Bootloader unlocking

From Wikipedia, the free encyclopedia
An unlocked Android bootloader, showing additional available options

Bootloader unlocking is the process of disabling the bootloader security that makes secure boot possible. It can make advanced customizations possible, such as installing a custom firmware. On smartphones, this can be a custom Android distribution or an other mobile operating system. Some bootloaders are not locked at all, others can be unlocked using a standard command, others need assistant from the manufacturer. Some do not include an unlocking method and can only be unlocked through a software exploit.

Platforms[]

Android[]

Unlocking the bootloader is typically done during the process to obtain root access.

Android bootloaders are typically proprietary software and based on the Qualcomm bootloader Little Kernel.[1]

In the context of Android, it is also called OEM Unlock.

The bootloaders of Nexus devices can be unlocked by using the fastboot command oem unlock.[1]

In 2012, Motorola released a limited tool for unlocking bootloaders.[2] They require accepting terms and conditions and creating an account before the bootloader can be unlocked for a Moto G.[3]

Sony requires the IMEI number to be filled in on their website for unlocking the bootloader.[4] For the Asus Transformer Prime TF201, Asus has released a special bootloader unlock tool.[5]

HTC Phones have an additional layer of lock called "S-OFF/S-ON".

Bootloaders can be unlocked using an exploit, or using a way that the vendor supplied. The latter method usually requires wiping all data on the device.[6]

In 2018, a developer from XDA Developers launched a service which allowed users to unlock the bootloader of some Nokia smartphone models.[7]

Huawei has announced plans to allow users to unlock the bootloader of the Mate 30 series, but retracted that later.[8] Huawei has stopped providing bootloader unlock codes since 2018.[9] A bootloader exploit named checkm30 has been developed for HiSilicon based Huawei phones.[10][non-primary source needed]

When the bootloader of the Samsung Galaxy Z Fold 3 is unlocked, the camera becomes less functional. This can be restored by re-locking the bootloader.[11] For the Samsung Galaxy S22 series, unlocking the bootloader has no effect on the camera.[12]

Windows Phone[]

The WPInternals tool developed by HeathCliff74 is able to unlock bootloaders of all Lumia phones.[13][14]

iOS[]

See also: Jailbreaking (iOS)

The boot ROM protection on iOS devices with an A11 processor or older can be bypassed with a hardware exploit known as checkm8, which makes it possible to run other operating systems including Linux.[15]

macOS[]

The bootloader on M1 based Macs can be unlocked.[16]

Chromebook[]

The equivalent of bootloader unlocking is called developer mode in Chromebooks.[17] Chromebooks use custom bootloaders that can be modified or overwritten by removing a Write-protect screw.[18]

Chromecast[]

In 2013, the bootloader of the Chromecast was hacked using an exploit.[19] In 2021, it was hacked again for newer versions.[20]

Windows RT[]

The slab bootloader used by Windows RT could be unlocked using a vulnerability, but was silently patched by Microsoft in 2016.[21]

Windows (x86)[]

See also: Secure boot

Relocking[]

On Android, it is possible to relock the bootloader again.[22]

Downsides[]

Unlocking the bootloader usually voids any warranties and may make the device susceptible to data theft.[23][24] On Chromebooks, enabling developer mode makes the system less secure than a standard laptop running Linux.[25] Unlocking the bootloader may lead to data loss on Android and Chrome OS devices, as some data is impossible to back up without root permission.

Opinions[]

Sascha Segan from PCMag considered a locked bootloader a mistake on the Qualcomm Snapdragon Insiders phone, which is targeted at advanced users.[26]

See also[]

References[]

