JPT - A quick & dirty GPT Partition Editor
/** * Quick GPT viewing/editing tool - 03/07/2018 * * By Jonathan Levin (@Morpheus______), http://NewAndroidBook.com * * I coded this because I grew frustrated with GNU parted while doing * some Android research. I reused a lot of code from my MacOS (H)FSleuth * tool (http://NewOSXBook.com), and since this is POSIX code I ended up * with a generic tool that works on all architectures. Hypothetically * this would also work on Windows through cygwin or Linux subsystem, * if you can get the raw device.. This was tested on several Android * devices (Samsung Tab S3, Nexus 6P and Pixel) as well as (naturally) MacOS. *
Usage:
angler:/ $ /data/local/tmp/jpt
Usage: /data/local/tmp/jpt _device_ _verb_
Where _verb_ is one of:
check: Just run a set of quick validation check over GPT data
headers: Show GPT headers (primary and backup)
list: List partitions
rename # name: Rename partition number # to name
remove #: Remove partition number #
sync: Sync the backup GPT header to match the primary header
save _file_: Save a copy of the primary GPT header to _file
restore [file] Restore primary GPT header to match backup, or a file
resize # [-]##: Resize partition number # to ## LBA units or until -LBA
add [#-##]: Add new partition (always last) from LBA # to LBA ## (or auto-fill)
This is jpt v1.0, free from http://NewAndroidBook.com
COMES WITH absolutely ZERO-WARRANTY AND LIABILITY. Please see license in jpt.c comment!
Examples:
sailfish:/ # /data/local/tmp/jpt /dev/block/sda list
1: 6-133 (508.0KB) flags: 0x3000000000000 77036CD4-03D5-42BB-8ED1-37E5A88BAA34 Label: bootlocker_a
2: 134-261 (508.0KB) flags: 0x1f000000000000 4A20058D-2D54-0D80-E6CC-4ADDDA723C2A Label: bootlocker_b
3: 262-389 (508.0KB) flags: 0x3000000000000 77036CD4-03D5-42BB-8ED1-37E5A88BAA34 Label: keymaster_a
4: 390-517 (508.0KB) flags: 0x5f000000000000 4F772165-0F3C-4BA3-BBCB-A829E9C969F9 Label: keymaster_b
5: 518-1029 (1.18MB) flags: 0x3000000000000 77036CD4-03D5-42BB-8ED1-37E5A88BAA34 Label: tz_a
6: 1030-1541 (1.18MB) flags: 0x5f000000000000 TrustZone Image (QCOM) Label: tz_b
...
35: 1275718-7785285 (24.14GB) flags: 0x3000000000000 EBD0A0A2-B9E5-4433-87C0-68B6B72699C7 Label: userdata
36: 7785286-7786490 (4.17GB) flags: 0x3000000000000 EBD0A0A2-B9E5-4433-87C0-68B6B72699C7 Label: reserve0
Consider a Nexus 6P (angler). The default partitioning is:
angler:/ # cat /proc/partitions
major minor #blocks name
254 0 520912 zram0
179 0 30535680 mmcblk0
179 1 81920 mmcblk0p1
...
259 12 26777083 mmcblk0p44
179 32 4096 mmcblk0rpmb
Using jpt, you can list the partitions:
angler:/# /data/local/tmp/jpt /dev/block/mmcblk0 list
1: 16384-180223 (79.149MB) flags: 0x1000000000000000 EBD0A0A2-B9E5-4433-87C0-68B6B72699C7 Label: modem
2: 180224-182271 (1023.0KB) flags: 0x0 DEA0BA2C-CBDD-4805-B4F9-F428251C3E98 Label: sbl1
..
