code.delx.au - refind/blob - refind/lib.c

   1 /*
   2  * refit/lib.c
   3  * General library functions
   4  *
   5  * Copyright (c) 2006-2009 Christoph Pfisterer
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions are
  10  * met:
  11  *
  12  *  * Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  *  * Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  *  * Neither the name of Christoph Pfisterer nor the names of the
  21  *    contributors may be used to endorse or promote products derived
  22  *    from this software without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  25  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  26  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  27  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  28  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  29  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  30  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  31  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  34  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  35  */
  36 /*
  37  * Modifications copyright (c) 2012 Roderick W. Smith
  38  *
  39  * Modifications distributed under the terms of the GNU General Public
  40  * License (GPL) version 3 (GPLv3), a copy of which must be distributed
  41  * with this source code or binaries made from it.
  42  *
  43  */
  44
  45 #include "global.h"
  46 #include "lib.h"
  47 #include "icns.h"
  48 #include "screen.h"
  49 #include "refit_call_wrapper.h"
  50
  51 // variables
  52
  53 EFI_HANDLE       SelfImageHandle;
  54 EFI_LOADED_IMAGE *SelfLoadedImage;
  55 EFI_FILE         *SelfRootDir;
  56 EFI_FILE         *SelfDir;
  57 CHAR16           *SelfDirPath;
  58
  59 REFIT_VOLUME     *SelfVolume = NULL;
  60 REFIT_VOLUME     **Volumes = NULL;
  61 UINTN            VolumesCount = 0;
  62
  63 // Maximum size for disk sectors
  64 #define SECTOR_SIZE 4096
  65
  66 // functions
  67
  68 static EFI_STATUS FinishInitRefitLib(VOID);
  69
  70 static VOID UninitVolumes(VOID);
  71
  72 //
  73 // self recognition stuff
  74 //
  75
  76 EFI_STATUS InitRefitLib(IN EFI_HANDLE ImageHandle)
  77 {
  78     EFI_STATUS  Status;
  79     CHAR16      *DevicePathAsString;
  80     CHAR16      BaseDirectory[256];
  81     UINTN       i;
  82
  83     SelfImageHandle = ImageHandle;
  84     Status = refit_call3_wrapper(BS->HandleProtocol, SelfImageHandle, &LoadedImageProtocol, (VOID **) &SelfLoadedImage);
  85     if (CheckFatalError(Status, L"while getting a LoadedImageProtocol handle"))
  86         return EFI_LOAD_ERROR;
  87
  88     // find the current directory
  89     DevicePathAsString = DevicePathToStr(SelfLoadedImage->FilePath);
  90     if (DevicePathAsString != NULL) {
  91         StrCpy(BaseDirectory, DevicePathAsString);
  92         FreePool(DevicePathAsString);
  93         for (i = StrLen(BaseDirectory); i > 0 && BaseDirectory[i] != '\\'; i--) ;
  94         BaseDirectory[i] = 0;
  95     } else
  96         BaseDirectory[0] = 0;
  97     SelfDirPath = StrDuplicate(BaseDirectory);
  98
  99     return FinishInitRefitLib();
 100 }
 101
 102 // called before running external programs to close open file handles
 103 VOID UninitRefitLib(VOID)
 104 {
 105     UninitVolumes();
 106
 107     if (SelfDir != NULL) {
 108         refit_call1_wrapper(SelfDir->Close, SelfDir);
 109         SelfDir = NULL;
 110     }
 111
 112     if (SelfRootDir != NULL) {
 113        refit_call1_wrapper(SelfRootDir->Close, SelfRootDir);
 114        SelfRootDir = NULL;
 115     }
 116 }
 117
 118 // called after running external programs to re-open file handles
 119 EFI_STATUS ReinitRefitLib(VOID)
 120 {
 121     ReinitVolumes();
 122
 123     // Below two lines were in rEFIt, but seem to cause problems on
 124     // most systems. OTOH, my Mac Mini produces (apparently harmless)
 125     // errors about "(re)opening our installation volume" (see the
 126     // next function) when returning from programs when these two lines
 127     // are removed. On the gripping hand, the Mac SOMETIMES crashes
 128     // when launching a second program even with these lines removed.
 129     // TODO: Figure out cause of above weirdness and fix it more
 130     // reliably!
 131     /* if (SelfVolume != NULL && SelfVolume->RootDir != NULL)
 132        SelfRootDir = SelfVolume->RootDir; */
 133
 134     return FinishInitRefitLib();
 135 }
 136
 137 static EFI_STATUS FinishInitRefitLib(VOID)
 138 {
 139     EFI_STATUS  Status;
 140
 141     if (SelfRootDir == NULL) {
 142         SelfRootDir = LibOpenRoot(SelfLoadedImage->DeviceHandle);
 143         if (SelfRootDir == NULL) {
 144             CheckError(EFI_LOAD_ERROR, L"while (re)opening our installation volume");
 145             return EFI_LOAD_ERROR;
 146         }
 147     }
 148
 149     Status = refit_call5_wrapper(SelfRootDir->Open, SelfRootDir, &SelfDir, SelfDirPath, EFI_FILE_MODE_READ, 0);
 150     if (CheckFatalError(Status, L"while opening our installation directory"))
 151         return EFI_LOAD_ERROR;
 152
 153     return EFI_SUCCESS;
 154 }
 155
 156 //
 157 // list functions
 158 //
 159
 160 VOID CreateList(OUT VOID ***ListPtr, OUT UINTN *ElementCount, IN UINTN InitialElementCount)
 161 {
 162     UINTN AllocateCount;
 163
 164     *ElementCount = InitialElementCount;
 165     if (*ElementCount > 0) {
 166         AllocateCount = (*ElementCount + 7) & ~7;   // next multiple of 8
