CGPT(1) System Administration Commands CGPT(1)NAME
cgpt - Utility to manipulate GPT partitions with Chromium OS extensions
SYNOPSIS
cgpt COMMAND [OPTIONS] DRIVE
DESCRIPTION
Cgpt is a tool to manipulate a GUID Partition Table from the command
line. Although several other utilities exist for the same basic purpose
- some with more features and a captive user interface - cgpt is unique
in that it also supports Chromium OS extensions. These extensions are
not generally useful; they are specific to the u-boot firmware found on
some Chromebooks. They may be used to change priority for kernel parti‐
tions and give other hints to u-boot Chromebook firmware. Use this
utility only to manipulate a partition table for compatible Chrome‐
books.
COMMANDS
Each action performed by this program - with the notable exception of
the -h OPTION - is initiated by a command which tells cgpt the type of
operation to perform. All available commands are described below.
create Create or reset GPT headers and tables.
add Add, edit, or remove a partition entry.
show Show the partition table and entries.
repair Repair damaged GPT headers and tables.
boot Edit the PMBR sector for legacy BIOSes.
If no BOOT OPTIONS are specified, this command will just print
the PMBR boot GUID.
find Find a partition by its GUID.
If no DRIVE is specified, this command will scan all physical
drives for a match.
prioritize
Reorder the priority of all ChromeOS kernel partitions.
If no options are specified, this command will set the lowest
active kernel to priority 1 while maintaining the original
order.
legacy Switch between GPT and Legacy GPT.
GENERAL OPTIONS
The options described in this section apply to every COMMAND supported
by this program.
-h For more detailed usage, use cgpt COMMAND -h
EXAMPLES
The following examples demonstrate valid syntax only. It is up to you
to interpret them based on the documentation in this manual.
cgpt show /dev/mmcblk0
cgpt create /dev/mmcblk0
cgpt add -i 2 -S 1 -T 15 -P 15 /dev/mmcblk0
cgpt add -i 1 -t data -l "STATE" /dev/mmcblk0
cgpt add -i 2 -t kernel -l "KERN-A" /dev/mmcblk0
cgpt add -i 3 -t rootfs -l "ROOT-A" /dev/mmcblk0
AUTHOR
This manual page was written by Karl Lenz <xorangekiller@gmail.com> for
the Debian project (but may be used by others).
COPYRIGHT
Cgpt is copyright 2010-2013, The Chromium OS Authors
This manual page is copyright 2014, Karl Lenz
Copying and distribution of this file, with or without modification,
are permitted in any medium without royalty provided the copyright
notice and this notice are preserved.
Cgpt is provided "as is" with no warranty. The exact terms under which
you may use and (re)distribute this program are detailed in the BSD
3-Clause License, which is distributed with this program in the LICENSE
file. On Debian systems, the complete text of the BSD 3-Clause License
can be found in /usr/share/common-licenses/BSD.
SEE ALSOparted(8), gdisk(8), gptsync(8)cgpt January 2014 CGPT(1)