Definitions of JB types plz

[Tamkis]

I hope this topic is not n00bish; it somewhat isn't. I've only recently discovered here that there are three types of jailbreaks: exploits, userland exploits, and iboot exploits. Could someone define the 3, give a comparison/contrastion of the three types, and explain how kernel/root/user mode relates to the 3 types?

Also, which type is the best in terms of stability when upgrading to a new firmware to use a new JB (e.g. Blackra1n+Spirit=disater). Lastly, which in your opinion is the best "brand" of JB?

Thanks in advance!

[Captinsmooth]

As far as a detailed inter workings I don't have much insight on that. But to my knowledge a bootrom exploit is the best and most stable Jb.

redsnow / blackrain = bootrom

spirit / jailbreakme.com = userland


A bootrom jb is a jb that can not be defeated by a simple firmware upgrade apple has to change hardware to prevent them, hence old and new 3gs bootroms. A bootroom injects at the hardware portion of the phone and takes effect before the startup.

A userland jb can be fixed by a firmware update. A userland injects a the user level as it exploits the firmware itself.


Im sure many others that are much more knowledgeable than myself will have more to add and maybe even correct my info.

[Tamkis]

I kind of thought that bootrom exploits were what you said, and that they are the best, since they can't be patched by firmware updates. I'm surprised that Blackra1n was a bootrom exploit, but now that I think about it, upon boot the blackra1n operated. If only I didn' break my ipt3, now I have to wait for a ipt4 bootrom JB (facepalming self). Though, at least I now have an ipod with a pic/vid camera and mic

Even though it was a bootrom exploit, it sure wasn't the greatest (esp. when tethered)! I knew what the sacrifices of a tethered JB meant, but geez, I didn't think it would crash that much from running out of RAM (even when I turned off uneeded mobile substrate extensions from Rock). I sure hope not all bootroms are as unstable as blackra1n was. (Not that it would really matter if it were untethered).

If the PSP hacking community is similar to the iphone's, user mode doesn't have kernel access, which means people with userland exploits can't use apps such as iFile nor can access the firmware file-strucutre (which I think is on disk partition on the iphone)? Correct me if I'm wrong. If userland exploits don't have kernel access, then how can mobile substrate extensions and tweaks work on userland exploits (you don't see Rock preventing you from downloading kernel-y apps because of not having kernel access).

[dhamien]

Blackra1n can't just have been a bootrom exploit since it worked on new bootrom devices (though tethered) and stopped working from firmware 3.1.3 and forward.

I don't know much about all this, so I'm also curious if anyone has more in-depth descriptions of the different types of jailbreaks. Also an explanation as to why it's said that two exploits are needed for each single jailbreak.

[korin125]

I was looking at the iPhone wiki and though I can't understand pretty much anything it looks like maybe it's bootrom for old bootrom and something else for tethered devices.