SGP311 & SGP312 only
Installation instructions in the second post, download links in the third
What is LittleKernel?
LittleKernel is an opensource bootloader for qualcomm devices available from codeaurora.
TL;DR VersionSony use a special method of booting into recovery for their updates, this is not available when you are unlocked, and there is no button combination to enter this mode. As a result the common method to get recovery on Xperia devices has been to use an initrd that has a script to load either normal boot or recovery boot based on a button press. This is a far from ideal solution as when you update your kernel it also updates your recovery. If something goes wrong you are stuck needing a computer to reflash the kernel partition.
LK allows running separate boot and recovery that are fully independant of eachother.
With the recent addition of TWRP support for the latest devices there have been advances made in this technique making recovery updatable it still requires the flashed boot image to support that method. This is less than ideal still as it reduces choice in what you want on your device, giving the decision to the dev of the rom you have flashed. This also leaves you in the position of needing your computer if a kernel update fails for any reason.
LK solves these problems by separating out boot and recovery to their own kernels with their own ramdisks like every other device, if you flash the boot kernel, recovery isn't touched and will be there for you as a failsafe in case anything goes wrong. This removes the need to have a computer near by in case of breakage occuring.
What progress has been made?
I have been working on LK for the Xperia Z phone and since the release for the Xperia T have managed to make things a little more portable between devices.
Once the hardware arrives I need to compare the expected configuration against what is expected and add these definitions into my Xperia modifications to the aboot module.
Are there any changes that devs should look at?
Yes, they are minor but I suggest that devs look at the implementation by Dees_Troy for flip flopping boot and fota kernel. Soon I will also publish a patch to kernel restart procedure so that reboot messages can be passed to LK from kernel without S1Boot intercepting and clearing them.
Reboot patch will be very similar to http://review.cyanogenmod.org/#/c/44366/
LK (LittleKernel) for Tablet Z, a Tool/Utility for the Sony Xperia Tablet Z
Current Beta Version: 1.0a
Beta Release Date: 2013-07-02
Last Updated 2013-08-26