Nt32Pkg/WinNtBusDriverDxe/WinNtBusDriver.c

   1 /**@file
   2
   3 Copyright (c) 2006 - 2009, Intel Corporation
   4 All rights reserved. This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12 Module Name:
  13
  14   WinNtBusDriver.c
  15
  16 Abstract:
  17
  18 This following section documents the envirnoment variables for the Win NT
  19 build.  These variables are used to define the (virtual) hardware
  20 configuration of the NT environment
  21
  22 A ! can be used to seperate multiple instances in a variable. Each
  23 instance represents a seperate hardware device.
  24
  25 EFI_WIN_NT_PHYSICAL_DISKS - maps to drives on your system
  26 EFI_WIN_NT_VIRTUAL_DISKS  - maps to a device emulated by a file
  27 EFI_WIN_NT_FILE_SYSTEM    - mouts a directory as a file system
  28 EFI_WIN_NT_CONSOLE        - make a logical comand line window (only one!)
  29 EFI_WIN_NT_GOP            - Builds GOP Windows of Width and Height
  30 EFI_WIN_NT_SERIAL_PORT    - maps physical serial ports
  31
  32  <F>ixed       - Fixed disk like a hard drive.
  33  <R>emovable   - Removable media like a floppy or CD-ROM.
  34  Read <O>nly   - Write protected device.
  35  Read <W>rite  - Read write device.
  36  <block count> - Decimal number of blocks a device supports.
  37  <block size>  - Decimal number of bytes per block.
  38
  39  NT envirnonment variable contents. '<' and '>' are not part of the variable,
  40  they are just used to make this help more readable. There should be no
  41  spaces between the ';'. Extra spaces will break the variable. A '!' is
  42  used to seperate multiple devices in a variable.
  43
  44  EFI_WIN_NT_VIRTUAL_DISKS =
  45    <F | R><O | W>;<block count>;<block size>[!...]
  46
  47  EFI_WIN_NT_PHYSICAL_DISKS =
  48    <drive letter>:<F | R><O | W>;<block count>;<block size>[!...]
  49
  50  Virtual Disks: These devices use a file to emulate a hard disk or removable
  51                 media device.
  52
  53    Thus a 20 MB emulated hard drive would look like:
  54    EFI_WIN_NT_VIRTUAL_DISKS=FW;40960;512
  55
  56    A 1.44MB emulated floppy with a block size of 1024 would look like:
  57    EFI_WIN_NT_VIRTUAL_DISKS=RW;1440;1024
  58
  59  Physical Disks: These devices use NT to open a real device in your system
  60
  61    Thus a 120 MB floppy would look like:
  62    EFI_WIN_NT_PHYSICAL_DISKS=B:RW;245760;512
  63
  64    Thus a standard CD-ROM floppy would look like:
  65    EFI_WIN_NT_PHYSICAL_DISKS=Z:RO;307200;2048
  66
  67  EFI_WIN_NT_FILE_SYSTEM =
  68    <directory path>[!...]
  69
  70    Mounting the two directories C:\FOO and C:\BAR would look like:
  71    EFI_WIN_NT_FILE_SYSTEM=c:\foo!c:\bar
  72
  73  EFI_WIN_NT_CONSOLE =
  74    <window title>
  75
  76    Declaring a text console window with the title "My EFI Console" woild look like:
  77    EFI_WIN_NT_CONSOLE=My EFI Console
  78
  79  EFI_WIN_NT_GOP =
  80    <width> <height>[!...]
  81
  82    Declaring a two GOP windows with resolutions of 800x600 and 1024x768 would look like:
  83    Example : EFI_WIN_NT_GOP=800 600!1024 768
  84
  85  EFI_WIN_NT_SERIAL_PORT =
  86    <port name>[!...]
