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authorRandy Dunlap <randy.dunlap@oracle.com>2008-03-07 21:53:50 +0100
committerBartlomiej Zolnierkiewicz <bzolnier@gmail.com>2008-03-07 21:53:50 +0100
commit331a5ad2a2ab6e93d1848b060c84fd2821c72e29 (patch)
tree78b8d2ce28f53602485b72d472bf23aafdf3a872 /Documentation/ide
parent0c6025d44448bd688dfd351a09bc620aafa4d1ff (diff)
downloadlinux-331a5ad2a2ab6e93d1848b060c84fd2821c72e29.tar.gz
ide: move ide.txt to Documentation/ide/
Cleanup some of Documentation directory: Move Documentation/ide.txt to the ide/ sub-directory. Fix trailing whitespace while there. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
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+
+ Information regarding the Enhanced IDE drive in Linux 2.6
+
+==============================================================================
+
+
+ The hdparm utility can be used to control various IDE features on a
+ running system. It is packaged separately. Please Look for it on popular
+ linux FTP sites.
+
+
+
+*** IMPORTANT NOTICES: BUGGY IDE CHIPSETS CAN CORRUPT DATA!!
+*** =================
+*** PCI versions of the CMD640 and RZ1000 interfaces are now detected
+*** automatically at startup when PCI BIOS support is configured.
+***
+*** Linux disables the "prefetch" ("readahead") mode of the RZ1000
+*** to prevent data corruption possible due to hardware design flaws.
+***
+*** For the CMD640, linux disables "IRQ unmasking" (hdparm -u1) on any
+*** drive for which the "prefetch" mode of the CMD640 is turned on.
+*** If "prefetch" is disabled (hdparm -p8), then "IRQ unmasking" can be
+*** used again.
+***
+*** For the CMD640, linux disables "32bit I/O" (hdparm -c1) on any drive
+*** for which the "prefetch" mode of the CMD640 is turned off.
+*** If "prefetch" is enabled (hdparm -p9), then "32bit I/O" can be
+*** used again.
+***
+*** The CMD640 is also used on some Vesa Local Bus (VLB) cards, and is *NOT*
+*** automatically detected by Linux. For safe, reliable operation with such
+*** interfaces, one *MUST* use the "cmd640.probe_vlb" kernel option.
+***
+*** Use of the "serialize" option is no longer necessary.
+
+================================================================================
+Common pitfalls:
+
+- 40-conductor IDE cables are capable of transferring data in DMA modes up to
+ udma2, but no faster.
+
+- If possible devices should be attached to separate channels if they are
+ available. Typically the disk on the first and CD-ROM on the second.
+
+- If you mix devices on the same cable, please consider using similar devices
+ in respect of the data transfer mode they support.
+
+- Even better try to stick to the same vendor and device type on the same
+ cable.
+
+================================================================================
+
+This is the multiple IDE interface driver, as evolved from hd.c.
+
+It supports up to 9 IDE interfaces per default, on one or more IRQs (usually
+14 & 15). There can be up to two drives per interface, as per the ATA-6 spec.
+
+Primary: ide0, port 0x1f0; major=3; hda is minor=0; hdb is minor=64
+Secondary: ide1, port 0x170; major=22; hdc is minor=0; hdd is minor=64
+Tertiary: ide2, port 0x1e8; major=33; hde is minor=0; hdf is minor=64
+Quaternary: ide3, port 0x168; major=34; hdg is minor=0; hdh is minor=64
+fifth.. ide4, usually PCI, probed
+sixth.. ide5, usually PCI, probed
+
+To access devices on interfaces > ide0, device entries please make sure that
+device files for them are present in /dev. If not, please create such
+entries, by using /dev/MAKEDEV.
+
+This driver automatically probes for most IDE interfaces (including all PCI
+ones), for the drives/geometries attached to those interfaces, and for the IRQ
+lines being used by the interfaces (normally 14, 15 for ide0/ide1).
+
+For special cases, interfaces may be specified using kernel "command line"
+options. For example,
+
+ ide3=0x168,0x36e,10 /* ioports 0x168-0x16f,0x36e, irq 10 */
+
+Normally the irq number need not be specified, as ide.c will probe for it:
+
+ ide3=0x168,0x36e /* ioports 0x168-0x16f,0x36e */
+
+The standard port, and irq values are these:
+
+ ide0=0x1f0,0x3f6,14
+ ide1=0x170,0x376,15
+ ide2=0x1e8,0x3ee,11
+ ide3=0x168,0x36e,10
+
+Note that the first parameter reserves 8 contiguous ioports, whereas the
+second value denotes a single ioport. If in doubt, do a 'cat /proc/ioports'.
+
+In all probability the device uses these ports and IRQs if it is attached
+to the appropriate ide channel. Pass the parameter for the correct ide
+channel to the kernel, as explained above.
+
+Any number of interfaces may share a single IRQ if necessary, at a slight
+performance penalty, whether on separate cards or a single VLB card.
