDROMRESUME
+ Resume paused Audio Operation
+
+
+ usage::
+
+ ioctl(fd, CDROMRESUME, 0);
+
+
+ inputs:
+ none
+
+
+ outputs:
+ none
+
+
+ error return:
+ - ENOSYS cd drive not audio-capable.
+
+
+CDROMPLAYMSF
+ Play Audio MSF
+
+ (struct cdrom_msf)
+
+
+ usage::
+
+ struct cdrom_msf msf;
+
+ ioctl(fd, CDROMPLAYMSF, &msf);
+
+ inputs:
+ cdrom_msf structure, describing a segment of music to play
+
+
+ outputs:
+ none
+
+
+ error return:
+ - ENOSYS cd drive not audio-capable.
+
+ notes:
+ - MSF stands for minutes-seconds-frames
+ - LBA stands for logical block address
+ - Segment is described as start and end times, where each time
+ is described as minutes:seconds:frames.
+ A frame is 1/75 of a second.
+
+
+CDROMPLAYTRKIND
+ Play Audio Track/index
+
+ (struct cdrom_ti)
+
+
+ usage::
+
+ struct cdrom_ti ti;
+
+ ioctl(fd, CDROMPLAYTRKIND, &ti);
+
+ inputs:
+ cdrom_ti structure, describing a segment of music to play
+
+
+ outputs:
+ none
+
+
+ error return:
+ - ENOSYS cd drive not audio-capable.
+
+ notes:
+ - Segment is described as start and end times, where each time
+ is described as a track and an index.
+
+
+
+CDROMREADTOCHDR
+ Read TOC header
+
+ (struct cdrom_tochdr)
+
+
+ usage::
+
+ cdrom_tochdr header;
+
+ ioctl(fd, CDROMREADTOCHDR, &header);
+
+ inputs:
+ cdrom_tochdr structure
+
+
+ outputs:
+ cdrom_tochdr structure
+
+
+ error return:
+ - ENOSYS cd drive not audio-capable.
+
+
+
+CDROMREADTOCENTRY
+ Read TOC entry
+
+ (struct cdrom_tocentry)
+
+
+ usage::
+
+ struct cdrom_tocentry entry;
+
+ ioctl(fd, CDROMREADTOCENTRY, &entry);
+
+ inputs:
+ cdrom_tocentry structure
+
+
+ outputs:
+ cdrom_tocentry structure
+
+
+ error return:
+ - ENOSYS cd drive not audio-capable.
+ - EINVAL entry.cdte_format not CDROM_MSF or CDROM_LBA
+ - EINVAL requested track out of bounds
+ - EIO I/O error reading TOC
+
+ notes:
+ - TOC stands for Table Of Contents
+ - MSF stands for minutes-seconds-frames
+ - LBA stands for logical block address
+
+
+
+CDROMSTOP
+ Stop the cdrom drive
+
+
+ usage::
+
+ ioctl(fd, CDROMSTOP, 0);
+
+
+ inputs:
+ none
+
+
+ outputs:
+ none
+
+
+ error return:
+ - ENOSYS cd drive not audio-capable.
+
+ notes:
+ - Exact interpretation of this ioctl depends on the device,
+ but most seem to spin the drive down.
+
+
+CDROMSTART
+ Start the cdrom drive
+
+
+ usage::
+
+ ioctl(fd, CDROMSTART, 0);
+
+
+ inputs:
+ none
+
+
+ outputs:
+ none
+
+
+ error return:
+ - ENOSYS cd drive not audio-capable.
+
+ notes:
+ - Exact interpretation of this ioctl depends on the device,
+ but most seem to spin the drive up and/or close the tray.
+ Other devices ignore the ioctl completely.
+
+
+CDROMEJECT
+ - Ejects the cdrom media
+
+
+ usage::
+
+ ioctl(fd, CDROMEJECT, 0);
+
+
+ inputs:
+ none
+
+
+ outputs:
+ none
+
+
+ error returns:
+ - ENOSYS cd drive not capable of ejecting
+ - EBUSY other processes are accessing drive, or door is locked
+
+ notes:
+ - See CDROM_LOCKDOOR, below.
+
+
+
+
+CDROMCLOSETRAY
+ pendant of CDROMEJECT
+
+
+ usage::
+
+ ioctl(fd, CDROMCLOSETRAY, 0);
+
+
+ inputs:
+ none
+
+
+ outputs:
+ none
+
+
+ error returns:
+ - ENOSYS cd drive not capable of closing the tray
+ - EBUSY other processes are accessing drive, or door is locked
+
+ notes:
+ - See CDROM_LOCKDOOR, below.
+
+
+
+
+CDROMVOLCTRL
+ Control output volume (struct cdrom_volctrl)
+
+
+ usage::
+
+ struct cdrom_volctrl volume;
+
+ ioctl(fd, CDROMVOLCTRL, &volume);
+
+ inputs:
+ cdrom_volctrl structure containing volumes for up to 4
+ channels.
+
+ outputs:
+ none
+
+
+ error return:
+ - ENOSYS cd drive not audio-capable.
+
+
+
+CDROMVOLREAD
+ Get the drive's volume setting
+
+ (struct cdrom_volctrl)
+
+
+ usage::
+
+ struct cdrom_volctrl volume;
+
+ ioctl(fd, CDROMVOLREAD, &volume);
+
+ inputs:
+ none
+
+
+ outputs:
+ The current volume settings.
+
+
+ error return:
+ - ENOSYS cd drive not audio-capable.
+
+
+
+CDROMSUBCHNL
+ Read subchannel data
+
+ (struct cdrom_subchnl)
+
+
+ usage::
+
+ struct cdrom_subchnl q;
+
+ ioctl(fd, CDROMSUBCHNL, &q);
+
+ inputs:
+ cdrom_subchnl structure
+
+
+ outputs:
+ cdrom_subchnl structure
+
+
+ error return:
+ - ENOSYS cd drive not audio-capable.
+ - EINVAL format not CDROM_MSF or CDROM_LBA
+
+ notes:
+ - Format is converted to CDROM_MSF or CDROM_LBA
+ as per user request on return
+
+
+
+CDROMREADRAW
+ read data in raw mode (2352 Bytes)
+
+ (struct cdrom_read)
+
+ usage::
+
+ union {
+
+ struct cdrom_msf msf; /* input */
+ char buffer[CD_FRAMESIZE_RAW]; /* return */
+ } arg;
+ ioctl(fd, CDROMREADRAW, &arg);
+
+ inputs:
+ cdrom_msf structure indicating an address to read.
+
+ Only the start values are significant.
+
+ outputs:
+ Data written to address provided by user.
+
+
+ error return:
+ - EINVAL address less than 0, or msf less than 0:2:0
+ - ENOMEM out of memory
+
+ notes:
+ - As of 2.6.8.1, comments in <linux/cdrom.h> indicate that this
+ ioctl accepts a cdrom_read structure, but actual source code
+ reads a cdrom_msf structure and writes a buffer of data to
+ the same address.
+
+ - MSF values are converted to LBA values via this formula::
+
+ lba = (((m * CD_SECS) + s) * CD_FRAMES + f) - CD_MSF_OFFSET;
+
+
+
+
+CDROMREADMODE1
+ Read CDROM mode 1 data (2048 Bytes)
+
+ (struct cdrom_read)
+
+ notes:
+ Identical to CDROMREADRAW except that block size is
+ CD_FRAMESIZE (2048) bytes
+
+
+
+CDROMREADMODE2
+ Read CDROM mode 2 data (2336 Bytes)
+
+ (struct cdrom_read)
+
+ notes:
+ Identical to CDROMREADRAW except that block size is
+ CD_FRAMESIZE_RAW0 (2336) bytes
+
+
+
+CDROMREADAUDIO
+ (struct cdrom_read_audio)
+
+ usage::
+
+ struct cdrom_read_audio ra;
+
+ ioctl(fd, CDROMREADAUDIO, &ra);
+
+ inputs:
+ cdrom_read_audio structure containing read start
+ point and length
+
+ outputs:
+ audio data, returned to buffer indicated by ra
+
+
+ error return:
+ - EINVAL format not CDROM_MSF or CDROM_LBA
+ - EINVAL nframes not in range [1 75]
+ - ENXIO drive has no queue (probably means invalid fd)
+ - ENOMEM out of memory
+
+
+CDROMEJECT_SW
+ enable(1)/disable(0) auto-ejecting
+
+
+ usage::
+
+ int val;
+
+ ioctl(fd, CDROMEJECT_SW, val);
+
+ inputs:
+ Flag specifying auto-eject flag.
+
+
+ outputs:
+ none
+
+
+ error return:
+ - ENOSYS Drive is not capable of ejecting.
+ - EBUSY Door is locked
+
+
+
+
+CDROMMULTISESSION
+ Obtain the start-of-last-session address of multi session disks
+
+ (struct cdrom_multisession)
+
+ usage::
+
+ struct cdrom_multisession ms_info;
+
+ ioctl(fd, CDROMMULTISESSION, &ms_info);
+
+ inputs:
+ cdrom_multisession structure containing desired
+
+ format.
+
+ outputs:
+ cdrom_multisession structure is filled with last_session
+ information.
+
+ error return:
+ - EINVAL format not CDROM_MSF or CDROM_LBA
+
+
+CDROM_GET_MCN
+ Obtain the "Universal Product Code"
+ if available
+
+ (struct cdrom_mcn)
+
+
+ usage::
+
+ struct cdrom_mcn mcn;
+
+ ioctl(fd, CDROM_GET_MCN, &mcn);
+
+ inputs:
+ none
+
+
+ outputs:
+ Universal Product Code
+
+
+ error return:
+ - ENOSYS Drive is not capable of reading MCN data.
+
+ notes:
+ - Source code comments state::
+
+ The following function is implemented, although very few
+ audio discs give Universal Product Code information, which
+ should just be the Medium Catalog Number on the box. Note,
+ that the way the code is written on the CD is /not/ uniform
+ across all discs!
+
+
+
+
+CDROM_GET_UPC
+ CDROM_GET_MCN (deprecated)
+
+
+ Not implemented, as of 2.6.8.1
+
+
+
+CDROMRESET
+ hard-reset the drive
+
+
+ usage::
+
+ ioctl(fd, CDROMRESET, 0);
+
+
+ inputs:
+ none
+
+
+ outputs:
+ none
+
+
+ error return:
+ - EACCES Access denied: requires CAP_SYS_ADMIN
+ - ENOSYS Drive is not capable of resetting.
