source: trunk/src/os2ahci/README@ 170

Last change on this file since 170 was 169, checked in by David Azarewicz, 12 years ago

Added a check for bad geometries reported by the BIOS and fix them.

File size: 18.3 KB
Line 
1====================================================================
2 eComStation AHCI Driver
3====================================================================
4
5
6Introduction
7============
8
9OS2AHCI is an AHCI driver for eComStation. It supports both ATA and
10ATAPI devices in a single driver, thus there's no need for an
11ATAPI/CDROM filter driver.
12
13
14Copyrights
15==========
16
17Copyright (c) 2011 thi.guten Software Development
18Copyright (c) 2011-2013 Mensys B.V.
19Portions copyright (c) 2013 David Azarewicz
20
21Authors: Christian Mueller, Markus Thielen
22
23Parts copied from/inspired by the Linux AHCI driver;
24those parts are (c) Linux AHCI/ATA maintainers
25
26 This program is free software; you can redistribute it and/or modify
27 it under the terms of the GNU General Public License as published by
28 the Free Software Foundation; either version 2 of the License, or
29 (at your option) any later version.
30
31 This program is distributed in the hope that it will be useful,
32 but WITHOUT ANY WARRANTY; without even the implied warranty of
33 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
34 GNU General Public License for more details.
35
36 You should have received a copy of the GNU General Public License
37 along with this program; if not, write to the Free Software
38 Foundation, Inc., 59 Temple Place, Suite 330, Boston,
39 MA 02111-1307 USA
40
41
42Licensing and Source Code
43=========================
44
45The *binary* delivery of OS2AHCI.ADD as obtained from ecomstation.nl,
46or as part of packaged eComStation releases, is licensed to run with
47eComStation only.
48
49The source code can be retrieved from http://svn.ecomstation.nl;
50in compliance to the GNU General Public License, the source code
51can of course be modified/compiled to run on other products as long
52as modifications will also be published as outlined in the GNU GPL2.
53
54Please note that builds other than the official binary delivered as
55part of eComStation releases or downloaded from ecomstation.nl are
56not officially supported by Mensys.
57
58
59Building The Driver
60-------------------
61
62The toolchain required for compilation consists of:
63
64 - IBM OS/2 DDK version 9.23 or later (see ddk\base\h\version.mak)
65 and that has been updated for SMP systems. (Used for include files)
66 - Open Watcom C/C++ package
67 (available from: http://www.openwatcom.org/index.php/Downloads)
68 - WCC 16-bit C Compiler (part of the Open Watcom package)
69 - WASM Assembler (part of the Open Watcom package)
70 - WLINK Linker (part of the Open Watcom package)
71 - MAPSYM (part of the DDK)
72
73Define DDK and WATCOM in the environment.
74Use "wmake" or "wmake -a" to build the driver. See _build.cmd.
75
76Installation
77============
78
79- Run the included update.cmd,
80 or copy the driver file, OS2AHCI.ADD, to \OS2\BOOT on your boot disk.
81
82- Add the following line to CONFIG.SYS:
83 BASEDEV=OS2AHCI.ADD
84
85
86Reporting Problems
87==================
88
89If you have problems with this driver, please read the Troubleshooting
90page at:
91
92 http://svn.ecomstation.nl/ahci/wiki/Troubleshooting
93
94You can open a ticket at:
95 http://svn.ecomstation.nl/ahci
96
97
98Driver Command Line Options
99===========================
100
101Global Options
102
103Option Description
104------------------------------------------------------------------------------
105/b:<baud> Initialize the COM port to the specified baud rate. Allowable
106 baud values are: 300, 600, 1200, 2400, 4800, 9600, 19200,
107 38400, 57600, and 115200. /b has no effect if /c is not also
108 specified. If /b is not specified, the COM port is not
109 initialized. For example, if you are using the kernel debugger,
110 the kernel debugger initializes the COM port so you should not
111 use this switch.
112
113/c:<n> Set debug COM port base address. Values for n can be:
114 1 = COM1
115 2 = COM2
116 a hex value (COM port base address) COM1=3f8, COM2=2f8
117 The default is 0. If set to 0 then no output goes to the COM port.
118
119/d[:n] Debug output to COM port/trace buffer. Values for n can be:
120 1 = requests
121 2 = detailed
122 3 = verbose, including MMIO operations
123 If :n is not specified the debug level is incremented for
124 each /d specified.
125
126/w Allows the trace buffer to wrap when full.
