| 1 | ==================================================================== | 
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| 2 | eComStation AHCI Driver | 
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| 3 | ==================================================================== | 
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| 4 |  | 
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| 5 |  | 
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| 6 | Introduction | 
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| 7 | ============ | 
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| 8 |  | 
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| 9 | OS2AHCI is an AHCI driver for eComStation. It supports both ATA and | 
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| 10 | ATAPI devices in a single driver, thus there's no need for an | 
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| 11 | ATAPI/CDROM filter driver. | 
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| 12 |  | 
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| 13 |  | 
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| 14 | Copyrights | 
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| 15 | ========== | 
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| 16 |  | 
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| 17 | Copyright (c) 2011 thi.guten Software Development | 
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| 18 | Copyright (c) 2011-2013 Mensys B.V. | 
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| 19 |  | 
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| 20 | Authors: Christian Mueller, Markus Thielen | 
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| 21 |  | 
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| 22 | Parts copied from/inspired by the Linux AHCI driver; | 
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| 23 | those parts are (c) Linux AHCI/ATA maintainers | 
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| 24 |  | 
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| 25 | This program is free software; you can redistribute it and/or modify | 
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| 26 | it under the terms of the GNU General Public License as published by | 
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| 27 | the Free Software Foundation; either version 2 of the License, or | 
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| 28 | (at your option) any later version. | 
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| 29 |  | 
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| 30 | This program is distributed in the hope that it will be useful, | 
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| 31 | but WITHOUT ANY WARRANTY; without even the implied warranty of | 
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| 32 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the | 
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| 33 | GNU General Public License for more details. | 
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| 34 |  | 
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| 35 | You should have received a copy of the GNU General Public License | 
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| 36 | along with this program; if not, write to the Free Software | 
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| 37 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, | 
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| 38 | MA  02111-1307  USA | 
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| 39 |  | 
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| 40 |  | 
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| 41 | Licensing and Source Code | 
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| 42 | ========================= | 
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| 43 |  | 
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| 44 | The *binary* delivery of OS2AHCI.ADD as obtained from ecomstation.nl, | 
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| 45 | or as part of packaged eComStation releases, is licensed to run with | 
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| 46 | eComStation, only. | 
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| 47 |  | 
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| 48 | The source code can be retrieved from http://svn.ecomstation.nl; | 
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| 49 | in compliance to the GNU General Public License, the source code | 
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| 50 | can of course be modified/compiled to run on other products as long | 
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| 51 | as modifications will also be published as outlined in the GNU GPL2. | 
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| 52 |  | 
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| 53 | Please note that builds other than the official binary delivered as | 
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| 54 | part of eComStation releases or downloaded from ecomstation.nl are | 
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| 55 | not officially supported by Mensys. | 
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| 56 |  | 
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| 57 |  | 
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| 58 | Building The Driver | 
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| 59 | ------------------- | 
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| 60 |  | 
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| 61 | The toolchain required for compilation consists of: | 
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| 62 |  | 
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| 63 | - IBM OS/2 DDK version 9.23 or later (see ddk\base\h\version.mak) | 
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| 64 | (Used for include files and qgrep) | 
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| 65 | - Open Watcom C/C++ package | 
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| 66 | (available from: http://www.openwatcom.org/index.php/Downloads) | 
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| 67 | - WCC 16-bit C Compiler (part of the Open Watcom package) | 
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| 68 | - WASM Assembler (part of the Open Watcom package) | 
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| 69 | - WLINK Linker (part of the Open Watcom package) | 
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| 70 | - MAPSYM (part of the DDK) | 
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| 71 |  | 
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| 72 | Simply use "wmake" or "wmake -a" to build the driver. | 
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| 73 |  | 
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| 74 | The driver can also be built using the DDK tools, but this build | 
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| 75 | is depreciated and is not kept up-to-date. | 
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| 76 |  | 
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| 77 | The toolchain required for compilation consists of: | 
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| 78 |  | 
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| 79 | - IBM OS/2 DDK version 9.23 or later (see ddk\base\h\version.mak) | 
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| 80 | - Microsoft C600 | 