+
+
+
+
+CDROMREADCOOKED
+ read data in cooked mode
+
+
+ usage::
+
+ u8 buffer[CD_FRAMESIZE]
+
+ ioctl(fd, CDROMREADCOOKED, buffer);
+
+ inputs:
+ none
+
+
+ outputs:
+ 2048 bytes of data, "cooked" mode.
+
+
+ notes:
+ Not implemented on all drives.
+
+
+
+
+
+CDROMREADALL
+ read all 2646 bytes
+
+
+ Same as CDROMREADCOOKED, but reads 2646 bytes.
+
+
+
+CDROMSEEK
+ seek msf address
+
+
+ usage::
+
+ struct cdrom_msf msf;
+
+ ioctl(fd, CDROMSEEK, &msf);
+
+ inputs:
+ MSF address to seek to.
+
+
+ outputs:
+ none
+
+
+
+
+CDROMPLAYBLK
+ scsi-cd only
+
+ (struct cdrom_blk)
+
+
+ usage::
+
+ struct cdrom_blk blk;
+
+ ioctl(fd, CDROMPLAYBLK, &blk);
+
+ inputs:
+ Region to play
+
+
+ outputs:
+ none
+
+
+
+
+CDROMGETSPINDOWN
+ usage::
+
+ char spindown;
+
+ ioctl(fd, CDROMGETSPINDOWN, &spindown);
+
+ inputs:
+ none
+
+
+ outputs:
+ The value of the current 4-bit spindown value.
+
+
+
+
+
+CDROMSETSPINDOWN
+ usage::
+
+ char spindown
+
+ ioctl(fd, CDROMSETSPINDOWN, &spindown);
+
+ inputs:
+ 4-bit value used to control spindown (TODO: more detail here)
+
+
+ outputs:
+ none
+
+
+
+
+
+
+CDROM_SET_OPTIONS
+ Set behavior options
+
+
+ usage::
+
+ int options;
+
+ ioctl(fd, CDROM_SET_OPTIONS, options);
+
+ inputs:
+ New values for drive options. The logical 'or' of:
+
+ ============== ==================================
+ CDO_AUTO_CLOSE close tray on first open(2)
+ CDO_AUTO_EJECT open tray on last release
+ CDO_USE_FFLAGS use O_NONBLOCK information on open
+ CDO_LOCK lock tray on open files
+ CDO_CHECK_TYPE check type on open for data
+ ============== ==================================
+
+ outputs:
+ Returns the resulting options settings in the
+ ioctl return value. Returns -1 on error.
+
+ error return:
+ - ENOSYS selected option(s) not supported by drive.
+
+
+
+
+CDROM_CLEAR_OPTIONS
+ Clear behavior options
+
+
+ Same as CDROM_SET_OPTIONS, except that selected options are
+ turned off.
+
+
+
+CDROM_SELECT_SPEED
+ Set the CD-ROM speed
+
+
+ usage::
+
+ int speed;
+
+ ioctl(fd, CDROM_SELECT_SPEED, speed);
+
+ inputs:
+ New drive speed.
+
+
+ outputs:
+ none
+
+
+ error return:
+ - ENOSYS speed selection not supported by drive.
+
+
+
+CDROM_SELECT_DISC
+ Select disc (for juke-boxes)
+
+
+ usage::
+
+ int disk;
+
+ ioctl(fd, CDROM_SELECT_DISC, disk);
+
+ inputs:
+ Disk to load into drive.
+
+
+ outputs:
+ none
+
+
+ error return:
+ - EINVAL Disk number beyond capacity of drive
+
+
+
+CDROM_MEDIA_CHANGED
+ Check is media changed
+
+
+ usage::
+
+ int slot;
+
+ ioctl(fd, CDROM_MEDIA_CHANGED, slot);
+
+ inputs:
+ Slot number to be tested, always zero except for jukeboxes.
+
+ May also be special values CDSL_NONE or CDSL_CURRENT
+
+ outputs:
+ Ioctl return value is 0 or 1 depending on whether the media
+
+ has been changed, or -1 on error.
+
+ error returns:
+ - ENOSYS Drive can't detect media change
+ - EINVAL Slot number beyond capacity of drive
+ - ENOMEM Out of memory
+
+
+
+CDROM_DRIVE_STATUS
+ Get tray position, etc.
+
+
+ usage::
+
+ int slot;
+
+ ioctl(fd, CDROM_DRIVE_STATUS, slot);
+
+ inputs:
+ Slot number to be tested, always zero except for jukeboxes.
+
+ May also be special values CDSL_NONE or CDSL_CURRENT
+
+ outputs:
+ Ioctl return value will be one of the following values
+
+ from <linux/cdrom.h>:
+
+ =================== ==========================
+ CDS_NO_INFO Information not available.
+ CDS_NO_DISC
+ CDS_TRAY_OPEN
+ CDS_DRIVE_NOT_READY
+ CDS_DISC_OK
+ -1 error
+ =================== ==========================
+
+ error returns:
+ - ENOSYS Drive can't detect drive status
+ - EINVAL Slot number beyond capacity of drive
+ - ENOMEM Out of memory
+
+
+
+
+CDROM_DISC_STATUS
+ Get disc type, etc.
+
+
+ usage::
+
+ ioctl(fd, CDROM_DISC_STATUS, 0);
+
+
+ inputs:
+ none
+
+
+ outputs:
+ Ioctl return value will be one of the following values
+
+ from <linux/cdrom.h>:
+
+ - CDS_NO_INFO
+ - CDS_AUDIO
+ - CDS_MIXED
+ - CDS_XA_2_2
+ - CDS_XA_2_1
+ - CDS_DATA_1
+
+ error returns:
+ none at present
+
+ notes:
+ - Source code comments state::
+
+
+ Ok, this is where problems start. The current interface for
+ the CDROM_DISC_STATUS ioctl is flawed. It makes the false
+ assumption that CDs are all CDS_DATA_1 or all CDS_AUDIO, etc.
+ Unfortunately, while this is often the case, it is also
+ very common for CDs to have some tracks with data, and some
+ tracks with audio. Just because I feel like it, I declare
+ the following to be the best way to cope. If the CD has
+ ANY data tracks on it, it will be returned as a data CD.
+ If it has any XA tracks, I will return it as that. Now I
+ could simplify this interface by combining these returns with
+ the above, but this more clearly demonstrates the problem
+ with the current interface. Too bad this wasn't designed
+ to use bitmasks... -Erik
+
+ Well, now we have the option CDS_MIXED: a mixed-type CD.
+ User level programmers might feel the ioctl is not very
+ useful.
+ ---david
+
+
+
+
+CDROM_CHANGER_NSLOTS
+ Get number of slots
+
+
+ usage::
+
+ ioctl(fd, CDROM_CHANGER_NSLOTS, 0);
+
+
+ inputs:
+ none
+
+
+ outputs:
+ The ioctl return value will be the number of slots in a
+ CD changer. Typically 1 for non-multi-disk devices.
+
+ error returns:
+ none
+
+
+
+CDROM_LOCKDOOR
+ lock or unlock door
+
+
+ usage::
+
+ int lock;
+
+ ioctl(fd, CDROM_LOCKDOOR, lock);
+
+ inputs:
+ Door lock flag, 1=lock, 0=unlock
+
+
+ outputs:
+ none
+
+
+ error returns:
+ - EDRIVE_CANT_DO_THIS
+
+ Door lock function not supported.
+ - EBUSY
+
+ Attempt to unlock when multiple users
+ have the drive open and not CAP_SYS_ADMIN
+
+ notes:
+ As of 2.6.8.1, the lock flag is a global lock, meaning that
+ all CD drives will be locked or unlocked together. This is
+ probably a bug.
+
+ The EDRIVE_CANT_DO_THIS value is defined in <linux/cdrom.h>
+ and is currently (2.6.8.1) the same as EOPNOTSUPP
+
+
+
+CDROM_DEBUG
+ Turn debug messages on/off
+
+
+ usage::
+
+ int debug;
+
+ ioctl(fd, CDROM_DEBUG, debug);
+
+ inputs:
+ Cdrom debug flag, 0=disable, 1=enable
+
+
+ outputs:
+ The ioctl return value will be the new debug flag.
+
+
+ error return:
+ - EACCES Access denied: requires CAP_SYS_ADMIN
+
+
+
+CDROM_GET_CAPABILITY
+ get capabilities
+
+
+ usage::
+
+ ioctl(fd, CDROM_GET_CAPABILITY, 0);
+
+
+ inputs:
+ none
+
+
+ outputs:
+ The ioctl return value is the current device capability
+ flags. See CDC_CLOSE_TRAY, CDC_OPEN_TRAY, etc.
+
+
+
+CDROMAUDIOBUFSIZ
+ set the audio buffer size
+
+
+ usage::
+
+ int arg;
+
+ ioctl(fd, CDROMAUDIOBUFSIZ, val);
+
+ inputs:
+ New audio buffer size
+
+
+ outputs:
+ The ioctl return value is the new audio buffer size, or -1
+ on error.
+
+ error return:
+ - ENOSYS Not supported by this driver.
+
+ notes:
+ Not supported by all drivers.
+
+
+
+
+DVD_READ_STRUCT Read structure
+
+ usage::
+
+ dvd_struct s;
+
+ ioctl(fd, DVD_READ_STRUCT, &s);
+
+ inputs:
+ dvd_struct structure, containing:
+
+ =================== ==========================================
+ type specifies the information desired, one of
+ DVD_STRUCT_PHYSICAL, DVD_STRUCT_COPYRIGHT,
+ DVD_STRUCT_DISCKEY, DVD_STRUCT_BCA,
+ DVD_STRUCT_MANUFACT
+ physical.layer_num desired layer, indexed from 0
+ copyright.layer_num desired layer, indexed from 0
+ disckey.agid
+ =================== ==========================================
+
+ outputs:
+ dvd_struct structure, containing:
+
+ =================== ================================
+ physical for type == DVD_STRUCT_PHYSICAL
+ copyright for type == DVD_STRUCT_COPYRIGHT
+ disckey.value for type == DVD_STRUCT_DISCKEY
+ bca.{len,value} for type == DVD_STRUCT_BCA
+ manufact.{len,valu} for type == DVD_STRUCT_MANUFACT
+ =================== ================================
+
+ error returns:
+ - EINVAL physical.layer_num exceeds number of layers
+ - EIO Received invalid response from drive
+
+
+
+DVD_WRITE_STRUCT Write structure
+
+ Not implemented, as of 2.6.8.1
+
+
+
+DVD_AUTH Authentication
+
+ usage::
+
+ dvd_authinfo ai;
+
+ ioctl(fd, DVD_AUTH, &ai);
+
+ inputs:
+ dvd_authinfo structure. See <linux/cdrom.h>
+
+
+ outputs:
+ dvd_authinfo structure.
