reactos操作系统实现(108)

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()

（编辑：李大同）

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