view Documentation/ide.txt @ 452:c7ed6fe5dca0

kexec: dont initialise regions in reserve_memory()

There is no need to initialise efi_memmap_res and boot_param_res in
reserve_memory() for the initial xen domain as it is done in
machine_kexec_setup_resources() using values from the kexec hypercall.

Signed-off-by: Simon Horman <horms@verge.net.au>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Feb 28 10:55:18 2008 +0000 (2008-02-28)
parents 831230e53067
line source
2 Information regarding the Enhanced IDE drive in Linux 2.6
4 ==============================================================================
7 The hdparm utility can be used to control various IDE features on a
8 running system. It is packaged separately. Please Look for it on popular
9 linux FTP sites.
14 *** =================
15 *** PCI versions of the CMD640 and RZ1000 interfaces are now detected
16 *** automatically at startup when PCI BIOS support is configured.
17 ***
18 *** Linux disables the "prefetch" ("readahead") mode of the RZ1000
19 *** to prevent data corruption possible due to hardware design flaws.
20 ***
21 *** For the CMD640, linux disables "IRQ unmasking" (hdparm -u1) on any
22 *** drive for which the "prefetch" mode of the CMD640 is turned on.
23 *** If "prefetch" is disabled (hdparm -p8), then "IRQ unmasking" can be
24 *** used again.
25 ***
26 *** For the CMD640, linux disables "32bit I/O" (hdparm -c1) on any drive
27 *** for which the "prefetch" mode of the CMD640 is turned off.
28 *** If "prefetch" is enabled (hdparm -p9), then "32bit I/O" can be
29 *** used again.
30 ***
31 *** The CMD640 is also used on some Vesa Local Bus (VLB) cards, and is *NOT*
32 *** automatically detected by Linux. For safe, reliable operation with such
33 *** interfaces, one *MUST* use the "ide0=cmd640_vlb" kernel option.
34 ***
35 *** Use of the "serialize" option is no longer necessary.
37 ================================================================================
38 Common pitfalls:
40 - 40-conductor IDE cables are capable of transferring data in DMA modes up to
41 udma2, but no faster.
43 - If possible devices should be attached to separate channels if they are
44 available. Typically the disk on the first and CD-ROM on the second.
46 - If you mix devices on the same cable, please consider using similar devices
47 in respect of the data transfer mode they support.
49 - Even better try to stick to the same vendor and device type on the same
50 cable.
52 ================================================================================
54 This is the multiple IDE interface driver, as evolved from hd.c.
56 It supports up to 9 IDE interfaces per default, on one or more IRQs (usually
57 14 & 15). There can be up to two drives per interface, as per the ATA-6 spec.
59 Primary: ide0, port 0x1f0; major=3; hda is minor=0; hdb is minor=64
60 Secondary: ide1, port 0x170; major=22; hdc is minor=0; hdd is minor=64
61 Tertiary: ide2, port 0x1e8; major=33; hde is minor=0; hdf is minor=64
62 Quaternary: ide3, port 0x168; major=34; hdg is minor=0; hdh is minor=64
63 fifth.. ide4, usually PCI, probed
64 sixth.. ide5, usually PCI, probed
66 To access devices on interfaces > ide0, device entries please make sure that
67 device files for them are present in /dev. If not, please create such
68 entries, by using /dev/MAKEDEV.
70 This driver automatically probes for most IDE interfaces (including all PCI
71 ones), for the drives/geometries attached to those interfaces, and for the IRQ
72 lines being used by the interfaces (normally 14, 15 for ide0/ide1).
74 For special cases, interfaces may be specified using kernel "command line"
75 options. For example,
77 ide3=0x168,0x36e,10 /* ioports 0x168-0x16f,0x36e, irq 10 */
79 Normally the irq number need not be specified, as ide.c will probe for it:
81 ide3=0x168,0x36e /* ioports 0x168-0x16f,0x36e */
83 The standard port, and irq values are these:
85 ide0=0x1f0,0x3f6,14
86 ide1=0x170,0x376,15
87 ide2=0x1e8,0x3ee,11
88 ide3=0x168,0x36e,10
90 Note that the first parameter reserves 8 contiguous ioports, whereas the
91 second value denotes a single ioport. If in doubt, do a 'cat /proc/ioports'.