  1. ^ a b Elenkov, Nikolay (2015). Android Security Internals: an In-Depth Guide to Android's Security Architecture. San Francisco, CA: No Starch Press. p. 350. ISBN 1-59327-581-1. OCLC 896723300.
  2. ^ Rodgers, Evan (2012-08-17). "Motorola unveils Android bootloader unlocking tool with limited device support". The Verge. Archived from the original on 2012-08-19. Retrieved 2021-09-10.
  3. ^ Viscomi, Rick; Andy Davies; Marcel Duran (2015). Using WebPageTest: web performance testing for novices and power users. Sebastopol, CA. ISBN 978-1-4919-0281-3. OCLC 927108295.
  4. ^ Kotipalli, Srinivasa Rao; Mohammed A. Imran (2016). Hacking Android: explore every nook and cranny of the Android OS to modify your device and guard it against security threats. Birmingham, UK. ISBN 978-1-78588-800-7. OCLC 957298786.
  5. ^ Tiefenthäler, Ronald. "Asus: Bootloader Unlock Tool für Tablet Transformer Prime TF201 verfügbar". Notebookcheck (in German). Retrieved 2021-08-04.
  6. ^ Afonin, Oleg (2016). Mobile Forensics ' Advanced Investigative Strategies (1 ed.). Packt Publishing. ISBN 1-78646-408-X. OCLC 960040717.
  7. ^ Rox, Ricci. "Nokia users can now unofficially unlock their bootloaders but the methodology is as sketchy as it gets". Notebookcheck. Retrieved 2021-09-06.
  8. ^ "Huawei Mate 30 will not have an unlocked bootloader". The Indian Express. 2019-09-25. Archived from the original on 2019-09-26. Retrieved 2021-09-06.
  9. ^ "Huawei will no longer offer bootloader unlock codes for its Android devices". 9to5Google. 2018-05-24. Retrieved 2021-09-06.
  10. ^ "Checkmate Mate 30 - Attack the bootrom of Huawei smartphones" (PDF). Archived (PDF) from the original on 2021-09-06.
  11. ^ Clark, Mitchell (2021-08-24). "Samsung will let you unlock your Z Fold 3's bootloader, but at the cost of your cameras". The Verge. Archived from the original on 2021-08-24. Retrieved 2021-09-06.
  12. ^ "Unlocking the bootloader doesn't break the camera on the Samsung Galaxy S22 series". xda-developers. 2022-02-26. Retrieved 2022-02-26.
  13. ^ "Tool van Nederlandse ontwikkelaar kan custom roms op alle Lumia's flashen". Tweakers (in Dutch). Retrieved 2021-08-04.
  14. ^ "Windows Phone Internals 2.2 Unlocks the Bootloader on all Windows 8 & 10 Lumia Smartphones". xda-developers. 2017-12-04. Retrieved 2021-08-04.
  15. ^ Lundberg, Anders. "16-year-old runs Linux on iPhone 7". Macworld UK. Retrieved 2021-08-04.
  16. ^ January 2021, Michelle Ehrhardt 19 (2021-01-19). "Linux is Finally on Apple M1...Kind Of". Tom's Hardware. Retrieved 2021-08-04.
  17. ^ December 2014, Lucian Armasu 31 (2014-12-31). "You Can Now Run Full Linux Apps Inside A Chrome OS Window". Tom's Hardware. Retrieved 2021-09-06.{{cite web}}: CS1 maint: url-status (link)
  18. ^ Robert, Foss (2017-03-08). "Quick hack: Removing the Chromebook Write-Protect screw". Collabora. Retrieved 2021-09-04.
  19. ^ "Chromecast bootloader exploit surfaces, opens up plenty of possibilities (video)". Engadget. Archived from the original on 2020-09-04. Retrieved 2021-09-06.
  20. ^ "Modders ontgrendelen bootloader van Google Chromecast met Google TV". Tweakers (in Dutch). Archived from the original on 2021-08-01. Retrieved 2021-09-06.
  21. ^ Francisco, Shaun Nichols in San. "Microsoft silently kills dev backdoor that boots Linux on locked-down Windows RT slabs". www.theregister.com. Retrieved 2021-09-06.
  22. ^ Wilde, Damien (2021-09-09). "How to downgrade from Android 12 Beta to Android 11 on Google Pixel [Video]". 9to5Google. Retrieved 2021-09-28.
  23. ^ Tamma, Rohit; Donnie Tindall (2015). Learning Android forensics: a hands-on guide to Android forensics, from setting up the forensic workstation to analyzing key forensic artifacts. Birmingham, UK. ISBN 978-1-78217-444-8. OCLC 910639389.
  24. ^ Hoffman, Chris. "The Security Risks of Unlocking Your Android Phone's Bootloader". How-To Geek. Retrieved 2021-08-04.
  25. ^ Porup, J. M. (2017-06-19). "How to install Linux on a Chromebook (and why you should)". Ars Technica. Archived from the original on 2017-06-19. Retrieved 2021-09-06.
  26. ^ "Qualcomm Smartphone for Snapdragon Insiders Review". PCMag. Archived from the original on 2021-08-16. Retrieved 2021-09-06.

External links[]

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