 167         *ListPtr = AllocatePool(sizeof(VOID *) * AllocateCount);
 168     } else {
 169         *ListPtr = NULL;
 170     }
 171 }
 172
 173 VOID AddListElement(IN OUT VOID ***ListPtr, IN OUT UINTN *ElementCount, IN VOID *NewElement)
 174 {
 175     UINTN AllocateCount;
 176
 177     if ((*ElementCount & 7) == 0) {
 178         AllocateCount = *ElementCount + 8;
 179         if (*ElementCount == 0)
 180             *ListPtr = AllocatePool(sizeof(VOID *) * AllocateCount);
 181         else
 182             *ListPtr = ReallocatePool(*ListPtr, sizeof(VOID *) * (*ElementCount), sizeof(VOID *) * AllocateCount);
 183     }
 184     (*ListPtr)[*ElementCount] = NewElement;
 185     (*ElementCount)++;
 186 } /* VOID AddListElement() */
 187
 188 VOID FreeList(IN OUT VOID ***ListPtr, IN OUT UINTN *ElementCount)
 189 {
 190     UINTN i;
 191
 192     if (*ElementCount > 0) {
 193         for (i = 0; i < *ElementCount; i++) {
 194             // TODO: call a user-provided routine for each element here
 195             FreePool((*ListPtr)[i]);
 196         }
 197         FreePool(*ListPtr);
 198     }
 199 }
 200
 201 //
 202 // firmware device path discovery
 203 //
 204
 205 static UINT8 LegacyLoaderMediaPathData[] = {
 206     0x04, 0x06, 0x14, 0x00, 0xEB, 0x85, 0x05, 0x2B,
 207     0xB8, 0xD8, 0xA9, 0x49, 0x8B, 0x8C, 0xE2, 0x1B,
 208     0x01, 0xAE, 0xF2, 0xB7, 0x7F, 0xFF, 0x04, 0x00,
 209 };
 210 static EFI_DEVICE_PATH *LegacyLoaderMediaPath = (EFI_DEVICE_PATH *)LegacyLoaderMediaPathData;
 211
 212 VOID ExtractLegacyLoaderPaths(EFI_DEVICE_PATH **PathList, UINTN MaxPaths, EFI_DEVICE_PATH **HardcodedPathList)
 213 {
 214     EFI_STATUS          Status;
 215     UINTN               HandleCount = 0;
 216     UINTN               HandleIndex, HardcodedIndex;
 217     EFI_HANDLE          *Handles;
 218     EFI_HANDLE          Handle;
 219     UINTN               PathCount = 0;
 220     UINTN               PathIndex;
 221     EFI_LOADED_IMAGE    *LoadedImage;
 222     EFI_DEVICE_PATH     *DevicePath;
 223     BOOLEAN             Seen;
 224
 225     MaxPaths--;  // leave space for the terminating NULL pointer
 226
 227     // get all LoadedImage handles
 228     Status = LibLocateHandle(ByProtocol, &LoadedImageProtocol, NULL,
 229                              &HandleCount, &Handles);
 230     if (CheckError(Status, L"while listing LoadedImage handles")) {
 231         if (HardcodedPathList) {
 232             for (HardcodedIndex = 0; HardcodedPathList[HardcodedIndex] && PathCount < MaxPaths; HardcodedIndex++)
 233                 PathList[PathCount++] = HardcodedPathList[HardcodedIndex];
 234         }
 235         PathList[PathCount] = NULL;
 236         return;
 237     }
 238     for (HandleIndex = 0; HandleIndex < HandleCount && PathCount < MaxPaths; HandleIndex++) {
 239         Handle = Handles[HandleIndex];
 240
 241         Status = refit_call3_wrapper(BS->HandleProtocol, Handle, &LoadedImageProtocol, (VOID **) &LoadedImage);
 242         if (EFI_ERROR(Status))
 243             continue;  // This can only happen if the firmware scewed up, ignore it.
 244
 245         Status = refit_call3_wrapper(BS->HandleProtocol, LoadedImage->DeviceHandle, &DevicePathProtocol, (VOID **) &DevicePath);
 246         if (EFI_ERROR(Status))
 247             continue;  // This happens, ignore it.
 248
 249         // Only grab memory range nodes
 250         if (DevicePathType(DevicePath) != HARDWARE_DEVICE_PATH || DevicePathSubType(DevicePath) != HW_MEMMAP_DP)
 251             continue;
 252
 253         // Check if we have this device path in the list already
 254         // WARNING: This assumes the first node in the device path is unique!
 255         Seen = FALSE;
 256         for (PathIndex = 0; PathIndex < PathCount; PathIndex++) {
 257             if (DevicePathNodeLength(DevicePath) != DevicePathNodeLength(PathList[PathIndex]))
 258                 continue;
 259             if (CompareMem(DevicePath, PathList[PathIndex], DevicePathNodeLength(DevicePath)) == 0) {
 260                 Seen = TRUE;
 261                 break;
 262             }
 263         }
 264         if (Seen)
 265             continue;
 266
 267         PathList[PathCount++] = AppendDevicePath(DevicePath, LegacyLoaderMediaPath);
 268     }
 269     FreePool(Handles);
 270
 271     if (HardcodedPathList) {
 272         for (HardcodedIndex = 0; HardcodedPathList[HardcodedIndex] && PathCount < MaxPaths; HardcodedIndex++)
 273             PathList[PathCount++] = HardcodedPathList[HardcodedIndex];
 274     }
 275     PathList[PathCount] = NULL;
 276 }
 277
 278 //
 279 // volume functions
 280 //
 281
 282 static VOID ScanVolumeBootcode(IN OUT REFIT_VOLUME *Volume, OUT BOOLEAN *Bootable)
 283 {
 284     EFI_STATUS              Status;
 285     UINT8                   SectorBuffer[SECTOR_SIZE];
 286     UINTN                   i;
 287     MBR_PARTITION_INFO      *MbrTable;
 288     BOOLEAN                 MbrTableFound;
 289
 290     Volume->HasBootCode = FALSE;
 291     Volume->OSIconName = NULL;
 292     Volume->OSName = NULL;
 293     *Bootable = FALSE;
 294
 295     if (Volume->BlockIO == NULL)
 296         return;
 297     if (Volume->BlockIO->Media->BlockSize > SECTOR_SIZE)
 298         return;   // our buffer is too small...
 299
 300     // look at the boot sector (this is used for both hard disks and El Torito images!)