  87
  88    Declaring two serial ports on COM1 and COM2 would look like:
  89    Example : EFI_WIN_NT_SERIAL_PORT=COM1!COM2
  90
  91  EFI_WIN_NT_PASS_THROUGH =
  92    <BaseAddress>;<Bus#>;<Device#>;<Function#>
  93
  94    Declaring a base address of 0xE0000000 (used for PCI Express devices)
  95    and having NT32 talk to a device located at bus 0, device 1, function 0:
  96    Example : EFI_WIN_NT_PASS_THROUGH=E000000;0;1;0
  97
  98 ---*/
  99
 100 //
 101 // The package level header files this module uses
 102 //
 103 #include <Uefi.h>
 104 #include <WinNtDxe.h>
 105 //
 106 // The protocols, PPI and GUID defintions for this module
 107 //
 108 #include <Protocol/WinNtThunk.h>
 109 #include <Protocol/WinNtIo.h>
 110 #include <Protocol/ComponentName.h>
 111 #include <Protocol/DriverBinding.h>
 112 #include <Protocol/DevicePath.h>
 113 //
 114 // The Library classes this module consumes
 115 //
 116 #include <Library/DebugLib.h>
 117 #include <Library/BaseLib.h>
 118 #include <Library/UefiDriverEntryPoint.h>
 119 #include <Library/UefiLib.h>
 120 #include <Library/PcdLib.h>
 121 #include <Library/BaseMemoryLib.h>
 122 #include <Library/UefiBootServicesTableLib.h>
 123 #include <Library/DevicePathLib.h>
 124 #include <Library/MemoryAllocationLib.h>
 125
 126 #include "WinNtBusDriver.h"
 127
 128 extern EFI_GUID gWinNtBusDriverGuid;
 129 //
 130 // DriverBinding protocol global
 131 //
 132 EFI_DRIVER_BINDING_PROTOCOL           gWinNtBusDriverBinding = {
 133   WinNtBusDriverBindingSupported,
 134   WinNtBusDriverBindingStart,
 135   WinNtBusDriverBindingStop,
 136   0xa,
 137   NULL,
 138   NULL
 139 };
 140
 141 #define NT_PCD_ARRAY_SIZE (sizeof(mPcdEnvironment)/sizeof(NT_PCD_ENTRY))
 142
 143 //
 144 // Table to map NT Environment variable to the GUID that should be in
 145 // device path.
 146 //
 147 NT_PCD_ENTRY  mPcdEnvironment[] = {
 148   PcdToken(PcdWinNtConsole),       &gEfiWinNtConsoleGuid,
 149   PcdToken(PcdWinNtGop),           &gEfiWinNtGopGuid,
 150   PcdToken(PcdWinNtSerialPort),    &gEfiWinNtSerialPortGuid,
 151   PcdToken(PcdWinNtFileSystem),    &gEfiWinNtFileSystemGuid,
 152   PcdToken(PcdWinNtVirtualDisk),   &gEfiWinNtVirtualDisksGuid,
 153   PcdToken(PcdWinNtPhysicalDisk),  &gEfiWinNtPhysicalDisksGuid
 154 };
 155
 156 /**
 157   The user Entry Point for module WinNtBusDriver. The user code starts with this function.
 158
 159   @param[in] ImageHandle    The firmware allocated handle for the EFI image.
 160   @param[in] SystemTable    A pointer to the EFI System Table.
 161
 162   @retval EFI_SUCCESS       The entry point is executed successfully.
 163   @retval other             Some error occurs when executing this entry point.
 164
 165 **/
 166 EFI_STATUS
 167 EFIAPI
 168 InitializeWinNtBusDriver(
 169   IN EFI_HANDLE           ImageHandle,
 170   IN EFI_SYSTEM_TABLE     *SystemTable
 171   )
 172 {
 173   EFI_STATUS              Status;
 174
 175   //
 176   // Install driver model protocol(s).