+The IDE driver automatically detects and handles this. However, this may
+or may not be harmful to your hardware.. two or more cards driving the same IRQ
+can potentially burn each other's bus driver, though in practice this
+seldom occurs. Be careful, and if in doubt, don't do it!
+
+Drives are normally found by auto-probing and/or examining the CMOS/BIOS data.
+For really weird situations, the apparent (fdisk) geometry can also be specified
+on the kernel "command line" using LILO. The format of such lines is:
+
+ hdx=cyls,heads,sects,wpcom,irq
+or hdx=cdrom
+
+where hdx can be any of hda through hdh, Three values are required
+(cyls,heads,sects). For example:
+
+ hdc=1050,32,64 hdd=cdrom
+
+either {hda,hdb} or {hdc,hdd}. The results of successful auto-probing may
+override the physical geometry/irq specified, though the "original" geometry
+may be retained as the "logical" geometry for partitioning purposes (fdisk).
+
+If the auto-probing during boot time confuses a drive (ie. the drive works
+with hd.c but not with ide.c), then an command line option may be specified
+for each drive for which you'd like the drive to skip the hardware
+probe/identification sequence. For example:
+
+ hdb=noprobe
+or
+ hdc=768,16,32
+ hdc=noprobe
+
+Note that when only one IDE device is attached to an interface, it should be
+jumpered as "single" or "master", *not* "slave". Many folks have had
+"trouble" with cdroms because of this requirement, so the driver now probes
+for both units, though success is more likely when the drive is jumpered
+correctly.
+
+Courtesy of Scott Snyder and others, the driver supports ATAPI cdrom drives
+such as the NEC-260 and the new MITSUMI triple/quad speed drives.
+Such drives will be identified at boot time, just like a hard disk.
+
+If for some reason your cdrom drive is *not* found at boot time, you can force
+the probe to look harder by supplying a kernel command line parameter
+via LILO, such as:
+
+ hdc=cdrom /* hdc = "master" on second interface */
+or
+ hdd=cdrom /* hdd = "slave" on second interface */
+
+For example, a GW2000 system might have a hard drive on the primary
+interface (/dev/hda) and an IDE cdrom drive on the secondary interface
+(/dev/hdc). To mount a CD in the cdrom drive, one would use something like:
+
+ ln -sf /dev/hdc /dev/cdrom
+ mkdir /mnt/cdrom
+ mount /dev/cdrom /mnt/cdrom -t iso9660 -o ro
+
+If, after doing all of the above, mount doesn't work and you see
+errors from the driver (with dmesg) complaining about `status=0xff',
+this means that the hardware is not responding to the driver's attempts
+to read it. One of the following is probably the problem:
+
+ - Your hardware is broken.
+
+ - You are using the wrong address for the device, or you have the
+ drive jumpered wrong. Review the configuration instructions above.
+
+ - Your IDE controller requires some nonstandard initialization sequence
+ before it will work properly. If this is the case, there will often
+ be a separate MS-DOS driver just for the controller. IDE interfaces
+ on sound cards usually fall into this category. Such configurations
+ can often be made to work by first booting MS-DOS, loading the
+ appropriate drivers, and then warm-booting linux (without powering
+ off). This can be automated using loadlin in the MS-DOS autoexec.
+
+If you always get timeout errors, interrupts from the drive are probably
+not making it to the host. Check how you have the hardware jumpered
+and make sure it matches what the driver expects (see the configuration
+instructions above). If you have a PCI system, also check the BIOS
+setup; I've had one report of a system which was shipped with IRQ 15
+disabled by the BIOS.
+
+The kernel is able to execute binaries directly off of the cdrom,
+provided it is mounted with the default block size of 1024 (as above).
+
+Please pass on any feedback on any of this stuff to the maintainer,
+whose address can be found in linux/MAINTAINERS.
+
+Note that if BOTH hd.c and ide.c are configured into the kernel,
+hd.c will normally be allowed to control the primary IDE interface.
+This is useful for older hardware that may be incompatible with ide.c,
+and still allows newer hardware to run on the 2nd/3rd/4th IDE ports
+under control of ide.c. To have ide.c also "take over" the primary
+IDE port in this situation, use the "command line" parameter: ide0=0x1f0
+
+The IDE driver is modularized. The high level disk/CD-ROM/tape/floppy
+drivers can always be compiled as loadable modules, the chipset drivers
+can only be compiled into the kernel, and the core code (ide.c) can be
+compiled as a loadable module provided no chipset support is needed.
+
+When using ide.c as a module in combination with kmod, add:
+
+ alias block-major-3 ide-probe
+
+to /etc/modprobe.conf.
+
+When ide.c is used as a module, you can pass command line parameters to the
+driver using the "options=" keyword to insmod, while replacing any ',' with
+';'. For example:
+
+ insmod ide.o options="ide0=serialize ide1=serialize ide2=0x1e8;0x3ee;11"
+
+
+================================================================================
+
+Summary of ide driver parameters for kernel command line
+--------------------------------------------------------
+
+ "hdx=" is recognized for all "x" from "a" to "h", such as "hdc".