 301     Status = refit_call5_wrapper(Volume->BlockIO->ReadBlocks,
 302                                  Volume->BlockIO, Volume->BlockIO->Media->MediaId,
 303                                  Volume->BlockIOOffset, SECTOR_SIZE, SectorBuffer);
 304     if (!EFI_ERROR(Status)) {
 305
 306         if (*((UINT16 *)(SectorBuffer + 510)) == 0xaa55 && SectorBuffer[0] != 0) {
 307             *Bootable = TRUE;
 308             Volume->HasBootCode = TRUE;
 309         }
 310
 311         // detect specific boot codes
 312         if (CompareMem(SectorBuffer + 2, "LILO", 4) == 0 ||
 313             CompareMem(SectorBuffer + 6, "LILO", 4) == 0 ||
 314             CompareMem(SectorBuffer + 3, "SYSLINUX", 8) == 0 ||
 315             FindMem(SectorBuffer, SECTOR_SIZE, "ISOLINUX", 8) >= 0) {
 316             Volume->HasBootCode = TRUE;
 317             Volume->OSIconName = L"linux";
 318             Volume->OSName = L"Linux";
 319
 320         } else if (FindMem(SectorBuffer, 512, "Geom\0Hard Disk\0Read\0 Error", 26) >= 0) {   // GRUB
 321             Volume->HasBootCode = TRUE;
 322             Volume->OSIconName = L"grub,linux";
 323             Volume->OSName = L"Linux";
 324
 325         } else if ((*((UINT32 *)(SectorBuffer + 502)) == 0 &&
 326                     *((UINT32 *)(SectorBuffer + 506)) == 50000 &&
 327                     *((UINT16 *)(SectorBuffer + 510)) == 0xaa55) ||
 328                     FindMem(SectorBuffer, SECTOR_SIZE, "Starting the BTX loader", 23) >= 0) {
 329             Volume->HasBootCode = TRUE;
 330             Volume->OSIconName = L"freebsd";
 331             Volume->OSName = L"FreeBSD";
 332
 333         } else if (FindMem(SectorBuffer, 512, "!Loading", 8) >= 0 ||
 334                    FindMem(SectorBuffer, SECTOR_SIZE, "/cdboot\0/CDBOOT\0", 16) >= 0) {
 335             Volume->HasBootCode = TRUE;
 336             Volume->OSIconName = L"openbsd";
 337             Volume->OSName = L"OpenBSD";
 338
 339         } else if (FindMem(SectorBuffer, 512, "Not a bootxx image", 18) >= 0 ||
 340                    *((UINT32 *)(SectorBuffer + 1028)) == 0x7886b6d1) {
 341             Volume->HasBootCode = TRUE;
 342             Volume->OSIconName = L"netbsd";
 343             Volume->OSName = L"NetBSD";
 344
 345         } else if (FindMem(SectorBuffer, SECTOR_SIZE, "NTLDR", 5) >= 0) {
 346             Volume->HasBootCode = TRUE;
 347             Volume->OSIconName = L"win";
 348             Volume->OSName = L"Windows";
 349
 350         } else if (FindMem(SectorBuffer, SECTOR_SIZE, "BOOTMGR", 7) >= 0) {
 351             Volume->HasBootCode = TRUE;
 352             Volume->OSIconName = L"winvista,win";
 353             Volume->OSName = L"Windows";
 354
 355         } else if (FindMem(SectorBuffer, 512, "CPUBOOT SYS", 11) >= 0 ||
 356                    FindMem(SectorBuffer, 512, "KERNEL  SYS", 11) >= 0) {
 357             Volume->HasBootCode = TRUE;
 358             Volume->OSIconName = L"freedos";
 359             Volume->OSName = L"FreeDOS";
 360
 361         } else if (FindMem(SectorBuffer, 512, "OS2LDR", 6) >= 0 ||
 362                    FindMem(SectorBuffer, 512, "OS2BOOT", 7) >= 0) {
 363             Volume->HasBootCode = TRUE;
 364             Volume->OSIconName = L"ecomstation";
 365             Volume->OSName = L"eComStation";
 366
 367         } else if (FindMem(SectorBuffer, 512, "Be Boot Loader", 14) >= 0) {
 368             Volume->HasBootCode = TRUE;
 369             Volume->OSIconName = L"beos";
 370             Volume->OSName = L"BeOS";
 371
 372         } else if (FindMem(SectorBuffer, 512, "yT Boot Loader", 14) >= 0) {
 373             Volume->HasBootCode = TRUE;
 374             Volume->OSIconName = L"zeta,beos";
 375             Volume->OSName = L"ZETA";
 376
 377         } else if (FindMem(SectorBuffer, 512, "\x04" "beos\x06" "system\x05" "zbeos", 18) >= 0 ||
 378                    FindMem(SectorBuffer, 512, "\x06" "system\x0c" "haiku_loader", 20) >= 0) {
 379             Volume->HasBootCode = TRUE;
 380             Volume->OSIconName = L"haiku,beos";
 381             Volume->OSName = L"Haiku";
 382
 383         }
 384
 385         // NOTE: If you add an operating system with a name that starts with 'W' or 'L', you
 386         //  need to fix AddLegacyEntry in main.c.
 387
 388 #if REFIT_DEBUG > 0
 389         Print(L"  Result of bootcode detection: %s %s (%s)\n",
 390               Volume->HasBootCode ? L"bootable" : L"non-bootable",
 391               Volume->OSName, Volume->OSIconName);
 392 #endif
 393
 394         if (FindMem(SectorBuffer, 512, "Non-system disk", 15) >= 0)   // dummy FAT boot sector
 395             Volume->HasBootCode = FALSE;
 396
 397         // check for MBR partition table
 398         if (*((UINT16 *)(SectorBuffer + 510)) == 0xaa55) {
 399             MbrTableFound = FALSE;
 400             MbrTable = (MBR_PARTITION_INFO *)(SectorBuffer + 446);
 401             for (i = 0; i < 4; i++)
 402                 if (MbrTable[i].StartLBA && MbrTable[i].Size)
 403                     MbrTableFound = TRUE;
 404             for (i = 0; i < 4; i++)
 405                 if (MbrTable[i].Flags != 0x00 && MbrTable[i].Flags != 0x80)
 406                     MbrTableFound = FALSE;
 407             if (MbrTableFound) {
 408                 Volume->MbrPartitionTable = AllocatePool(4 * 16);
 409                 CopyMem(Volume->MbrPartitionTable, MbrTable, 4 * 16);
 410             }
 411         }
 412
 413     } else {
 414 #if REFIT_DEBUG > 0
 415         CheckError(Status, L"while reading boot sector");
 416 #endif
 417     }
 418 }
 419
 420 // default volume icon based on disk kind
 421 static VOID ScanVolumeDefaultIcon(IN OUT REFIT_VOLUME *Volume)
 422 {
 423     switch (Volume->DiskKind) {
 424        case DISK_KIND_INTERNAL:
 425           Volume->VolBadgeImage = BuiltinIcon(BUILTIN_ICON_VOL_INTERNAL);
 426           break;
 427        case DISK_KIND_EXTERNAL:
 428           Volume->VolBadgeImage = BuiltinIcon(BUILTIN_ICON_VOL_EXTERNAL);
 429           break;
 430        case DISK_KIND_OPTICAL:
 431           Volume->VolBadgeImage = BuiltinIcon(BUILTIN_ICON_VOL_OPTICAL);
 432           break;
 433     } // switch()
 434 }
 435
 436 static VOID ScanVolume(IN OUT REFIT_VOLUME *Volume)
 437 {
 438     EFI_STATUS              Status;
 439     EFI_DEVICE_PATH         *DevicePath, *NextDevicePath;
 440     EFI_DEVICE_PATH         *DiskDevicePath, *RemainingDevicePath;
 441     EFI_HANDLE              WholeDiskHandle;
 442     UINTN                   PartialLength;
 443     EFI_FILE_SYSTEM_INFO    *FileSystemInfoPtr;
 444     BOOLEAN                 Bootable;
 445
 446     // get device path
 447     Volume->DevicePath = DuplicateDevicePath(DevicePathFromHandle(Volume->DeviceHandle));
 448 #if REFIT_DEBUG > 0