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| 81 | - ALP Assembler (part of DDK) | 
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| 82 | - link.exe (part of DDK) | 
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| 83 | - MAPSYM (part of the DDK) | 
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| 84 |  | 
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| 85 | Use "nmake -f Makefile.old" or "nmake -f Makefile.old -a" to build | 
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| 86 | the driver. | 
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| 87 |  | 
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| 88 | When switching between building with the DDK and Open Watcom, it is | 
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| 89 | recommended to do a clean first (wmake clean or nmake -f Makefile.old clean). | 
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| 90 |  | 
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| 91 |  | 
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| 92 | Installation | 
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| 93 | ============ | 
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| 94 |  | 
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| 95 | - Copy the driver file, OS2AHCI.ADD, to C:\OS2\BOOT | 
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| 96 |  | 
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| 97 | - Add the following line to CONFIG.SYS: | 
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| 98 | BASEDEV=OS2AHCI.ADD | 
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| 99 |  | 
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| 100 |  | 
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| 101 | Driver Command Line Options | 
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| 102 | =========================== | 
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| 103 |  | 
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| 104 | Global Options | 
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| 105 |  | 
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| 106 | Option                 Description | 
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| 107 | ------------------------------------------------------------------------------ | 
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| 108 | /c:<addr>              Set debug COM port base address in hex (default = 3f8); | 
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| 109 | if used, this option should come before any /d options. | 
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| 110 | If <addr> is set to 0, the COM port is turned off and | 
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| 111 | all output is directed to an internal trace ring buffer | 
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| 112 | that can be dumped on an OS/2 command prompt with the | 
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| 113 | command "type os2ahci$"; see the OS2AHCI project page | 
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| 114 | at http://svn.ecomstation.nl/ahci/wiki/AhciTrace | 
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| 115 | for more info. | 
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| 116 | /d                     Debug output on COM port/trace buffer; multiple "/d" | 
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| 117 | options will increase verbosity: | 
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| 118 | 1 = requests | 
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| 119 | 2 = detailed | 
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| 120 | 3 = verbose, including MMIO operations | 
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| 121 | /v                     display adapter info during boot | 
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| 122 | /g:<vendor>:<device>   Add generic PCI ID to list of supported AHCI adapters | 
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| 123 | (e.g. /g:8086:2829) | 
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| 124 | /t                     Perform thorough PCI ID scan; default = on, can be | 
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| 125 | turned off with /!t to perform only a PCI class scan | 
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| 126 | /f                     Force the use of the HW write cache when using NCQ | 
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| 127 | commands; see "Native Command Queuing" below for | 
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| 128 | further explanation (default = off) | 
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| 129 | /r                     Reset ports during initialization (default = on) | 
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| 130 | Can be turned off with /!r, however, when the | 
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| 131 | [Intel] AHCI controller was found to be | 
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| 132 | initialized by the BIOS in SATA mode, ports will | 
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| 133 | always be reset even when /!r was specified | 
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| 134 | /a                     Set adapter for adapter-specific options | 
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| 135 | (default = -1, all adapters) | 
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| 136 | /p                     Set port for port-specific options | 
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| 137 | (default = -1, all ports) | 
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| 138 |  | 
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| 139 | Adapter-specific Options | 
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| 140 |  | 
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| 141 | Option                 Description | 
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| 142 | ------------------------------------------------------------------------------ | 
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| 143 | /i                     Ignore current adapter | 
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| 144 |  | 
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| 145 | Port-specific Options | 
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| 146 |  | 
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| 147 | Option                 Description | 
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| 148 | ------------------------------------------------------------------------------ | 
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| 149 | /s                     Enable SCSI emulation for ATAPI units (default = off) | 
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| 150 | SCSI emulation is required for tools like cdrecord. | 
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| 151 | /n                     Enable NCQ (Native Command Queuing) for hard disks | 
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| 152 | (default = off) | 
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| 153 | /ls                    Set link speed (default = 0): | 
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| 154 | 0 = maximum, | 
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| 155 | 1 = limit to generation 1 | 
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| 156 | 2 = limit to generation 2 | 
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| 157 | 3 = limit to generation 3 | 
