Added new fold_linux_kernels option, which combines Linux kernels in a

[refind] / refind / config.c

/*
 * refind/config.c
 * Configuration file functions
 *
 * Copyright (c) 2006 Christoph Pfisterer
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the
 *    distribution.
 *
 *  * Neither the name of Christoph Pfisterer nor the names of the
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Modifications copyright (c) 2012-2015 Roderick W. Smith
 * 
 * Modifications distributed under the terms of the GNU General Public
 * License (GPL) version 3 (GPLv3), a copy of which must be distributed
 * with this source code or binaries made from it.
 * 
 */

#include "global.h"
#include "lib.h"
#include "icns.h"
#include "menu.h"
#include "config.h"
#include "screen.h"
#include "../include/refit_call_wrapper.h"
#include "../mok/mok.h"

// constants

#define LINUX_OPTIONS_FILENAMES  L"refind_linux.conf,refind-linux.conf"
#define MAXCONFIGFILESIZE        (128*1024)

#define ENCODING_ISO8859_1  (0)
#define ENCODING_UTF8       (1)
#define ENCODING_UTF16_LE   (2)

#define GetTime ST->RuntimeServices->GetTime
#define LAST_MINUTE 1439 /* Last minute of a day */

extern REFIT_MENU_ENTRY MenuEntryReturn;
//static REFIT_MENU_ENTRY MenuEntryReturn   = { L"Return to Main Menu", TAG_RETURN, 0, 0, 0, NULL, NULL, NULL };

//
// read a file into a buffer
//

EFI_STATUS ReadFile(IN EFI_FILE_HANDLE BaseDir, IN CHAR16 *FileName, IN OUT REFIT_FILE *File, OUT UINTN *size)
{
    EFI_STATUS      Status;
    EFI_FILE_HANDLE FileHandle;
    EFI_FILE_INFO   *FileInfo;
    UINT64          ReadSize;
    CHAR16          Message[256];

    File->Buffer = NULL;
    File->BufferSize = 0;

    // read the file, allocating a buffer on the way
    Status = refit_call5_wrapper(BaseDir->Open, BaseDir, &FileHandle, FileName, EFI_FILE_MODE_READ, 0);
    SPrint(Message, 255, L"while loading the file '%s'", FileName);
    if (CheckError(Status, Message))
        return Status;

    FileInfo = LibFileInfo(FileHandle);
    if (FileInfo == NULL) {
        // TODO: print and register the error
        refit_call1_wrapper(FileHandle->Close, FileHandle);
        return EFI_LOAD_ERROR;
    }
    ReadSize = FileInfo->FileSize;
    FreePool(FileInfo);

    File->BufferSize = (UINTN)ReadSize;
    File->Buffer = AllocatePool(File->BufferSize);
    if (File->Buffer == NULL) {
       size = 0;
       return EFI_OUT_OF_RESOURCES;
    } else {
       *size = File->BufferSize;
    } // if/else
    Status = refit_call3_wrapper(FileHandle->Read, FileHandle, &File->BufferSize, File->Buffer);
    if (CheckError(Status, Message)) {
        MyFreePool(File->Buffer);
        File->Buffer = NULL;
        refit_call1_wrapper(FileHandle->Close, FileHandle);
        return Status;
    }
    Status = refit_call1_wrapper(FileHandle->Close, FileHandle);

    // setup for reading
    File->Current8Ptr  = (CHAR8 *)File->Buffer;
    File->End8Ptr      = File->Current8Ptr + File->BufferSize;
    File->Current16Ptr = (CHAR16 *)File->Buffer;
    File->End16Ptr     = File->Current16Ptr + (File->BufferSize >> 1);

    // detect encoding
    File->Encoding = ENCODING_ISO8859_1;   // default: 1:1 translation of CHAR8 to CHAR16
    if (File->BufferSize >= 4) {
        if (File->Buffer[0] == 0xFF && File->Buffer[1] == 0xFE) {
            // BOM in UTF-16 little endian (or UTF-32 little endian)
            File->Encoding = ENCODING_UTF16_LE;   // use CHAR16 as is
            File->Current16Ptr++;
        } else if (File->Buffer[0] == 0xEF && File->Buffer[1] == 0xBB && File->Buffer[2] == 0xBF) {
            // BOM in UTF-8
            File->Encoding = ENCODING_UTF8;       // translate from UTF-8 to UTF-16
            File->Current8Ptr += 3;
        } else if (File->Buffer[1] == 0 && File->Buffer[3] == 0) {
            File->Encoding = ENCODING_UTF16_LE;   // use CHAR16 as is
        }
        // TODO: detect other encodings as they are implemented
    }

    return EFI_SUCCESS;
}

//
// get a single line of text from a file
//

static CHAR16 *ReadLine(REFIT_FILE *File)
{
    CHAR16  *Line, *q;
    UINTN   LineLength;

    if (File->Buffer == NULL)
        return NULL;

    if (File->Encoding == ENCODING_ISO8859_1 || File->Encoding == ENCODING_UTF8) {

        CHAR8 *p, *LineStart, *LineEnd;

        p = File->Current8Ptr;
        if (p >= File->End8Ptr)
            return NULL;

        LineStart = p;
        for (; p < File->End8Ptr; p++)
            if (*p == 13 || *p == 10)
                break;
        LineEnd = p;
        for (; p < File->End8Ptr; p++)
            if (*p != 13 && *p != 10)
                break;
        File->Current8Ptr = p;

        LineLength = (UINTN)(LineEnd - LineStart) + 1;
        Line = AllocatePool(LineLength * sizeof(CHAR16));
        if (Line == NULL)
            return NULL;

        q = Line;
        if (File->Encoding == ENCODING_ISO8859_1) {
            for (p = LineStart; p < LineEnd; )
                *q++ = *p++;
        } else if (File->Encoding == ENCODING_UTF8) {
            // TODO: actually handle UTF-8
            for (p = LineStart; p < LineEnd; )
                *q++ = *p++;
        }
        *q = 0;

    } else if (File->Encoding == ENCODING_UTF16_LE) {

        CHAR16 *p, *LineStart, *LineEnd;

        p = File->Current16Ptr;
        if (p >= File->End16Ptr)
            return NULL;

        LineStart = p;
        for (; p < File->End16Ptr; p++)
            if (*p == 13 || *p == 10)
                break;
        LineEnd = p;
        for (; p < File->End16Ptr; p++)
            if (*p != 13 && *p != 10)
                break;
        File->Current16Ptr = p;