 177   //
 178   Status = EfiLibInstallDriverBindingComponentName2 (
 179              ImageHandle,
 180              SystemTable,
 181              &gWinNtBusDriverBinding,
 182              ImageHandle,
 183              &gWinNtBusDriverComponentName,
 184              &gWinNtBusDriverComponentName2
 185              );
 186   ASSERT_EFI_ERROR (Status);
 187
 188
 189   return Status;
 190 }
 191
 192 VOID *
 193 AllocateMemory (
 194   IN  UINTN   Size
 195   )
 196 {
 197   VOID        *Buffer;
 198
 199   Buffer = AllocatePool (Size);
 200   ASSERT (Buffer != NULL);
 201
 202   return Buffer;
 203 }
 204
 205
 206 EFI_STATUS
 207 EFIAPI
 208 WinNtBusDriverBindingSupported (
 209   IN  EFI_DRIVER_BINDING_PROTOCOL  *This,
 210   IN  EFI_HANDLE                   ControllerHandle,
 211   IN  EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath
 212   )
 213 /*++
 214
 215 Routine Description:
 216
 217 Arguments:
 218
 219 Returns:
 220
 221   None
 222
 223 **/
 224 // TODO:    This - add argument and description to function comment
 225 // TODO:    ControllerHandle - add argument and description to function comment
 226 // TODO:    RemainingDevicePath - add argument and description to function comment
 227 // TODO:    EFI_UNSUPPORTED - add return value to function comment
 228 // TODO:    EFI_UNSUPPORTED - add return value to function comment
 229 // TODO:    EFI_SUCCESS - add return value to function comment
 230 // TODO:    EFI_SUCCESS - add return value to function comment
 231 {
 232   EFI_STATUS                Status;
 233   EFI_DEVICE_PATH_PROTOCOL  *ParentDevicePath;
 234   EFI_WIN_NT_THUNK_PROTOCOL *WinNtThunk;
 235   UINTN                     Index;
 236
 237   //
 238   // Check the contents of the first Device Path Node of RemainingDevicePath to make sure
 239   // it is a legal Device Path Node for this bus driver's children.
 240   //
 241   if (RemainingDevicePath != NULL) {
 242     //
 243     // Check if RemainingDevicePath is the End of Device Path Node,
 244     // if yes, go on checking other conditions
 245     //
 246     if (!IsDevicePathEnd (RemainingDevicePath)) {
 247       //
 248       // If RemainingDevicePath isn't the End of Device Path Node,
 249       // check its validation
 250       //
 251       if (RemainingDevicePath->Type != HARDWARE_DEVICE_PATH ||
 252           RemainingDevicePath->SubType != HW_VENDOR_DP ||
 253           DevicePathNodeLength(RemainingDevicePath) != sizeof(WIN_NT_VENDOR_DEVICE_PATH_NODE)) {
 254         return EFI_UNSUPPORTED;
 255       }
 256
 257       for (Index = 0; Index < NT_PCD_ARRAY_SIZE; Index++) {
 258         if (CompareGuid (&((VENDOR_DEVICE_PATH *) RemainingDevicePath)->Guid, mPcdEnvironment[Index].DevicePathGuid)) {
 259           break;
 260         }
 261       }
 262
 263       if (Index >= NT_PCD_ARRAY_SIZE) {
 264         return EFI_UNSUPPORTED;
 265       }
 266     }
 267   }
 268
 269   //
 270   // Open the IO Abstraction(s) needed to perform the supported test
 271   //
 272   Status = gBS->OpenProtocol (
 273                   ControllerHandle,
 274                   &gEfiWinNtThunkProtocolGuid,
 275                   (VOID **) &WinNtThunk,
 276                   This->DriverBindingHandle,
 277                   ControllerHandle,
 278                   EFI_OPEN_PROTOCOL_BY_DRIVER
 279                   );
 280   if (Status == EFI_ALREADY_STARTED) {
