Added some options for randomizing GUIDs and setting GUIDs via sgdisk

CHANGELOG

@@ -1,3 +1,27 @@
+0.6.8 (?/?/2010):
+-----------------
+
+- Fixed compile problem for FreeBSD (its math library lacks a log2()
+  function). Also created separate Makefile.freebsd with a couple of
+  FreeBSD-specific options.
+
+- Added -N (--largest-new) command to sgdisk. This command creates a single
+  partition that fills the largest single unpartitioned block of space on
+  the disk.
+
+- Fixed sgdisk man page error: the --change-name option was incorrectly
+  listed as --change.
+
+- Added 'h' option to gdisk experts' menu (-C or --recompute-chs in sgdisk)
+  to recompute all protective/hybrid MBR CHS values. This option is
+  intended to work around a bug in at least one BIOS that prevents the
+  computer from booting when the GPT-mandated (but technically illegal)
+  0xFFFFFF CHS value is used as the end point for a protective MBR. The
+  recomputed values will be legal (e.g., 0xFEFFFF instead of 0xFFFFFF),
+  but incorrect in GPT terms, and will therefore enable at least one
+  BIOS to boot with a GPT disk. See http://www.rodsbooks.com/gdisk/bios.html
+  for all I know about BIOS/GPT incompatibilities.
+
 0.6.7 (5/1/2010):
 -----------------
 

Makefile

@@ -12,10 +12,10 @@ DEPEND= makedepend $(CXXFLAGS)
 all:	gdisk sgdisk
 
 gdisk:	$(LIB_OBJS) gdisk.o gpttext.o
-	$(CXX) $(LIB_OBJS) gdisk.o gpttext.o -L/opt/local/lib -L/usr/local/lib $(LDFLAGS) -luuid -o gdisk
+	$(CXX) $(LIB_OBJS) gdisk.o gpttext.o $(LDFLAGS) -luuid -o gdisk
 
 sgdisk: $(LIB_OBJS) sgdisk.o
-	$(CXX) $(LIB_OBJS) sgdisk.o -L/opt/local/lib -L/usr/local/lib $(LDFLAGS) -luuid -lpopt -o sgdisk
+	$(CXX) $(LIB_OBJS) sgdisk.o $(LDFLAGS) -luuid -lpopt -o sgdisk
 
 lint:	#no pre-reqs
 	lint $(SRCS)

README

@@ -69,14 +69,15 @@ compiler for C++. In addition, note these requirements:
 When all the necessary development tools and libraries are installed, you
 can uncompress the package and type "make" at the command prompt in the
 resulting directory. (You may need to type "make -f Makefile.mac" on Mac OS
-X or "make -f Makefile.mingw" to compile using MinGW for Windows.) You may
+X, "make -f Makefile.freebsd" on FreeBSD, or "make -f Makefile.mingw" to
-also need to add header (include) directories or library directories by
+compile using MinGW for Windows.) You may also need to add header (include)
-setting the CXXFLAGS environment variable or by editing the Makefile. The
+directories or library directories by setting the CXXFLAGS environment
-result should be program files called gdisk and sgdisk. Typing "make gdisk"
+variable or by editing the Makefile. The result should be program files
-or "make sgdisk" will compile only the requested programs. You can use
+called gdisk and sgdisk. Typing "make gdisk" or "make sgdisk" will compile
-these programs in place or copy the files to a suitable directory, such as
+only the requested programs. You can use these programs in place or copy
-/usr/local/sbin. You can copy the man pages (gdisk.8 and sgdisk.8) to
+the files to a suitable directory, such as /usr/local/sbin. You can copy
-/usr/local/man/man8 to make them available.
+the man pages (gdisk.8 and sgdisk.8) to /usr/local/man/man8 to make them
+available.
 