 449     if (Volume->DevicePath != NULL) {
 450         Print(L"* %s\n", DevicePathToStr(Volume->DevicePath));
 451 #if REFIT_DEBUG >= 2
 452         DumpHex(1, 0, DevicePathSize(Volume->DevicePath), Volume->DevicePath);
 453 #endif
 454     }
 455 #endif
 456
 457     Volume->DiskKind = DISK_KIND_INTERNAL;  // default
 458
 459     // get block i/o
 460     Status = refit_call3_wrapper(BS->HandleProtocol, Volume->DeviceHandle, &BlockIoProtocol, (VOID **) &(Volume->BlockIO));
 461     if (EFI_ERROR(Status)) {
 462         Volume->BlockIO = NULL;
 463         Print(L"Warning: Can't get BlockIO protocol.\n");
 464     } else {
 465         if (Volume->BlockIO->Media->BlockSize == 2048)
 466             Volume->DiskKind = DISK_KIND_OPTICAL;
 467     }
 468
 469     // scan for bootcode and MBR table
 470     Bootable = FALSE;
 471     ScanVolumeBootcode(Volume, &Bootable);
 472
 473     // detect device type
 474     DevicePath = Volume->DevicePath;
 475     while (DevicePath != NULL && !IsDevicePathEndType(DevicePath)) {
 476         NextDevicePath = NextDevicePathNode(DevicePath);
 477
 478         if (DevicePathType(DevicePath) == MESSAGING_DEVICE_PATH &&
 479             (DevicePathSubType(DevicePath) == MSG_USB_DP ||
 480              DevicePathSubType(DevicePath) == MSG_USB_CLASS_DP ||
 481              DevicePathSubType(DevicePath) == MSG_1394_DP ||
 482              DevicePathSubType(DevicePath) == MSG_FIBRECHANNEL_DP))
 483             Volume->DiskKind = DISK_KIND_EXTERNAL;    // USB/FireWire/FC device -> external
 484         if (DevicePathType(DevicePath) == MEDIA_DEVICE_PATH &&
 485             DevicePathSubType(DevicePath) == MEDIA_CDROM_DP) {
 486             Volume->DiskKind = DISK_KIND_OPTICAL;     // El Torito entry -> optical disk
 487             Bootable = TRUE;
 488         }
 489
 490         if (DevicePathType(DevicePath) == MEDIA_DEVICE_PATH && DevicePathSubType(DevicePath) == MEDIA_VENDOR_DP) {
 491             Volume->IsAppleLegacy = TRUE;             // legacy BIOS device entry
 492             // TODO: also check for Boot Camp GUID
 493             Bootable = FALSE;   // this handle's BlockIO is just an alias for the whole device
 494         }
 495
 496         if (DevicePathType(DevicePath) == MESSAGING_DEVICE_PATH) {
 497             // make a device path for the whole device
 498             PartialLength = (UINT8 *)NextDevicePath - (UINT8 *)(Volume->DevicePath);
 499             DiskDevicePath = (EFI_DEVICE_PATH *)AllocatePool(PartialLength + sizeof(EFI_DEVICE_PATH));
 500             CopyMem(DiskDevicePath, Volume->DevicePath, PartialLength);
 501             CopyMem((UINT8 *)DiskDevicePath + PartialLength, EndDevicePath, sizeof(EFI_DEVICE_PATH));
 502
 503             // get the handle for that path
 504             RemainingDevicePath = DiskDevicePath;
 505             //Print(L"  * looking at %s\n", DevicePathToStr(RemainingDevicePath));
 506             Status = refit_call3_wrapper(BS->LocateDevicePath, &BlockIoProtocol, &RemainingDevicePath, &WholeDiskHandle);
 507             //Print(L"  * remaining: %s\n", DevicePathToStr(RemainingDevicePath));
 508             FreePool(DiskDevicePath);
 509
 510             if (!EFI_ERROR(Status)) {
 511                 //Print(L"  - original handle: %08x - disk handle: %08x\n", (UINT32)DeviceHandle, (UINT32)WholeDiskHandle);
 512
 513                 // get the device path for later
 514                 Status = refit_call3_wrapper(BS->HandleProtocol, WholeDiskHandle, &DevicePathProtocol, (VOID **) &DiskDevicePath);
 515                 if (!EFI_ERROR(Status)) {
 516                     Volume->WholeDiskDevicePath = DuplicateDevicePath(DiskDevicePath);
 517                 }
 518
 519                 // look at the BlockIO protocol
 520                 Status = refit_call3_wrapper(BS->HandleProtocol, WholeDiskHandle, &BlockIoProtocol, (VOID **) &Volume->WholeDiskBlockIO);
 521                 if (!EFI_ERROR(Status)) {
 522
 523                     // check the media block size
 524                     if (Volume->WholeDiskBlockIO->Media->BlockSize == 2048)
 525                         Volume->DiskKind = DISK_KIND_OPTICAL;
 526
 527                 } else {
 528                     Volume->WholeDiskBlockIO = NULL;
 529                     //CheckError(Status, L"from HandleProtocol");
 530                 }
 531             } //else
 532               //  CheckError(Status, L"from LocateDevicePath");
 533         }
 534
 535         DevicePath = NextDevicePath;
 536     } // while
 537
 538     if (!Bootable) {
 539 #if REFIT_DEBUG > 0
 540         if (Volume->HasBootCode)
 541             Print(L"  Volume considered non-bootable, but boot code is present\n");
 542 #endif
 543         Volume->HasBootCode = FALSE;
 544     }
 545
 546     // default volume icon based on disk kind
 547     ScanVolumeDefaultIcon(Volume);
 548
 549     // open the root directory of the volume
 550     Volume->RootDir = LibOpenRoot(Volume->DeviceHandle);
 551     if (Volume->RootDir == NULL) {
 552         return;
 553     }
 554
 555     // get volume name
 556     FileSystemInfoPtr = LibFileSystemInfo(Volume->RootDir);
 557     if (FileSystemInfoPtr != NULL) {
 558         Volume->VolName = StrDuplicate(FileSystemInfoPtr->VolumeLabel);
 559         FreePool(FileSystemInfoPtr);
 560     }
 561
 562     // TODO: if no official volume name is found or it is empty, use something else, e.g.:
 563     //   - name from bytes 3 to 10 of the boot sector
 564     //   - partition number
 565     //   - name derived from file system type or partition type
 566
 567     // get custom volume icon if present
 568     if (FileExists(Volume->RootDir, L".VolumeIcon.icns"))
 569         Volume->VolBadgeImage = LoadIcns(Volume->RootDir, L".VolumeIcon.icns", 32);
 570 }
 571
 572 static VOID ScanExtendedPartition(REFIT_VOLUME *WholeDiskVolume, MBR_PARTITION_INFO *MbrEntry)
 573 {
 574     EFI_STATUS              Status;
 575     REFIT_VOLUME            *Volume;
 576     UINT32                  ExtBase, ExtCurrent, NextExtCurrent;
 577     UINTN                   i;
 578     UINTN                   LogicalPartitionIndex = 4;
 579     UINT8                   SectorBuffer[512];
 580     BOOLEAN                 Bootable;
 581     MBR_PARTITION_INFO      *EMbrTable;
 582
 583     ExtBase = MbrEntry->StartLBA;
 584
 585     for (ExtCurrent = ExtBase; ExtCurrent; ExtCurrent = NextExtCurrent) {
 586         // read current EMBR
 587       Status = refit_call5_wrapper(WholeDiskVolume->BlockIO->ReadBlocks,
 588                                    WholeDiskVolume->BlockIO,
 589                                    WholeDiskVolume->BlockIO->Media->MediaId,
 590                                    ExtCurrent, 512, SectorBuffer);