+
+
+ error return:
+ - ENOTTY ai.type not recognized.
+
+
+
+CDROM_SEND_PACKET
+ send a packet to the drive
+
+
+ usage::
+
+ struct cdrom_generic_command cgc;
+
+ ioctl(fd, CDROM_SEND_PACKET, &cgc);
+
+ inputs:
+ cdrom_generic_command structure containing the packet to send.
+
+
+ outputs:
+ none
+
+ cdrom_generic_command structure containing results.
+
+ error return:
+ - EIO
+
+ command failed.
+ - EPERM
+
+ Operation not permitted, either because a
+ write command was attempted on a drive which
+ is opened read-only, or because the command
+ requires CAP_SYS_RAWIO
+ - EINVAL
+
+ cgc.data_direction not set
+
+
+
+CDROM_NEXT_WRITABLE
+ get next writable block
+
+
+ usage::
+
+ long next;
+
+ ioctl(fd, CDROM_NEXT_WRITABLE, &next);
+
+ inputs:
+ none
+
+
+ outputs:
+ The next writable block.
+
+
+ notes:
+ If the device does not support this ioctl directly, the
+
+ ioctl will return CDROM_LAST_WRITTEN + 7.
+
+
+
+CDROM_LAST_WRITTEN
+ get last block written on disc
+
+
+ usage::
+
+ long last;
+
+ ioctl(fd, CDROM_LAST_WRITTEN, &last);
+
+ inputs:
+ none
+
+
+ outputs:
+ The last block written on disc
+
+
+ notes:
+ If the device does not support this ioctl directly, the
+ result is derived from the disc's table of contents. If the
+ table of contents can't be read, this ioctl returns an
+ error.
+++ /dev/null
- Summary of CDROM ioctl calls.
- ============================
-
- Edward A. Falk <efalk@google.com>
-
- November, 2004
-
-This document attempts to describe the ioctl(2) calls supported by
-the CDROM layer. These are by-and-large implemented (as of Linux 2.6)
-in drivers/cdrom/cdrom.c and drivers/block/scsi_ioctl.c
-
-ioctl values are listed in <linux/cdrom.h>. As of this writing, they
-are as follows:
-
- CDROMPAUSE Pause Audio Operation
- CDROMRESUME Resume paused Audio Operation
- CDROMPLAYMSF Play Audio MSF (struct cdrom_msf)
- CDROMPLAYTRKIND Play Audio Track/index (struct cdrom_ti)
- CDROMREADTOCHDR Read TOC header (struct cdrom_tochdr)
- CDROMREADTOCENTRY Read TOC entry (struct cdrom_tocentry)
- CDROMSTOP Stop the cdrom drive
- CDROMSTART Start the cdrom drive
- CDROMEJECT Ejects the cdrom media
- CDROMVOLCTRL Control output volume (struct cdrom_volctrl)
- CDROMSUBCHNL Read subchannel data (struct cdrom_subchnl)
- CDROMREADMODE2 Read CDROM mode 2 data (2336 Bytes)
- (struct cdrom_read)
- CDROMREADMODE1 Read CDROM mode 1 data (2048 Bytes)
- (struct cdrom_read)
- CDROMREADAUDIO (struct cdrom_read_audio)
- CDROMEJECT_SW enable(1)/disable(0) auto-ejecting
- CDROMMULTISESSION Obtain the start-of-last-session
- address of multi session disks
- (struct cdrom_multisession)
- CDROM_GET_MCN Obtain the "Universal Product Code"
- if available (struct cdrom_mcn)
- CDROM_GET_UPC Deprecated, use CDROM_GET_MCN instead.
- CDROMRESET hard-reset the drive
- CDROMVOLREAD Get the drive's volume setting
- (struct cdrom_volctrl)
- CDROMREADRAW read data in raw mode (2352 Bytes)
- (struct cdrom_read)
- CDROMREADCOOKED read data in cooked mode
- CDROMSEEK seek msf address
- CDROMPLAYBLK scsi-cd only, (struct cdrom_blk)
- CDROMREADALL read all 2646 bytes
- CDROMGETSPINDOWN return 4-bit spindown value
- CDROMSETSPINDOWN set 4-bit spindown value
- CDROMCLOSETRAY pendant of CDROMEJECT
- CDROM_SET_OPTIONS Set behavior options
- CDROM_CLEAR_OPTIONS Clear behavior options
- CDROM_SELECT_SPEED Set the CD-ROM speed
- CDROM_SELECT_DISC Select disc (for juke-boxes)
- CDROM_MEDIA_CHANGED Check is media changed
- CDROM_DRIVE_STATUS Get tray position, etc.
- CDROM_DISC_STATUS Get disc type, etc.
- CDROM_CHANGER_NSLOTS Get number of slots
- CDROM_LOCKDOOR lock or unlock door
- CDROM_DEBUG Turn debug messages on/off
- CDROM_GET_CAPABILITY get capabilities
- CDROMAUDIOBUFSIZ set the audio buffer size
- DVD_READ_STRUCT Read structure
- DVD_WRITE_STRUCT Write structure
- DVD_AUTH Authentication
- CDROM_SEND_PACKET send a packet to the drive
- CDROM_NEXT_WRITABLE get next writable block
- CDROM_LAST_WRITTEN get last block written on disc
-
-
-The information that follows was determined from reading kernel source
-code. It is likely that some corrections will be made over time.
-
-
-
-
-
-
-
-General:
-
- Unless otherwise specified, all ioctl calls return 0 on success
- and -1 with errno set to an appropriate value on error. (Some
- ioctls return non-negative data values.)
-
- Unless otherwise specified, all ioctl calls return -1 and set
- errno to EFAULT on a failed attempt to copy data to or from user
- address space.
-
- Individual drivers may return error codes not listed here.
-
- Unless otherwise specified, all data structures and constants
- are defined in <linux/cdrom.h>
-
-
-
-
-CDROMPAUSE Pause Audio Operation
-
- usage:
-
- ioctl(fd, CDROMPAUSE, 0);
-
- inputs: none
-
- outputs: none
-
- error return:
- ENOSYS cd drive not audio-capable.
-
-
-CDROMRESUME Resume paused Audio Operation
-
- usage:
-
- ioctl(fd, CDROMRESUME, 0);
-
- inputs: none
-
- outputs: none
-
- error return:
- ENOSYS cd drive not audio-capable.
-
-
-CDROMPLAYMSF Play Audio MSF (struct cdrom_msf)
-
- usage:
-
- struct cdrom_msf msf;
- ioctl(fd, CDROMPLAYMSF, &msf);
-
- inputs:
- cdrom_msf structure, describing a segment of music to play
-
- outputs: none
-
- error return:
- ENOSYS cd drive not audio-capable.
-
- notes:
- MSF stands for minutes-seconds-frames
- LBA stands for logical block address
-
- Segment is described as start and end times, where each time
- is described as minutes:seconds:frames. A frame is 1/75 of
- a second.
-
-
-CDROMPLAYTRKIND Play Audio Track/index (struct cdrom_ti)
-
- usage:
-
- struct cdrom_ti ti;
- ioctl(fd, CDROMPLAYTRKIND, &ti);
-
- inputs:
- cdrom_ti structure, describing a segment of music to play
-
- outputs: none
-
- error return:
- ENOSYS cd drive not audio-capable.
-
- notes:
- Segment is described as start and end times, where each time
- is described as a track and an index.
-
-
-
-CDROMREADTOCHDR Read TOC header (struct cdrom_tochdr)
-
- usage:
-
- cdrom_tochdr header;
- ioctl(fd, CDROMREADTOCHDR, &header);
-
- inputs:
- cdrom_tochdr structure
-
- outputs:
- cdrom_tochdr structure
-
- error return:
- ENOSYS cd drive not audio-capable.
-
-
-
-CDROMREADTOCENTRY Read TOC entry (struct cdrom_tocentry)
-
- usage:
-
- struct cdrom_tocentry entry;
- ioctl(fd, CDROMREADTOCENTRY, &entry);
-
- inputs:
- cdrom_tocentry structure
-
- outputs:
- cdrom_tocentry structure
-
- error return:
- ENOSYS cd drive not audio-capable.
- EINVAL entry.cdte_format not CDROM_MSF or CDROM_LBA
- EINVAL requested track out of bounds
- EIO I/O error reading TOC
-
- notes:
- TOC stands for Table Of Contents
- MSF stands for minutes-seconds-frames
- LBA stands for logical block address
-
-
-
-CDROMSTOP Stop the cdrom drive
-
- usage:
-
- ioctl(fd, CDROMSTOP, 0);
-
- inputs: none
-
- outputs: none
-
- error return:
- ENOSYS cd drive not audio-capable.
-
- notes:
- Exact interpretation of this ioctl depends on the device,
- but most seem to spin the drive down.
-
-
-CDROMSTART Start the cdrom drive
-
- usage:
-
- ioctl(fd, CDROMSTART, 0);
-
- inputs: none
-
- outputs: none
-
- error return:
- ENOSYS cd drive not audio-capable.
-
- notes:
- Exact interpretation of this ioctl depends on the device,
- but most seem to spin the drive up and/or close the tray.
- Other devices ignore the ioctl completely.
-
-
-CDROMEJECT Ejects the cdrom media
-
- usage:
-
- ioctl(fd, CDROMEJECT, 0);
-
- inputs: none
-
- outputs: none
-
- error returns:
- ENOSYS cd drive not capable of ejecting
- EBUSY other processes are accessing drive, or door is locked
-
- notes:
- See CDROM_LOCKDOOR, below.
-
-
-
-CDROMCLOSETRAY pendant of CDROMEJECT
-
- usage:
-
- ioctl(fd, CDROMCLOSETRAY, 0);
-
- inputs: none
-
- outputs: none
-
- error returns:
- ENOSYS cd drive not capable of closing the tray
- EBUSY other processes are accessing drive, or door is locked
-
- notes:
- See CDROM_LOCKDOOR, below.