        LineLength = (UINTN)(LineEnd - LineStart) + 1;
        Line = AllocatePool(LineLength * sizeof(CHAR16));
        if (Line == NULL)
            return NULL;

        for (p = LineStart, q = Line; p < LineEnd; )
            *q++ = *p++;
        *q = 0;

    } else
        return NULL;   // unsupported encoding

    return Line;
}

// Returns FALSE if *p points to the end of a token, TRUE otherwise.
// Also modifies *p **IF** the first and second characters are both
// quotes ('"'); it deletes one of them.
static BOOLEAN KeepReading(IN OUT CHAR16 *p, IN OUT BOOLEAN *IsQuoted) {
   BOOLEAN MoreToRead = FALSE;
   CHAR16  *Temp = NULL;

   if ((p == NULL) || (IsQuoted == NULL))
      return FALSE;

   if (*p == L'\0')
      return FALSE;

   if ((*p != ' ' && *p != '\t' && *p != '=' && *p != '#' && *p != ',') || *IsQuoted) {
      MoreToRead = TRUE;
   }
   if (*p == L'"') {
      if (p[1] == L'"') {
         Temp = StrDuplicate(&p[1]);
         if (Temp != NULL) {
            StrCpy(p, Temp);
            FreePool(Temp);
         }
         MoreToRead = TRUE;
      } else {
         *IsQuoted = !(*IsQuoted);
         MoreToRead = FALSE;
      } // if/else second character is a quote
   } // if first character is a quote

   return MoreToRead;
} // BOOLEAN KeepReading()

//
// get a line of tokens from a file
//
UINTN ReadTokenLine(IN REFIT_FILE *File, OUT CHAR16 ***TokenList)
{
    BOOLEAN         LineFinished, IsQuoted = FALSE;
    CHAR16          *Line, *Token, *p;
    UINTN           TokenCount = 0;

    *TokenList = NULL;

    while (TokenCount == 0) {
        Line = ReadLine(File);
        if (Line == NULL)
            return(0);
        if (Line[0] == L'\0') {
            MyFreePool(Line);
            return(0);
        } // if

        p = Line;
        LineFinished = FALSE;
        while (!LineFinished) {
            // skip whitespace & find start of token
            while ((*p == ' ' || *p == '\t' || *p == '=' || *p == ',') && !IsQuoted)
                p++;
            if (*p == 0 || *p == '#')
                break;

            if (*p == '"') {
               IsQuoted = !IsQuoted;
               p++;
            } // if
            Token = p;

            // find end of token
            while (KeepReading(p, &IsQuoted)) {
               if ((*p == L'/') && !IsQuoted) // Switch Unix-style to DOS-style directory separators
                  *p = L'\\';
               p++;
            } // while
            if (*p == L'\0' || *p == L'#')
                LineFinished = TRUE;
            *p++ = 0;

            AddListElement((VOID ***)TokenList, &TokenCount, (VOID *)StrDuplicate(Token));
        }

        FreePool(Line);
    }
    return (TokenCount);
} /* ReadTokenLine() */

VOID FreeTokenLine(IN OUT CHAR16 ***TokenList, IN OUT UINTN *TokenCount)
{
    // TODO: also free the items
    FreeList((VOID ***)TokenList, TokenCount);
}

// handle a parameter with a single integer argument
static VOID HandleInt(IN CHAR16 **TokenList, IN UINTN TokenCount, OUT UINTN *Value)
{
    if (TokenCount == 2) {
       if (StriCmp(TokenList[1], L"-1") == 0)
          *Value = -1;
       else
          *Value = Atoi(TokenList[1]);
    }
}

// handle a parameter with a single string argument
static VOID HandleString(IN CHAR16 **TokenList, IN UINTN TokenCount, OUT CHAR16 **Target) {
   if ((TokenCount == 2) && Target) {
      if ((StrLen(TokenList[1]) > 1) && (TokenList[1][0] == L'+') &&
          ((TokenList[1][1] == L',') || (TokenList[1][1] == L' '))) {
         if (*Target) {
            MergeStrings(Target, TokenList[1] + 2, L',');
         } else {
            *Target = StrDuplicate(TokenList[1] + 2);
         } // if/else
      } else {
         MyFreePool(*Target);
         *Target = StrDuplicate(TokenList[1]);
      } // if/else
   } // if
} // static VOID HandleString()

// Handle a parameter with a series of string arguments, to replace or be added to a
// comma-delimited list. Passes each token through the CleanUpPathNameSlashes() function
// to ensure consistency in subsequent comparisons of filenames. If the first
// non-keyword token is "+", the list is added to the existing target string; otherwise,
// the tokens replace the current string.
static VOID HandleStrings(IN CHAR16 **TokenList, IN UINTN TokenCount, OUT CHAR16 **Target) {
   UINTN i;
   BOOLEAN AddMode = FALSE;

   if ((TokenCount > 2) && (StriCmp(TokenList[1], L"+") == 0)) {
      AddMode = TRUE;
   }

   if ((*Target != NULL) && !AddMode) {
      FreePool(*Target);
      *Target = NULL;
   } // if
   for (i = 1; i < TokenCount; i++) {
      if ((i != 1) || !AddMode) {
         CleanUpPathNameSlashes(TokenList[i]);
         MergeStrings(Target, TokenList[i], L',');
      } // if
   } // for
} // static VOID HandleStrings()

// Convert TimeString (in "HH:MM" format) to a pure-minute format. Values should be
// in the range from 0 (for 00:00, or midnight) to 1439 (for 23:59; aka LAST_MINUTE).
// Any value outside that range denotes an error in the specification. Note that if
// the input is a number that includes no colon, this function will return the original
// number in UINTN form.
static UINTN HandleTime(IN CHAR16 *TimeString) {
   UINTN Hour = 0, Minute = 0, TimeLength, i = 0;

   TimeLength = StrLen(TimeString);
   while (i < TimeLength) {
      if (TimeString[i] == L':') {
         Hour = Minute;
         Minute = 0;
      } // if
      if ((TimeString[i] >= L'0') && (TimeString[i] <= '9')) {
         Minute *= 10;
         Minute += (TimeString[i] - L'0');
      } // if
      i++;
   } // while
   return (Hour * 60 + Minute);
} // BOOLEAN HandleTime()

static BOOLEAN HandleBoolean(IN CHAR16 **TokenList, IN UINTN TokenCount) {
   BOOLEAN TruthValue = TRUE;

   if ((TokenCount >= 2) && ((StriCmp(TokenList[1], L"0") == 0) ||
                             (StriCmp(TokenList[1], L"false") == 0) ||
                             (StriCmp(TokenList[1], L"off") == 0))) {
      TruthValue = FALSE;
   } // if

   return TruthValue;
} // BOOLEAN HandleBoolean

// Sets the default boot loader IF the current time is within the bounds
// defined by the third and fourth tokens in the TokenList.
static VOID SetDefaultByTime(IN CHAR16 **TokenList, OUT CHAR16 **Default) {
   EFI_STATUS            Status;
   EFI_TIME              CurrentTime;
   UINTN                 StartTime, EndTime, Now;
   BOOLEAN               SetIt = FALSE;