 591         if (EFI_ERROR(Status))
 592             break;
 593         if (*((UINT16 *)(SectorBuffer + 510)) != 0xaa55)
 594             break;
 595         EMbrTable = (MBR_PARTITION_INFO *)(SectorBuffer + 446);
 596
 597         // scan logical partitions in this EMBR
 598         NextExtCurrent = 0;
 599         for (i = 0; i < 4; i++) {
 600             if ((EMbrTable[i].Flags != 0x00 && EMbrTable[i].Flags != 0x80) ||
 601                 EMbrTable[i].StartLBA == 0 || EMbrTable[i].Size == 0)
 602                 break;
 603             if (IS_EXTENDED_PART_TYPE(EMbrTable[i].Type)) {
 604                 // set next ExtCurrent
 605                 NextExtCurrent = ExtBase + EMbrTable[i].StartLBA;
 606                 break;
 607             } else {
 608
 609                 // found a logical partition
 610                 Volume = AllocateZeroPool(sizeof(REFIT_VOLUME));
 611                 Volume->DiskKind = WholeDiskVolume->DiskKind;
 612                 Volume->IsMbrPartition = TRUE;
 613                 Volume->MbrPartitionIndex = LogicalPartitionIndex++;
 614                 Volume->VolName = PoolPrint(L"Partition %d", Volume->MbrPartitionIndex + 1);
 615                 Volume->BlockIO = WholeDiskVolume->BlockIO;
 616                 Volume->BlockIOOffset = ExtCurrent + EMbrTable[i].StartLBA;
 617                 Volume->WholeDiskBlockIO = WholeDiskVolume->BlockIO;
 618
 619                 Bootable = FALSE;
 620                 ScanVolumeBootcode(Volume, &Bootable);
 621                 if (!Bootable)
 622                     Volume->HasBootCode = FALSE;
 623
 624                 ScanVolumeDefaultIcon(Volume);
 625
 626                 AddListElement((VOID ***) &Volumes, &VolumesCount, Volume);
 627
 628             }
 629         }
 630     }
 631 }
 632
 633 VOID ScanVolumes(VOID)
 634 {
 635     EFI_STATUS              Status;
 636     UINTN                   HandleCount = 0;
 637     UINTN                   HandleIndex;
 638     EFI_HANDLE              *Handles;
 639     REFIT_VOLUME            *Volume, *WholeDiskVolume;
 640     UINTN                   VolumeIndex, VolumeIndex2;
 641     MBR_PARTITION_INFO      *MbrTable;
 642     UINTN                   PartitionIndex;
 643     UINT8                   *SectorBuffer1, *SectorBuffer2;
 644     UINTN                   SectorSum, i;
 645
 646     FreePool(Volumes);
 647     Volumes = NULL;
 648     VolumesCount = 0;
 649
 650     // get all filesystem handles
 651     Status = LibLocateHandle(ByProtocol, &BlockIoProtocol, NULL, &HandleCount, &Handles);
 652     // was: &FileSystemProtocol
 653     if (Status == EFI_NOT_FOUND)
 654         return;  // no filesystems. strange, but true...
 655     if (CheckError(Status, L"while listing all file systems"))
 656         return;
 657
 658     // first pass: collect information about all handles
 659     for (HandleIndex = 0; HandleIndex < HandleCount; HandleIndex++) {
 660         Volume = AllocateZeroPool(sizeof(REFIT_VOLUME));
 661         Volume->DeviceHandle = Handles[HandleIndex];
 662         ScanVolume(Volume);
 663
 664         AddListElement((VOID ***) &Volumes, &VolumesCount, Volume);
 665
 666         if (Volume->DeviceHandle == SelfLoadedImage->DeviceHandle)
 667             SelfVolume = Volume;
 668     }
 669     FreePool(Handles);
 670
 671     if (SelfVolume == NULL)
 672         Print(L"WARNING: SelfVolume not found");
 673
 674     // second pass: relate partitions and whole disk devices
 675     for (VolumeIndex = 0; VolumeIndex < VolumesCount; VolumeIndex++) {
 676         Volume = Volumes[VolumeIndex];
 677         // check MBR partition table for extended partitions
 678         if (Volume->BlockIO != NULL && Volume->WholeDiskBlockIO != NULL &&
 679             Volume->BlockIO == Volume->WholeDiskBlockIO && Volume->BlockIOOffset == 0 &&
 680             Volume->MbrPartitionTable != NULL) {
 681             MbrTable = Volume->MbrPartitionTable;
 682             for (PartitionIndex = 0; PartitionIndex < 4; PartitionIndex++) {
 683                 if (IS_EXTENDED_PART_TYPE(MbrTable[PartitionIndex].Type)) {
 684                    ScanExtendedPartition(Volume, MbrTable + PartitionIndex);
 685                 }
 686             }
 687         }
 688
 689         // search for corresponding whole disk volume entry
 690         WholeDiskVolume = NULL;
 691         if (Volume->BlockIO != NULL && Volume->WholeDiskBlockIO != NULL &&
 692             Volume->BlockIO != Volume->WholeDiskBlockIO) {
 693             for (VolumeIndex2 = 0; VolumeIndex2 < VolumesCount; VolumeIndex2++) {
 694                 if (Volumes[VolumeIndex2]->BlockIO == Volume->WholeDiskBlockIO &&
 695                     Volumes[VolumeIndex2]->BlockIOOffset == 0)
 696                     WholeDiskVolume = Volumes[VolumeIndex2];
 697             }
 698         }
 699
 700         if (WholeDiskVolume != NULL && WholeDiskVolume->MbrPartitionTable != NULL) {
 701             // check if this volume is one of the partitions in the table
 702             MbrTable = WholeDiskVolume->MbrPartitionTable;
 703             SectorBuffer1 = AllocatePool(512);
 704             SectorBuffer2 = AllocatePool(512);
 705             for (PartitionIndex = 0; PartitionIndex < 4; PartitionIndex++) {
 706                 // check size
 707                 if ((UINT64)(MbrTable[PartitionIndex].Size) != Volume->BlockIO->Media->LastBlock + 1)
 708                     continue;
 709
 710                 // compare boot sector read through offset vs. directly
 711                 Status = refit_call5_wrapper(Volume->BlockIO->ReadBlocks,
 712                                              Volume->BlockIO, Volume->BlockIO->Media->MediaId,
 713                                              Volume->BlockIOOffset, 512, SectorBuffer1);
 714                 if (EFI_ERROR(Status))
 715                     break;
 716                 Status = refit_call5_wrapper(Volume->WholeDiskBlockIO->ReadBlocks,
 717                                              Volume->WholeDiskBlockIO, Volume->WholeDiskBlockIO->Media->MediaId,
 718                                              MbrTable[PartitionIndex].StartLBA, 512, SectorBuffer2);
 719                 if (EFI_ERROR(Status))
 720                     break;
 721                 if (CompareMem(SectorBuffer1, SectorBuffer2, 512) != 0)
 722                     continue;
 723                 SectorSum = 0;
 724                 for (i = 0; i < 512; i++)
 725                     SectorSum += SectorBuffer1[i];
 726                 if (SectorSum < 1000)
 727                     continue;
 728
 729                 // TODO: mark entry as non-bootable if it is an extended partition
 730
 731                 // now we're reasonably sure the association is correct...
