Bios Xbox 360 -

As Microsoft patched software vulnerabilities, the scene moved to hardware: JTAG (Joint Test Action Group):

The console's operating system and subsequent bootloaders are stored on a flash memory chip called the NAND. This is where "firmware updates" or dashboard versions are installed. bios xbox 360

A special, uniquely encrypted area of the NAND that contains the console’s unique encryption keys, CPU key, and serial number. 2. The Role of NAND and Keyvault in Emulation (Xenia) As Microsoft patched software vulnerabilities