How do new kernels stop jtag?

[talkboxier]

I was just curious to know how they stop jtaging systems. Does the efuses on the cpu only remove the ability to read and write the nand?

[Arakon]

This has already been explained. They don't stop the jtagging, they stop the running of the exploitable kernels that are required to make any use of the jtag.

[52aces]

Each kernel has  (a)  CB(s). the updated xboxes have the 4*** kernel CBs blacklisted. From the 4*** kernels we would exploit them to run unsigned code.