checkm8 a5

• The main recommendation for A5(X) devices is to just use kDFU mode as much as possible. For the procedures that need pwned DFU mode (like tethered downgrade/boot), continue reading this section.
• For A5(X) devices, additional hardware is required to enter pwned DFU mode.

There are 2 methods of using checkm8-a5: Arduino and USB Host Shield, or Raspberry Pi Pico

Arduino and USB Host Shield

• Use my fork of checkm8-a5 with an Arduino and USB Host Shield: https://github.com/LukeZGD/checkm8-a5
• Note about clone Arduinos: Clones may work just fine as long as they have the ATmega chip. They may be listed as "DIP" in some listings.
  • Avoid using CH340 "SMD" clone Arduinos. They are very unreliable for checkm8-a5.
• Proceed here for a video tutorial on how to install and use checkm8-a5 Arduino: https://www.youtube.com/watch?v=efAxIXieCLM
  • Stop the video tutorial around 7:12 since the steps beyond this part are no longer necessary.
• Here is also a tutorial from ios.cfw.guide: https://ios.cfw.guide/using-checkm8-a5

Raspberry Pi Pico

• checkm8-a5 for the Raspberry Pi Pico is also an option: https://www.reddit.com/r/LegacyJailbreak/comments/1djuprf/working_checkm8a5_on_the_raspberry_pi_pico/
  • Get the UF2 files at the link on the bottom of the post, also linked here: https://mega.nz/file/RSd3AKAT#bfGaz1ThDtGcq-_9PYj5wF0m99Z-ZyvJABt6kLbR64A
• Original instructions here: https://blog.elcomsoft.com/2022/05/checkm8-unlocking-and-imaging-the-iphone-4s/
  • Note: You do NOT need to get their iOS Forensic Toolkit for this. Also do not get the UF2 files from here.

Notes

• If entering pwnDFU mode and/or sending pwned iBSS failed, the downgrade/restore will not work, and you need to force restart and try pwning again.
• Also make sure that you have not sent a pwned iBSS yet.