93 In all probability the device uses these ports and IRQs if it is attached
94 to the appropriate ide channel. Pass the parameter for the correct ide
95 channel to the kernel, as explained above.
97 Any number of interfaces may share a single IRQ if necessary, at a slight
98 performance penalty, whether on separate cards or a single VLB card.
99 The IDE driver automatically detects and handles this. However, this may
100 or may not be harmful to your hardware.. two or more cards driving the same IRQ
101 can potentially burn each other's bus driver, though in practice this
102 seldom occurs. Be careful, and if in doubt, don't do it!
104 Drives are normally found by auto-probing and/or examining the CMOS/BIOS data.
105 For really weird situations, the apparent (fdisk) geometry can also be specified
106 on the kernel "command line" using LILO. The format of such lines is:
108 hdx=cyls,heads,sects,wpcom,irq
109 or hdx=cdrom
111 where hdx can be any of hda through hdh, Three values are required
112 (cyls,heads,sects). For example:
114 hdc=1050,32,64 hdd=cdrom
116 either {hda,hdb} or {hdc,hdd}. The results of successful auto-probing may
117 override the physical geometry/irq specified, though the "original" geometry
118 may be retained as the "logical" geometry for partitioning purposes (fdisk).
120 If the auto-probing during boot time confuses a drive (ie. the drive works
121 with hd.c but not with ide.c), then an command line option may be specified
122 for each drive for which you'd like the drive to skip the hardware
123 probe/identification sequence. For example:
125 hdb=noprobe
126 or
127 hdc=768,16,32
128 hdc=noprobe
130 Note that when only one IDE device is attached to an interface, it should be
131 jumpered as "single" or "master", *not* "slave". Many folks have had
132 "trouble" with cdroms because of this requirement, so the driver now probes
133 for both units, though success is more likely when the drive is jumpered
134 correctly.
136 Courtesy of Scott Snyder and others, the driver supports ATAPI cdrom drives
137 such as the NEC-260 and the new MITSUMI triple/quad speed drives.
138 Such drives will be identified at boot time, just like a hard disk.
140 If for some reason your cdrom drive is *not* found at boot time, you can force
141 the probe to look harder by supplying a kernel command line parameter
142 via LILO, such as:
144 hdc=cdrom /* hdc = "master" on second interface */
145 or
146 hdd=cdrom /* hdd = "slave" on second interface */
148 For example, a GW2000 system might have a hard drive on the primary
149 interface (/dev/hda) and an IDE cdrom drive on the secondary interface
150 (/dev/hdc). To mount a CD in the cdrom drive, one would use something like:
152 ln -sf /dev/hdc /dev/cdrom
153 mkdir /mnt/cdrom
154 mount /dev/cdrom /mnt/cdrom -t iso9660 -o ro
156 If, after doing all of the above, mount doesn't work and you see
157 errors from the driver (with dmesg) complaining about `status=0xff',
158 this means that the hardware is not responding to the driver's attempts
159 to read it. One of the following is probably the problem:
161 - Your hardware is broken.
163 - You are using the wrong address for the device, or you have the
164 drive jumpered wrong. Review the configuration instructions above.
166 - Your IDE controller requires some nonstandard initialization sequence
167 before it will work properly. If this is the case, there will often
168 be a separate MS-DOS driver just for the controller. IDE interfaces
169 on sound cards usually fall into this category. Such configurations
170 can often be made to work by first booting MS-DOS, loading the
171 appropriate drivers, and then warm-booting linux (without powering
172 off). This can be automated using loadlin in the MS-DOS autoexec.
174 If you always get timeout errors, interrupts from the drive are probably
175 not making it to the host. Check how you have the hardware jumpered
176 and make sure it matches what the driver expects (see the configuration
177 instructions above). If you have a PCI system, also check the BIOS
178 setup; I've had one report of a system which was shipped with IRQ 15
179 disabled by the BIOS.
181 The kernel is able to execute binaries directly off of the cdrom,
182 provided it is mounted with the default block size of 1024 (as above).