   StartTime = HandleTime(TokenList[2]);
   EndTime = HandleTime(TokenList[3]);

   if ((StartTime <= LAST_MINUTE) && (EndTime <= LAST_MINUTE)) {
      Status = refit_call2_wrapper(GetTime, &CurrentTime, NULL);
      if (Status != EFI_SUCCESS)
         return;
      Now = CurrentTime.Hour * 60 + CurrentTime.Minute;

      if (Now > LAST_MINUTE) { // Shouldn't happen; just being paranoid
         Print(L"Warning: Impossible system time: %d:%d\n", CurrentTime.Hour, CurrentTime.Minute);
         return;
      } // if impossible time

      if (StartTime < EndTime) { // Time range does NOT cross midnight
         if ((Now >= StartTime) && (Now <= EndTime))
            SetIt = TRUE;
      } else { // Time range DOES cross midnight
         if ((Now >= StartTime) && (Now <= EndTime))
            SetIt = TRUE;
      } // if/else time range crosses midnight

      if (SetIt) {
         MyFreePool(*Default);
         *Default = StrDuplicate(TokenList[1]);
      } // if (SetIt)
   } // if ((StartTime <= LAST_MINUTE) && (EndTime <= LAST_MINUTE))
} // VOID SetDefaultByTime()

// read config file
VOID ReadConfig(CHAR16 *FileName)
{
    EFI_STATUS      Status;
    REFIT_FILE      File;
    CHAR16          **TokenList;
    CHAR16          *FlagName;
    CHAR16          *TempStr = NULL;
    UINTN           TokenCount, i;
    EFI_GUID        RefindGuid = REFIND_GUID_VALUE;

    // Set a few defaults only if we're loading the default file.
    if (StriCmp(FileName, GlobalConfig.ConfigFilename) == 0) {
       MyFreePool(GlobalConfig.AlsoScan);
       GlobalConfig.AlsoScan = StrDuplicate(ALSO_SCAN_DIRS);
       MyFreePool(GlobalConfig.DontScanDirs);
       if (SelfVolume) {
          if (SelfVolume->VolName) {
             TempStr = SelfVolume->VolName ? StrDuplicate(SelfVolume->VolName) : NULL;
          } else {
             TempStr = AllocateZeroPool(256 * sizeof(CHAR16));
             if (TempStr != NULL)
                SPrint(TempStr, 255, L"fs%d", SelfVolume->VolNumber);
          } // if/else
       }
       MergeStrings(&TempStr, SelfDirPath, L':');
       MergeStrings(&TempStr, MEMTEST_LOCATIONS, L',');
       GlobalConfig.DontScanDirs = TempStr;
       MyFreePool(GlobalConfig.DontScanFiles);
       GlobalConfig.DontScanFiles = StrDuplicate(DONT_SCAN_FILES);
       MergeStrings(&(GlobalConfig.DontScanFiles), MOK_NAMES, L',');
       MyFreePool(GlobalConfig.DontScanVolumes);
       GlobalConfig.DontScanVolumes = StrDuplicate(DONT_SCAN_VOLUMES);
       GlobalConfig.WindowsRecoveryFiles = StrDuplicate(WINDOWS_RECOVERY_FILES);
       if (GlobalConfig.DefaultSelection != NULL) {
          MyFreePool(GlobalConfig.DefaultSelection);
          GlobalConfig.DefaultSelection = NULL;
       }
       Status = EfivarGetRaw(&RefindGuid, L"PreviousBoot", (CHAR8**) &(GlobalConfig.DefaultSelection), &i);
       if (Status != EFI_SUCCESS)
          GlobalConfig.DefaultSelection = NULL;
    } // if

    if (!FileExists(SelfDir, FileName)) {
       Print(L"Configuration file '%s' missing!\n", FileName);
       if (!FileExists(SelfDir, L"icons")) {
          Print(L"Icons directory doesn't exist; setting textonly = TRUE!\n");
          GlobalConfig.TextOnly = TRUE;
       }
       return;
    }

    Status = ReadFile(SelfDir, FileName, &File, &i);
    if (EFI_ERROR(Status))
        return;

    for (;;) {
        TokenCount = ReadTokenLine(&File, &TokenList);
        if (TokenCount == 0)
            break;

        if (StriCmp(TokenList[0], L"timeout") == 0) {
            HandleInt(TokenList, TokenCount, &(GlobalConfig.Timeout));

        } else if (StriCmp(TokenList[0], L"hideui") == 0) {
            for (i = 1; i < TokenCount; i++) {
                FlagName = TokenList[i];
                if (StriCmp(FlagName, L"banner") == 0) {
                   GlobalConfig.HideUIFlags |= HIDEUI_FLAG_BANNER;
                } else if (StriCmp(FlagName, L"label") == 0) {
                   GlobalConfig.HideUIFlags |= HIDEUI_FLAG_LABEL;
                } else if (StriCmp(FlagName, L"singleuser") == 0) {
                   GlobalConfig.HideUIFlags |= HIDEUI_FLAG_SINGLEUSER;
                } else if (StriCmp(FlagName, L"hwtest") == 0) {
                   GlobalConfig.HideUIFlags |= HIDEUI_FLAG_HWTEST;
                } else if (StriCmp(FlagName, L"arrows") == 0) {
                   GlobalConfig.HideUIFlags |= HIDEUI_FLAG_ARROWS;
                } else if (StriCmp(FlagName, L"hints") == 0) {
                   GlobalConfig.HideUIFlags |= HIDEUI_FLAG_HINTS;
                } else if (StriCmp(FlagName, L"editor") == 0) {
                   GlobalConfig.HideUIFlags |= HIDEUI_FLAG_EDITOR;
                } else if (StriCmp(FlagName, L"safemode") == 0) {
                   GlobalConfig.HideUIFlags |= HIDEUI_FLAG_SAFEMODE;
                } else if (StriCmp(FlagName, L"badges") == 0) {
                   GlobalConfig.HideUIFlags |= HIDEUI_FLAG_BADGES;
                } else if (StriCmp(FlagName, L"all") == 0) {
                   GlobalConfig.HideUIFlags = HIDEUI_FLAG_ALL;
                } else {
                    Print(L" unknown hideui flag: '%s'\n", FlagName);
                }
            }