 Caveats
 -------
@@ -93,10 +94,10 @@ RAID arrays over 2TiB in size, though.
 My main development platform is a system running the 64-bit version of
 Gentoo Linux (previously Ubuntu 8.04). I've also tested on 64-bit OpenSuSE,
 32-bit Fedora 10, 32-bit Fedora 11, 32-bit Ubuntu 6.10, 64-bit Ubunut 9.10,
-32-bit PowerPC Debian Linux, 32-bit Intel-based Mac OS X 10.5 and 10.6, and
+32-bit PowerPC Debian Linux, 32-bit Intel-based Mac OS X 10.5 and 10.6,
-64-bit FreeBSD 7.1. Problems relating to 64-bit integers on the 32-bit
+64-bit FreeBSD 7.1, and Windows 7. Problems relating to 64-bit integers on
-Linux have been common during development and may crop up in the future.
+the 32-bit Linux have been common during development and may crop up in the
-The Mac OS X, FreeBSD, and big-endian (PowerPC) support are new.
+future.
 
 Redistribution
 --------------
@@ -113,8 +114,8 @@ other GPLed programs:
   Krzysztof Dabrowski and ElysiuM deeZine. (See the crc32.h and
   crc32.cc source code files.)
 
-- A function to find the disk size is taken from Linux fdisk by
+- A function to find the disk size is taken from Linux fdisk by A. V. Le
-  A. V. Le Blanc.
+  Blanc. This code has subsequently been heavily modified.
 
 Additional code contributors include:
 

gdisk.8

@@ -435,12 +435,29 @@ you've added disks to a RAID array, thus creating a virtual disk with space
 that follows the backup GPT data structures. This command moves the backup
 GPT data structures to the end of the disk, where they belong.
 
+.TP
+.B f
+Randomize the disk's GUID and all partitions' unique GUIDs (but not their
+partition type code GUIDs). This function may be used after cloning a disk
+with another utility in order to render all GUIDs once again unique.
+
 .TP 
 .B g
 Change disk GUID. Each disk has a unique GUID code, which \fBgdisk\fR
 assigns randomly upon creation of the GPT data structures. You can generate
 a fresh random GUID or enter one manually with this option.
 
+.TP
+.B h
+Recompute CHS values in protective or hybrid MBR. This option can sometimes
+help if a disk utility, OS, or BIOS doesn't like the CHS values used by the
+partitions in the protective or hybrid MBR. In particular, the GPT
+specification requires a CHS value of 0xFFFFFF for over-8GiB partitions,
+but this value is technically illegal by the usual standards. Some BIOSes
+hang if they encounter this value. This option will recompute a more normal
+CHS value -- 0xFEFFFF for over-8GiB partitions, enabling these BIOSes to
+boot.
+
 .TP 
 .B i
 Show detailed partition information. This option is identical to the 'i'

gdisk.cc

@@ -349,10 +349,16 @@ void ExpertsMenu(string filename, GPTDataTextUI* theGPT) {
             cout << "Relocating backup data structures to the end of the disk\n";
             theGPT->MoveSecondHeaderToEnd();
             break;
+         case 'f': case 'F':
+            theGPT->RandomizeGUIDs();
+            break;
          case 'g': case 'G':
             cout << "Enter the disk's unique GUID:\n";
             theGPT->SetDiskGUID(aGUID.GetGUIDFromUser());
             break;
+         case 'h': case 'H':
+            theGPT->RecomputeCHS();
+            break;
          case 'i': case 'I':
             theGPT->ShowDetails();
             break;
@@ -415,6 +421,7 @@ void ShowExpertCommands(void) {
    cout << "d\tdisplay the sector alignment value\n";
    cout << "e\trelocate backup data structures to the end of the disk\n";
    cout << "g\tchange disk GUID\n";
+   cout << "h\trecompute CHS values in protective/hybrid MBR\n";
    cout << "i\tshow detailed information on a partition\n";
    cout << "l\tset the sector alignment value\n";
    cout << "m\treturn to main menu\n";

gpt.cc

@@ -30,6 +30,11 @@
 
 using namespace std;
 