 281     return EFI_SUCCESS;
 282   }
 283
 284   if (EFI_ERROR (Status)) {
 285     return Status;
 286   }
 287
 288   //
 289   // Close the I/O Abstraction(s) used to perform the supported test
 290   //
 291   gBS->CloseProtocol (
 292         ControllerHandle,
 293         &gEfiWinNtThunkProtocolGuid,
 294         This->DriverBindingHandle,
 295         ControllerHandle
 296         );
 297
 298   //
 299   // Open the EFI Device Path protocol needed to perform the supported test
 300   //
 301   Status = gBS->OpenProtocol (
 302                   ControllerHandle,
 303                   &gEfiDevicePathProtocolGuid,
 304                   (VOID **) &ParentDevicePath,
 305                   This->DriverBindingHandle,
 306                   ControllerHandle,
 307                   EFI_OPEN_PROTOCOL_BY_DRIVER
 308                   );
 309   if (Status == EFI_ALREADY_STARTED) {
 310     return EFI_SUCCESS;
 311   }
 312
 313   if (EFI_ERROR (Status)) {
 314     return Status;
 315   }
 316
 317   //
 318   // Since we call through WinNtThunk we need to make sure it's valid
 319   //
 320   Status = EFI_SUCCESS;
 321   if (WinNtThunk->Signature != EFI_WIN_NT_THUNK_PROTOCOL_SIGNATURE) {
 322     Status = EFI_UNSUPPORTED;
 323   }
 324
 325   //
 326   // Close protocol, don't use device path protocol in the Support() function
 327   //
 328   gBS->CloseProtocol (
 329         ControllerHandle,
 330         &gEfiDevicePathProtocolGuid,
 331         This->DriverBindingHandle,
 332         ControllerHandle
 333         );
 334
 335   return Status;
 336 }
 337
 338 EFI_STATUS
 339 EFIAPI
 340 WinNtBusDriverBindingStart (
 341   IN  EFI_DRIVER_BINDING_PROTOCOL  *This,
 342   IN  EFI_HANDLE                   ControllerHandle,
 343   IN  EFI_DEVICE_PATH_PROTOCOL     *RemainingDevicePath
 344   )
 345 /*++
 346
 347 Routine Description:
 348
 349 Arguments:
 350
 351 Returns:
 352
 353   None
 354
 355 --*/
 356 // TODO:    This - add argument and description to function comment
 357 // TODO:    ControllerHandle - add argument and description to function comment
 358 // TODO:    RemainingDevicePath - add argument and description to function comment
 359 // TODO:    EFI_OUT_OF_RESOURCES - add return value to function comment
 360 // TODO:    EFI_OUT_OF_RESOURCES - add return value to function comment
 361 // TODO:    EFI_SUCCESS - add return value to function comment
 362 {
 363   EFI_STATUS                      Status;
 364   EFI_WIN_NT_THUNK_PROTOCOL       *WinNtThunk;
 365   EFI_DEVICE_PATH_PROTOCOL        *ParentDevicePath;
 366   WIN_NT_BUS_DEVICE               *WinNtBusDevice;
 367   WIN_NT_IO_DEVICE                *WinNtDevice;
 368   UINTN                           Index;
 369   CHAR16                          *StartString;
 370   CHAR16                          *SubString;
 371   UINT16                          Count;
 372   UINTN                           StringSize;
 373   UINT16                          ComponentName[MAX_NT_ENVIRNMENT_VARIABLE_LENGTH];
 374   WIN_NT_VENDOR_DEVICE_PATH_NODE  *Node;
 375   BOOLEAN                         CreateDevice;
 376   CHAR16                          *TempStr;
 377   CHAR16                          *PcdTempStr;
 378   UINTN                           TempStrSize;
 379
 380   Status = EFI_UNSUPPORTED;
 381
 382   //
 383   // Grab the protocols we need
 384   //
 385   Status = gBS->OpenProtocol (