43: 1225704-7517159 (2.149GB) flags: 0x0 97D7B011-54DA-4835-B3C4-917AD6E73D74 Label: system
44: 7517160-61071326 (25.107GB) flags: 0x0 1B81E7E6-F50D-419B-A739-2AEEF8DA3335 Label: userdata
To resize, we provide the partition number (44, since jpt counts from 1, like the 'mmcblk0p1..') and either the size in LBA, or "-" with the last LBA. Putting it at 34,000,000, it looks like this:
angler:/ # /data/local/tmp/jpt /dev/block/mmcblk0 resize 44 -34000000
Resizing partition #44: 7517160-34000000
Updating CRC to 0x6fd9e7e1
seek: 512 to LBA 1 (LBA SIZE: 512)
GPT Committed Table Header:
Revision: 0x10000
Header Size: 92 bytes
CRC32: 0x8c5316d3 (correct)
CurrentLBA: 1 BackupLBA: 61071359
UsableLBA: 34-61071326 (29.24GB)
StartingLBA: 2
#Entries: 44
Partition Entry size: 128 bytes
Array CRC: 0x6fd9e7e1
Writing partition array (5632 bytes) to LBA 2
Committing primary to backup
seek: 31268535808 to LBA 61071359 (LBA SIZE: 512)
GPT Committed Table Header:
Revision: 0x10000
Header Size: 92 bytes
CRC32: 0x307c46db (correct)
CurrentLBA: 61071359 BackupLBA: 1
UsableLBA: 34-61071326 (29.24GB)
StartingLBA: 61071327
#Entries: 44
Partition Entry size: 128 bytes
Array CRC: 0x6fd9e7e1
Writing partition array (5632 bytes) to LBA 61071327
sync and reboot, and you're all done!
NOTE THIS WILL DESTROY YOUR /data, so it has the effect of a factory reset. But it's easy to backup and restore. Indeed, rebooting and re-rooting we see:
angler:/# cat /proc/partitions major minor #blocks name 254 0 520912 zram0 179 0 30535680 mmcblk0 179 1 81920 mmcblk0p1 .. 259 11 3145728 mmcblk0p43 259 12 13241420 mmcblk0p44 179 32 4096 mmcblk0rpmb angler:/# data/local/tmp/jpt /dev/block/mmcblk0 list 1: 16384-180223 (79.149MB) flags: 0x1000000000000000 EBD0A0A2-B9E5-4433-87C0-68B6B72699C7 Label: modem 2: 180224-182271 (1023.0KB) flags: 0x0 DEA0BA2C-CBDD-4805-B4F9-F428251C3E98 Label: sbl1 3: 182272-182463 (95.0KB) flags: 0x0 D4E0D938-B7FA-48C1-9D21-BC5ED5C4B203 Label: sdi 4: 182464-184511 (1023.0KB) flags: 0x0 TrustZone Image (QCOM) Label: tz ... 43: 1225704-7517159 (2.149GB) flags: 0x0 97D7B011-54DA-4835-B3C4-917AD6E73D74 Label: system 44: 7517160-34000000 (12.125GB) flags: 0x0 1B81E7E6-F50D-419B-A739-2AEEF8DA3335 Label: userdata
And what can we do after we reduce a partition to half? Why, add another partition, of course. Using 'add' with no arguments will auto-fill:
angler:/ # /data/local/tmp/jpt /dev/block/mmcblk0 add Adding partition 45 at LBA 34000001-61071326 (12.131GB) Updating CRC to 0x50cd9dbf seek: 512 to LBA 1 (LBA SIZE: 512) GPT Committed Table Header: Revision: 0x10000 Header Size: 92 bytes CRC32: 0xfd8a35c3 (correct) CurrentLBA: 1 BackupLBA: 61071359 UsableLBA: 34-61071326 (29.24GB) StartingLBA: 2 #Entries: 45 Partition Entry size: 128 bytes Array CRC: 0x50cd9dbf HEADER PARTITION CRC: 0x50cd9dbf WRITE RC: 92 Writing partition array (5760 bytes) to LBA 2 Committing primary to backup seek: 31268535808 to LBA 61071359 (LBA SIZE: 512) Committing primary to backup (3) GPT Committed Table Header: Revision: 0x10000 Header Size: 92 bytes CRC32: 0x41a565cb (correct) CurrentLBA: 61071359 BackupLBA: 1 UsableLBA: 34-61071326 (29.24GB) StartingLBA: 61071327 #Entries: 45 Partition Entry size: 128 bytes Array CRC: 0x50cd9dbf HEADER PARTITION CRC: 0x50cd9dbf WRITE RC: 92 Writing partition array (5760 bytes) to LBA 61071327 angler:/ # /data/local/tmp/jpt /dev/block/mmcblk0 list | grep 45: 45: 34000001-61071326 (12.131GB) flags: 0x0 24242424-2424-2424-2424-242424242424 (no label)
You can always rename the partition, and you can of course remove and add as many times as you want.