+#ifdef __FreeBSD__ 
+#define log2(x) (log(x) / M_LN2)
+#endif // __FreeBSD__
+
+
 /****************************************
  *                                      *
  * GPTData class and related structures *
@@ -1818,6 +1823,18 @@ int GPTData::SetPartitionGUID(uint32_t pn, GUIDData theGUID) {
    return retval;
 } // GPTData::SetPartitionGUID()
 
+// Set new random GUIDs for the disk and all partitions. Intended to be used
+// after disk cloning or similar operations that don't randomize the GUIDs.
+void GPTData::RandomizeGUIDs(void) {
+   uint32_t i;
+
+   mainHeader.diskGUID.Randomize();
+   secondHeader.diskGUID = mainHeader.diskGUID;
+   for (i = 0; i < numParts; i++)
+      if (partitions[i].IsUsed())
+         partitions[i].RandomizeUniqueGUID();
+} // GPTData::RandomizeGUIDs()
+
 // Change partition type code non-interactively. Returns 1 if
 // successful, 0 if not....
 int GPTData::ChangePartType(uint32_t partNum, uint16_t hexCode) {
@@ -1829,6 +1846,16 @@ int GPTData::ChangePartType(uint32_t partNum, uint16_t hexCode) {
    return retval;
 } // GPTData::ChangePartType()
 
+// Recompute the CHS values of all the MBR partitions. Used to reset
+// CHS values that some BIOSes require, despite the fact that the
+// resulting CHS values violate the GPT standard.
+void GPTData::RecomputeCHS(void) {
+   int i;
+
+   for (i = 0; i < 4; i++)
+      protectiveMBR.RecomputeCHS(i);
+} // GPTData::RecomputeCHS()
+
 // Adjust sector number so that it falls on a sector boundary that's a
 // multiple of sectorAlignment. This is done to improve the performance
 // of Western Digital Advanced Format disks and disks with similar
@@ -2140,10 +2167,7 @@ int GPTData::IsFreePartNum(uint32_t partNum) {
 // Set partition alignment value; partitions will begin on multiples of
 // the specified value
 void GPTData::SetAlignment(uint32_t n) {
-   uint32_t l2;
-
    sectorAlignment = n;
-   l2 = (uint32_t) log2(n);
 } // GPTData::SetAlignment()
 
 // Compute sector alignment based on the current partitions (if any). Each

gpt.h

@@ -16,7 +16,7 @@
 #ifndef __GPTSTRUCTS
 #define __GPTSTRUCTS
 
-#define GPTFDISK_VERSION "0.6.7"
+#define GPTFDISK_VERSION "0.6.8-pre2"
 
 // Constants used by GPTData::PartsToMBR(). MBR_EMPTY must be the lowest-
 // numbered value to refer to partition numbers. (Most will be 0 or positive,
@@ -160,8 +160,10 @@ public:
    int SetName(uint32_t partNum, const string & theName = "");
    void SetDiskGUID(GUIDData newGUID);
    int SetPartitionGUID(uint32_t pn, GUIDData theGUID);
+   void RandomizeGUIDs(void);
    int ChangePartType(uint32_t pn, uint16_t hexCode);
    void MakeProtectiveMBR(void) {protectiveMBR.MakeProtectiveMBR();}
+   void RecomputeCHS(void);
    int Align(uint64_t* sector);
 
    // Return data about the GPT structures....

mbr.cc

@@ -767,6 +767,23 @@ void MBRData::OptimizeEESize(void) {
    } // if
 } // MBRData::OptimizeEESize()
 