 732                 Volume->IsMbrPartition = TRUE;
 733                 Volume->MbrPartitionIndex = PartitionIndex;
 734                 if (Volume->VolName == NULL)
 735                     Volume->VolName = PoolPrint(L"Partition %d", PartitionIndex + 1);
 736                 break;
 737             }
 738
 739             FreePool(SectorBuffer1);
 740             FreePool(SectorBuffer2);
 741         }
 742
 743     }
 744 } /* VOID ScanVolumes() */
 745
 746 static VOID UninitVolumes(VOID)
 747 {
 748     REFIT_VOLUME            *Volume;
 749     UINTN                   VolumeIndex;
 750
 751     for (VolumeIndex = 0; VolumeIndex < VolumesCount; VolumeIndex++) {
 752         Volume = Volumes[VolumeIndex];
 753
 754         if (Volume->RootDir != NULL) {
 755             refit_call1_wrapper(Volume->RootDir->Close, Volume->RootDir);
 756             Volume->RootDir = NULL;
 757         }
 758
 759         Volume->DeviceHandle = NULL;
 760         Volume->BlockIO = NULL;
 761         Volume->WholeDiskBlockIO = NULL;
 762     }
 763 }
 764
 765 VOID ReinitVolumes(VOID)
 766 {
 767     EFI_STATUS              Status;
 768     REFIT_VOLUME            *Volume;
 769     UINTN                   VolumeIndex;
 770     EFI_DEVICE_PATH         *RemainingDevicePath;
 771     EFI_HANDLE              DeviceHandle, WholeDiskHandle;
 772
 773     for (VolumeIndex = 0; VolumeIndex < VolumesCount; VolumeIndex++) {
 774         Volume = Volumes[VolumeIndex];
 775
 776         if (Volume->DevicePath != NULL) {
 777             // get the handle for that path
 778             RemainingDevicePath = Volume->DevicePath;
 779             Status = refit_call3_wrapper(BS->LocateDevicePath, &BlockIoProtocol, &RemainingDevicePath, &DeviceHandle);
 780
 781             if (!EFI_ERROR(Status)) {
 782                 Volume->DeviceHandle = DeviceHandle;
 783
 784                 // get the root directory
 785                 Volume->RootDir = LibOpenRoot(Volume->DeviceHandle);
 786
 787             } else
 788                 CheckError(Status, L"from LocateDevicePath");
 789         }
 790
 791         if (Volume->WholeDiskDevicePath != NULL) {
 792             // get the handle for that path
 793             RemainingDevicePath = Volume->WholeDiskDevicePath;
 794             Status = refit_call3_wrapper(BS->LocateDevicePath, &BlockIoProtocol, &RemainingDevicePath, &WholeDiskHandle);
 795
 796             if (!EFI_ERROR(Status)) {
 797                 // get the BlockIO protocol
 798                 Status = refit_call3_wrapper(BS->HandleProtocol, WholeDiskHandle, &BlockIoProtocol, (VOID **) &Volume->WholeDiskBlockIO);
 799                 if (EFI_ERROR(Status)) {
 800                     Volume->WholeDiskBlockIO = NULL;
 801                     CheckError(Status, L"from HandleProtocol");
 802                 }
 803             } else
 804                 CheckError(Status, L"from LocateDevicePath");
 805         }
 806     }
 807 }
 808
 809 //
 810 // file and dir functions
 811 //
 812
 813 BOOLEAN FileExists(IN EFI_FILE *BaseDir, IN CHAR16 *RelativePath)
 814 {
 815     EFI_STATUS         Status;
 816     EFI_FILE_HANDLE    TestFile;
 817
 818     Status = refit_call5_wrapper(BaseDir->Open, BaseDir, &TestFile, RelativePath, EFI_FILE_MODE_READ, 0);
 819     if (Status == EFI_SUCCESS) {
 820         refit_call1_wrapper(TestFile->Close, TestFile);
 821         return TRUE;
 822     }
 823     return FALSE;
 824 }
 825
 826 EFI_STATUS DirNextEntry(IN EFI_FILE *Directory, IN OUT EFI_FILE_INFO **DirEntry, IN UINTN FilterMode)
 827 {
 828     EFI_STATUS Status;
 829     VOID *Buffer;
 830     UINTN LastBufferSize, BufferSize;
 831     INTN IterCount;
 832
 833     for (;;) {
 834
 835         // free pointer from last call
 836         if (*DirEntry != NULL) {
 837             FreePool(*DirEntry);
 838             *DirEntry = NULL;
 839         }
 840
 841         // read next directory entry
 842         LastBufferSize = BufferSize = 256;
 843         Buffer = AllocatePool(BufferSize);
 844         for (IterCount = 0; ; IterCount++) {
 845             Status = refit_call3_wrapper(Directory->Read, Directory, &BufferSize, Buffer);
 846             if (Status != EFI_BUFFER_TOO_SMALL || IterCount >= 4)
 847                 break;
 848             if (BufferSize <= LastBufferSize) {
 849                 Print(L"FS Driver requests bad buffer size %d (was %d), using %d instead\n", BufferSize, LastBufferSize, LastBufferSize * 2);
 850                 BufferSize = LastBufferSize * 2;
 851 #if REFIT_DEBUG > 0
 852             } else {
 853                 Print(L"Reallocating buffer from %d to %d\n", LastBufferSize, BufferSize);
 854 #endif
 855             }
 856             Buffer = ReallocatePool(Buffer, LastBufferSize, BufferSize);
 857             LastBufferSize = BufferSize;
 858         }
 859         if (EFI_ERROR(Status)) {
 860             FreePool(Buffer);
 861             break;
 862         }
 863
 864         // check for end of listing
 865         if (BufferSize == 0) {    // end of directory listing
 866             FreePool(Buffer);
 867             break;
 868         }
 869
 870         // entry is ready to be returned