        } else if (StriCmp(TokenList[0], L"icons_dir") == 0) {
           HandleString(TokenList, TokenCount, &(GlobalConfig.IconsDir));

        } else if (StriCmp(TokenList[0], L"scanfor") == 0) {
           for (i = 0; i < NUM_SCAN_OPTIONS; i++) {
              if (i < TokenCount)
                 GlobalConfig.ScanFor[i] = TokenList[i][0];
              else
                 GlobalConfig.ScanFor[i] = ' ';
           }

        } else if (StriCmp(TokenList[0], L"uefi_deep_legacy_scan") == 0) {
           GlobalConfig.DeepLegacyScan = HandleBoolean(TokenList, TokenCount);

        } else if ((StriCmp(TokenList[0], L"scan_delay") == 0) && (TokenCount == 2)) {
           HandleInt(TokenList, TokenCount, &(GlobalConfig.ScanDelay));

        } else if (StriCmp(TokenList[0], L"also_scan_dirs") == 0) {
            HandleStrings(TokenList, TokenCount, &(GlobalConfig.AlsoScan));

        } else if ((StriCmp(TokenList[0], L"don't_scan_volumes") == 0) || (StriCmp(TokenList[0], L"dont_scan_volumes") == 0)) {
           // Note: Don't use HandleStrings() because it modifies slashes, which might be present in volume name
           MyFreePool(GlobalConfig.DontScanVolumes);
           GlobalConfig.DontScanVolumes = NULL;
           for (i = 1; i < TokenCount; i++) {
              MergeStrings(&GlobalConfig.DontScanVolumes, TokenList[i], L',');
           }

        } else if ((StriCmp(TokenList[0], L"don't_scan_dirs") == 0) || (StriCmp(TokenList[0], L"dont_scan_dirs") == 0)) {
            HandleStrings(TokenList, TokenCount, &(GlobalConfig.DontScanDirs));

        } else if ((StriCmp(TokenList[0], L"don't_scan_files") == 0) || (StriCmp(TokenList[0], L"dont_scan_files") == 0)) {
           HandleStrings(TokenList, TokenCount, &(GlobalConfig.DontScanFiles));

        } else if (StriCmp(TokenList[0], L"windows_recovery_files") == 0) {
           HandleStrings(TokenList, TokenCount, &(GlobalConfig.WindowsRecoveryFiles));

        } else if (StriCmp(TokenList[0], L"scan_driver_dirs") == 0) {
            HandleStrings(TokenList, TokenCount, &(GlobalConfig.DriverDirs));

        } else if (StriCmp(TokenList[0], L"showtools") == 0) {
            SetMem(GlobalConfig.ShowTools, NUM_TOOLS * sizeof(UINTN), 0);
            for (i = 1; (i < TokenCount) && (i < NUM_TOOLS); i++) {
                FlagName = TokenList[i];
                if (StriCmp(FlagName, L"shell") == 0) {
                    GlobalConfig.ShowTools[i - 1] = TAG_SHELL;
                } else if (StriCmp(FlagName, L"gptsync") == 0) {
                    GlobalConfig.ShowTools[i - 1] = TAG_GPTSYNC;
                } else if (StriCmp(FlagName, L"gdisk") == 0) {
                   GlobalConfig.ShowTools[i - 1] = TAG_GDISK;
                } else if (StriCmp(FlagName, L"about") == 0) {
                   GlobalConfig.ShowTools[i - 1] = TAG_ABOUT;
                } else if (StriCmp(FlagName, L"exit") == 0) {
                   GlobalConfig.ShowTools[i - 1] = TAG_EXIT;
                } else if (StriCmp(FlagName, L"reboot") == 0) {
                   GlobalConfig.ShowTools[i - 1] = TAG_REBOOT;
                } else if (StriCmp(FlagName, L"shutdown") == 0) {
                   GlobalConfig.ShowTools[i - 1] = TAG_SHUTDOWN;
                } else if (StriCmp(FlagName, L"apple_recovery") == 0) {
                   GlobalConfig.ShowTools[i - 1] = TAG_APPLE_RECOVERY;
                } else if (StriCmp(FlagName, L"windows_recovery") == 0) {
                   GlobalConfig.ShowTools[i - 1] = TAG_WINDOWS_RECOVERY;
                } else if (StriCmp(FlagName, L"mok_tool") == 0) {
                   GlobalConfig.ShowTools[i - 1] = TAG_MOK_TOOL;
                } else if (StriCmp(FlagName, L"firmware") == 0) {
                   GlobalConfig.ShowTools[i - 1] = TAG_FIRMWARE;
                } else if ((StriCmp(FlagName, L"memtest86") == 0) || (StriCmp(FlagName, L"memtest") == 0)) {
                   GlobalConfig.ShowTools[i - 1] = TAG_MEMTEST;
                } else if (StriCmp(FlagName, L"netboot") == 0) {
                   GlobalConfig.ShowTools[i - 1] = TAG_NETBOOT;
                } else {
                   Print(L" unknown showtools flag: '%s'\n", FlagName);
                }
            } // showtools options

        } else if (StriCmp(TokenList[0], L"banner") == 0) {
           HandleString(TokenList, TokenCount, &(GlobalConfig.BannerFileName));

        } else if ((StriCmp(TokenList[0], L"banner_scale") == 0) && (TokenCount == 2)) {
           if (StriCmp(TokenList[1], L"noscale") == 0) {
              GlobalConfig.BannerScale = BANNER_NOSCALE;
           } else if ((StriCmp(TokenList[1], L"fillscreen") == 0) || (StriCmp(TokenList[1], L"fullscreen") == 0)) {
              GlobalConfig.BannerScale = BANNER_FILLSCREEN;
           } else {
              Print(L" unknown banner_type flag: '%s'\n", TokenList[1]);
           } // if/else

        } else if ((StriCmp(TokenList[0], L"small_icon_size") == 0) && (TokenCount == 2)) {
           HandleInt(TokenList, TokenCount, &i);
           if (i >= 32)
              GlobalConfig.IconSizes[ICON_SIZE_SMALL] = i;

        } else if ((StriCmp(TokenList[0], L"big_icon_size") == 0) && (TokenCount == 2)) {
           HandleInt(TokenList, TokenCount, &i);
           if (i >= 32) {
              GlobalConfig.IconSizes[ICON_SIZE_BIG] = i;
              GlobalConfig.IconSizes[ICON_SIZE_BADGE] = i / 4;
           }