-
-
-
-CDROMVOLCTRL Control output volume (struct cdrom_volctrl)
-
- usage:
-
- struct cdrom_volctrl volume;
- ioctl(fd, CDROMVOLCTRL, &volume);
-
- inputs:
- cdrom_volctrl structure containing volumes for up to 4
- channels.
-
- outputs: none
-
- error return:
- ENOSYS cd drive not audio-capable.
-
-
-
-CDROMVOLREAD Get the drive's volume setting
- (struct cdrom_volctrl)
-
- usage:
-
- struct cdrom_volctrl volume;
- ioctl(fd, CDROMVOLREAD, &volume);
-
- inputs: none
-
- outputs:
- The current volume settings.
-
- error return:
- ENOSYS cd drive not audio-capable.
-
-
-
-CDROMSUBCHNL Read subchannel data (struct cdrom_subchnl)
-
- usage:
-
- struct cdrom_subchnl q;
- ioctl(fd, CDROMSUBCHNL, &q);
-
- inputs:
- cdrom_subchnl structure
-
- outputs:
- cdrom_subchnl structure
-
- error return:
- ENOSYS cd drive not audio-capable.
- EINVAL format not CDROM_MSF or CDROM_LBA
-
- notes:
- Format is converted to CDROM_MSF or CDROM_LBA
- as per user request on return
-
-
-
-CDROMREADRAW read data in raw mode (2352 Bytes)
- (struct cdrom_read)
-
- usage:
-
- union {
- struct cdrom_msf msf; /* input */
- char buffer[CD_FRAMESIZE_RAW]; /* return */
- } arg;
- ioctl(fd, CDROMREADRAW, &arg);
-
- inputs:
- cdrom_msf structure indicating an address to read.
- Only the start values are significant.
-
- outputs:
- Data written to address provided by user.
-
- error return:
- EINVAL address less than 0, or msf less than 0:2:0
- ENOMEM out of memory
-
- notes:
- As of 2.6.8.1, comments in <linux/cdrom.h> indicate that this
- ioctl accepts a cdrom_read structure, but actual source code
- reads a cdrom_msf structure and writes a buffer of data to
- the same address.
-
- MSF values are converted to LBA values via this formula:
-
- lba = (((m * CD_SECS) + s) * CD_FRAMES + f) - CD_MSF_OFFSET;
-
-
-
-
-CDROMREADMODE1 Read CDROM mode 1 data (2048 Bytes)
- (struct cdrom_read)
-
- notes:
- Identical to CDROMREADRAW except that block size is
- CD_FRAMESIZE (2048) bytes
-
-
-
-CDROMREADMODE2 Read CDROM mode 2 data (2336 Bytes)
- (struct cdrom_read)
-
- notes:
- Identical to CDROMREADRAW except that block size is
- CD_FRAMESIZE_RAW0 (2336) bytes
-
-
-
-CDROMREADAUDIO (struct cdrom_read_audio)
-
- usage:
-
- struct cdrom_read_audio ra;
- ioctl(fd, CDROMREADAUDIO, &ra);
-
- inputs:
- cdrom_read_audio structure containing read start
- point and length
-
- outputs:
- audio data, returned to buffer indicated by ra
-
- error return:
- EINVAL format not CDROM_MSF or CDROM_LBA
- EINVAL nframes not in range [1 75]
- ENXIO drive has no queue (probably means invalid fd)
- ENOMEM out of memory
-
-
-CDROMEJECT_SW enable(1)/disable(0) auto-ejecting
-
- usage:
-
- int val;
- ioctl(fd, CDROMEJECT_SW, val);
-
- inputs:
- Flag specifying auto-eject flag.
-
- outputs: none
-
- error return:
- ENOSYS Drive is not capable of ejecting.
- EBUSY Door is locked
-
-
-
-
-CDROMMULTISESSION Obtain the start-of-last-session
- address of multi session disks
- (struct cdrom_multisession)
- usage:
-
- struct cdrom_multisession ms_info;
- ioctl(fd, CDROMMULTISESSION, &ms_info);
-
- inputs:
- cdrom_multisession structure containing desired
- format.
-
- outputs:
- cdrom_multisession structure is filled with last_session
- information.
-
- error return:
- EINVAL format not CDROM_MSF or CDROM_LBA
-
-
-CDROM_GET_MCN Obtain the "Universal Product Code"
- if available (struct cdrom_mcn)
-
- usage:
-
- struct cdrom_mcn mcn;
- ioctl(fd, CDROM_GET_MCN, &mcn);
-
- inputs: none
-
- outputs:
- Universal Product Code
-
- error return:
- ENOSYS Drive is not capable of reading MCN data.
-
- notes:
- Source code comments state:
-
- The following function is implemented, although very few
- audio discs give Universal Product Code information, which
- should just be the Medium Catalog Number on the box. Note,
- that the way the code is written on the CD is /not/ uniform
- across all discs!
-
-
-
-
-CDROM_GET_UPC CDROM_GET_MCN (deprecated)
-
- Not implemented, as of 2.6.8.1
-
-
-
-CDROMRESET hard-reset the drive
-
- usage:
-
- ioctl(fd, CDROMRESET, 0);
-
- inputs: none
-
- outputs: none
-
- error return:
- EACCES Access denied: requires CAP_SYS_ADMIN
- ENOSYS Drive is not capable of resetting.
-
-
-
-
-CDROMREADCOOKED read data in cooked mode
-
- usage:
-
- u8 buffer[CD_FRAMESIZE]
- ioctl(fd, CDROMREADCOOKED, buffer);
-
- inputs: none
-
- outputs:
- 2048 bytes of data, "cooked" mode.
-
- notes:
- Not implemented on all drives.
-
-
-
-
-CDROMREADALL read all 2646 bytes
-
- Same as CDROMREADCOOKED, but reads 2646 bytes.
-
-
-
-CDROMSEEK seek msf address
-
- usage:
-
- struct cdrom_msf msf;
- ioctl(fd, CDROMSEEK, &msf);
-
- inputs:
- MSF address to seek to.
-
- outputs: none
-
-
-
-CDROMPLAYBLK scsi-cd only, (struct cdrom_blk)
-
- usage:
-
- struct cdrom_blk blk;
- ioctl(fd, CDROMPLAYBLK, &blk);
-
- inputs:
- Region to play
-
- outputs: none
-
-
-
-CDROMGETSPINDOWN
-
- usage:
-
- char spindown;
- ioctl(fd, CDROMGETSPINDOWN, &spindown);
-
- inputs: none
-
- outputs:
- The value of the current 4-bit spindown value.
-
-
-
-
-CDROMSETSPINDOWN
-
- usage:
-
- char spindown
- ioctl(fd, CDROMSETSPINDOWN, &spindown);
-
- inputs:
- 4-bit value used to control spindown (TODO: more detail here)
-
- outputs: none
-
-
-
-
-
-CDROM_SET_OPTIONS Set behavior options
-
- usage:
-
- int options;
- ioctl(fd, CDROM_SET_OPTIONS, options);
-
- inputs:
- New values for drive options. The logical 'or' of:
- CDO_AUTO_CLOSE close tray on first open(2)
- CDO_AUTO_EJECT open tray on last release
- CDO_USE_FFLAGS use O_NONBLOCK information on open
- CDO_LOCK lock tray on open files
- CDO_CHECK_TYPE check type on open for data
-
- outputs:
- Returns the resulting options settings in the
- ioctl return value. Returns -1 on error.
-
- error return:
- ENOSYS selected option(s) not supported by drive.
-
-
-
-
-CDROM_CLEAR_OPTIONS Clear behavior options
-
- Same as CDROM_SET_OPTIONS, except that selected options are
- turned off.
-
-
-
-CDROM_SELECT_SPEED Set the CD-ROM speed
-
- usage:
-
- int speed;
- ioctl(fd, CDROM_SELECT_SPEED, speed);
-
- inputs:
- New drive speed.
-
- outputs: none
-
- error return:
- ENOSYS speed selection not supported by drive.
-
-
-
-CDROM_SELECT_DISC Select disc (for juke-boxes)
-
- usage:
-
- int disk;
- ioctl(fd, CDROM_SELECT_DISC, disk);
-
- inputs:
- Disk to load into drive.
-
- outputs: none
-
- error return:
- EINVAL Disk number beyond capacity of drive
-
-
-
-CDROM_MEDIA_CHANGED Check is media changed
-
- usage:
-
- int slot;
- ioctl(fd, CDROM_MEDIA_CHANGED, slot);
-
- inputs:
- Slot number to be tested, always zero except for jukeboxes.
- May also be special values CDSL_NONE or CDSL_CURRENT
-
- outputs:
- Ioctl return value is 0 or 1 depending on whether the media
- has been changed, or -1 on error.
-
- error returns:
- ENOSYS Drive can't detect media change
- EINVAL Slot number beyond capacity of drive
- ENOMEM Out of memory
-
-
-
-CDROM_DRIVE_STATUS Get tray position, etc.
-
- usage:
-
- int slot;
- ioctl(fd, CDROM_DRIVE_STATUS, slot);
-
- inputs:
- Slot number to be tested, always zero except for jukeboxes.
- May also be special values CDSL_NONE or CDSL_CURRENT
-
- outputs:
- Ioctl return value will be one of the following values
- from <linux/cdrom.h>:
-
- CDS_NO_INFO Information not available.
- CDS_NO_DISC
- CDS_TRAY_OPEN
- CDS_DRIVE_NOT_READY
- CDS_DISC_OK
- -1 error
-
- error returns:
- ENOSYS Drive can't detect drive status
- EINVAL Slot number beyond capacity of drive
- ENOMEM Out of memory
-
-
-
-
-CDROM_DISC_STATUS Get disc type, etc.
-
- usage:
-
- ioctl(fd, CDROM_DISC_STATUS, 0);
-
- inputs: none
-
- outputs:
- Ioctl return value will be one of the following values
- from <linux/cdrom.h>:
- CDS_NO_INFO
- CDS_AUDIO
- CDS_MIXED
- CDS_XA_2_2
- CDS_XA_2_1
- CDS_DATA_1
-
- error returns: none at present
-
- notes:
- Source code comments state:
-
- Ok, this is where problems start. The current interface for
- the CDROM_DISC_STATUS ioctl is flawed. It makes the false
- assumption that CDs are all CDS_DATA_1 or all CDS_AUDIO, etc.