+// Recomputes the CHS values for the specified partition and adjusts the value.
+// Note that this will create a technically incorrect CHS value for EFI GPT (0xEE)
+// protective partitions, but this is required by some buggy BIOSes, so I'm
+// providing a function to do this deliberately at the user's command.
+// This function does nothing if the partition's length is 0.
+void MBRData::RecomputeCHS(int partNum) {
+   uint64_t firstLBA, lengthLBA;
+
+   firstLBA = (uint64_t) partitions[partNum].firstLBA;
+   lengthLBA = (uint64_t) partitions[partNum].lengthLBA;
+
+   if (lengthLBA > 0) {
+      LBAtoCHS(firstLBA, partitions[partNum].firstSector);
+      LBAtoCHS(firstLBA + lengthLBA - 1, partitions[partNum].lastSector);
+   } // if
+} // MBRData::RecomputeCHS()
+
 // Creates an MBR extended partition holding logical partitions that
 // correspond to the list of GPT partitions in theList. The extended
 // partition is placed in position #4 (counting from 1) in the MBR.

mbr.h

@@ -124,6 +124,7 @@ public:
    void DeletePartition(int i);
    int DeleteByLocation(uint64_t start64, uint64_t length64);
    void OptimizeEESize(void);
+   void RecomputeCHS(int partNum);
    int CreateLogicals(PartNotes& notes);
 
    // Functions to find information on free space....

sgdisk.8

@@ -166,7 +166,7 @@ the backup may not accurately reflect the damaged state; instead, they
 will reflect GPT fdisk's first\-pass interpretation of the GPT.
 
 .TP 
-.B \-c, \-\-change=partnum:name
+.B \-c, \-\-change\-name=partnum:name
 Change the GPT name of a partition. This name is encoded as a UTF\-16
 string, but \fBsgdisk\fR
 supports only ASCII characters as names. For the most part, Linux ignores
@@ -177,6 +177,17 @@ that includes a space, enclose it in quotation marks, as in
 partition is distinct from the filesystem name, which is encoded in the
 filesystem's data structures.
 
+.TP
+.B \-C, \-\-recompute-chs
+Recompute CHS values in protective or hybrid MBR. This option can sometimes
+help if a disk utility, OS, or BIOS doesn't like the CHS values used by the
+partitions in the protective or hybrid MBR. In particular, the GPT
+specification requires a CHS value of 0xFFFFFF for over-8GiB partitions,
+but this value is technically illegal by the usual standards. Some BIOSes
+hang if they encounter this value. This option will recompute a more normal
+CHS value -- 0xFEFFFF for over-8GiB partitions, enabling these BIOSes to
+boot.
+
 .TP 
 .B \-d, \-\-delete=partnum
 Delete a partition. This action deletes the entry from the partition table
@@ -218,6 +229,12 @@ Convert an MBR or BSD disklabel disk to a GPT disk. As a safety measure, use of
 this option is required on MBR or BSD disklabel disks if you intend to save your
 changes, in order to prevent accidentally damaging such disks.
 
+.TP
+.B \-G, \-\-randomize\-guids
+Randomize the disk's GUID and all partitions' unique GUIDs (but not their
+partition type code GUIDs). This function may be used after cloning a disk
+in order to render all GUIDs once again unique.
+
 .TP 
 .B \-h, \-\-hybrid
 Create a hybrid MBR. This option takes from one to three partition numbers,
@@ -286,6 +303,15 @@ sector. Pressing the Enter key with no input specifies the default value,
 which is the start of the largest available block for the start sector and
 the end of the same block for the end sector.
 
+.TP
+.B \-N, \-\-largest\-new
+Create a new partition that fills the largest available block of space on
+the disk. Note that if used on a completely blank disk, this is likely to
+result in a sector-moved warning, since the first available sector
+(normally 34) doesn't fall on a 2048-sector boundary (the default for
+alignment). You can use the \fI\-a\fR (\fI\-\-set\-alignment\fR) option to
+adjust the alignment, if desired.
+
 .TP 
 .B \-o, \-\-clear
 Clear out all partition data. This includes GPT header data,
@@ -337,6 +363,14 @@ partitions that are unusable. The many BSD variants means that the
 probability of \fBsgdisk\fR being unable to convert a BSD disklabel is
 high compared to the likelihood of problems with an MBR conversion.
 