 386                   ControllerHandle,
 387                   &gEfiDevicePathProtocolGuid,
 388                   (VOID **) &ParentDevicePath,
 389                   This->DriverBindingHandle,
 390                   ControllerHandle,
 391                   EFI_OPEN_PROTOCOL_BY_DRIVER
 392                   );
 393   if (EFI_ERROR (Status) && Status != EFI_ALREADY_STARTED) {
 394     return Status;
 395   }
 396
 397   Status = gBS->OpenProtocol (
 398                   ControllerHandle,
 399                   &gEfiWinNtThunkProtocolGuid,
 400                   (VOID **) &WinNtThunk,
 401                   This->DriverBindingHandle,
 402                   ControllerHandle,
 403                   EFI_OPEN_PROTOCOL_BY_DRIVER
 404                   );
 405   if (EFI_ERROR (Status) && Status != EFI_ALREADY_STARTED) {
 406     return Status;
 407   }
 408
 409   if (Status != EFI_ALREADY_STARTED) {
 410     WinNtBusDevice = AllocatePool (sizeof (WIN_NT_BUS_DEVICE));
 411     if (WinNtBusDevice == NULL) {
 412       return EFI_OUT_OF_RESOURCES;
 413     }
 414
 415     WinNtBusDevice->Signature           = WIN_NT_BUS_DEVICE_SIGNATURE;
 416     WinNtBusDevice->ControllerNameTable = NULL;
 417
 418     AddUnicodeString2 (
 419       "eng",
 420       gWinNtBusDriverComponentName.SupportedLanguages,
 421       &WinNtBusDevice->ControllerNameTable,
 422       L"Windows Bus Controller",
 423       TRUE
 424       );
 425     AddUnicodeString2 (
 426       "en",
 427       gWinNtBusDriverComponentName2.SupportedLanguages,
 428       &WinNtBusDevice->ControllerNameTable,
 429       L"Windows Bus Controller",
 430       FALSE
 431       );
 432
 433
 434     Status = gBS->InstallMultipleProtocolInterfaces (
 435                     &ControllerHandle,
 436                     &gWinNtBusDriverGuid,
 437                     WinNtBusDevice,
 438                     NULL
 439                     );
 440     if (EFI_ERROR (Status)) {
 441       FreeUnicodeStringTable (WinNtBusDevice->ControllerNameTable);
 442       FreePool (WinNtBusDevice);
 443       return Status;
 444     }
 445   }
 446
 447   //
 448   // Loop on the Variable list. Parse each variable to produce a set of handles that
 449   // represent virtual hardware devices.
 450   //
 451   for (Index = 0; Index < NT_PCD_ARRAY_SIZE; Index++) {
 452     PcdTempStr = (VOID *)LibPcdGetPtr (mPcdEnvironment[Index].Token);
 453     ASSERT (PcdTempStr != NULL);
 454
 455     TempStrSize = StrLen (PcdTempStr);
 456     TempStr = AllocateMemory ((TempStrSize * sizeof (CHAR16)) + 1);
 457     StrCpy (TempStr, PcdTempStr);
 458
 459     StartString = TempStr;
 460
 461     //
 462     // Parse the envirnment variable into sub strings using '!' as a delimator.
 463     // Each substring needs it's own handle to be added to the system. This code
 464     // does not understand the sub string. Thats the device drivers job.
 465     //
 466     Count = 0;
 467     while (*StartString != '\0') {
 468
 469       //
 470       // Find the end of the sub string
 471       //
 472       SubString = StartString;
 473       while (*SubString != '\0' && *SubString != '!') {
 474         SubString++;
 475       }
 476
 477       if (*SubString == '!') {
 478         //
 479         // Replace token with '\0' to make sub strings. If this is the end
 480         //  of the string SubString will already point to NULL.