Rebooting, we then see the new partition show up in
angler:/ # tail -4 /proc/partitions
259 11 3145728 mmcblk0p43
259 12 13241420 mmcblk0p44
259 13 13535663 mmcblk0p45
179 32 4096 mmcblk0rpmb
LICENSE
* License: Free for personal use, provided you give credit. DO NOT put this * on GitHUB after you've cut/pasted my code and comments about, and * try to pass this as your own. That's plagiarism, and it's bad karma. * NOT free for commercial use. If you want to do so, ask me first. * Open source != (Obtain Free && Close && Profit) * * Disclaimer: All code abides by Lubarsky's Law of Cybernetic Entomology. * I therefore assume ABSOLUTELY NO responsibility WHAT-SO-EVER if, * through using any part of this code, running this code or * even being remotely inspired by it, you end up nuking your * partition table, or suffer ANY data loss, of 1 bit or more. *
Requests
* Request: If you do find a bug, PLEASE report it to me, and do keep in mind - * This was really quick and dirty. But just A) fussing about them * over social media or B) discovering exploitable overflows or * C) keeping them to yourself won't really help. This was built * around my (very specific) use-cases, and therefore I could neither * i) be aware of all the other use cases nor ii) know (or care much) * about the crazy abuse cases. * * Ditto for feature requests. I will be happy to incorporate more * features, if it's not too much code. If you want to help, a good * idea is compiling more GPT Partition type GUIDs. It's a lousy job, * but a community effort might amortize it. Also a portable i18n * for those (quite common, but not in US) cases where labels are * not in English. *
Other notes:
* And - you might want to check out HFSleuth (if you're a Mac/iOS user) or * the upcoming FSleuth (which will be made public in or around MOXiI * Volume II). Either tool goes past the partition table and into filesystems, * and the latter is especially useful with Apple's new (and as yet * undocumented) APFS. * * Free advice: watch out for the baobabs! * Or for any tree if, when laden with snow, it may fall on your house. *
FAQ:
- Why not GNU parted?: Try running it on a Pixel, with an LBA size of 0x1000, and see for yourself:
sailfish:/ # /data/local/tmp/parted /dev/block/sda Warning: Device /dev/block/sda has a logical sector size of 4096. Not all parts of GNU Parted support this at the moment, and the working code is HIGHLY EXPERIMENTAL. GNU Parted 1.8.8.1.179-aef3 Using /dev/block/sda Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) print print You found a bug in GNU Parted! Here's what you have to do: Don't panic! The bug has most likely not affected any of your data. Help us to fix this bug by doing the following: Check whether the bug has already been fixed by checking the last version of GNU Parted that you can find at: http://ftp.gnu.org/gnu/parted/ Please check this version prior to bug reporting. If this has not been fixed yet or if you don't know how to check, please visit the GNU Parted website: http://www.gnu.org/software/parted for further information. Your report should contain the version of this release (1.8.8.1.179-aef3) along with the error message below, the output of parted DEVICE unit co print unit s print and the following history of commands you entered. Also include any additional information about your setup you consider important. Error: SEGV_MAPERR (Address not mapped to object) Aborted - The tool crashes! I LOST DATA! Shows you haven't read the license... or the usage note. If you want to report a bug, I'll be happy to fix it.