127
128/v[:n] Display informational messages during boot. Values for n can be:
129 1 = Display sign on banner
130 2 = Display adapter information
131 If :n is not specified the verbosity level is incremented for
132 each /v specified.
133
134/g:<vendor>:<device> Add generic PCI ID to list of supported AHCI adapters
135 (e.g. /g:8086:2829)
136
137/t Perform thorough PCI ID scan; default = on, can be
138 turned off with /!t to perform only a PCI class scan
139
140/f Force the use of the HW write cache when using NCQ
141 commands; see "Native Command Queuing" below for
142 further explanation (default = off)
143
144/r Reset ports during initialization (default = on)
145 Can be turned off with /!r, however, when the
146 [Intel] AHCI controller was found to be
147 initialized by the BIOS in SATA mode, ports will
148 always be reset even when /!r was specified
149
150/a:n Set adapter to n for adapter-specific options
151 (default = -1, all adapters)
152
153/p:n Set port to n for port-specific options
154 (default = -1, all ports)
155
156/i Ignore current adapter if no port has been specified.
157 Otherwise, ignore the current port on the current adapter.
158
159Port-specific Options
160
161Option Description
162------------------------------------------------------------------------------
163/s Enable SCSI emulation for ATAPI units (default = on)
164 SCSI emulation is required for tools like cdrecord.
165
166/n Enable NCQ (Native Command Queuing) for hard disks
167 (default = off)
168
169/ls Set link speed (default = 0):
170 0 = maximum,
171 1 = limit to generation 1
172 2 = limit to generation 2
173 3 = limit to generation 3
174
175/lp Set link power management (default = 0):
176 0 = full power management,
177 1 = transitions to "partial slumber state" disabled,
178 2 = transitions to "slumber state" disabled,
179 3 = transitions to both partial and slumber states disabled
180
181/4 Force track size to be 56 sectors regardless of the
182 reported disk geometry to optimize partition boundaries
183 for hard disks with 4096 byte sectors.
184
185Port-specific options depend on the currently active adapter
186and port selector (/a and /p). Those selectors are -1 per default
187which means "all" adapters/ports. The scope can be reduced by limiting
188it to an adapter (/a) or an adapter and a port (/a and /p). The scope
189can be reset by setting the corresponding option back to -1.
190
191For example:
192
193 BASEDEV=OS2AHCI.ADD /n /a:0 /p:5 /!n /a:1 /p:-1 /!n
194
195This has the following effect:
196
197 - Enable NCQ for all hard disks
198 - Disable NCQ for hard disk on adapter #0, port #5
199 - Disable NCQ for all hard disks on adapter #1
200
201
202Native Command Queuing
203======================
204
205Native Command Queuing (NCQ) is a feature which allows sending multiple I/O
206requests to hard disks before waiting for any of the requests to complete,
207much like Tagged Command Queuing for SCSI devices. This allows the disks
208to reorder I/O requests to minimize head movements, resulting in improved
209performance when executing random I/Os. In practice, this will be most
210noticable when multiple programs request I/O services to different parts
211of the disk -- a single program typically won't queue up I/O's but instead
212will wait for each I/O to complete (with the exception of programs like
213database servers).
214
215While we believe NCQ will work with the majority of controllers and hard
216disks, it's currently turned off by default until we have more feedback
217from eComStation users. In order to turn on NCQ, just add the command line
218option "/n" to OS2AHCI.ADD.
219
220NCQ and HW Caches
221-----------------
222
223In NCQ mode, OS2AHCI supports a request flag which allows upstream code
224(e.g. file systems) to force writes to go directly to the disk instead
225of being buffered in the HW disk cache. However, at least JFS doesn't
226support this flag properly which effectively disables the HW disk cache
227for write operations across the board, resulting in a substantial
228performance loss. In order to prevent OS2AHCI from disabling the HW
229cache when so requested by upstream code, please use the command line
230option "/f".
231
232This may, of course, result in data loss in case of power failures but
233apparently this was the situation with previous IDE drivers as well thus
234shouldn't make much difference in the field. The JFS code also seems to
235imply that this flag has never been widely supported by [IDE] drivers;
236otherwise, the JFS developers should have stumbled over the performance
237loss a long time ago and fixed the code.
238
239NOTES:
240
241 - Without NCQ, OS2AHCI behaves like former IDE drivers, i.e. the HW
242 cache will always be enabled (on modern disks).
243
244 - When suspending, rebooting or shutting down, OS2AHCI always flushes
245 the HW disk cache regardless of the "/f" or "/n" command line options.