 481         //
 482         *SubString = '\0';
 483         SubString++;
 484       }
 485
 486       CreateDevice = TRUE;
 487       if (RemainingDevicePath != NULL) {
 488         CreateDevice  = FALSE;
 489         //
 490         // Check if RemainingDevicePath is the End of Device Path Node,
 491         // if yes, don't create any child device
 492         //
 493         if (!IsDevicePathEnd (RemainingDevicePath)) {
 494           //
 495           // If RemainingDevicePath isn't the End of Device Path Node,
 496           // check its validation
 497           //
 498           Node          = (WIN_NT_VENDOR_DEVICE_PATH_NODE *) RemainingDevicePath;
 499           if (Node->VendorDevicePath.Header.Type == HARDWARE_DEVICE_PATH &&
 500               Node->VendorDevicePath.Header.SubType == HW_VENDOR_DP &&
 501               DevicePathNodeLength (&Node->VendorDevicePath.Header) == sizeof (WIN_NT_VENDOR_DEVICE_PATH_NODE)
 502               ) {
 503             if (CompareGuid (&Node->VendorDevicePath.Guid, mPcdEnvironment[Index].DevicePathGuid) &&
 504                 Node->Instance == Count
 505                 ) {
 506               CreateDevice = TRUE;
 507             }
 508           }
 509         }
 510       }
 511
 512       if (CreateDevice) {
 513
 514         //
 515         // Allocate instance structure, and fill in parent information.
 516         //
 517         WinNtDevice = AllocateMemory (sizeof (WIN_NT_IO_DEVICE));
 518         if (WinNtDevice == NULL) {
 519           return EFI_OUT_OF_RESOURCES;
 520         }
 521
 522         WinNtDevice->Handle             = NULL;
 523         WinNtDevice->ControllerHandle   = ControllerHandle;
 524         WinNtDevice->ParentDevicePath   = ParentDevicePath;
 525
 526         WinNtDevice->WinNtIo.WinNtThunk = WinNtThunk;
 527
 528         //
 529         // Plus 2 to account for the NULL at the end of the Unicode string
 530         //
 531         StringSize = (UINTN) ((UINT8 *) SubString - (UINT8 *) StartString) + sizeof (CHAR16);
 532         WinNtDevice->WinNtIo.EnvString = AllocateMemory (StringSize);
 533         if (WinNtDevice->WinNtIo.EnvString != NULL) {
 534           CopyMem (WinNtDevice->WinNtIo.EnvString, StartString, StringSize);
 535         }
 536
 537         WinNtDevice->ControllerNameTable = NULL;
 538
 539         WinNtThunk->SPrintf (ComponentName, sizeof (ComponentName), L"%s", WinNtDevice->WinNtIo.EnvString);
 540
 541         WinNtDevice->DevicePath = WinNtBusCreateDevicePath (
 542                                     ParentDevicePath,
 543                                     mPcdEnvironment[Index].DevicePathGuid,
 544                                     Count
 545                                     );
 546         if (WinNtDevice->DevicePath == NULL) {
 547           FreePool (WinNtDevice);
 548           return EFI_OUT_OF_RESOURCES;
 549         }
 550
 551         AddUnicodeString2 (
 552           "eng",
 553           gWinNtBusDriverComponentName.SupportedLanguages,
 554           &WinNtDevice->ControllerNameTable,
 555           ComponentName,
 556           TRUE
 557           );
 558         AddUnicodeString2 (
 559           "en",
 560           gWinNtBusDriverComponentName2.SupportedLanguages,
 561           &WinNtDevice->ControllerNameTable,
 562           ComponentName,
 563           FALSE
 564           );
 565
 566
 567         WinNtDevice->WinNtIo.TypeGuid       = mPcdEnvironment[Index].DevicePathGuid;
 568         WinNtDevice->WinNtIo.InstanceNumber = Count;
 569
 570         WinNtDevice->Signature              = WIN_NT_IO_DEVICE_SIGNATURE;
 571
 572         Status = gBS->InstallMultipleProtocolInterfaces (
 573                         &WinNtDevice->Handle,
 574                         &gEfiDevicePathProtocolGuid,
 575                         WinNtDevice->DevicePath,
 576                         &gEfiWinNtIoProtocolGuid,
 577                         &WinNtDevice->WinNtIo,
 578                         NULL
 579                         );
 580         if (EFI_ERROR (Status)) {
 581           FreeUnicodeStringTable (WinNtDevice->ControllerNameTable);
 582           FreePool (WinNtDevice);
 583         } else {
 584           //
 585           // Open For Child Device
 586           //
 587           Status = gBS->OpenProtocol (
 588                           ControllerHandle,
 589                           &gEfiWinNtThunkProtocolGuid,
 590                           (VOID **) &WinNtThunk,
 591                           This->DriverBindingHandle,
 592                           WinNtDevice->Handle,
 593                           EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER
 594                           );
 595         }
 596       }
 597
 598       //
 599       // Parse Next sub string. This will point to '\0' if we are at the end.