- Unfortunately, while this is often the case, it is also
- very common for CDs to have some tracks with data, and some
- tracks with audio. Just because I feel like it, I declare
- the following to be the best way to cope. If the CD has
- ANY data tracks on it, it will be returned as a data CD.
- If it has any XA tracks, I will return it as that. Now I
- could simplify this interface by combining these returns with
- the above, but this more clearly demonstrates the problem
- with the current interface. Too bad this wasn't designed
- to use bitmasks... -Erik
-
- Well, now we have the option CDS_MIXED: a mixed-type CD.
- User level programmers might feel the ioctl is not very
- useful.
- ---david
-
-
-
-
-CDROM_CHANGER_NSLOTS Get number of slots
-
- usage:
-
- ioctl(fd, CDROM_CHANGER_NSLOTS, 0);
-
- inputs: none
-
- outputs:
- The ioctl return value will be the number of slots in a
- CD changer. Typically 1 for non-multi-disk devices.
-
- error returns: none
-
-
-
-CDROM_LOCKDOOR lock or unlock door
-
- usage:
-
- int lock;
- ioctl(fd, CDROM_LOCKDOOR, lock);
-
- inputs:
- Door lock flag, 1=lock, 0=unlock
-
- outputs: none
-
- error returns:
- EDRIVE_CANT_DO_THIS Door lock function not supported.
- EBUSY Attempt to unlock when multiple users
- have the drive open and not CAP_SYS_ADMIN
-
- notes:
- As of 2.6.8.1, the lock flag is a global lock, meaning that
- all CD drives will be locked or unlocked together. This is
- probably a bug.
-
- The EDRIVE_CANT_DO_THIS value is defined in <linux/cdrom.h>
- and is currently (2.6.8.1) the same as EOPNOTSUPP
-
-
-
-CDROM_DEBUG Turn debug messages on/off
-
- usage:
-
- int debug;
- ioctl(fd, CDROM_DEBUG, debug);
-
- inputs:
- Cdrom debug flag, 0=disable, 1=enable
-
- outputs:
- The ioctl return value will be the new debug flag.
-
- error return:
- EACCES Access denied: requires CAP_SYS_ADMIN
-
-
-
-CDROM_GET_CAPABILITY get capabilities
-
- usage:
-
- ioctl(fd, CDROM_GET_CAPABILITY, 0);
-
- inputs: none
-
- outputs:
- The ioctl return value is the current device capability
- flags. See CDC_CLOSE_TRAY, CDC_OPEN_TRAY, etc.
-
-
-
-CDROMAUDIOBUFSIZ set the audio buffer size
-
- usage:
-
- int arg;
- ioctl(fd, CDROMAUDIOBUFSIZ, val);
-
- inputs:
- New audio buffer size
-
- outputs:
- The ioctl return value is the new audio buffer size, or -1
- on error.
-
- error return:
- ENOSYS Not supported by this driver.
-
- notes:
- Not supported by all drivers.
-
-
-
-DVD_READ_STRUCT Read structure
-
- usage:
-
- dvd_struct s;
- ioctl(fd, DVD_READ_STRUCT, &s);
-
- inputs:
- dvd_struct structure, containing:
- type specifies the information desired, one of
- DVD_STRUCT_PHYSICAL, DVD_STRUCT_COPYRIGHT,
- DVD_STRUCT_DISCKEY, DVD_STRUCT_BCA,
- DVD_STRUCT_MANUFACT
- physical.layer_num desired layer, indexed from 0
- copyright.layer_num desired layer, indexed from 0
- disckey.agid
-
- outputs:
- dvd_struct structure, containing:
- physical for type == DVD_STRUCT_PHYSICAL
- copyright for type == DVD_STRUCT_COPYRIGHT
- disckey.value for type == DVD_STRUCT_DISCKEY
- bca.{len,value} for type == DVD_STRUCT_BCA
- manufact.{len,valu} for type == DVD_STRUCT_MANUFACT
-
- error returns:
- EINVAL physical.layer_num exceeds number of layers
- EIO Received invalid response from drive
-
-
-
-DVD_WRITE_STRUCT Write structure
-
- Not implemented, as of 2.6.8.1
-
-
-
-DVD_AUTH Authentication
-
- usage:
-
- dvd_authinfo ai;
- ioctl(fd, DVD_AUTH, &ai);
-
- inputs:
- dvd_authinfo structure. See <linux/cdrom.h>
-
- outputs:
- dvd_authinfo structure.
-
- error return:
- ENOTTY ai.type not recognized.
-
-
-
-CDROM_SEND_PACKET send a packet to the drive
-
- usage:
-
- struct cdrom_generic_command cgc;
- ioctl(fd, CDROM_SEND_PACKET, &cgc);
-
- inputs:
- cdrom_generic_command structure containing the packet to send.
-
- outputs: none
- cdrom_generic_command structure containing results.
-
- error return:
- EIO command failed.
- EPERM Operation not permitted, either because a
- write command was attempted on a drive which
- is opened read-only, or because the command
- requires CAP_SYS_RAWIO
- EINVAL cgc.data_direction not set
-
-
-
-CDROM_NEXT_WRITABLE get next writable block
-
- usage:
-
- long next;
- ioctl(fd, CDROM_NEXT_WRITABLE, &next);
-
- inputs: none
-
- outputs:
- The next writable block.
-
- notes:
- If the device does not support this ioctl directly, the
- ioctl will return CDROM_LAST_WRITTEN + 7.
-
-
-
-CDROM_LAST_WRITTEN get last block written on disc
-
- usage:
-
- long last;
- ioctl(fd, CDROM_LAST_WRITTEN, &last);
-
- inputs: none
-
- outputs:
- The last block written on disc
-
- notes:
- If the device does not support this ioctl directly, the
- result is derived from the disc's table of contents. If the
- table of contents can't be read, this ioctl returns an
- error.
- Summary of HDIO_ ioctl calls.
- ============================
+==============================
+Summary of `HDIO_` ioctl calls
+==============================
- Edward A. Falk <efalk@google.com>
+- Edward A. Falk <efalk@google.com>
- November, 2004
+November, 2004
This document attempts to describe the ioctl(2) calls supported by
the HD/IDE layer. These are by-and-large implemented (as of Linux 2.6)
ioctls that pass argument pointers to user space:
+ ======================= =======================================
HDIO_GETGEO get device geometry
HDIO_GET_UNMASKINTR get current unmask setting
HDIO_GET_MULTCOUNT get current IDE blockmode setting
HDIO_DRIVE_TASK execute task and special drive command
HDIO_DRIVE_CMD execute a special drive command
HDIO_DRIVE_CMD_AEB HDIO_DRIVE_TASK
+ ======================= =======================================
ioctls that pass non-pointer values:
+ ======================= =======================================
HDIO_SET_MULTCOUNT change IDE blockmode
HDIO_SET_UNMASKINTR permit other irqs during I/O
HDIO_SET_KEEPSETTINGS keep ioctl settings on reset
HDIO_SET_IDE_SCSI Set scsi emulation mode on/off
HDIO_SET_SCSI_IDE not implemented yet
+ ======================= =======================================
The information that follows was determined from reading kernel source
code. It is likely that some corrections will be made over time.
-
-
-
-
-
+------------------------------------------------------------------------------
General:
Unless otherwise specified, all data structures and constants
are defined in <linux/hdreg.h>
+------------------------------------------------------------------------------
+HDIO_GETGEO
+ get device geometry
-HDIO_GETGEO get device geometry
- usage:
+ usage::
struct hd_geometry geom;
+
ioctl(fd, HDIO_GETGEO, &geom);
- inputs: none
+ inputs:
+ none
+
+
outputs:
+ hd_geometry structure containing:
- hd_geometry structure containing:
+ ========= ==================================
heads number of heads
sectors number of sectors/track
cylinders number of cylinders, mod 65536
start starting sector of this partition.
+ ========= ==================================
error returns:
- EINVAL if the device is not a disk drive or floppy drive,
- or if the user passes a null pointer
+ - EINVAL
+
+ if the device is not a disk drive or floppy drive,
+ or if the user passes a null pointer
notes:
+ Not particularly useful with modern disk drives, whose geometry
+ is a polite fiction anyway. Modern drives are addressed
+ purely by sector number nowadays (lba addressing), and the
+ drive geometry is an abstraction which is actually subject
+ to change. Currently (as of Nov 2004), the geometry values
+ are the "bios" values -- presumably the values the drive had
+ when Linux first booted.
- Not particularly useful with modern disk drives, whose geometry
- is a polite fiction anyway. Modern drives are addressed
- purely by sector number nowadays (lba addressing), and the
- drive geometry is an abstraction which is actually subject
- to change. Currently (as of Nov 2004), the geometry values
- are the "bios" values -- presumably the values the drive had
- when Linux first booted.
+ In addition, the cylinders field of the hd_geometry is an
+ unsigned short, meaning that on most architectures, this
+ ioctl will not return a meaningful value on drives with more
+ than 65535 tracks.
- In addition, the cylinders field of the hd_geometry is an
- unsigned short, meaning that on most architectures, this
- ioctl will not return a meaningful value on drives with more
- than 65535 tracks.
+ The start field is unsigned long, meaning that it will not
+ contain a meaningful value for disks over 219 Gb in size.
- The start field is unsigned long, meaning that it will not
- contain a meaningful value for disks over 219 Gb in size.
+HDIO_GET_UNMASKINTR
+ get current unmask setting
-HDIO_GET_UNMASKINTR get current unmask setting
- usage:
+ usage::
long val;
+
ioctl(fd, HDIO_GET_UNMASKINTR, &val);
- inputs: none
+ inputs:
+ none
+
+
outputs:
- The value of the drive's current unmask setting
+ The value of the drive's current unmask setting
-HDIO_SET_UNMASKINTR permit other irqs during I/O
- usage:
+
+HDIO_SET_UNMASKINTR
+ permit other irqs during I/O
+
+
+ usage::
unsigned long val;
+
ioctl(fd, HDIO_SET_UNMASKINTR, val);
inputs:
- New value for unmask flag
+ New value for unmask flag
+
+
+
+ outputs:
+ none
+
- outputs: none
error return:
- EINVAL (bdev != bdev->bd_contains) (not sure what this means)
- EACCES Access denied: requires CAP_SYS_ADMIN
- EINVAL value out of range [0 1]
- EBUSY Controller busy
+ - EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ - EACCES Access denied: requires CAP_SYS_ADMIN
+ - EINVAL value out of range [0 1]
+ - EBUSY Controller busy
+
+HDIO_GET_MULTCOUNT
+ get current IDE blockmode setting
-HDIO_GET_MULTCOUNT get current IDE blockmode setting
- usage:
+ usage::
long val;
+
ioctl(fd, HDIO_GET_MULTCOUNT, &val);
- inputs: none
+ inputs:
+ none
+
+
outputs:
- The value of the current IDE block mode setting. This
- controls how many sectors the drive will transfer per
- interrupt.