 871         *DirEntry = (EFI_FILE_INFO *)Buffer;
 872
 873         // filter results
 874         if (FilterMode == 1) {   // only return directories
 875             if (((*DirEntry)->Attribute & EFI_FILE_DIRECTORY))
 876                 break;
 877         } else if (FilterMode == 2) {   // only return files
 878             if (((*DirEntry)->Attribute & EFI_FILE_DIRECTORY) == 0)
 879                 break;
 880         } else                   // no filter or unknown filter -> return everything
 881             break;
 882
 883     }
 884     return Status;
 885 }
 886
 887 VOID DirIterOpen(IN EFI_FILE *BaseDir, IN CHAR16 *RelativePath OPTIONAL, OUT REFIT_DIR_ITER *DirIter)
 888 {
 889     if (RelativePath == NULL) {
 890         DirIter->LastStatus = EFI_SUCCESS;
 891         DirIter->DirHandle = BaseDir;
 892         DirIter->CloseDirHandle = FALSE;
 893     } else {
 894         DirIter->LastStatus = refit_call5_wrapper(BaseDir->Open, BaseDir, &(DirIter->DirHandle), RelativePath, EFI_FILE_MODE_READ, 0);
 895         DirIter->CloseDirHandle = EFI_ERROR(DirIter->LastStatus) ? FALSE : TRUE;
 896     }
 897     DirIter->LastFileInfo = NULL;
 898 }
 899
 900 BOOLEAN DirIterNext(IN OUT REFIT_DIR_ITER *DirIter, IN UINTN FilterMode, IN CHAR16 *FilePattern OPTIONAL,
 901                     OUT EFI_FILE_INFO **DirEntry)
 902 {
 903     if (DirIter->LastFileInfo != NULL) {
 904         FreePool(DirIter->LastFileInfo);
 905         DirIter->LastFileInfo = NULL;
 906     }
 907
 908     if (EFI_ERROR(DirIter->LastStatus))
 909         return FALSE;   // stop iteration
 910
 911     for (;;) {
 912         DirIter->LastStatus = DirNextEntry(DirIter->DirHandle, &(DirIter->LastFileInfo), FilterMode);
 913         if (EFI_ERROR(DirIter->LastStatus))
 914             return FALSE;
 915         if (DirIter->LastFileInfo == NULL)  // end of listing
 916             return FALSE;
 917         if (FilePattern != NULL) {
 918             if ((DirIter->LastFileInfo->Attribute & EFI_FILE_DIRECTORY))
 919                 break;
 920             if (MetaiMatch(DirIter->LastFileInfo->FileName, FilePattern))
 921                 break;
 922             // else continue loop
 923         } else
 924             break;
 925     }
 926
 927     *DirEntry = DirIter->LastFileInfo;
 928     return TRUE;
 929 }
 930
 931 EFI_STATUS DirIterClose(IN OUT REFIT_DIR_ITER *DirIter)
 932 {
 933     if (DirIter->LastFileInfo != NULL) {
 934         FreePool(DirIter->LastFileInfo);
 935         DirIter->LastFileInfo = NULL;
 936     }
 937     if (DirIter->CloseDirHandle)
 938         refit_call1_wrapper(DirIter->DirHandle->Close, DirIter->DirHandle);
 939     return DirIter->LastStatus;
 940 }
 941
 942 //
 943 // file name manipulation
 944 //
 945
 946 // Returns the filename portion (minus path name) of the
 947 // specified file
 948 CHAR16 * Basename(IN CHAR16 *Path)
 949 {
 950     CHAR16  *FileName;
 951     UINTN   i;
 952
 953     FileName = Path;
 954
 955     if (Path != NULL) {
 956         for (i = StrLen(Path); i > 0; i--) {
 957             if (Path[i-1] == '\\' || Path[i-1] == '/') {
 958                 FileName = Path + i;
 959                 break;
 960             }
 961         }
 962     }
 963
 964     return FileName;
 965 }
 966
 967 VOID ReplaceExtension(IN OUT CHAR16 *Path, IN CHAR16 *Extension)
 968 {
 969     UINTN i;
 970
 971     for (i = StrLen(Path); i >= 0; i--) {
 972         if (Path[i] == '.') {
 973             Path[i] = 0;
 974             break;
 975         }
 976         if (Path[i] == '\\' || Path[i] == '/')
 977             break;
 978     }
 979     StrCat(Path, Extension);
 980 }
 981
 982 //
 983 // memory string search
 984 //
 985
 986 INTN FindMem(IN VOID *Buffer, IN UINTN BufferLength, IN VOID *SearchString, IN UINTN SearchStringLength)
 987 {
 988     UINT8 *BufferPtr;
 989     UINTN Offset;
 990
 991     BufferPtr = Buffer;
 992     BufferLength -= SearchStringLength;
 993     for (Offset = 0; Offset < BufferLength; Offset++, BufferPtr++) {
 994         if (CompareMem(BufferPtr, SearchString, SearchStringLength) == 0)
 995             return (INTN)Offset;
 996     }
 997
 998     return -1;
 999 }
1000
1001 // Performs a case-insensitive search of BigStr for SmallStr.
1002 // Returns TRUE if found, FALSE if not.
1003 BOOLEAN StriSubCmp(IN CHAR16 *SmallStr, IN CHAR16 *BigStr) {
1004    CHAR16 *SmallCopy, *BigCopy;
1005    BOOLEAN Found = FALSE;
1006    UINTN StartPoint = 0, NumCompares = 0, SmallLen = 0;
1007
1008    if ((SmallStr != NULL) && (BigStr != NULL) && (StrLen(BigStr) >= StrLen(SmallStr))) {
1009       SmallCopy = StrDuplicate(SmallStr);
1010       BigCopy = StrDuplicate(BigStr);
1011       StrLwr(SmallCopy);
1012       StrLwr(BigCopy);
1013       SmallLen = StrLen(SmallCopy);
1014       NumCompares = StrLen(BigCopy) - SmallLen + 1;
1015       while ((!Found) && (StartPoint < NumCompares)) {
1016          Found = (StrnCmp(SmallCopy, &BigCopy[StartPoint++], SmallLen) == 0);
1017       } // while
1018       FreePool(SmallCopy);
1019       FreePool(BigCopy);
1020    } // if
1021
1022    return (Found);
1023 } // BOOLEAN StriSubCmp()
1024
1025 // Merges two strings, creating a new one and returning a pointer to it.
