Following yesterday’s report that iOS hacker pod2g was nearing completion of an untethered iPhone 4S jailbreak, pod2g has since updated his report, noting that he has finally figured out the problem, and will now be able to complete the jailbreak.
OK, figured it out, the A5 cache is not a problem anymore.
I sorted it out by doing the untether in a single thread and by flushing all the dcache then all the icache in a row at a strategical point of the process.
It took me like a hundred of tests to find the key. Hard for the nerves.
For the tech guys, here is a link explaining issues related to self modifying code ( or code patching ) on the ARM platform : http://blogs.arm.com/software-enablement/141-caches-and-self-modifying-code/
Another news : I discussed with @saurik today about the launchd boot process, and he’s found one missing piece of the puzzle I needed to have a perfectly stable jailbreak. He’s definitly one of the best iOS gurus out there. Thank you saurik!
The trouble was mainly due to to a caching issue with Apple’s latest A5 processor, but now, with some help from Cydia developer Jay Freeman, that issue is no longer a concern.
While an iPhone 4S jailbreak has yet to be released, this should be taken as excellent news that such a jailbreak may be coming in the very near future.