+ The value of the current IDE block mode setting. This
+ controls how many sectors the drive will transfer per
+ interrupt.
+
+HDIO_SET_MULTCOUNT
+ change IDE blockmode
-HDIO_SET_MULTCOUNT change IDE blockmode
- usage:
+ usage::
int val;
+
ioctl(fd, HDIO_SET_MULTCOUNT, val);
inputs:
- New value for IDE block mode setting. This controls how many
- sectors the drive will transfer per interrupt.
+ New value for IDE block mode setting. This controls how many
+ sectors the drive will transfer per interrupt.
+
+ outputs:
+ none
+
- outputs: none
error return:
- EINVAL (bdev != bdev->bd_contains) (not sure what this means)
- EACCES Access denied: requires CAP_SYS_ADMIN
- EINVAL value out of range supported by disk.
- EBUSY Controller busy or blockmode already set.
- EIO Drive did not accept new block mode.
+ - EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ - EACCES Access denied: requires CAP_SYS_ADMIN
+ - EINVAL value out of range supported by disk.
+ - EBUSY Controller busy or blockmode already set.
+ - EIO Drive did not accept new block mode.
notes:
-
- Source code comments read:
+ Source code comments read::
This is tightly woven into the driver->do_special cannot
touch. DON'T do it again until a total personality rewrite
is committed.
If blockmode has already been set, this ioctl will fail with
- EBUSY
+ -EBUSY
-HDIO_GET_QDMA get use-qdma flag
+HDIO_GET_QDMA
+ get use-qdma flag
+
Not implemented, as of 2.6.8.1
-HDIO_SET_XFER set transfer rate via proc
+HDIO_SET_XFER
+ set transfer rate via proc
+
Not implemented, as of 2.6.8.1
-HDIO_OBSOLETE_IDENTITY OBSOLETE, DO NOT USE
+HDIO_OBSOLETE_IDENTITY
+ OBSOLETE, DO NOT USE
+
Same as HDIO_GET_IDENTITY (see below), except that it only
returns the first 142 bytes of drive identity information.
-HDIO_GET_IDENTITY get IDE identification info
+HDIO_GET_IDENTITY
+ get IDE identification info
+
- usage:
+ usage::
unsigned char identity[512];
+
ioctl(fd, HDIO_GET_IDENTITY, identity);
- inputs: none
+ inputs:
+ none
- outputs:
- ATA drive identity information. For full description, see
- the IDENTIFY DEVICE and IDENTIFY PACKET DEVICE commands in
- the ATA specification.
+
+ outputs:
+ ATA drive identity information. For full description, see
+ the IDENTIFY DEVICE and IDENTIFY PACKET DEVICE commands in
+ the ATA specification.
error returns:
- EINVAL (bdev != bdev->bd_contains) (not sure what this means)
- ENOMSG IDENTIFY DEVICE information not available
+ - EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ - ENOMSG IDENTIFY DEVICE information not available
notes:
+ Returns information that was obtained when the drive was
+ probed. Some of this information is subject to change, and
+ this ioctl does not re-probe the drive to update the
+ information.
- Returns information that was obtained when the drive was
- probed. Some of this information is subject to change, and
- this ioctl does not re-probe the drive to update the
- information.
+ This information is also available from /proc/ide/hdX/identify
- This information is also available from /proc/ide/hdX/identify
+HDIO_GET_KEEPSETTINGS
+ get keep-settings-on-reset flag
-HDIO_GET_KEEPSETTINGS get keep-settings-on-reset flag
- usage:
+ usage::
long val;
+
ioctl(fd, HDIO_GET_KEEPSETTINGS, &val);
- inputs: none
+ inputs:
+ none
+
+
outputs:
- The value of the current "keep settings" flag
+ The value of the current "keep settings" flag
+
+
notes:
+ When set, indicates that kernel should restore settings
+ after a drive reset.
- When set, indicates that kernel should restore settings
- after a drive reset.
+HDIO_SET_KEEPSETTINGS
+ keep ioctl settings on reset
-HDIO_SET_KEEPSETTINGS keep ioctl settings on reset
- usage:
+ usage::
long val;
+
ioctl(fd, HDIO_SET_KEEPSETTINGS, val);
inputs:
- New value for keep_settings flag
+ New value for keep_settings flag
+
+
+
+ outputs:
+ none
+
- outputs: none
error return:
- EINVAL (bdev != bdev->bd_contains) (not sure what this means)
- EACCES Access denied: requires CAP_SYS_ADMIN
- EINVAL value out of range [0 1]
- EBUSY Controller busy
+ - EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ - EACCES Access denied: requires CAP_SYS_ADMIN
+ - EINVAL value out of range [0 1]
+ - EBUSY Controller busy
+
+HDIO_GET_32BIT
+ get current io_32bit setting
-HDIO_GET_32BIT get current io_32bit setting
- usage:
+ usage::
long val;
+
ioctl(fd, HDIO_GET_32BIT, &val);
- inputs: none
+ inputs:
+ none
+
+
outputs:
- The value of the current io_32bit setting
+ The value of the current io_32bit setting
+
+
notes:
+ 0=16-bit, 1=32-bit, 2,3 = 32bit+sync
+
- 0=16-bit, 1=32-bit, 2,3 = 32bit+sync
-HDIO_GET_NOWERR get ignore-write-error flag
+HDIO_GET_NOWERR
+ get ignore-write-error flag
- usage:
+
+ usage::
long val;
+
ioctl(fd, HDIO_GET_NOWERR, &val);
- inputs: none
+ inputs:
+ none
+
+
outputs:
- The value of the current ignore-write-error flag
+ The value of the current ignore-write-error flag
-HDIO_GET_DMA get use-dma flag
- usage:
+
+HDIO_GET_DMA
+ get use-dma flag
+
+
+ usage::
long val;
+
ioctl(fd, HDIO_GET_DMA, &val);
- inputs: none
+ inputs:
+ none
+
+
outputs:
- The value of the current use-dma flag
+ The value of the current use-dma flag
-HDIO_GET_NICE get nice flags
- usage:
+
+HDIO_GET_NICE
+ get nice flags
+
+
+ usage::
long nice;
+
ioctl(fd, HDIO_GET_NICE, &nice);
- inputs: none
+ inputs:
+ none
+
+
outputs:
+ The drive's "nice" values.
+
- The drive's "nice" values.
notes:
+ Per-drive flags which determine when the system will give more
+ bandwidth to other devices sharing the same IDE bus.
- Per-drive flags which determine when the system will give more
- bandwidth to other devices sharing the same IDE bus.
- See <linux/hdreg.h>, near symbol IDE_NICE_DSC_OVERLAP.
+ See <linux/hdreg.h>, near symbol IDE_NICE_DSC_OVERLAP.
-HDIO_SET_NICE set nice flags
+HDIO_SET_NICE
+ set nice flags
- usage:
+
+ usage::
unsigned long nice;
+
...
ioctl(fd, HDIO_SET_NICE, nice);
inputs:
- bitmask of nice flags.
+ bitmask of nice flags.
+
+
+
+ outputs:
+ none
+
- outputs: none
error returns:
- EACCES Access denied: requires CAP_SYS_ADMIN
- EPERM Flags other than DSC_OVERLAP and NICE_1 set.
- EPERM DSC_OVERLAP specified but not supported by drive
+ - EACCES Access denied: requires CAP_SYS_ADMIN
+ - EPERM Flags other than DSC_OVERLAP and NICE_1 set.
+ - EPERM DSC_OVERLAP specified but not supported by drive
notes:
+ This ioctl sets the DSC_OVERLAP and NICE_1 flags from values
+ provided by the user.
- This ioctl sets the DSC_OVERLAP and NICE_1 flags from values
- provided by the user.
+ Nice flags are listed in <linux/hdreg.h>, starting with
+ IDE_NICE_DSC_OVERLAP. These values represent shifts.
- Nice flags are listed in <linux/hdreg.h>, starting with
- IDE_NICE_DSC_OVERLAP. These values represent shifts.
+HDIO_GET_WCACHE
+ get write cache mode on|off
-HDIO_GET_WCACHE get write cache mode on|off
- usage:
+ usage::
long val;
+
ioctl(fd, HDIO_GET_WCACHE, &val);
- inputs: none
+ inputs:
+ none
+
+
outputs:
- The value of the current write cache mode
+ The value of the current write cache mode
-HDIO_GET_ACOUSTIC get acoustic value
- usage:
+
+HDIO_GET_ACOUSTIC
+ get acoustic value
+
+
+ usage::
long val;
+
ioctl(fd, HDIO_GET_ACOUSTIC, &val);
- inputs: none
+ inputs:
+ none
+
+
outputs:
- The value of the current acoustic settings
+ The value of the current acoustic settings
+
+
notes:
+ See HDIO_SET_ACOUSTIC
+
- See HDIO_SET_ACOUSTIC
HDIO_GET_ADDRESS
+ usage::
- usage:
long val;
+
ioctl(fd, HDIO_GET_ADDRESS, &val);
- inputs: none
+ inputs:
+ none
+
+
outputs:
- The value of the current addressing mode:
- 0 = 28-bit
- 1 = 48-bit
- 2 = 48-bit doing 28-bit
- 3 = 64-bit
+ The value of the current addressing mode:
+
+ = ===================
+ 0 28-bit
+ 1 48-bit
+ 2 48-bit doing 28-bit
+ 3 64-bit
+ = ===================
-HDIO_GET_BUSSTATE get the bus state of the hwif
+HDIO_GET_BUSSTATE
+ get the bus state of the hwif
- usage:
+
+ usage::
long state;
+
ioctl(fd, HDIO_SCAN_HWIF, &state);
- inputs: none
+ inputs:
+ none
+
+
outputs:
- Current power state of the IDE bus. One of BUSSTATE_OFF,
- BUSSTATE_ON, or BUSSTATE_TRISTATE
+ Current power state of the IDE bus. One of BUSSTATE_OFF,
+ BUSSTATE_ON, or BUSSTATE_TRISTATE
error returns:
- EACCES Access denied: requires CAP_SYS_ADMIN
+ - EACCES Access denied: requires CAP_SYS_ADMIN
-HDIO_SET_BUSSTATE set the bus state of the hwif
+HDIO_SET_BUSSTATE
+ set the bus state of the hwif
- usage:
+
+ usage::
int state;
+
...