        } else if (StriCmp(TokenList[0], L"selection_small") == 0) {
           HandleString(TokenList, TokenCount, &(GlobalConfig.SelectionSmallFileName));

        } else if (StriCmp(TokenList[0], L"selection_big") == 0) {
           HandleString(TokenList, TokenCount, &(GlobalConfig.SelectionBigFileName));

        } else if (StriCmp(TokenList[0], L"default_selection") == 0) {
           if (TokenCount == 4) {
              SetDefaultByTime(TokenList, &(GlobalConfig.DefaultSelection));
           } else {
              HandleString(TokenList, TokenCount, &(GlobalConfig.DefaultSelection));
           }

        } else if (StriCmp(TokenList[0], L"textonly") == 0) {
           GlobalConfig.TextOnly = HandleBoolean(TokenList, TokenCount);

        } else if (StriCmp(TokenList[0], L"textmode") == 0) {
           HandleInt(TokenList, TokenCount, &(GlobalConfig.RequestedTextMode));

        } else if ((StriCmp(TokenList[0], L"resolution") == 0) && ((TokenCount == 2) || (TokenCount == 3))) {
           GlobalConfig.RequestedScreenWidth = Atoi(TokenList[1]);
           if (TokenCount == 3)
              GlobalConfig.RequestedScreenHeight = Atoi(TokenList[2]);
           else
              GlobalConfig.RequestedScreenHeight = 0;

        } else if (StriCmp(TokenList[0], L"screensaver") == 0) {
           HandleInt(TokenList, TokenCount, &(GlobalConfig.ScreensaverTime));

        } else if (StriCmp(TokenList[0], L"use_graphics_for") == 0) {
           if ((TokenCount == 2) || ((TokenCount > 2) && (StriCmp(TokenList[1], L"+") != 0)))
              GlobalConfig.GraphicsFor = 0;
           for (i = 1; i < TokenCount; i++) {
              if (StriCmp(TokenList[i], L"osx") == 0) {
                 GlobalConfig.GraphicsFor |= GRAPHICS_FOR_OSX;
              } else if (StriCmp(TokenList[i], L"linux") == 0) {
                 GlobalConfig.GraphicsFor |= GRAPHICS_FOR_LINUX;
              } else if (StriCmp(TokenList[i], L"elilo") == 0) {
                 GlobalConfig.GraphicsFor |= GRAPHICS_FOR_ELILO;
              } else if (StriCmp(TokenList[i], L"grub") == 0) {
                 GlobalConfig.GraphicsFor |= GRAPHICS_FOR_GRUB;
              } else if (StriCmp(TokenList[i], L"windows") == 0) {
                 GlobalConfig.GraphicsFor |= GRAPHICS_FOR_WINDOWS;
              }
           } // for (graphics_on tokens)

        } else if ((StriCmp(TokenList[0], L"font") == 0) && (TokenCount == 2)) {
           egLoadFont(TokenList[1]);

        } else if (StriCmp(TokenList[0], L"scan_all_linux_kernels") == 0) {
           GlobalConfig.ScanAllLinux = HandleBoolean(TokenList, TokenCount);

        } else if (StriCmp(TokenList[0], L"fold_linux_kernels") == 0) {
            GlobalConfig.FoldLinuxKernels = HandleBoolean(TokenList, TokenCount);

        } else if (StriCmp(TokenList[0], L"max_tags") == 0) {
           HandleInt(TokenList, TokenCount, &(GlobalConfig.MaxTags));

        } else if (StriCmp(TokenList[0], L"enable_and_lock_vmx") == 0) {
           GlobalConfig.EnableAndLockVMX = HandleBoolean(TokenList, TokenCount);

        } else if ((StriCmp(TokenList[0], L"include") == 0) && (TokenCount == 2) &&
                   (StriCmp(FileName, GlobalConfig.ConfigFilename) == 0)) {
           if (StriCmp(TokenList[1], FileName) != 0) {
              ReadConfig(TokenList[1]);
           }

        }

        FreeTokenLine(&TokenList, &TokenCount);
    }
    if ((GlobalConfig.DontScanFiles) && (GlobalConfig.WindowsRecoveryFiles))
       MergeStrings(&(GlobalConfig.DontScanFiles), GlobalConfig.WindowsRecoveryFiles, L',');
    MyFreePool(File.Buffer);

    if (!FileExists(SelfDir, L"icons") && !FileExists(SelfDir, GlobalConfig.IconsDir)) {
       Print(L"Icons directory doesn't exist; setting textonly = TRUE!\n");
       GlobalConfig.TextOnly = TRUE;
    }
} /* VOID ReadConfig() */

// Finds a volume with the specified Identifier (a filesystem label, a
// partition name, a partition GUID, or a number followed by a colon). If
// found, sets *Volume to point to that volume. If not, leaves it unchanged.
// Returns TRUE if a match was found, FALSE if not.
static BOOLEAN FindVolume(REFIT_VOLUME **Volume, CHAR16 *Identifier) {
   UINTN     i = 0, CountedVolumes = 0, Length;
   INTN      Number = -1;
   BOOLEAN   Found = FALSE, IdIsGuid = FALSE;
   EFI_GUID  VolGuid, NullGuid = NULL_GUID_VALUE;

   VolGuid = StringAsGuid(Identifier);
   Length = StrLen(Identifier);
   if ((Length >= 2) && (Identifier[Length - 1] == L':') &&
       (Identifier[0] >= L'0') && (Identifier[0] <= L'9')) {
      Number = (INTN) Atoi(Identifier);
   } else if (IsGuid(Identifier)) {
      IdIsGuid = TRUE;
   }
   while ((i < VolumesCount) && (!Found)) {
      if (Number >= 0) { // User specified a volume by number
         if (Volumes[i]->IsReadable) {
            if (CountedVolumes == Number) {
               *Volume = Volumes[i];
               Found = TRUE;
            }
            CountedVolumes++;
         } // if
      } else { // User specified a volume by label or GUID
         if ((StriCmp(Identifier, Volumes[i]->VolName) == 0) ||
             (StriCmp(Identifier, Volumes[i]->PartName) == 0)) {
            *Volume = Volumes[i];
            Found = TRUE;
         } // if
         if (IdIsGuid && !Found) {
            if (GuidsAreEqual(&VolGuid, &(Volumes[i]->PartGuid)) && !GuidsAreEqual(&NullGuid, &(Volumes[i]->PartGuid))) {
               *Volume = Volumes[i];
               Found = TRUE;
            } // if
         } // if
      } // if/else
      i++;
   } // while()
   return (Found);
} // static VOID FindVolume()

static VOID AddSubmenu(LOADER_ENTRY *Entry, REFIT_FILE *File, REFIT_VOLUME *Volume, CHAR16 *Title) {
   REFIT_MENU_SCREEN  *SubScreen;
   LOADER_ENTRY       *SubEntry;
   UINTN              TokenCount;
   CHAR16             **TokenList;