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| 158 | /lp                    Set link power management (default = 0): | 
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| 159 | 0 = full power management, | 
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| 160 | 1 = transitions to "partial slumber state" disabled, | 
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| 161 | 2 = transitions to "slumber state" disabled, | 
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| 162 | 3 = transitions to both partial and slumber states | 
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| 163 | disabled | 
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| 164 | /4                     Force track size to be 56 sectors regardless of the | 
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| 165 | reported disk geometry to optimize partition boundaries | 
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| 166 | for hard disks with 4096 byte sectors. | 
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| 167 |  | 
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| 168 | Port-specific options depend on the currently active adapter | 
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| 169 | and port selector (/a and /p). Those selectors are -1 per default | 
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| 170 | which means "all" adapters/ports. The scope can be reduced by limiting | 
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| 171 | it to an adapter (/a) or an adapter and a port (/a and /p). The scope | 
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| 172 | can be reset by setting the corresponding option back to -1. | 
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| 173 |  | 
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| 174 | For example: | 
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| 175 |  | 
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| 176 | BASEDEV=OS2AHCI.ADD /n /a:0 /p:5 /!n /a:1 /p:-1 /!n | 
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| 177 |  | 
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| 178 | This has the following effect: | 
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| 179 |  | 
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| 180 | - Enable NCQ for all hard disks | 
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| 181 | - Disable NCQ for hard disk on adapter #0, port #5 | 
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| 182 | - Disable NCQ for all hard disks on adapter #1 | 
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| 183 |  | 
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| 184 |  | 
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| 185 | Native Command Queuing | 
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| 186 | ====================== | 
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| 187 |  | 
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| 188 | Native Command Queuing (NCQ) is a feature which allows sending multiple I/O | 
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| 189 | requests to hard disks before waiting for any of the requests to complete, | 
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| 190 | much like Tagged Command Queuing for SCSI devices. This allows the disks | 
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| 191 | to reorder I/O requests to minimize head movements, resulting in improved | 
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| 192 | performance when executing random I/Os. In practice, this will be most | 
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| 193 | noticable when multiple programs request I/O services to different parts | 
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| 194 | of the disk -- a single program typically won't queue up I/O's but instead | 
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| 195 | will wait for each I/O to complete (with the exception of programs like | 
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| 196 | database servers). | 
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| 197 |  | 
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| 198 | While we believe NCQ will work with the majority of controllers and hard | 
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| 199 | disks, it's currently turned off by default until we have more feedback | 
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| 200 | from eComStation users. In order to turn on NCQ, just add the command line | 
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| 201 | option "/n" to OS2AHCI.ADD. | 
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| 202 |  | 
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| 203 | NCQ and HW Caches | 
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| 204 | ----------------- | 
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| 205 |  | 
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| 206 | In NCQ mode, OS2AHCI supports a request flag which allows upstream code | 
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| 207 | (e.g. file systems) to force writes to go directly to the disk instead | 
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| 208 | of being buffered in the HW disk cache. However, at least JFS doesn't | 
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| 209 | support this flag properly which effectively disables the HW disk cache | 
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| 210 | for write operations across the board, resulting in a substantial | 
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| 211 | performance loss. In order to prevent OS2AHCI from disabling the HW | 
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| 212 | cache when so requested by upstream code, please use the command line | 
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| 213 | option "/f". | 
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| 214 |  | 
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| 215 | This may, of course, result in data loss in case of power failures but | 
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| 216 | apparently this was the situation with previous IDE drivers as well thus | 
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| 217 | shouldn't make much difference in the field. The JFS code also seems to | 
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| 218 | imply that this flag has never been widely supported by [IDE] drivers; | 
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| 219 | otherwise, the JFS developers should have stumbled over the performance | 
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| 220 | loss a long time ago and fixed the code. | 
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| 221 |  | 
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| 222 | NOTES: | 
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| 223 |  | 
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| 224 | - Without NCQ, OS2AHCI behaves like former IDE drivers, i.e. the HW | 
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| 225 | cache will always be enabled (on modern disks). | 
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| 226 |  | 
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| 227 | - When suspending, rebooting or shutting down, OS2AHCI always flushes | 
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| 228 | the HW disk cache regardless of the "/f" or "/n" command line options. | 
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| 229 |  | 