ioctl(fd, HDIO_SCAN_HWIF, state);
inputs:
- Desired IDE power state. One of BUSSTATE_OFF, BUSSTATE_ON,
- or BUSSTATE_TRISTATE
+ Desired IDE power state. One of BUSSTATE_OFF, BUSSTATE_ON,
+ or BUSSTATE_TRISTATE
+
+ outputs:
+ none
+
- outputs: none
error returns:
- EACCES Access denied: requires CAP_SYS_RAWIO
- EOPNOTSUPP Hardware interface does not support bus power control
+ - EACCES Access denied: requires CAP_SYS_RAWIO
+ - EOPNOTSUPP Hardware interface does not support bus power control
+
+HDIO_TRISTATE_HWIF
+ execute a channel tristate
-HDIO_TRISTATE_HWIF execute a channel tristate
Not implemented, as of 2.6.8.1. See HDIO_SET_BUSSTATE
-HDIO_DRIVE_RESET execute a device reset
+HDIO_DRIVE_RESET
+ execute a device reset
+
- usage:
+ usage::
int args[3]
+
...
ioctl(fd, HDIO_DRIVE_RESET, args);
- inputs: none
+ inputs:
+ none
+
+
+
+ outputs:
+ none
+
- outputs: none
error returns:
- EACCES Access denied: requires CAP_SYS_ADMIN
- ENXIO No such device: phy dead or ctl_addr == 0
- EIO I/O error: reset timed out or hardware error
+ - EACCES Access denied: requires CAP_SYS_ADMIN
+ - ENXIO No such device: phy dead or ctl_addr == 0
+ - EIO I/O error: reset timed out or hardware error
notes:
- Execute a reset on the device as soon as the current IO
- operation has completed.
+ - Execute a reset on the device as soon as the current IO
+ operation has completed.
- Executes an ATAPI soft reset if applicable, otherwise
- executes an ATA soft reset on the controller.
+ - Executes an ATAPI soft reset if applicable, otherwise
+ executes an ATA soft reset on the controller.
-HDIO_DRIVE_TASKFILE execute raw taskfile
+HDIO_DRIVE_TASKFILE
+ execute raw taskfile
- Note: If you don't have a copy of the ANSI ATA specification
- handy, you should probably ignore this ioctl.
- Execute an ATA disk command directly by writing the "taskfile"
- registers of the drive. Requires ADMIN and RAWIO access
- privileges.
+ Note:
+ If you don't have a copy of the ANSI ATA specification
+ handy, you should probably ignore this ioctl.
+
+ - Execute an ATA disk command directly by writing the "taskfile"
+ registers of the drive. Requires ADMIN and RAWIO access
+ privileges.
- usage:
+ usage::
struct {
+
ide_task_request_t req_task;
u8 outbuf[OUTPUT_SIZE];
u8 inbuf[INPUT_SIZE];
(See below for details on memory area passed to ioctl.)
+ ============ ===================================================
io_ports[8] values to be written to taskfile registers
hob_ports[8] high-order bytes, for extended commands.
out_flags flags indicating which registers are valid
out_size size of output buffer
outbuf buffer of data to be transmitted to disk
inbuf buffer of data to be received from disk (see [1])
+ ============ ===================================================
outputs:
+ =========== ====================================================
io_ports[] values returned in the taskfile registers
hob_ports[] high-order bytes, for extended commands.
out_flags flags indicating which registers are valid (see [2])
in_flags flags indicating which registers should be returned
outbuf buffer of data to be transmitted to disk (see [1])
inbuf buffer of data to be received from disk
+ =========== ====================================================
error returns:
- EACCES CAP_SYS_ADMIN or CAP_SYS_RAWIO privilege not set.
- ENOMSG Device is not a disk drive.
- ENOMEM Unable to allocate memory for task
- EFAULT req_cmd == TASKFILE_IN_OUT (not implemented as of 2.6.8)
- EPERM req_cmd == TASKFILE_MULTI_OUT and drive
- multi-count not yet set.
- EIO Drive failed the command.
+ - EACCES CAP_SYS_ADMIN or CAP_SYS_RAWIO privilege not set.
+ - ENOMSG Device is not a disk drive.
+ - ENOMEM Unable to allocate memory for task
+ - EFAULT req_cmd == TASKFILE_IN_OUT (not implemented as of 2.6.8)
+ - EPERM
+
+ req_cmd == TASKFILE_MULTI_OUT and drive
+ multi-count not yet set.
+ - EIO Drive failed the command.
notes:
Command is passed to the disk drive via the ide_task_request_t
structure, which contains these fields:
+ ============ ===============================================
io_ports[8] values for the taskfile registers
hob_ports[8] high-order bytes, for extended commands
out_flags flags indicating which entries in the
- io_ports[] and hob_ports[] arrays
+ io_ports[] and hob_ports[] arrays
contain valid values. Type ide_reg_valid_t.
in_flags flags indicating which entries in the
- io_ports[] and hob_ports[] arrays
+ io_ports[] and hob_ports[] arrays
are expected to contain valid values
on return.
data_phase See below
req_cmd Command type, see below
out_size output (user->drive) buffer size, bytes
in_size input (drive->user) buffer size, bytes
+ ============ ===============================================
When out_flags is zero, the following registers are loaded.
+ ============ ===============================================
HOB_FEATURE If the drive supports LBA48
HOB_NSECTOR If the drive supports LBA48
HOB_SECTOR If the drive supports LBA48
SELECT First, masked with 0xE0 if LBA48, 0xEF
otherwise; then, or'ed with the default
value of SELECT.
+ ============ ===============================================
If any bit in out_flags is set, the following registers are loaded.
+ ============ ===============================================
HOB_DATA If out_flags.b.data is set. HOB_DATA will
travel on DD8-DD15 on little endian machines
and on DD0-DD7 on big endian machines.
HCYL If out_flags.b.hcyl is set
SELECT Or'ed with the default value of SELECT and
loaded regardless of out_flags.b.select.
+ ============ ===============================================
Taskfile registers are read back from the drive into
{io|hob}_ports[] after the command completes iff one of the
2. One or more than one bits are set in out_flags.
3. The requested data_phase is TASKFILE_NO_DATA.
+ ============ ===============================================
HOB_DATA If in_flags.b.data is set. It will contain
DD8-DD15 on little endian machines and
DD0-DD7 on big endian machines.
SECTOR
LCYL
HCYL
+ ============ ===============================================
The data_phase field describes the data transfer to be
performed. Value is one of:
+ =================== ========================================
TASKFILE_IN
TASKFILE_MULTI_IN
TASKFILE_OUT
TASKFILE_P_OUT unimplemented
TASKFILE_P_OUT_DMA unimplemented
TASKFILE_P_OUT_DMAQ unimplemented
+ =================== ========================================
The req_cmd field classifies the command type. It may be
one of:
+ ======================== =======================================
IDE_DRIVE_TASK_NO_DATA
IDE_DRIVE_TASK_SET_XFER unimplemented
IDE_DRIVE_TASK_IN
IDE_DRIVE_TASK_OUT unimplemented
IDE_DRIVE_TASK_RAW_WRITE
+ ======================== =======================================
[6] Do not access {in|out}_flags->all except for resetting
all the bits. Always access individual bit fields. ->all
-HDIO_DRIVE_CMD execute a special drive command
+HDIO_DRIVE_CMD
+ execute a special drive command
+
Note: If you don't have a copy of the ANSI ATA specification
handy, you should probably ignore this ioctl.
- usage:
+ usage::
u8 args[4+XFER_SIZE];
+
...
ioctl(fd, HDIO_DRIVE_CMD, args);
inputs:
+ Commands other than WIN_SMART:
- Commands other than WIN_SMART
+ ======= =======
args[0] COMMAND
args[1] NSECTOR
args[2] FEATURE
args[3] NSECTOR
+ ======= =======
+
+ WIN_SMART:
- WIN_SMART
+ ======= =======
args[0] COMMAND
args[1] SECTOR
args[2] FEATURE
args[3] NSECTOR
+ ======= =======
outputs:
+ args[] buffer is filled with register values followed by any
+
- args[] buffer is filled with register values followed by any
data returned by the disk.
+
+ ======== ====================================================
args[0] status
args[1] error
args[2] NSECTOR
args[3] undefined
args[4+] NSECTOR * 512 bytes of data returned by the command.
+ ======== ====================================================
error returns:
- EACCES Access denied: requires CAP_SYS_RAWIO
- ENOMEM Unable to allocate memory for task
- EIO Drive reports error
+ - EACCES Access denied: requires CAP_SYS_RAWIO
+ - ENOMEM Unable to allocate memory for task
+ - EIO Drive reports error
notes:
-HDIO_DRIVE_TASK execute task and special drive command
+HDIO_DRIVE_TASK
+ execute task and special drive command
+
Note: If you don't have a copy of the ANSI ATA specification
handy, you should probably ignore this ioctl.
- usage:
+ usage::
u8 args[7];
+
...
ioctl(fd, HDIO_DRIVE_TASK, args);
inputs:
+ Taskfile register values:
- Taskfile register values:
+ ======= =======
args[0] COMMAND
args[1] FEATURE
args[2] NSECTOR
args[4] LCYL
args[5] HCYL
args[6] SELECT
+ ======= =======
outputs:
+ Taskfile register values:
+
- Taskfile register values:
+ ======= =======
args[0] status
args[1] error
args[2] NSECTOR
args[4] LCYL
args[5] HCYL
args[6] SELECT
+ ======= =======
error returns:
- EACCES Access denied: requires CAP_SYS_RAWIO
- ENOMEM Unable to allocate memory for task
- ENOMSG Device is not a disk drive.
- EIO Drive failed the command.
+ - EACCES Access denied: requires CAP_SYS_RAWIO
+ - ENOMEM Unable to allocate memory for task
+ - ENOMSG Device is not a disk drive.
