README - platform/external/gptfdisk - Gitiles

 GPT fdisk (aka gdisk)
 by Roderick W. Smith, rodsmith@rodsbooks.com

 Introduction
 ------------

 This software is intended as a (somewhat) fdisk-workalike program for
 GPT-partitioned disks. Although libparted and programs that use it (GNU
 Parted, gparted, etc.) provide the ability to handle GPT disks, they have
 certain limitations that gdisk overcomes. Specific advantages of gdisk and
 sgdisk include:

 * The ability to convert MBR-partitioned disks in-place to GPT format,
   without losing data

 * The ability to convert BSD disklabels in-place to create GPT
   partitions, without losing data

 * The ability to specify sector-exact partition sizes

 * More flexible specification of filesystem type code GUIDs, which
   GNU Parted tends to corrupt (particularly for FAT partitions)

 * Clear identification of the number of unallocated sectors on a
   disk

 * A user interface that's familiar to long-time users of Linux
   fdisk (gdisk only)

 * The MBR boot loader code is left alone (GNU Parted tends to
   wipe it out with every change)

 * The ability to create a hybrid MBR, which permits GPT-unaware
   OSes to access up to three GPT partitions on the disk

 Of course, GPT fdisk isn't without its limitations. Most notably, it lacks
 the filesystem awareness and filesystem-related features of GNU Parted. You
 can't resize a partition's filesystem or create a partition with a
 filesystem already in place with gdisk, for instance. There's no GUI
 version of gdisk.

 The GPT fdisk package provides two program files: the interactive text-mode
 gdisk and the command-line-driven sgdisk. The former is intended for use in
 manually partitioning disks or changing partitioning details; the latter is
 intended for use in scripts to help automate tasks such as disk cloning or
 preparing multiple disks for Linux installation.

 Installing
 ----------

 To compile GPT fdisk, you must have appropriate development tools
 installed, most notably the GNU Compiler Collection (GCC) and its g++
 compiler for C++. The sgdisk program also requires the popt library and its
 development files (headers). Most Linux distributions install popt by
 default, but you may need to install a package called popt-dev, popt-devel,
 or something similar to obtain the header files. Mac OS users can find a
 version of popt for Mac OS from http://popt.darwinports.com; however,
 you'll first need to install DarwinPorts (instructions exist on the
 preceding page). Alternatively, you can compile gdisk alone, without
 sgdisk; gdisk doesn't require popt.

 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. The result should be program files called gdisk and
 sgdisk. Typing "make gdisk" or "make sgdisk" will compile only the requested
 programs. You can use these programs in place or copy the files to a
 suitable directory, such as /usr/local/sbin. You can copy the man pages
 (gdisk.8 and sgdisk.8) to /usr/local/man/man8 to make them available.

 Caveats
 -------

 THIS SOFTWARE IS BETA SOFTWARE! IF IT WIPES OUT YOUR HARD DISK OR EATS YOUR
 CAT, DON'T BLAME ME! To date, I've tested the software on several USB flash
 drives, a handful of PATA and SATA hard disks, and several virtual disks in
 a QEMU environment. I believe all data-corruption bugs to be squashed, but
 I know full well that the odds of my missing something are high. This is
 particularly true for large drives; my only direct testing with such disks
 is with virtual QEMU disks. I've received user reports of success with
 RAID arrays over 2TiB in size, though.

 My main development platform is a system running the 64-bit version of
 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, 64-bit Gentoo, 32-bit
 PowerPC Debian Linux, 32-bit Intel-based Mac OS X 10.5 and 10.6, and 64-bit
 FreeBSD 7.1. Problems relating to 64-bit integers on the 32-bit Linux have
 been common during development and may crop up in the future. The Mac OS X,
 FreeBSD, and big-endian (PowerPC) support are new.

 Redistribution
 --------------

 This program is licensed under terms of the GNU GPL (see the file COPYING).

 Acknowledgements
 ----------------

 This code is mostly my own; however, I've used three functions from two
 other GPLed programs:

 - The code used to generate CRCs is taken from the efone program by
   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. V. Le Blanc.