+.TP
+.B \-u, \-\-partition-guid=partnum:guid
+Set the partition unique GUID for an individual partition.
+
+.TP
+.B \-U, \-\-disk-guid=guid
+Set the GUID for the disk.
+
 .TP 
 .B \-\-usage
 Print a brief summary of available options.

sgdisk.cc

@@ -32,7 +32,9 @@ int CountColons(char* argument);
 int main(int argc, char *argv[]) {
    GPTData theGPT;
    int opt, numOptions = 0, saveData = 0, neverSaveData = 0;
-   int partNum = 0, deletePartNum = 0, infoPartNum = 0, bsdPartNum = 0, saveNonGPT = 1;
+   int partNum = 0, deletePartNum = 0, infoPartNum = 0, bsdPartNum = 0, largestPartNum = 0;
+   int saveNonGPT = 1;
+   uint32_t gptPartNum = 0;
    int alignment = DEFAULT_ALIGNMENT, retval = 0, pretend = 0;
    unsigned int hexCode;
    uint32_t tableSize = 128;
@@ -40,6 +42,7 @@ int main(int argc, char *argv[]) {
    char *device = NULL;
    char *newPartInfo = NULL, *typeCode = NULL, *partName = NULL;
    char *backupFile = NULL, *twoParts = NULL, *hybrids = NULL, *mbrParts;
+   char *partGUID = NULL, *diskGUID = NULL;
    PartType typeHelper;
 