+ - EIO Drive failed the command.
notes:
-HDIO_DRIVE_CMD_AEB HDIO_DRIVE_TASK
+HDIO_DRIVE_CMD_AEB
+ HDIO_DRIVE_TASK
+
Not implemented, as of 2.6.8.1
-HDIO_SET_32BIT change io_32bit flags
+HDIO_SET_32BIT
+ change io_32bit flags
+
- usage:
+ usage::
int val;
+
ioctl(fd, HDIO_SET_32BIT, val);
inputs:
- New value for io_32bit flag
+ New value for io_32bit flag
+
+
+
+ outputs:
+ none
+
- outputs: none
error return:
- EINVAL (bdev != bdev->bd_contains) (not sure what this means)
- EACCES Access denied: requires CAP_SYS_ADMIN
- EINVAL value out of range [0 3]
- EBUSY Controller busy
+ - EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ - EACCES Access denied: requires CAP_SYS_ADMIN
+ - EINVAL value out of range [0 3]
+ - EBUSY Controller busy
-HDIO_SET_NOWERR change ignore-write-error flag
+HDIO_SET_NOWERR
+ change ignore-write-error flag
- usage:
+
+ usage::
int val;
+
ioctl(fd, HDIO_SET_NOWERR, val);
inputs:
- New value for ignore-write-error flag. Used for ignoring
+ New value for ignore-write-error flag. Used for ignoring
+
+
WRERR_STAT
- outputs: none
+ outputs:
+ none
+
+
error return:
- EINVAL (bdev != bdev->bd_contains) (not sure what this means)
- EACCES Access denied: requires CAP_SYS_ADMIN
- EINVAL value out of range [0 1]
- EBUSY Controller busy
+ - EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ - EACCES Access denied: requires CAP_SYS_ADMIN
+ - EINVAL value out of range [0 1]
+ - EBUSY Controller busy
+
+HDIO_SET_DMA
+ change use-dma flag
-HDIO_SET_DMA change use-dma flag
- usage:
+ usage::
long val;
+
ioctl(fd, HDIO_SET_DMA, val);
inputs:
- New value for use-dma flag
+ New value for use-dma flag
+
+
+
+ outputs:
+ none
+
- outputs: none
error return:
- EINVAL (bdev != bdev->bd_contains) (not sure what this means)
- EACCES Access denied: requires CAP_SYS_ADMIN
- EINVAL value out of range [0 1]
- EBUSY Controller busy
+ - EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ - EACCES Access denied: requires CAP_SYS_ADMIN
+ - EINVAL value out of range [0 1]
+ - EBUSY Controller busy
+
+HDIO_SET_PIO_MODE
+ reconfig interface to new speed
-HDIO_SET_PIO_MODE reconfig interface to new speed
- usage:
+ usage::
long val;
+
ioctl(fd, HDIO_SET_PIO_MODE, val);
inputs:
- New interface speed.
+ New interface speed.
+
+
+
+ outputs:
+ none
+
- outputs: none
error return:
- EINVAL (bdev != bdev->bd_contains) (not sure what this means)
- EACCES Access denied: requires CAP_SYS_ADMIN
- EINVAL value out of range [0 255]
- EBUSY Controller busy
+ - EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ - EACCES Access denied: requires CAP_SYS_ADMIN
+ - EINVAL value out of range [0 255]
+ - EBUSY Controller busy
+
+HDIO_SCAN_HWIF
+ register and (re)scan interface
-HDIO_SCAN_HWIF register and (re)scan interface
- usage:
+ usage::
int args[3]
+
...
ioctl(fd, HDIO_SCAN_HWIF, args);
inputs:
+
+ ======= =========================
args[0] io address to probe
+
+
args[1] control address to probe
args[2] irq number
+ ======= =========================
+
+ outputs:
+ none
+
- outputs: none
error returns:
- EACCES Access denied: requires CAP_SYS_RAWIO
- EIO Probe failed.
+ - EACCES Access denied: requires CAP_SYS_RAWIO
+ - EIO Probe failed.
notes:
+ This ioctl initializes the addresses and irq for a disk
+ controller, probes for drives, and creates /proc/ide
+ interfaces as appropriate.
- This ioctl initializes the addresses and irq for a disk
- controller, probes for drives, and creates /proc/ide
- interfaces as appropriate.
+HDIO_UNREGISTER_HWIF
+ unregister interface
-HDIO_UNREGISTER_HWIF unregister interface
- usage:
+ usage::
int index;
+
ioctl(fd, HDIO_UNREGISTER_HWIF, index);
inputs:
- index index of hardware interface to unregister
+ index index of hardware interface to unregister
+
+
+
+ outputs:
+ none
+
- outputs: none
error returns:
- EACCES Access denied: requires CAP_SYS_RAWIO
+ - EACCES Access denied: requires CAP_SYS_RAWIO
notes:
+ This ioctl removes a hardware interface from the kernel.
- This ioctl removes a hardware interface from the kernel.
+ Currently (2.6.8) this ioctl silently fails if any drive on
+ the interface is busy.
- Currently (2.6.8) this ioctl silently fails if any drive on
- the interface is busy.
+HDIO_SET_WCACHE
+ change write cache enable-disable
-HDIO_SET_WCACHE change write cache enable-disable
- usage:
+ usage::
int val;
+
ioctl(fd, HDIO_SET_WCACHE, val);
inputs:
- New value for write cache enable
+ New value for write cache enable
+
+
+
+ outputs:
+ none
+
- outputs: none
error return:
- EINVAL (bdev != bdev->bd_contains) (not sure what this means)
- EACCES Access denied: requires CAP_SYS_ADMIN
- EINVAL value out of range [0 1]
- EBUSY Controller busy
+ - EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ - EACCES Access denied: requires CAP_SYS_ADMIN
+ - EINVAL value out of range [0 1]
+ - EBUSY Controller busy
+
+HDIO_SET_ACOUSTIC
+ change acoustic behavior
-HDIO_SET_ACOUSTIC change acoustic behavior
- usage:
+ usage::
int val;
+
ioctl(fd, HDIO_SET_ACOUSTIC, val);
inputs:
- New value for drive acoustic settings
+ New value for drive acoustic settings
+
+
+
+ outputs:
+ none
+
- outputs: none
error return:
- EINVAL (bdev != bdev->bd_contains) (not sure what this means)
- EACCES Access denied: requires CAP_SYS_ADMIN
- EINVAL value out of range [0 254]
- EBUSY Controller busy
+ - EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ - EACCES Access denied: requires CAP_SYS_ADMIN
+ - EINVAL value out of range [0 254]
+ - EBUSY Controller busy
-HDIO_SET_QDMA change use-qdma flag
+HDIO_SET_QDMA
+ change use-qdma flag
+
Not implemented, as of 2.6.8.1
-HDIO_SET_ADDRESS change lba addressing modes
+HDIO_SET_ADDRESS
+ change lba addressing modes
+
- usage:
+ usage::
int val;
+
ioctl(fd, HDIO_SET_ADDRESS, val);
inputs:
- New value for addressing mode
- 0 = 28-bit
- 1 = 48-bit
- 2 = 48-bit doing 28-bit
+ New value for addressing mode
+
+ = ===================
+ 0 28-bit
+ 1 48-bit
+ 2 48-bit doing 28-bit
+ = ===================
+
+ outputs:
+ none
+
- outputs: none
error return:
- EINVAL (bdev != bdev->bd_contains) (not sure what this means)
- EACCES Access denied: requires CAP_SYS_ADMIN
- EINVAL value out of range [0 2]
- EBUSY Controller busy
- EIO Drive does not support lba48 mode.
+ - EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ - EACCES Access denied: requires CAP_SYS_ADMIN
+ - EINVAL value out of range [0 2]
+ - EBUSY Controller busy
+ - EIO Drive does not support lba48 mode.
HDIO_SET_IDE_SCSI
+ usage::
- usage:
long val;
+
ioctl(fd, HDIO_SET_IDE_SCSI, val);
inputs:
- New value for scsi emulation mode (?)
+ New value for scsi emulation mode (?)
- outputs: none
- error return:
- EINVAL (bdev != bdev->bd_contains) (not sure what this means)
- EACCES Access denied: requires CAP_SYS_ADMIN
- EINVAL value out of range [0 1]
- EBUSY Controller busy
+ outputs:
+ none
-HDIO_SET_SCSI_IDE
- Not implemented, as of 2.6.8.1
+ error return:
+ - EINVAL (bdev != bdev->bd_contains) (not sure what this means)
+ - EACCES Access denied: requires CAP_SYS_ADMIN
+ - EINVAL value out of range [0 1]
+ - EBUSY Controller busy
+
+HDIO_SET_SCSI_IDE
+ Not implemented, as of 2.6.8.1
--- /dev/null
+:orphan:
+
+======
+IOCTLs
+======
+
+.. toctree::
+ :maxdepth: 1
+
+ ioctl-number
+
+ botching-up-ioctls
+ ioctl-decoding
+
+ cdrom
+ hdio
+==============================
+Decoding an IOCTL Magic Number
+==============================
+
To decode a hex IOCTL code:
Most architectures use this generic format, but check
include/ARCH/ioctl.h for specifics, e.g. powerpc
uses 3 bits to encode read/write and 13 bits for size.
- bits meaning
+ ====== ==================================
+ bits meaning
+ ====== ==================================
31-30 00 - no parameters: uses _IO macro
10 - read: _IOR
01 - write: _IOW
unique to each driver
7-0 function #
+ ====== ==================================
So for example 0x82187201 is a read with arg length of 0x218,
-character 'r' function 1. Grepping the source reveals this is:
+character 'r' function 1. Grepping the source reveals this is::
-#define VFAT_IOCTL_READDIR_BOTH _IOR('r', 1, struct dirent [2])
+ #define VFAT_IOCTL_READDIR_BOTH _IOR('r', 1, struct dirent [2])
* };
*
* Please make sure that you follow all the best practices from
- * ``Documentation/ioctl/botching-up-ioctls.txt``. Note that drm_ioctl()
+ * ``Documentation/ioctl/botching-up-ioctls.rst``. Note that drm_ioctl()
* automatically zero-extends structures, hence make sure you can add more stuff
* at the end, i.e. don't put a variable sized array there.
*
git.samba.org / sfrench / cifs-2.6.git / commitdiff