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| 230 |  | 
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| 231 | Interoperability With IDE Drivers | 
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| 232 | ================================= | 
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| 233 |  | 
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| 234 | There are three kinds of IDE/ATA/SATA controllers: | 
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| 235 |  | 
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| 236 | 1. Legacy controllers (IDE or SATA) without AHCI support | 
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| 237 | This kind of controller will only be recognized by IDE drivers | 
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| 238 | (IBM1S506.ADD or DANIS506.ADD). | 
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| 239 |  | 
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| 240 | 2. AHCI-capable controllers which supports IDE/SATA legacy interfaces | 
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| 241 | This kind of controller will work with IDE or AHCI drivers and it's | 
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| 242 | up to the user to decide which driver to use. | 
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| 243 |  | 
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| 244 | 3. AHCI-only controllers | 
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| 245 | This kind of controller will only be recognized by OS2AHCI. | 
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| 246 |  | 
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| 247 | If there's a mix of controllers of types 1 and 3, both an IDE and an AHCI | 
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| 248 | driver will be required. | 
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| 249 |  | 
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| 250 | If type 2 controllers are involved, it's up to the user to decide which | 
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| 251 | driver to use. Both DANIS506.ADD and OS2AHCI.ADD will verify whether another | 
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| 252 | driver has already allocated the corresponding adapter, thus the only | 
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| 253 | decision to take for mixed configurations is whether type-2 controllers | 
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| 254 | should be handled by DANIS506.ADD or OS2AHCI.ADD and this can be done by | 
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| 255 | having the desired driver's BASEDEV statement coming first in CONFIG.SYS. | 
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| 256 |  | 
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| 257 | NOTE: Older versions of DANIS506.ADD did not verify whether the resources | 
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| 258 | of a particular adapter were already allocated by another driver. | 
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| 259 | DANIS506.ADD 1.8.8 or later is required for this to work. | 
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| 260 |  | 
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| 261 | When using earlier versions of DANI1S506.ADD, the options "/A:x /I" | 
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| 262 | will be required to tell DANI1S506.ADD to ignore adapters to be | 
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| 263 | driven by OS2AHCI.ADD. The same applies to IBM1S506.ADD | 
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| 264 |  | 
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| 265 | Mixed Controller Example | 
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| 266 | ------------------------ | 
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| 267 |  | 
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| 268 | Assume a DELL D630 or a Thinkpad T60. The hard disk is attached to the | 
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| 269 | SATA/AHCI controller of the ICH-7 hub while the CDROM is attached to the | 
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| 270 | legacy PATA IDE controller. This allows two different configurations: | 
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| 271 |  | 
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| 272 | 1. Drive HDD and CDROM via DANIS506.ADD | 
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| 273 | 2. Drive HDD via OS2AHCI.ADD and CDROM via DANI1S506.ADD | 
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| 274 |  | 
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| 275 | OS2AHCI.ADD can't drive the CDROM because it's attached to a legacy PATA | 
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| 276 | IDE controller which doesn't support AHCI. | 
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| 277 |  | 
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| 278 | - If OS2AHCI.ADD comes first in CONFIG.SYS, it will take over the SATA/AHCI | 
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| 279 | controller and drive the HDD. DANIS506.ADD will take care of the PATA/IDE | 
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| 280 | controller for the CDROM. | 
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| 281 | - If DANIS506.ADD comes first in CONFIG.SYS, it will take over both the | 
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| 282 | SATA/AHCI and the PATA/IDE controller and OS2AHCI.ADD will silently exit. | 
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| 283 |  | 
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| 284 | Advantages of AHCI | 
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| 285 | ------------------ | 
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| 286 |  | 
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| 287 | The interfaces provided by the various [Intel] controllers could be | 
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| 288 | summarized like this (the term ATA as driver interface being a bit of our | 
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| 289 | own invention): | 
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| 290 |  | 
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| 291 | - Intel PIIX: IDE (I/O registers) and ATA (taskfile) | 
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| 292 | - Intel ICH6: IDE (I/O registers), ATA (taskfile) and SATA | 
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| 293 | (FIS, vendor-specific) | 
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| 294 | - Intel ICH7: IDE (I/O registers), ATA (taskfile), SATA | 
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| 295 | (FIS, vendor-specific) and AHCI (FIS) | 
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| 296 | - Intel PCH: AHCI (FIS) | 
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| 297 |  | 
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| 298 | Taskfiles are regions in memory with ATA commands which the IDE/ATA | 
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| 299 | controller can read and process autonomously. FIS (Frame Information | 
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| 300 | Structures) are pretty much the same but they are specific to the SATA | 
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| 301 | communication protocol on the serial link. The most important FIS type | 
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| 302 | for AHCI drivers is the H2D (host to device) FIS which basically contains | 