184 Please pass on any feedback on any of this stuff to the maintainer,
185 whose address can be found in linux/MAINTAINERS.
187 Note that if BOTH hd.c and ide.c are configured into the kernel,
188 hd.c will normally be allowed to control the primary IDE interface.
189 This is useful for older hardware that may be incompatible with ide.c,
190 and still allows newer hardware to run on the 2nd/3rd/4th IDE ports
191 under control of ide.c. To have ide.c also "take over" the primary
192 IDE port in this situation, use the "command line" parameter: ide0=0x1f0
194 The IDE driver is modularized. The high level disk/CD-ROM/tape/floppy
195 drivers can always be compiled as loadable modules, the chipset drivers
196 can only be compiled into the kernel, and the core code (ide.c) can be
197 compiled as a loadable module provided no chipset support is needed.
199 When using ide.c as a module in combination with kmod, add:
201 alias block-major-3 ide-probe
203 to /etc/modprobe.conf.
205 When ide.c is used as a module, you can pass command line parameters to the
206 driver using the "options=" keyword to insmod, while replacing any ',' with
207 ';'. For example:
209 insmod ide.o options="ide0=serialize ide1=serialize ide2=0x1e8;0x3ee;11"
212 ================================================================================
214 Summary of ide driver parameters for kernel command line
215 --------------------------------------------------------
217 "hdx=" is recognized for all "x" from "a" to "h", such as "hdc".
219 "idex=" is recognized for all "x" from "0" to "3", such as "ide1".
221 "hdx=noprobe" : drive may be present, but do not probe for it
223 "hdx=none" : drive is NOT present, ignore cmos and do not probe
225 "hdx=nowerr" : ignore the WRERR_STAT bit on this drive
227 "hdx=cdrom" : drive is present, and is a cdrom drive
229 "hdx=cyl,head,sect" : disk drive is present, with specified geometry
231 "hdx=remap" : remap access of sector 0 to sector 1 (for EZDrive)
233 "hdx=remap63" : remap the drive: add 63 to all sector numbers
234 (for DM OnTrack)
236 "hdx=autotune" : driver will attempt to tune interface speed
237 to the fastest PIO mode supported,
238 if possible for this drive only.
239 Not fully supported by all chipset types,
240 and quite likely to cause trouble with
241 older/odd IDE drives.
243 "hdx=swapdata" : when the drive is a disk, byte swap all data
245 "hdx=bswap" : same as above..........
247 "hdx=scsi" : the return of the ide-scsi flag, this is useful for
248 allowing ide-floppy, ide-tape, and ide-cdrom|writers
249 to use ide-scsi emulation on a device specific option.
251 "idebus=xx" : inform IDE driver of VESA/PCI bus speed in MHz,
252 where "xx" is between 20 and 66 inclusive,
253 used when tuning chipset PIO modes.
254 For PCI bus, 25 is correct for a P75 system,
255 30 is correct for P90,P120,P180 systems,
256 and 33 is used for P100,P133,P166 systems.
257 If in doubt, use idebus=33 for PCI.
258 As for VLB, it is safest to not specify it.
259 Bigger values are safer than smaller ones.
261 "idex=noprobe" : do not attempt to access/use this interface
263 "idex=base" : probe for an interface at the addr specified,
264 where "base" is usually 0x1f0 or 0x170
265 and "ctl" is assumed to be "base"+0x206
267 "idex=base,ctl" : specify both base and ctl
269 "idex=base,ctl,irq" : specify base, ctl, and irq number
271 "idex=autotune" : driver will attempt to tune interface speed
272 to the fastest PIO mode supported,
273 for all drives on this interface.
274 Not fully supported by all chipset types,
275 and quite likely to cause trouble with
276 older/odd IDE drives.
278 "idex=noautotune" : driver will NOT attempt to tune interface speed
279 This is the default for most chipsets,
280 except the cmd640.
282 "idex=serialize" : do not overlap operations on idex. Please note
283 that you will have to specify this option for
284 both the respecitve primary and secondary channel
285 to take effect.