    poptContext poptCon;
@@ -48,18 +51,21 @@ int main(int argc, char *argv[]) {
       {"set-alignment", 'a', POPT_ARG_INT, &alignment, 'a', "set sector alignment", "value"},
       {"backup", 'b', POPT_ARG_STRING, &backupFile, 'b', "backup GPT to file", "file"},
       {"change-name", 'c', POPT_ARG_STRING, &partName, 'c', "change partition's name", "partnum:name"},
+      {"recompute-chs", 'C', POPT_ARG_NONE, NULL, 'C', "recompute CHS values in protective/hybrid MBR", ""},
       {"delete", 'd', POPT_ARG_INT, &deletePartNum, 'd', "delete a partition", "partnum"},
       {"display-alignment", 'D', POPT_ARG_NONE, NULL, 'D', "show number of sectors per allocation block", ""},
       {"move-second-header", 'e', POPT_ARG_NONE, NULL, 'e', "move second header to end of disk", ""},
       {"end-of-largest", 'E', POPT_ARG_NONE, NULL, 'E', "show end of largest free block", ""},
       {"first-in-largest", 'f', POPT_ARG_NONE, NULL, 'f', "show start of the largest free block", ""},
       {"mbrtogpt", 'g', POPT_ARG_NONE, NULL, 'g', "convert MBR to GPT", ""},
+      {"randomize-guids", 'G', POPT_ARG_NONE, NULL, 'G', "randomize disk and partition GUIDs", ""},
       {"hybrid", 'h', POPT_ARG_STRING, &hybrids, 'h', "create hybrid MBR", "partnum[:partnum...]"},
       {"info", 'i', POPT_ARG_INT, &infoPartNum, 'i', "show detailed information on partition", "partnum"},
       {"load-backup", 'l', POPT_ARG_STRING, &backupFile, 'l', "load GPT backup from file", "file"},
       {"list-types", 'L', POPT_ARG_NONE, NULL, 'L', "list known partition types", ""},
       {"gpttombr", 'm', POPT_ARG_STRING, &mbrParts, 'm', "convert GPT to MBR", "partnum[:partnum...]"},
       {"new", 'n', POPT_ARG_STRING, &newPartInfo, 'n', "create new partition", "partnum:start:end"},
+      {"largest-new", 'N', POPT_ARG_INT, &largestPartNum, 'N', "create largest possible new partition", "partnum"},
       {"clear", 'o', POPT_ARG_NONE, NULL, 'o', "clear partition table", ""},
       {"print", 'p', POPT_ARG_NONE, NULL, 'p', "print partition table", ""},
       {"pretend", 'P', POPT_ARG_NONE, NULL, 'P', "make changes in memory, but don't write them", ""},
@@ -68,6 +74,8 @@ int main(int argc, char *argv[]) {
       {"resize-table", 'S', POPT_ARG_INT, &tableSize, 'S', "resize partition table", "numparts"},
       {"typecode", 't', POPT_ARG_STRING, &typeCode, 't', "change partition type code", "partnum:hexcode"},
       {"transform-bsd", 'T', POPT_ARG_INT, &bsdPartNum, 'T', "transform BSD disklabel partition to GPT", "partnum"},
+      {"partition-guid", 'u', POPT_ARG_STRING, &partGUID, 'u', "set partition GUID", "partnum:guid"},
+      {"disk-guid", 'U', POPT_ARG_STRING, &diskGUID, 'U', "set disk GUID", "guid"},
       {"verify", 'v', POPT_ARG_NONE, NULL, 'v', "check partition table integrity", ""},
       {"version", 'V', POPT_ARG_NONE, NULL, 'V', "display version information", ""},
       {"zap", 'z', POPT_ARG_NONE, NULL, 'z', "zap (destroy) GPT (but not MBR) data structures", ""},
@@ -161,6 +169,11 @@ int main(int argc, char *argv[]) {
                   saveData = 1;
                   saveNonGPT = 1;
                   break;
+               case 'G':
+                  theGPT.JustLooking(0);
+                  saveData = 1;
+                  theGPT.RandomizeGUIDs();
+                  break;
                case 'h':
                   theGPT.JustLooking(0);
                   if (BuildMBR(&theGPT, hybrids, 1) == 1)
@@ -208,6 +221,18 @@ int main(int argc, char *argv[]) {
                   } // if/else
                   free(newPartInfo);
                   break;
+               case 'N':
+                  theGPT.JustLooking(0);
+                  startSector = theGPT.FindFirstInLargest();
+                  endSector = theGPT.FindLastInFree(startSector);
+                  if (theGPT.CreatePartition(largestPartNum - 1, startSector, endSector)) {
+                     saveData = 1;
+                  } else {
+                     cerr << "Could not create partition " << largestPartNum << " from "
+                          << startSector << " to " << endSector << "\n";
+                     neverSaveData = 1;
+                  } // if/else
+                  break;
                case 'o':
                   theGPT.JustLooking(0);
                   theGPT.ClearGPTData();
@@ -229,6 +254,11 @@ int main(int argc, char *argv[]) {
                      cerr << "Cannot swap partitions " << p1 + 1 << " and " << p2 + 1 << "\n";
                   } else saveData = 1;
                   break;
+               case 'R':
+                  theGPT.JustLooking(0);
+                  theGPT.RecomputeCHS();
+                  saveData = 1;
+                  break;
                case 's':
                   theGPT.JustLooking(0);
                   theGPT.SortGPT();
@@ -259,6 +289,17 @@ int main(int argc, char *argv[]) {
                   theGPT.XFormDisklabel(bsdPartNum - 1);
                   saveData = 1;
                   break;
+               case 'u':
+                  theGPT.JustLooking(0);
+                  saveData = 1;
+                  gptPartNum = (int) GetInt(partGUID, 1) - 1;
+                  theGPT.SetPartitionGUID(gptPartNum, GetString(partGUID, 2).c_str());
+                  break;
+               case 'U':
+                  theGPT.JustLooking(0);
+                  saveData = 1;
+                  theGPT.SetDiskGUID(diskGUID);
+                  break;
                case 'v':
                   theGPT.Verify();
                   break;