246
247
248Interoperability With IDE Drivers
249=================================
250
251There are three kinds of IDE/ATA/SATA controllers:
252
253 1. Legacy controllers (IDE or SATA) without AHCI support
254 This kind of controller will only be recognized by IDE drivers
255 (IBM1S506.ADD or DANIS506.ADD).
256
257 2. AHCI-capable controllers which supports IDE/SATA legacy interfaces
258 This kind of controller will work with IDE or AHCI drivers and it's
259 up to the user to decide which driver to use.
260
261 3. AHCI-only controllers
262 This kind of controller will only be recognized by OS2AHCI.
263
264If there's a mix of controllers of types 1 and 3, both an IDE and an AHCI
265driver will be required.
266
267If type 2 controllers are involved, it's up to the user to decide which
268driver to use. Both DANIS506.ADD and OS2AHCI.ADD will verify whether another
269driver has already allocated the corresponding adapter, thus the only
270decision to take for mixed configurations is whether type-2 controllers
271should be handled by DANIS506.ADD or OS2AHCI.ADD and this can be done by
272having the desired driver's BASEDEV statement coming first in CONFIG.SYS.
273
274NOTE: Older versions of DANIS506.ADD did not verify whether the resources
275 of a particular adapter were already allocated by another driver.
276 DANIS506.ADD 1.8.8 or later is required for this to work.
277
278 When using earlier versions of DANI1S506.ADD, the options "/A:x /I"
279 will be required to tell DANI1S506.ADD to ignore adapters to be
280 driven by OS2AHCI.ADD. The same applies to IBM1S506.ADD
281
282Mixed Controller Example
283------------------------
284
285Assume a DELL D630 or a Thinkpad T60. The hard disk is attached to the
286SATA/AHCI controller of the ICH-7 hub while the CDROM is attached to the
287legacy PATA IDE controller. This allows two different configurations:
288
289 1. Drive HDD and CDROM via DANIS506.ADD
290 2. Drive HDD via OS2AHCI.ADD and CDROM via DANI1S506.ADD
291
292OS2AHCI.ADD can't drive the CDROM because it's attached to a legacy PATA
293IDE controller which doesn't support AHCI.
294
295 - If OS2AHCI.ADD comes first in CONFIG.SYS, it will take over the SATA/AHCI
296 controller and drive the HDD. DANIS506.ADD will take care of the PATA/IDE
297 controller for the CDROM.
298 - If DANIS506.ADD comes first in CONFIG.SYS, it will take over both the
299 SATA/AHCI and the PATA/IDE controller and OS2AHCI.ADD will silently exit.
300
301Advantages of AHCI
302------------------
303
304The interfaces provided by the various [Intel] controllers could be
305summarized like this (the term ATA as driver interface being a bit of our
306own invention):
307
308 - Intel PIIX: IDE (I/O registers) and ATA (taskfile)
309 - Intel ICH6: IDE (I/O registers), ATA (taskfile) and SATA
310 (FIS, vendor-specific)
311 - Intel ICH7: IDE (I/O registers), ATA (taskfile), SATA
312 (FIS, vendor-specific) and AHCI (FIS)
313 - Intel PCH: AHCI (FIS)
314
315Taskfiles are regions in memory with ATA commands which the IDE/ATA
316controller can read and process autonomously. FIS (Frame Information
317Structures) are pretty much the same but they are specific to the SATA
318communication protocol on the serial link. The most important FIS type
319for AHCI drivers is the H2D (host to device) FIS which basically contains
320the ATA command to be executed.
321
322The big advantage of AHCI controllers, apart from being vendor-neutral,
323is that they take care of a lot of things which previous-generation
324drivers like DANI1S506 would have to do step by step. For example, in
325order to send an ATAPI command, DANIS506 would have to do the following:
326
327 * Send ATA "PACKET" command to device (via IDE registers, ATA taskfiles
328 or SATA FIS)
329 * Wait until device signals via interrupt it's ready for the ATAPI command
330 * Send ATAPI command to device via PIO
331 * Wait until device signals via interrupt it's ready to transfer data
332 * Send/Receive any data that might come along with the ATAPI command via
333 PIO, or wait for DMA transfer to complete
334 * Wait until device signals via interrupt that command and data transfer
335 have completed
336
337For OS2AHCI, the same operation looks like this:
338
339 * Fill in AHCI command header, FIS with ATA "PACKET" command and the ATAPI
340 command
341 * Tell port engine to process the command
342 * Wait until controller signals via interrupt that command and data
343 transfer have completed
344
345The AHCI controller automatically takes care of all underlying bits and
346pieces. OS2AHCI doesn't even have to know whether a particular message is
347sent via PIO or DMA because this is handled by the AHCI controller, too.