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| 303 | the ATA command to be executed. | 
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| 304 |  | 
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| 305 | The big advantage of AHCI controllers, apart from being vendor-neutral, | 
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| 306 | is that they take care of a lot of things which previous-generation | 
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| 307 | drivers like DANI1S506 would have to do step by step. For example, in | 
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| 308 | order to send an ATAPI command, DANIS506 would have to do the following: | 
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| 309 |  | 
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| 310 | * Send ATA "PACKET" command to device (via IDE registers, ATA taskfiles | 
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| 311 | or SATA FIS) | 
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| 312 | * Wait until device signals via interrupt it's ready for the ATAPI command | 
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| 313 | * Send ATAPI command to device via PIO | 
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| 314 | * Wait until device signals via interrupt it's ready to transfer data | 
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| 315 | * Send/Receive any data that might come along with the ATAPI command via | 
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| 316 | PIO, or wait for DMA transfer to complete | 
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| 317 | * Wait until device signals via interrupt that command and data transfer | 
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| 318 | have completed | 
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| 319 |  | 
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| 320 | For OS2AHCI, the same operation looks like this: | 
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| 321 |  | 
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| 322 | * Fill in AHCI command header, FIS with ATA "PACKET" command and the ATAPI | 
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| 323 | command | 
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| 324 | * Tell port engine to process the command | 
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| 325 | * Wait until controller signals via interrupt that command and data | 
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| 326 | transfer have completed | 
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| 327 |  | 
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| 328 | The AHCI controller automatically takes care of all underlying bits and | 
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| 329 | pieces. OS2AHCI doesn't even have to know whether a particular message is | 
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| 330 | sent via PIO or DMA because this is handled by the AHCI controller, too. | 
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| 331 | And the whole concept of PIO and DMA is only relevant between AHCI controller | 
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| 332 | and the device -- all transfers between OS2AHCI and the AHCI controller are | 
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| 333 | always done via DMA. | 
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| 334 |  | 
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| 335 |  | 
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| 336 | SMART Support | 
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| 337 | ============= | 
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| 338 |  | 
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| 339 | Starting with version 1.22, OS2AHCI supports the IOCTL interface required by | 
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| 340 | existing SMART monitoring tools. Since those tools are hard-coded to open | 
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| 341 | the character device named "IBMS506$", OS2AHCI will now register a device | 
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| 342 | with this name, too. | 
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| 343 |  | 
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| 344 | NOTES: | 
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| 345 |  | 
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| 346 | - If multiple drivers exporting this character device name are loaded at | 
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| 347 | the same time, the driver loaded last will receive all [SMART] requests. | 
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| 348 | This means that if both DANIS506 and OS2AHCI are loaded and SMART support | 
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| 349 | for OS2AHCI-controlled hard disks is desired, OS2AHCI will have to be | 
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| 350 | loaded after DANIS506. It also means that DANIS506 may have to be told | 
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| 351 | to ignore type 2 controllers (i.e. controllers supporting both SATA and | 
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| 352 | AHCI) using the command line options "/A:x /I". | 
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| 353 |  | 
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| 354 | - The IOCTL interface for SMART is based on the idea of IDE controllers | 
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| 355 | with a master and a slave drive. OS2AHCI maps all devices (ATA or ATAPI) | 
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| 356 | sequentially to this pattern. If, for example, you have 4 hard disks and | 
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| 357 | one CDROM attached to a single controller on ports 1, 2, 5, 7, and 11, | 
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| 358 | SMART tools will see 3 controllers as follows: | 
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| 359 |  | 
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| 360 | - controller 0, master: HD on port 1 | 
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| 361 | - controller 0, slave:  HD on port 2 | 
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| 362 | - controller 1, master: HD on port 5 | 
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| 363 | - controller 1, slave:  HD on port 7 | 
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| 364 | - controller 2, master: CDROM on port 11 | 
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| 365 |  | 
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| 366 | - The DSKSP_GEN_GET_COUNTERS interface is currently unsupported; calls to | 
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| 367 | the corresponding IOCTL will return 0 for all counters. SMART counters | 
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| 368 | are not affected by this limitation, i.e. SMART tools will be able to | 
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| 369 | report counters from the physical disk; this limitation only affects | 
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| 370 | the software counters maintained by ADD drivers which do support the | 
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| 371 | DSKSP_GEN_GET_COUNTERS IOCTL request. | 
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| 372 |  | 
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