The One Time Programmable memory is used to store 32 4byte words. It is programmed sometime during the factory process and can never be changed afterwards. Next to the Wii's shared and public keys it also contains a random number generation seed and the boot1 hash which basically makes it impossible for us to change boot1. This memory may or may not be described in claims 141 and 142 in http://www.freepatentsonline.com/y2005/0132217.html
|Access size||32 bits|
|Byte order||Big Endian|
|RD||Set to one to execute a read command. If clear, then the data in HW_OTP_DATA is unchanged.|
|ADDR||Word address to read|
This register contains the command sent to the OTP. It is unknown whether is register is also used during the factory process to program the OTP.
This register contains the output data for the last issued OTP read command. The execution of a read operation via the HW_OTP_COMMAND register immediately changes this register without any delay.
The following things are stored inside the OTP:
|0-4||boot1 hash||Expected hash checked against actual boot1 hash by boot0|
|5-8||common key||Used to encrypt title keys in tickets|
|9||NG id||Used to name the NG certificate|
|a-11||NG private key||Per-console key that signs save files|
|11-15||NAND HMAC (overlaps with NG private key)||Per-console key that signs NAND blocks|
|16-19||NAND key||Per-console key that encrypts the NAND|
|1a-1d||RNG seed||Used for crypto-related random number generation|
|1e-1f||Unknown||Appears to vary between units|