287 "idex=four" : four drives on idex and ide(x^1) share same ports
289 "idex=reset" : reset interface after probe
291 "idex=dma" : automatically configure/use DMA if possible.
293 "idex=ata66" : informs the interface that it has an 80c cable
294 for chipsets that are ATA-66 capable, but the
295 ability to bit test for detection is currently
296 unknown.
298 "ide=reverse" : formerly called to pci sub-system, but now local.
300 "ide=nodma" : disable DMA globally for the IDE subsystem.
302 The following are valid ONLY on ide0, which usually corresponds
303 to the first ATA interface found on the particular host, and the defaults for
304 the base,ctl ports must not be altered.
306 "ide0=dtc2278" : probe/support DTC2278 interface
307 "ide0=ht6560b" : probe/support HT6560B interface
308 "ide0=cmd640_vlb" : *REQUIRED* for VLB cards with the CMD640 chip
309 (not for PCI -- automatically detected)
310 "ide0=qd65xx" : probe/support qd65xx interface
311 "ide0=ali14xx" : probe/support ali14xx chipsets (ALI M1439/M1443/M1445)
312 "ide0=umc8672" : probe/support umc8672 chipsets
314 "ide=doubler" : probe/support IDE doublers on Amiga
316 There may be more options than shown -- use the source, Luke!
318 Everything else is rejected with a "BAD OPTION" message.
320 ================================================================================
322 IDE ATAPI streaming tape driver
323 -------------------------------
325 This driver is a part of the Linux ide driver and works in co-operation
326 with linux/drivers/block/ide.c.
328 The driver, in co-operation with ide.c, basically traverses the
329 request-list for the block device interface. The character device
330 interface, on the other hand, creates new requests, adds them
331 to the request-list of the block device, and waits for their completion.
333 Pipelined operation mode is now supported on both reads and writes.
335 The block device major and minor numbers are determined from the
336 tape's relative position in the ide interfaces, as explained in ide.c.
338 The character device interface consists of the following devices:
340 ht0 major 37, minor 0 first IDE tape, rewind on close.
341 ht1 major 37, minor 1 second IDE tape, rewind on close.
342 ...
343 nht0 major 37, minor 128 first IDE tape, no rewind on close.
344 nht1 major 37, minor 129 second IDE tape, no rewind on close.
345 ...
347 Run /dev/MAKEDEV to create the above entries.
349 The general magnetic tape commands compatible interface, as defined by
350 include/linux/mtio.h, is accessible through the character device.
352 General ide driver configuration options, such as the interrupt-unmask
353 flag, can be configured by issuing an ioctl to the block device interface,
354 as any other ide device.
356 Our own ide-tape ioctl's can be issued to either the block device or
357 the character device interface.
359 Maximal throughput with minimal bus load will usually be achieved in the
360 following scenario:
362 1. ide-tape is operating in the pipelined operation mode.
363 2. No buffering is performed by the user backup program.
367 ================================================================================
369 Some Terminology
370 ----------------
371 IDE = Integrated Drive Electronics, meaning that each drive has a built-in
372 controller, which is why an "IDE interface card" is not a "controller card".
374 ATA = AT (the old IBM 286 computer) Attachment Interface, a draft American
375 National Standard for connecting hard drives to PCs. This is the official
376 name for "IDE".
378 The latest standards define some enhancements, known as the ATA-6 spec,
379 which grew out of vendor-specific "Enhanced IDE" (EIDE) implementations.
381 ATAPI = ATA Packet Interface, a new protocol for controlling the drives,
382 similar to SCSI protocols, created at the same time as the ATA2 standard.
383 ATAPI is currently used for controlling CDROM, TAPE and FLOPPY (ZIP or
384 LS120/240) devices, removable R/W cartridges, and for high capacity hard disk
385 drives.
387 mlord@pobox.com
388 --
390 Wed Apr 17 22:52:44 CEST 2002 edited by Marcin Dalecki, the current
391 maintainer.
393 Wed Aug 20 22:31:29 CEST 2003 updated ide boot uptions to current ide.c
394 comments at 2.6.0-test4 time. Maciej Soltysiak <solt@dns.toxicfilms.tv>