 600       //
 601       Count++;
 602       StartString = SubString;
 603     }
 604
 605     FreePool (TempStr);
 606   }
 607
 608   return EFI_SUCCESS;
 609 }
 610
 611
 612 EFI_STATUS
 613 EFIAPI
 614 WinNtBusDriverBindingStop (
 615   IN  EFI_DRIVER_BINDING_PROTOCOL  *This,
 616   IN  EFI_HANDLE                   ControllerHandle,
 617   IN  UINTN                        NumberOfChildren,
 618   IN  EFI_HANDLE                   *ChildHandleBuffer
 619   )
 620 /*++
 621
 622 Routine Description:
 623
 624 Arguments:
 625
 626 Returns:
 627
 628     None
 629
 630 --*/
 631 // TODO:    This - add argument and description to function comment
 632 // TODO:    ControllerHandle - add argument and description to function comment
 633 // TODO:    NumberOfChildren - add argument and description to function comment
 634 // TODO:    ChildHandleBuffer - add argument and description to function comment
 635 // TODO:    EFI_SUCCESS - add return value to function comment
 636 // TODO:    EFI_DEVICE_ERROR - add return value to function comment
 637 // TODO:    EFI_SUCCESS - add return value to function comment
 638 {
 639   EFI_STATUS                Status;
 640   UINTN                     Index;
 641   BOOLEAN                   AllChildrenStopped;
 642   EFI_WIN_NT_IO_PROTOCOL    *WinNtIo;
 643   WIN_NT_BUS_DEVICE         *WinNtBusDevice;
 644   WIN_NT_IO_DEVICE          *WinNtDevice;
 645   EFI_WIN_NT_THUNK_PROTOCOL *WinNtThunk;
 646
 647   //
 648   // Complete all outstanding transactions to Controller.
 649   // Don't allow any new transaction to Controller to be started.
 650   //
 651
 652   if (NumberOfChildren == 0) {
 653     //
 654     // Close the bus driver
 655     //
 656     Status = gBS->OpenProtocol (
 657                     ControllerHandle,
 658                     &gWinNtBusDriverGuid,
 659                     (VOID **) &WinNtBusDevice,
 660                     This->DriverBindingHandle,
 661                     ControllerHandle,
 662                     EFI_OPEN_PROTOCOL_GET_PROTOCOL
 663                     );
 664     if (EFI_ERROR (Status)) {
 665       return Status;
 666     }
 667
 668     gBS->UninstallMultipleProtocolInterfaces (
 669           ControllerHandle,
 670           &gWinNtBusDriverGuid,
 671           WinNtBusDevice,
 672           NULL
 673           );
 674
 675     FreeUnicodeStringTable (WinNtBusDevice->ControllerNameTable);
 676
 677     FreePool (WinNtBusDevice);
 678
 679     gBS->CloseProtocol (
 680           ControllerHandle,
 681           &gEfiWinNtThunkProtocolGuid,
 682           This->DriverBindingHandle,
 683           ControllerHandle
 684           );
 685
 686     gBS->CloseProtocol (
 687           ControllerHandle,
 688           &gEfiDevicePathProtocolGuid,
 689           This->DriverBindingHandle,
 690           ControllerHandle
 691           );
 692     return EFI_SUCCESS;
 693   }
 694
 695   AllChildrenStopped = TRUE;
 696
 697   for (Index = 0; Index < NumberOfChildren; Index++) {
 698
 699     Status = gBS->OpenProtocol (
 700                     ChildHandleBuffer[Index],
 701                     &gEfiWinNtIoProtocolGuid,
 702                     (VOID **) &WinNtIo,
 703                     This->DriverBindingHandle,