   SubScreen = InitializeSubScreen(Entry);

   // Set defaults for the new entry; will be modified based on lines read from the config. file....
   SubEntry = InitializeLoaderEntry(Entry);

   if ((SubEntry == NULL) || (SubScreen == NULL))
      return;
   SubEntry->me.Title        = StrDuplicate(Title);

   while (((TokenCount = ReadTokenLine(File, &TokenList)) > 0) && (StriCmp(TokenList[0], L"}") != 0)) {

      if ((StriCmp(TokenList[0], L"loader") == 0) && (TokenCount > 1)) { // set the boot loader filename
         MyFreePool(SubEntry->LoaderPath);
         SubEntry->LoaderPath = StrDuplicate(TokenList[1]);
         SubEntry->DevicePath = FileDevicePath(Volume->DeviceHandle, SubEntry->LoaderPath);

      } else if ((StriCmp(TokenList[0], L"volume") == 0) && (TokenCount > 1)) {
         if (FindVolume(&Volume, TokenList[1])) {
            if ((Volume != NULL) && (Volume->IsReadable) && (Volume->RootDir)) {
               MyFreePool(SubEntry->me.Title);
               SubEntry->me.Title        = AllocateZeroPool(256 * sizeof(CHAR16));
               SPrint(SubEntry->me.Title, 255, L"Boot %s from %s", (Title != NULL) ? Title : L"Unknown", Volume->VolName);
               SubEntry->me.BadgeImage   = Volume->VolBadgeImage;
               SubEntry->VolName         = Volume->VolName;
            } // if volume is readable
         } // if match found

      } else if (StriCmp(TokenList[0], L"initrd") == 0) {
         MyFreePool(SubEntry->InitrdPath);
         SubEntry->InitrdPath = NULL;
         if (TokenCount > 1) {
            SubEntry->InitrdPath = StrDuplicate(TokenList[1]);
         }

      } else if (StriCmp(TokenList[0], L"options") == 0) {
         MyFreePool(SubEntry->LoadOptions);
         SubEntry->LoadOptions = NULL;
         if (TokenCount > 1) {
            SubEntry->LoadOptions = StrDuplicate(TokenList[1]);
         } // if/else

      } else if ((StriCmp(TokenList[0], L"add_options") == 0) && (TokenCount > 1)) {
         MergeStrings(&SubEntry->LoadOptions, TokenList[1], L' ');

      } else if ((StriCmp(TokenList[0], L"graphics") == 0) && (TokenCount > 1)) {
         SubEntry->UseGraphicsMode = (StriCmp(TokenList[1], L"on") == 0);

      } else if (StriCmp(TokenList[0], L"disabled") == 0) {
         SubEntry->Enabled = FALSE;
      } // ief/elseif

      FreeTokenLine(&TokenList, &TokenCount);
   } // while()

   if (SubEntry->InitrdPath != NULL) {
      MergeStrings(&SubEntry->LoadOptions, L"initrd=", L' ');
      MergeStrings(&SubEntry->LoadOptions, SubEntry->InitrdPath, 0);
      MyFreePool(SubEntry->InitrdPath);
      SubEntry->InitrdPath = NULL;
   } // if
   if (SubEntry->Enabled == TRUE) {
      AddMenuEntry(SubScreen, (REFIT_MENU_ENTRY *)SubEntry);
   }
   Entry->me.SubScreen = SubScreen;
} // VOID AddSubmenu()

// Adds the options from a SINGLE refind.conf stanza to a new loader entry and returns
// that entry. The calling function is then responsible for adding the entry to the
// list of entries.
static LOADER_ENTRY * AddStanzaEntries(REFIT_FILE *File, REFIT_VOLUME *Volume, CHAR16 *Title) {
   CHAR16       **TokenList;
   UINTN        TokenCount;
   LOADER_ENTRY *Entry;
   BOOLEAN      DefaultsSet = FALSE, AddedSubmenu = FALSE;
   REFIT_VOLUME *CurrentVolume = Volume;

   // prepare the menu entry
   Entry = InitializeLoaderEntry(NULL);
   if (Entry == NULL)
      return NULL;

   Entry->Title           = StrDuplicate(Title);
   Entry->me.Title        = AllocateZeroPool(256 * sizeof(CHAR16));
   SPrint(Entry->me.Title, 255, L"Boot %s from %s", (Title != NULL) ? Title : L"Unknown", CurrentVolume->VolName);
   Entry->me.Row          = 0;
   Entry->me.BadgeImage   = CurrentVolume->VolBadgeImage;
   Entry->VolName         = CurrentVolume->VolName;

   // Parse the config file to add options for a single stanza, terminating when the token
   // is "}" or when the end of file is reached.
   while (((TokenCount = ReadTokenLine(File, &TokenList)) > 0) && (StriCmp(TokenList[0], L"}") != 0)) {
      if ((StriCmp(TokenList[0], L"loader") == 0) && (TokenCount > 1)) { // set the boot loader filename
         Entry->LoaderPath = StrDuplicate(TokenList[1]);
         Entry->DevicePath = FileDevicePath(CurrentVolume->DeviceHandle, Entry->LoaderPath);
         SetLoaderDefaults(Entry, TokenList[1], CurrentVolume);
         MyFreePool(Entry->LoadOptions);
         Entry->LoadOptions = NULL; // Discard default options, if any
         DefaultsSet = TRUE;

      } else if ((StriCmp(TokenList[0], L"volume") == 0) && (TokenCount > 1)) {
         if (FindVolume(&CurrentVolume, TokenList[1])) {
            if ((CurrentVolume != NULL) && (CurrentVolume->IsReadable) && (CurrentVolume->RootDir)) {
               MyFreePool(Entry->me.Title);
               Entry->me.Title        = AllocateZeroPool(256 * sizeof(CHAR16));
               SPrint(Entry->me.Title, 255, L"Boot %s from %s", (Title != NULL) ? Title : L"Unknown", CurrentVolume->VolName);
               Entry->me.BadgeImage   = CurrentVolume->VolBadgeImage;
               Entry->VolName         = CurrentVolume->VolName;
            } // if volume is readable
         } // if match found