 Additional code contributors include:

 - Yves Blusseau (1otnwmz02@sneakemail.com)

 - David Hubbard (david.c.hubbard@gmail.com)
	GPT fdisk (aka gdisk)
	by Roderick W. Smith, rodsmith@rodsbooks.com

	Introduction
	------------

	This software is intended as a (somewhat) fdisk-workalike program for
	GPT-partitioned disks. Although libparted and programs that use it (GNU
	Parted, gparted, etc.) provide the ability to handle GPT disks, they have
	certain limitations that gdisk overcomes. Specific advantages of gdisk and
	sgdisk include:

	* The ability to convert MBR-partitioned disks in-place to GPT format,
	without losing data

	* The ability to convert BSD disklabels in-place to create GPT
	partitions, without losing data

	* The ability to specify sector-exact partition sizes

	* More flexible specification of filesystem type code GUIDs, which
	GNU Parted tends to corrupt (particularly for FAT partitions)

	* Clear identification of the number of unallocated sectors on a
	disk

	* A user interface that's familiar to long-time users of Linux
	fdisk (gdisk only)

	* The MBR boot loader code is left alone (GNU Parted tends to
	wipe it out with every change)

	* The ability to create a hybrid MBR, which permits GPT-unaware
	OSes to access up to three GPT partitions on the disk

	Of course, GPT fdisk isn't without its limitations. Most notably, it lacks
	the filesystem awareness and filesystem-related features of GNU Parted. You
	can't resize a partition's filesystem or create a partition with a
	filesystem already in place with gdisk, for instance. There's no GUI
	version of gdisk.

	The GPT fdisk package provides two program files: the interactive text-mode
	gdisk and the command-line-driven sgdisk. The former is intended for use in
	manually partitioning disks or changing partitioning details; the latter is
	intended for use in scripts to help automate tasks such as disk cloning or
	preparing multiple disks for Linux installation.

	Installing
	----------

	To compile GPT fdisk, you must have appropriate development tools
	installed, most notably the GNU Compiler Collection (GCC) and its g++
	compiler for C++. The sgdisk program also requires the popt library and its
	development files (headers). Most Linux distributions install popt by
	default, but you may need to install a package called popt-dev, popt-devel,
	or something similar to obtain the header files. Mac OS users can find a
	version of popt for Mac OS from http://popt.darwinports.com; however,
	you'll first need to install DarwinPorts (instructions exist on the
	preceding page). Alternatively, you can compile gdisk alone, without
	sgdisk; gdisk doesn't require popt.

	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. The result should be program files called gdisk and
	sgdisk. Typing "make gdisk" or "make sgdisk" will compile only the requested
	programs. You can use these programs in place or copy the files to a
	suitable directory, such as /usr/local/sbin. You can copy the man pages
	(gdisk.8 and sgdisk.8) to /usr/local/man/man8 to make them available.

	Caveats
	-------

	THIS SOFTWARE IS BETA SOFTWARE! IF IT WIPES OUT YOUR HARD DISK OR EATS YOUR
	CAT, DON'T BLAME ME! To date, I've tested the software on several USB flash
	drives, a handful of PATA and SATA hard disks, and several virtual disks in
	a QEMU environment. I believe all data-corruption bugs to be squashed, but
	I know full well that the odds of my missing something are high. This is
	particularly true for large drives; my only direct testing with such disks
	is with virtual QEMU disks. I've received user reports of success with
	RAID arrays over 2TiB in size, though.

	My main development platform is a system running the 64-bit version of
	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, 64-bit Gentoo, 32-bit
	PowerPC Debian Linux, 32-bit Intel-based Mac OS X 10.5 and 10.6, and 64-bit
	FreeBSD 7.1. Problems relating to 64-bit integers on the 32-bit Linux have
	been common during development and may crop up in the future. The Mac OS X,
	FreeBSD, and big-endian (PowerPC) support are new.

	Redistribution
	--------------

	This program is licensed under terms of the GNU GPL (see the file COPYING).

	Acknowledgements
	----------------

	This code is mostly my own; however, I've used three functions from two
	other GPLed programs:

	- The code used to generate CRCs is taken from the efone program by
	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. V. Le Blanc.

	Additional code contributors include:

	- Yves Blusseau (1otnwmz02@sneakemail.com)

	- David Hubbard (david.c.hubbard@gmail.com)