Uploaded July 2015 | Updated September 2026, 9 minutes ago

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For this video, I did a dualboot with iOS 5.1.1 and iOS 6.1.6 on my iPod Touch 4th. This time, I resized actual LWVM partitions instead of overwriting the whole table. With this method, I keep the initial restored firmware and it's properly signed bootchain. This means that the lastest iOS 6.1.6 firmware can boot untethered. A signed bootchain also means no weird sleep bug which causes dead LCD screen for other iOS versions. Read here theiphonewiki.com/wiki/Tethered_Downgrade about this weird bug. To switch between firmwares, RedSn0w's Tethered Boot (A4 and older) or Winocm's KexecUtils (on some newer devices) can be used to load operating systems from the DFU bootchain. Even the iPhone 3Gs old BootROM would require a tool such kloader to get an untethered dual boot. If you dual boot iOS 6.x and 5.x and you set nvram rd=disk0s1s3 (iOS 5.x), the iOS 6.x PWNiBoot will attempt to load an iOS 5.x kernelcache, which would result in some panics. Using Winocm's tool, it's possible to bootstrap a pwned 5.x DFU bootchain to chainload 5.x firmwares from 6.x userland. There is a little exception with BootROM exploited devices which we can set nvram variables. An untethered dual boot may be possible if it involves two same generation firmwares, like 5.1 with 5.1.1 or two same firmware. The only thing is that the flashed bootchain must be able to load both firmwares. My next goal with that dual boot is to make it untethered. The hardest part will be to get a fully automated DFU bootstrap using kloader. I now have to play with iBoot for hours.