      } else if ((StriCmp(TokenList[0], L"icon") == 0) && (TokenCount > 1)) {
         MyFreePool(Entry->me.Image);
         Entry->me.Image = egLoadIcon(CurrentVolume->RootDir, TokenList[1], GlobalConfig.IconSizes[ICON_SIZE_BIG]);
         if (Entry->me.Image == NULL) {
            Entry->me.Image = DummyImage(GlobalConfig.IconSizes[ICON_SIZE_BIG]);
         }

      } else if ((StriCmp(TokenList[0], L"initrd") == 0) && (TokenCount > 1)) {
         MyFreePool(Entry->InitrdPath);
         Entry->InitrdPath = StrDuplicate(TokenList[1]);

      } else if ((StriCmp(TokenList[0], L"options") == 0) && (TokenCount > 1)) {
         MyFreePool(Entry->LoadOptions);
         Entry->LoadOptions = StrDuplicate(TokenList[1]);

      } else if ((StriCmp(TokenList[0], L"ostype") == 0) && (TokenCount > 1)) {
         if (TokenCount > 1) {
            Entry->OSType = TokenList[1][0];
         }

      } else if ((StriCmp(TokenList[0], L"graphics") == 0) && (TokenCount > 1)) {
         Entry->UseGraphicsMode = (StriCmp(TokenList[1], L"on") == 0);

      } else if (StriCmp(TokenList[0], L"disabled") == 0) {
         Entry->Enabled = FALSE;

      } else if ((StriCmp(TokenList[0], L"submenuentry") == 0) && (TokenCount > 1)) {
         AddSubmenu(Entry, File, CurrentVolume, TokenList[1]);
         AddedSubmenu = TRUE;

      } // set options to pass to the loader program
      FreeTokenLine(&TokenList, &TokenCount);
   } // while()

   if (AddedSubmenu)
       AddMenuEntry(Entry->me.SubScreen, &MenuEntryReturn);

   if (Entry->InitrdPath) {
      MergeStrings(&Entry->LoadOptions, L"initrd=", L' ');
      MergeStrings(&Entry->LoadOptions, Entry->InitrdPath, 0);
      MyFreePool(Entry->InitrdPath);
      Entry->InitrdPath = NULL;
   } // if

   if (!DefaultsSet)
      SetLoaderDefaults(Entry, L"\\EFI\\BOOT\\nemo.efi", CurrentVolume); // user included no "loader" line; use bogus one

   return(Entry);
} // static VOID AddStanzaEntries()

// Read the user-configured menu entries from refind.conf and add or delete
// entries based on the contents of that file....
VOID ScanUserConfigured(CHAR16 *FileName)
{
   EFI_STATUS        Status;
   REFIT_FILE        File;
   REFIT_VOLUME      *Volume;
   CHAR16            **TokenList;
   CHAR16            *Title = NULL;
   UINTN             TokenCount, size;
   LOADER_ENTRY      *Entry;

   if (FileExists(SelfDir, FileName)) {
      Status = ReadFile(SelfDir, FileName, &File, &size);
      if (EFI_ERROR(Status))
         return;

      Volume = SelfVolume;

      while ((TokenCount = ReadTokenLine(&File, &TokenList)) > 0) {
         if ((StriCmp(TokenList[0], L"menuentry") == 0) && (TokenCount > 1)) {
            Title = StrDuplicate(TokenList[1]);
            Entry = AddStanzaEntries(&File, Volume, TokenList[1]);
            if (Entry->Enabled) {
               if (Entry->me.SubScreen == NULL)
                  GenerateSubScreen(Entry, Volume, TRUE);
               AddPreparedLoaderEntry(Entry);
            } else {
               MyFreePool(Entry);
            } // if/else
            MyFreePool(Title);

         } else if ((StriCmp(TokenList[0], L"include") == 0) && (TokenCount == 2) &&
                    (StriCmp(FileName, GlobalConfig.ConfigFilename) == 0)) {
            if (StriCmp(TokenList[1], FileName) != 0) {
               ScanUserConfigured(TokenList[1]);
            }

         } // if/else if...
         FreeTokenLine(&TokenList, &TokenCount);
      } // while()
   } // if()
} // VOID ScanUserConfigured()

// Create an options file based on /etc/fstab. The resulting file has two options
// lines, one of which boots the system with "ro root={rootfs}" and the other of
// which boots the system with "ro root={rootfs} single", where "{rootfs}" is the
// filesystem identifier associated with the "/" line in /etc/fstab.
static REFIT_FILE * GenerateOptionsFromEtcFstab(REFIT_VOLUME *Volume) {
   UINTN        TokenCount, i;
   REFIT_FILE   *Options = NULL, *Fstab = NULL;
   EFI_STATUS   Status;
   CHAR16       **TokenList, *Line, Root[100];

   if (FileExists(Volume->RootDir, L"\\etc\\fstab")) {
      Options = AllocateZeroPool(sizeof(REFIT_FILE));
      Fstab = AllocateZeroPool(sizeof(REFIT_FILE));
      Status = ReadFile(Volume->RootDir, L"\\etc\\fstab", Fstab, &i);
      if (CheckError(Status, L"while reading /etc/fstab")) {
         if (Options != NULL)
            FreePool(Options);
         if (Fstab != NULL)
            FreePool(Fstab);
         Options = NULL;
         Fstab = NULL;
      } else { // File read; locate root fs and create entries
         Options->Encoding = ENCODING_UTF16_LE;
         while ((TokenCount = ReadTokenLine(Fstab, &TokenList)) > 0) {
            if (TokenCount > 2) {
               Root[0] = '\0';
               if (StriCmp(TokenList[1], L"\\") == 0) {
                  SPrint(Root, 99, L"%s", TokenList[0]);
               } else if (StriCmp(TokenList[2], L"\\") == 0) {
                  SPrint(Root, 99, L"%s=%s", TokenList[0], TokenList[1]);
               } // if/elseif/elseif
               if (Root[0] != L'\0') {
                  for (i = 0; i < StrLen(Root); i++)
                     if (Root[i] == '\\')
                        Root[i] = '/';
                  Line = PoolPrint(L"\"Boot with normal options\"    \"ro root=%s\"\n", Root);
                  MergeStrings((CHAR16 **) &(Options->Buffer), Line, 0);
                  MyFreePool(Line);
                  Line = PoolPrint(L"\"Boot into single-user mode\"  \"ro root=%s single\"\n", Root);
                  MergeStrings((CHAR16**) &(Options->Buffer), Line, 0);
                  Options->BufferSize = StrLen((CHAR16*) Options->Buffer) * sizeof(CHAR16);
               } // if
            } // if
            FreeTokenLine(&TokenList, &TokenCount);
         } // while

