To quote: A 'rebooter', allows to 'reboot' the 360 into an MS kernel after starting it with the JTAG Hack... in this case (freeBOOT v0.01) it should reboot the console into MS kernel 8498 (but I assume 8507 will be possible too, and it's probably also the first step into rebooting into patched/modified MS kernels).
The readme says it requires the Cygnos360 v2 chip atm, I'm assuming they need it to automatically reset the SMC back to original.
Booting your 360 into 849x+ and keeping the JTAG Hack working was impossible until now, because updating to 849x+ via the MS update procedures burned a CB-fuse which made it impossible to still perform the JTAG Hack.
If you already updated your console to 849x+ via normal update methods there is still no solution for you, but if you have a JTAG 'hackable' console (kernel 7371 or lower on NAND) freeBOOT should allow you to 're boot' it into 8498 via the JTAG Hack.
Finally, here it is - freeBOOT, a rebooter for the Microsoft Xbox 360. This version of freeBOOT allows you to reboot into kernel 2.0.8498 on a Xenon or Falcon console, which can be exploited by the JTAG hack. Support for Zephyr, Opus, and Jasper consoles will follow shortly.
As freeBOOT needs a second flash memory to store kernel 2.0.8498 and associated data, a Cygnos360 is required at the moment.
Read through the following instructions carefully. Building your own images is yet a complicated task involving many steps. Future versions of freeBOOT will be easier to build.
Power on your Xbox 360. If everything went correctly, you should see the blue LED light up a few seconds later, followed by the usual boot animation. If you power on your Xbox 360 with the DVD tray eject button, XeLL will be loaded instead.
Writing freeBOOT would not have been possible without the great work done by many hackers. Kudoz to arnezami, Redline99, Robinsod, SeventhSon, Tiros, tmbinc, xorloser, and anyone else I may have missed.
Features planned for the next release(s):
-support for all consoles
-update to the latest kernel