 704                     ControllerHandle,
 705                     EFI_OPEN_PROTOCOL_GET_PROTOCOL
 706                     );
 707     if (!EFI_ERROR (Status)) {
 708
 709       WinNtDevice = WIN_NT_IO_DEVICE_FROM_THIS (WinNtIo);
 710
 711       Status = gBS->CloseProtocol (
 712                       ControllerHandle,
 713                       &gEfiWinNtThunkProtocolGuid,
 714                       This->DriverBindingHandle,
 715                       WinNtDevice->Handle
 716                       );
 717
 718       Status = gBS->UninstallMultipleProtocolInterfaces (
 719                       WinNtDevice->Handle,
 720                       &gEfiDevicePathProtocolGuid,
 721                       WinNtDevice->DevicePath,
 722                       &gEfiWinNtIoProtocolGuid,
 723                       &WinNtDevice->WinNtIo,
 724                       NULL
 725                       );
 726
 727       if (EFI_ERROR (Status)) {
 728         gBS->OpenProtocol (
 729               ControllerHandle,
 730               &gEfiWinNtThunkProtocolGuid,
 731               (VOID **) &WinNtThunk,
 732               This->DriverBindingHandle,
 733               WinNtDevice->Handle,
 734               EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER
 735               );
 736       } else {
 737         //
 738         // Close the child handle
 739         //
 740         FreeUnicodeStringTable (WinNtDevice->ControllerNameTable);
 741         FreePool (WinNtDevice);
 742       }
 743     }
 744
 745     if (EFI_ERROR (Status)) {
 746       AllChildrenStopped = FALSE;
 747     }
 748   }
 749
 750   if (!AllChildrenStopped) {
 751     return EFI_DEVICE_ERROR;
 752   }
 753
 754   return EFI_SUCCESS;
 755 }
 756
 757 EFI_DEVICE_PATH_PROTOCOL *
 758 WinNtBusCreateDevicePath (
 759   IN  EFI_DEVICE_PATH_PROTOCOL  *RootDevicePath,
 760   IN  EFI_GUID                  *Guid,
 761   IN  UINT16                    InstanceNumber
 762   )
 763 /*++
 764
 765 Routine Description:
 766   Create a device path node using Guid and InstanceNumber and append it to
 767   the passed in RootDevicePath
 768
 769 Arguments:
 770   RootDevicePath - Root of the device path to return.
 771
 772   Guid           - GUID to use in vendor device path node.
 773
 774   InstanceNumber - Instance number to use in the vendor device path. This
 775                     argument is needed to make sure each device path is unique.
 776
 777 Returns:
 778
 779   EFI_DEVICE_PATH_PROTOCOL
 780
 781 --*/
 782 {
 783   WIN_NT_VENDOR_DEVICE_PATH_NODE  DevicePath;
 784
 785   DevicePath.VendorDevicePath.Header.Type     = HARDWARE_DEVICE_PATH;
 786   DevicePath.VendorDevicePath.Header.SubType  = HW_VENDOR_DP;
 787   SetDevicePathNodeLength (&DevicePath.VendorDevicePath.Header, sizeof (WIN_NT_VENDOR_DEVICE_PATH_NODE));
 788
 789   //
 790   // The GUID defines the Class
 791   //
 792   CopyMem (&DevicePath.VendorDevicePath.Guid, Guid, sizeof (EFI_GUID));
 793
 794   //
 795   // Add an instance number so we can make sure there are no Device Path
 796   // duplication.
 797   //
 798   DevicePath.Instance = InstanceNumber;
 799
 800   return AppendDevicePathNode (
 801           RootDevicePath,
 802           (EFI_DEVICE_PATH_PROTOCOL *) &DevicePath
 803           );
 804 }