1026 // If AddChar != 0, the specified character is placed between the two original
1027 // strings (unless the first string is NULL). The original input string
1028 // *First is de-allocated and replaced by the new merged string.
1029 // This is similar to StrCat, but safer and more flexible because
1030 // MergeStrings allocates memory that's the correct size for the
1031 // new merged string, so it can take a NULL *First and it cleans
1032 // up the old memory. It should *NOT* be used with a constant
1033 // *First, though....
1034 VOID MergeStrings(IN OUT CHAR16 **First, IN CHAR16 *Second, CHAR16 AddChar) {
1035    UINTN Length1 = 0, Length2 = 0;
1036    CHAR16* NewString;
1037
1038    if (*First != NULL)
1039       Length1 = StrLen(*First);
1040    if (Second != NULL)
1041       Length2 = StrLen(Second);
1042    NewString = AllocatePool(sizeof(CHAR16) * (Length1 + Length2 + 2));
1043    NewString[0] = 0;
1044    if (NewString != NULL) {
1045       if (*First != NULL) {
1046          StrCat(NewString, *First);
1047          if (AddChar) {
1048             NewString[Length1] = AddChar;
1049             NewString[Length1 + 1] = 0;
1050          } // if (AddChar)
1051       } // if (*First != NULL)
1052       if (First != NULL)
1053          StrCat(NewString, Second);
1054       FreePool(*First);
1055       *First = NewString;
1056    } else {
1057       Print(L"Error! Unable to allocate memory in MergeStrings()!\n");
1058    } // if/else
1059 } // static CHAR16* MergeStrings()
1060
1061 // Takes an input pathname (*Path) and locates the final directory component
1062 // of that name. For instance, if the input path is 'EFI\foo\bar.efi', this
1063 // function returns the string 'foo'.
1064 // Assumes the pathname is separated with backslashes.
1065 CHAR16 *FindLastDirName(IN CHAR16 *Path) {
1066    UINTN i, StartOfElement = 0, EndOfElement = 0, PathLength, CopyLength;
1067    CHAR16 *Found = NULL;
1068
1069    PathLength = StrLen(Path);
1070    // Find start & end of target element
1071    for (i = 0; i < PathLength; i++) {
1072       if (Path[i] == '\\') {
1073          StartOfElement = EndOfElement;
1074          EndOfElement = i;
1075       } // if
1076    } // for
1077    // Extract the target element
1078    if (EndOfElement > 0) {
1079       while ((StartOfElement < PathLength) && (Path[StartOfElement] == '\\')) {
1080          StartOfElement++;
1081       } // while
1082       EndOfElement--;
1083       if (EndOfElement >= StartOfElement) {
1084          CopyLength = EndOfElement - StartOfElement + 1;
1085          Found = StrDuplicate(&Path[StartOfElement]);
1086          if (Found != NULL)
1087             Found[CopyLength] = 0;
1088       } // if (EndOfElement >= StartOfElement)
1089    } // if (EndOfElement > 0)
1090    return (Found);
1091 } // CHAR16 *FindLastDirName
1092
1093 // Returns the directory portion of a pathname. For instance,
1094 // if FullPath is 'EFI\foo\bar.efi', this function returns the
1095 // string 'EFI\foo'.
1096 CHAR16 *FindPath(IN CHAR16* FullPath) {
1097    UINTN i, LastBackslash = 0;
1098    CHAR16 *PathOnly;
1099
1100    for (i = 0; i < StrLen(FullPath); i++) {
1101       if (FullPath[i] == '\\')
1102          LastBackslash = i;
1103    } // for
1104    PathOnly = StrDuplicate(FullPath);
1105    PathOnly[LastBackslash] = 0;
1106    return (PathOnly);
1107 }
1108
1109 // Returns all the digits in the input string, including intervening
1110 // non-digit characters. For instance, if InString is "foo-3.3.4-7.img",
1111 // this function returns "3.3.4-7". If InString contains no digits,
1112 // the return value is NULL.
1113 CHAR16 *FindNumbers(IN CHAR16 *InString) {
1114    UINTN i, StartOfElement, EndOfElement = 0, InLength, CopyLength;
1115    CHAR16 *Found = NULL;
1116
1117    InLength = StartOfElement = StrLen(InString);
1118    // Find start & end of target element
1119    for (i = 0; i < InLength; i++) {
1120       if ((InString[i] >= '0') && (InString[i] <= '9')) {
1121          if (StartOfElement > i)
1122             StartOfElement = i;
1123          if (EndOfElement < i)
1124             EndOfElement = i;
1125       } // if
1126    } // for
1127    // Extract the target element
1128    if (EndOfElement > 0) {
1129       if (EndOfElement >= StartOfElement) {
1130          CopyLength = EndOfElement - StartOfElement + 1;
1131          Found = StrDuplicate(&InString[StartOfElement]);
1132          if (Found != NULL)
1133             Found[CopyLength] = 0;
1134       } // if (EndOfElement >= StartOfElement)
1135    } // if (EndOfElement > 0)
1136    return (Found);
1137 } // CHAR16 *FindNumbers()
1138
1139 // Find the #Index element (numbered from 0) in a comma-delimited string
1140 // of elements.
1141 // Returns the found element, or NULL if Index is out of range of InString
1142 // is NULL.
1143 CHAR16 *FindCommaDelimited(IN CHAR16 *InString, IN UINTN Index) {
1144    UINTN    StartPos = 0, CurPos = 0;
1145    BOOLEAN  Found = FALSE;
1146    CHAR16   *FoundString = NULL;
1147
1148    if (InString != NULL) {
1149       // After while() loop, StartPos marks start of item #Index
1150       while ((Index > 0) && (CurPos < StrLen(InString))) {
1151          if (InString[CurPos] == L',') {
1152             Index--;
1153             StartPos = CurPos + 1;
1154          } // if
1155          CurPos++;
1156       } // while
1157       // After while() loop, CurPos is one past the end of the element
1158       while ((CurPos < StrLen(InString)) && (!Found)) {
1159          if (InString[CurPos] == L',')
1160             Found = TRUE;
1161          else
1162             CurPos++;
1163       } // while
1164    } // if
1165    if (Index == 0)
1166       FoundString = StrDuplicate(&InString[StartPos]);
1167    if (FoundString != NULL)
1168       FoundString[CurPos - StartPos] = 0;
1169    return (FoundString);
1170 } // CHAR16 *FindCommaDelimited()