348And the whole concept of PIO and DMA is only relevant between AHCI controller
349and the device -- all transfers between OS2AHCI and the AHCI controller are
350always done via DMA.
351
352
353SMART Support
354=============
355
356Starting with version 1.22, OS2AHCI supports the IOCTL interface required by
357existing SMART monitoring tools. Since those tools are hard-coded to open
358the character device named "IBMS506$", they will not work with OS2AHCI unless
359modified to open the OS2AHCI$ device. Previous versions of OS2AHCI used to
360register register a duplicate device with the IBMS506$ name, however since
361that caused so many unacceptable problems, that is no longer done. You must
362have a SMART utility that opens the OS2AHCI$ device to access the AHCI driver.
363
364A patched version of the smartctl.exe program is included in the OS2AHCI
365distribution. This patched version simply has the name "IBMS506$" changed
366to "OS2AHCI$" and is otherwise identical. This patched program has been
367renamed to smartahci.exe to distinguish it from the unpatched version.
368The patched smartahci.exe program is provided AS-IS and is completely
369UNSUPPORTED. Use of this program is at your own risk.
370
371NOTES:
372
373 - The IOCTL interface for SMART is based on the idea of IDE controllers
374 with a master and a slave drive. OS2AHCI maps all devices (ATA or ATAPI)
375 sequentially to this pattern. If, for example, you have 4 hard disks and
376 one CDROM attached to a single controller on ports 1, 2, 5, 7, and 11,
377 SMART tools will see 3 controllers as follows:
378
379 - controller 0, master: HD on port 1
380 - controller 0, slave: HD on port 2
381 - controller 1, master: HD on port 5
382 - controller 1, slave: HD on port 7
383 - controller 2, master: CDROM on port 11
384
385 - The DSKSP_GEN_GET_COUNTERS interface is currently unsupported; calls to
386 the corresponding IOCTL will return 0 for all counters. SMART counters
387 are not affected by this limitation, i.e. SMART tools will be able to
388 report counters from the physical disk; this limitation only affects
389 the software counters maintained by ADD drivers which do support the
390 DSKSP_GEN_GET_COUNTERS IOCTL request.
391
392
393Change Log
394==========
395
396v.1.31 04-Aug-2013 - David Azarewicz
397 Enhanced debug output.
398 Added code to check for bad geometries reported by the BIOS and fix them.
399
400v.1.30 29-Jun-2013 - David Azarewicz
401 Enhanced debug log output
402 Removed the IBMS506 header that was causing problems and shouldn't
403 be there anyway.
404 Fixed a defect in the SMART IOCtl.
405 Added ability to ignore individual ports.
406
407v.1.29 12-Jun-2013 - David Azarewicz
408 Changed scsi emulation to be on by default.
409
410v.1.28 01-Jun-2013 - David Azarewicz
411 Reworked trap dump kernel exit
412 Removed unused IDC entry point.
413 Reworked suspend/resume routines.
414 Implemented a temporary hack to make resume work reasonably well.
415 Suspend/resume is only supported on eCS systems with ACPI.
416 Suspend/resume is known to not work reliably and cannot be further
417 addressed in this driver.
418
419v.1.27 23-Apr-2013 - David Azarewicz
420 Added LVM aware disk geometry reporting.
421 Begin to add disk information report - not finished yet.
422 Removed undocumented /q switch and made the driver quiet by default.
423 Debug output improvements.
424 Added /b switch for setting debug baud rate.
425 Fixed up time delay functions
426
427v.1.26 26-Mar-2013 - David Azarewicz
428 Fix spin-up / power-up issue on some hardware
429 Reorganized and improved debug output.
430
431v.1.26 21-Feb-2013 - rousseau
432 Virtual box fix
433 Some SMP fixes
434 Changed default for port reset to always
435
436v.1.25 02-Oct-2012 - markus.thi
437 Added support for trap dumps
438
439v.1.24 21-May-2012 - markus.thi
440 Fixed JFS long format hang (ticket 16)
441
442V.1.23 16-May-2012 - markus.thi
443 added IDC entry point to allow switching back to BIOS mode
444
445v.1.22 17-Oct-2011 - markus.thi
446 Added "IBMS506" header to accomodate broken SMART tools.
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