+
+ "idex=" is recognized for all "x" from "0" to "3", such as "ide1".
+
+ "hdx=noprobe" : drive may be present, but do not probe for it
+
+ "hdx=none" : drive is NOT present, ignore cmos and do not probe
+
+ "hdx=nowerr" : ignore the WRERR_STAT bit on this drive
+
+ "hdx=cdrom" : drive is present, and is a cdrom drive
+
+ "hdx=cyl,head,sect" : disk drive is present, with specified geometry
+
+ "hdx=remap" : remap access of sector 0 to sector 1 (for EZDrive)
+
+ "hdx=remap63" : remap the drive: add 63 to all sector numbers
+ (for DM OnTrack)
+
+ "idex=noautotune" : driver will NOT attempt to tune interface speed
+
+ "hdx=autotune" : driver will attempt to tune interface speed
+ to the fastest PIO mode supported,
+ if possible for this drive only.
+ Not fully supported by all chipset types,
+ and quite likely to cause trouble with
+ older/odd IDE drives.
+
+ "hdx=nodma" : disallow DMA
+
+ "hdx=scsi" : the return of the ide-scsi flag, this is useful for
+ allowing ide-floppy, ide-tape, and ide-cdrom|writers
+ to use ide-scsi emulation on a device specific option.
+
+ "idebus=xx" : inform IDE driver of VESA/PCI bus speed in MHz,
+ where "xx" is between 20 and 66 inclusive,
+ used when tuning chipset PIO modes.
+ For PCI bus, 25 is correct for a P75 system,
+ 30 is correct for P90,P120,P180 systems,
+ and 33 is used for P100,P133,P166 systems.
+ If in doubt, use idebus=33 for PCI.
+ As for VLB, it is safest to not specify it.
+ Bigger values are safer than smaller ones.
+
+ "idex=base" : probe for an interface at the addr specified,
+ where "base" is usually 0x1f0 or 0x170
+ and "ctl" is assumed to be "base"+0x206
+
+ "idex=base,ctl" : specify both base and ctl
+
+ "idex=base,ctl,irq" : specify base, ctl, and irq number
+
+ "idex=serialize" : do not overlap operations on idex. Please note
+ that you will have to specify this option for
+ both the respective primary and secondary channel
+ to take effect.
+
+ "idex=four" : four drives on idex and ide(x^1) share same ports
+
+ "idex=reset" : reset interface after probe
+
+ "idex=ata66" : informs the interface that it has an 80c cable
+ for chipsets that are ATA-66 capable, but the
+ ability to bit test for detection is currently
+ unknown.
+
+ "ide=reverse" : formerly called to pci sub-system, but now local.
+
+The following are valid ONLY on ide0, which usually corresponds
+to the first ATA interface found on the particular host, and the defaults for
+the base,ctl ports must not be altered.
+
+ "ide=doubler" : probe/support IDE doublers on Amiga
+
+There may be more options than shown -- use the source, Luke!
+
+Everything else is rejected with a "BAD OPTION" message.
+
+For legacy IDE VLB host drivers (ali14xx/dtc2278/ht6560b/qd65xx/umc8672)
+you need to explicitly enable probing by using "probe" kernel parameter,
+i.e. to enable probing for ALI M14xx chipsets (ali14xx host driver) use:
+
+* "ali14xx.probe" boot option when ali14xx driver is built-in the kernel
+
+* "probe" module parameter when ali14xx driver is compiled as module
+ ("modprobe ali14xx probe")
+
+Also for legacy CMD640 host driver (cmd640) you need to use "probe_vlb"
+kernel paremeter to enable probing for VLB version of the chipset (PCI ones
+are detected automatically).
+
+================================================================================
+
+Some Terminology
+----------------
+IDE = Integrated Drive Electronics, meaning that each drive has a built-in
+controller, which is why an "IDE interface card" is not a "controller card".
+
+ATA = AT (the old IBM 286 computer) Attachment Interface, a draft American
+National Standard for connecting hard drives to PCs. This is the official
+name for "IDE".
+
+The latest standards define some enhancements, known as the ATA-6 spec,
+which grew out of vendor-specific "Enhanced IDE" (EIDE) implementations.
+
+ATAPI = ATA Packet Interface, a new protocol for controlling the drives,
+similar to SCSI protocols, created at the same time as the ATA2 standard.
+ATAPI is currently used for controlling CDROM, TAPE and FLOPPY (ZIP or
+LS120/240) devices, removable R/W cartridges, and for high capacity hard disk
+drives.
+
+mlord@pobox.com
+--
+
+Wed Apr 17 22:52:44 CEST 2002 edited by Marcin Dalecki, the current
+maintainer.
+
+Wed Aug 20 22:31:29 CEST 2003 updated ide boot options to current ide.c
+comments at 2.6.0-test4 time. Maciej Soltysiak <solt@dns.toxicfilms.tv>