         Options->Current8Ptr  = (CHAR8 *)Options->Buffer;
         Options->End8Ptr      = Options->Current8Ptr + Options->BufferSize;
         Options->Current16Ptr = (CHAR16 *)Options->Buffer;
         Options->End16Ptr     = Options->Current16Ptr + (Options->BufferSize >> 1);

         MyFreePool(Fstab->Buffer);
         MyFreePool(Fstab);
      } // if/else file read error
   } // if /etc/fstab exists
   return Options;
} // GenerateOptionsFromEtcFstab()

// Create options from partition type codes. Specifically, if the earlier
// partition scan found a partition with a type code corresponding to a root
// filesystem according to the Freedesktop.org Discoverable Partitions Spec
// (http://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/),
// this function returns an appropriate file with two lines, one with
// "ro root=PARTUUID={GUID}" and the other with that plus "single".
// Note that this function returns the LAST partition found with the
// appropriate type code, so this will work poorly on dual-boot systems or
// if the type code is set incorrectly.
static REFIT_FILE * GenerateOptionsFromPartTypes(VOID) {
    REFIT_FILE   *Options = NULL;
    CHAR16       *Line, *GuidString;

    if (GlobalConfig.DiscoveredRoot) {
        Options = AllocateZeroPool(sizeof(REFIT_FILE));
        if (Options) {
            Options->Encoding = ENCODING_UTF16_LE;
            GuidString = GuidAsString(&(GlobalConfig.DiscoveredRoot->PartGuid));
            ToLower(GuidString);
            if (GuidString) {
                Line = PoolPrint(L"\"Boot with normal options\"    \"ro root=/dev/disk/by-partuuid/%s\"\n", GuidString);
                MergeStrings((CHAR16 **) &(Options->Buffer), Line, 0);
                MyFreePool(Line);
                Line = PoolPrint(L"\"Boot into single-user mode\"  \"ro root=/dev/disk/by-partuuid/%s single\"\n", GuidString);
                MergeStrings((CHAR16**) &(Options->Buffer), Line, 0);
                MyFreePool(Line);
                MyFreePool(GuidString);
            } // if (GuidString)
            Options->BufferSize = StrLen((CHAR16*) Options->Buffer) * sizeof(CHAR16);

            Options->Current8Ptr  = (CHAR8 *)Options->Buffer;
            Options->End8Ptr      = Options->Current8Ptr + Options->BufferSize;
            Options->Current16Ptr = (CHAR16 *)Options->Buffer;
            Options->End16Ptr     = Options->Current16Ptr + (Options->BufferSize >> 1);
        } // if (Options allocated OK)
    } // if (partition has root GUID)
    return Options;
} // REFIT_FILE * GenerateOptionsFromPartTypes()

// Read a Linux kernel options file for a Linux boot loader into memory. The LoaderPath
// and Volume variables identify the location of the options file, but not its name --
// you pass this function the filename of the Linux kernel, initial RAM disk, or other
// file in the target directory, and this function finds the file with a name in the
// comma-delimited list of names specified by LINUX_OPTIONS_FILENAMES within that
// directory and loads it. This function tries multiple files because I originally
// used the filename linux.conf, but close on the heels of that decision, the Linux
// kernel developers decided to use that name for a similar purpose, but with a
// different file format. Thus, I'm migrating rEFInd to use the name refind_linux.conf,
// but I want a migration period in which both names are used.
// If a rEFInd options file can't be found, try to generate minimal options from
// /etc/fstab on the same volume as the kernel. This typically works only if the
// kernel is being read from the Linux root filesystem.
//
// The return value is a pointer to the REFIT_FILE handle for the file, or NULL if
// it wasn't found.
REFIT_FILE * ReadLinuxOptionsFile(IN CHAR16 *LoaderPath, IN REFIT_VOLUME *Volume) {
   CHAR16       *OptionsFilename, *FullFilename;
   BOOLEAN      GoOn = TRUE, FileFound = FALSE;
   UINTN        i = 0, size;
   REFIT_FILE   *File = NULL;
   EFI_STATUS   Status;

   do {
      OptionsFilename = FindCommaDelimited(LINUX_OPTIONS_FILENAMES, i++);
      FullFilename = FindPath(LoaderPath);
      if ((OptionsFilename != NULL) && (FullFilename != NULL)) {
         MergeStrings(&FullFilename, OptionsFilename, '\\');
         if (FileExists(Volume->RootDir, FullFilename)) {
            File = AllocateZeroPool(sizeof(REFIT_FILE));
            Status = ReadFile(Volume->RootDir, FullFilename, File, &size);
            if (CheckError(Status, L"while loading the Linux options file")) {
               if (File != NULL)
                  FreePool(File);
               File = NULL;
            } else {
               GoOn = FALSE;
               FileFound = TRUE;
            } // if/else error
         } // if file exists
      } else { // a filename string is NULL
         GoOn = FALSE;
      } // if/else
      MyFreePool(OptionsFilename);
      MyFreePool(FullFilename);
      OptionsFilename = FullFilename = NULL;
   } while (GoOn);
   if (!FileFound) {
      // No refind_linux.conf file; look for /etc/fstab and try to pull values from there....
      File = GenerateOptionsFromEtcFstab(Volume);
      // If still no joy, try to use Freedesktop.org Discoverable Partitions Spec....
      if (!File)
         File = GenerateOptionsFromPartTypes();
   } // if
   return (File);
} // static REFIT_FILE * ReadLinuxOptionsFile()

// Retrieve a single line of options from a Linux kernel options file
CHAR16 * GetFirstOptionsFromFile(IN CHAR16 *LoaderPath, IN REFIT_VOLUME *Volume) {
   UINTN        TokenCount;
   CHAR16       *Options = NULL;
   CHAR16       **TokenList;
   REFIT_FILE   *File;

   File = ReadLinuxOptionsFile(LoaderPath, Volume);
   if (File != NULL) {
      TokenCount = ReadTokenLine(File, &TokenList);
      if (TokenCount > 1)
         Options = StrDuplicate(TokenList[1]);
      FreeTokenLine(&TokenList, &TokenCount);
      FreePool(File);
   } // if
   return Options;
} // static CHAR16 * GetOptionsFile()