AtapiHwInitialize函数初始化不是ATAPT设备，设置它支持多块传送。接着判断那些设备是CD-ROM设备，还清除忙状态。具体实现代码如下：

#001  BOOLEAN

#002  NTAPI

#003  AtapiHwInitialize(

#004      IN PVOID HwDeviceExtension

#005      )

#006

#007  /*++

#008

#009  Routine Description:

#010

#011  Arguments:

#012

#013      HwDeviceExtension - HBA miniport driver's adapter data storage

#014

#015  Return Value:

#016

#017      TRUE - if initialization successful.

#018      FALSE - if initialization unsuccessful.

#019

#020  --*/

#021

#022  {

#023      PHW_DEVICE_EXTENSION deviceExtension = HwDeviceExtension;

#024      PIDE_REGISTERS_1     baseIoAddress;

#025      ULONG i;

#026      UCHAR statusByte, errorByte;

#027

#028

对于两个通道4个IDE控制器进行初始化。

#029      for (i = 0; i < 4; i++) {

如果IDE的设备存在，就进行处理。

#030          if (deviceExtension->DeviceFlags[i] & DFLAGS_DEVICE_PRESENT) {

#031

如果这个设备不是ATAPI设备，就进入下面初始化。

#032              if (!(deviceExtension->DeviceFlags[i] & DFLAGS_ATAPI_DEVICE)) {

#033

#034                  //

#035                  // Enable media status notification

#036                  //

#037

获取基地址。

#038                  baseIoAddress = deviceExtension->BaseIoAddress1[i >> 1];

#039

设置媒体感知。

#040                  IdeMediaStatus(TRUE,HwDeviceExtension,i);

#041

如果支持多块传送，就设置多块传送参数。

#042                  //

#043                  // If supported, setup Multi-block transfers.

#044                  //

#045                  if (deviceExtension->MaximumBlockXfer[i]) {

#046

#047                      //

#048                      // Select the device.

#049                      //

#050

#051                      ScsiPortWritePortUchar(&baseIoAddress->DriveSelect,

#052                                             (UCHAR)(((i & 0x1) << 4) | 0xA0));

#053

#054                      //

#055                      // Setup sector count to reflect the # of blocks.

#056                      //

#057

#058                      ScsiPortWritePortUchar(&baseIoAddress->BlockCount,

#059                                             deviceExtension->MaximumBlockXfer[i]);

#060

#061                      //

#062                      // Issue the command.

#063                      //

#064

设置多块传送。

#065                      ScsiPortWritePortUchar(&baseIoAddress->Command,

#066                                             IDE_COMMAND_SET_MULTIPLE);

#067

#068                      //

#069                      // Wait for busy to drop.

#070                      //

#071

#072                      WaitOnBaseBusy(baseIoAddress,statusByte);

#073

#074                      //

#075                      // Check for errors. Reset the value to 0 (disable MultiBlock) if the

#076                      // command was aborted.

#077                      //

#078

如果设置多块传送命令失败，就设置为不支持多块传送。

#079                      if (statusByte & IDE_STATUS_ERROR) {

#080

#081                          //

#082                          // Read the error register.

#083                          //

#084

#085                          errorByte = ScsiPortReadPortUchar((PUCHAR)baseIoAddress + 1);

#086

#087                          DebugPrint((1,

#088                                      "AtapiHwInitialize: Error setting multiple mode. Status %x, error byte %x/n",

#089                                      statusByte,

#090                                      errorByte));

#091                          //

#092                          // Adjust the devExt. value, if necessary.

#093                          //

#094

#095                          deviceExtension->MaximumBlockXfer[i] = 0;

#096

#097                      } else {

#098                          DebugPrint((2,

#099                                      "AtapiHwInitialize: Using Multiblock on Device %d. Blocks / int - %d/n",

#100                                      i,

#101                                      deviceExtension->MaximumBlockXfer[i]));

#102                      }

#103                  }

#104              } else if (!(deviceExtension->DeviceFlags[i] & DFLAGS_CHANGER_INITED)){

如果这个设备还没有初始化，就进行初始化设置。

#105

#106                  ULONG j;

#107                  BOOLEAN isSanyo = FALSE;

#108                  UCHAR vendorId[26];

#109

#110                  //

#111                  // Attempt to identify any special-case devices - psuedo-atapi changers, atapi changers, etc.

#112                  //

#113

判断这个IDE设备是否为CR-ROM设备。

#114                  for (j = 0; j < 13; j += 2) {

#115

#116                      //

#117                      // Build a buffer based on the identify data.

#118                      //

#119

#120                      vendorId[j] = ((PUCHAR)deviceExtension->IdentifyData[i].ModelNumber)[j + 1];

#121                      vendorId[j+1] = ((PUCHAR)deviceExtension->IdentifyData[i].ModelNumber)[j];

#122                  }

#123

比较IDE设备标识是否为CD-ROM。

#124                  if (!AtapiStringCmp ((PCHAR)vendorId, "CD-ROM  CDR", 11)) {

#125

#126                      //

#127                      // Inquiry string for older model had a '-', newer is '_'

#128                      //

#129

#130                      if (vendorId[12] == 'C') {

#131

#132                          //

#133                          // Torisan changer. Set the bit. This will be used in several places

#134                          // acting like 1) a multi-lun device and 2) building the 'special' TUR's.

#135                          //

#136

设置设备已经初始化。

#137                          deviceExtension->DeviceFlags[i] |= (DFLAGS_CHANGER_INITED | DFLAGS_SANYO_ATAPI_CHANGER);

#138                          deviceExtension->DiscsPresent[i] = 3;

#139                          isSanyo = TRUE;

#140                      }

#141                  }

#142              }

#143

#144              //

#145              // We need to get our device ready for action before

#146              // returning from this function

#147              //

#148              // According to the atapi spec 2.5 or 2.6, an atapi device

#149              // clears its status BSY bit when it is ready for atapi commands.

#150              // However, some devices (Panasonic SQ-TC500N) are still

#151              // not ready even when the status BSY is clear.  They don't react

#152              // to atapi commands.

#153              //

#154              // Since there is really no other indication that tells us

#155              // the drive is really ready for action.  We are going to check BSY

#156              // is clear and then just wait for an arbitrary amount of time!

#157              //

下面开始清除忙状态。

#158              if (deviceExtension->DeviceFlags[i] & DFLAGS_ATAPI_DEVICE) {

#159                  //PIDE_REGISTERS_1     baseIoAddress1 = deviceExtension->BaseIoAddress1[i >> 1];

#160                  PIDE_REGISTERS_2     baseIoAddress2 = deviceExtension->BaseIoAddress2[i >> 1];

#161                  ULONG waitCount;

#162

#163                  // have to get out of the loop sometime!

#164                  // 10000 * 100us = 1000,000us = 1000ms = 1s

#165                  waitCount = 10000;

#166                  GetStatus(baseIoAddress2, statusByte);

#167                  while ((statusByte & IDE_STATUS_BUSY) && waitCount) {

#168                      //

#169                      // Wait for Busy to drop.

#170                      //

#171                      ScsiPortStallExecution(100);

#172                      GetStatus(baseIoAddress2, statusByte);

#173                      waitCount--;

#174                  }

#175

#176                  // 5000 * 100us = 500,000us = 500ms = 0.5s

#177                  waitCount = 5000;

#178                  do {

#179                      ScsiPortStallExecution(100);

#180                  } while (waitCount--);

#181              }

#182          }

#183      }

#184

#185      return TRUE;

#186

#187  } // end AtapiHwInitialize()