Wii factory process
This article describes the process of how production Wii consoles are set up at the factory, from initial manufacturing of the chips to retail shipment.
- During initial programming of the NAND chip, a "prewrite" image is flashed to NAND. This image contains boot1 and a special boot2 known as "sd_boot".
- At the packaging plant, the Wii is powered on for the first time with SD card number 1 inserted. This SD card contains an image with various BroadOn-format WADs; sd_boot will load one of these WADs, an installer program which installs the other WADs to NAND. These WADs typically include a System Menu, IOS4, and IOS9.
- Once the System Menu is installed, the "123J" disc is inserted. It is unknown what the actual title of this disc is, however it possibly serves the purpose of encrypting the NAND filesystem, updating boot1, and setting the console's eFuses. This disc seems to contain a partition with the title ID "0000dead", which may contain the program which encrypts the NAND filesystem.
- Another disc known as RVL_UJI_DIAG (or 121J) is inserted, along with another SD card ("#1.5"). This disc runs test programs on the system to validate the operation of the hardware, writing logs to testlog.txt in the process; it then registers the console's serial number (over Waikiki), generates the system's Setting.txt, and other actions to prepare for the next step of the process.
- The final disc, known as 122E, is then inserted; this disc installs a WAD called "DataChk.wad" from the SD card, which contains Data Check and Log Check.
- Data Check and Log Check (0002) verifies the results of 121J, to ensure that the logs and product info data on the system are correct.
- The contents of 122E's update partition are then installed, containing the standard set of channels for retail along with the production Wii System Menu.
Every Wii is preloaded at the hardware level with a few pieces of software; these are already present on the Wii and will run when the Wii is powered on at the factory. The first of these pieces of software is boot0, the first piece of code ran on the Wii after power-on (which will stay the same from when it is physically programmed onto the chip to after factory setup, since it cannot physically be modified), which will check the stored boot1 hash in the Wii's eFuses, and seeing that it is blank (as it is written to later in the process, using up its one opportunity to program it), determines that it is in the factory and continues with boot by loading boot1 from the NAND. boot1 works as usual by verifying the signature of the boot2 on the NAND, then loading it.
Next, boot2 loads; the version of boot2 installed at the factory is "sd_boot", a special boot2 which does not read or write to NAND and instead boots from the SD card; a SD card (designated as SD#1) is prepared containing a number of BroadOn-format WAD files (stored raw with no filesystem); one of these files has its contents executed as an ARM binary on the IOP, said file being an installer program which will install the other WADs on the SD card to the NAND. On production systems, this typically includes a NDEV Menu, IOS4, and IOS9, although other variations have been seen such as images which install BC and MIOS. The NDEV Menu will then be booted, allowing for the next phase of setup to occur when a disc is inserted.
At this point, a disc would be inserted to begin the process of setting up the system. While this disc presumably has an official name which is currently unknown, it will be referred to as "123J", as 123J is the GameID of the disc (as evidenced by its presence in the uid.sys logs of all Wiis, as well as other NAND remnants). This disc's exact purpose is unknown as no code from it has been recovered, but it is presumed that it plays the role of setting eFuse bits (which results in setting console-unique keys and finalizing the installed boot1 version), possibly also updating boot1 and boot2 to prepare for the Wii to boot from a production encrypted NAND filesystem. This process likely would be done using a Waikiki from a PC host. This disc may contain a second partition with ID "0000dead".
The next disc inserted is RVL_UJI_DIAG, with GameID 121J. The copy of this disc obtained from an RVT-H Reader includes several testing programs which could be used to ensure the integrity of a unit's hardware, as well as programs that run pre-defined tests, the results of which are then written to testlog.txt. It also contains serNoReg, the program which registers the console's serial number using a mentioned but unseen piece of PC software, and "PreWrite.dol", a program which seems to write data to NAND over EXI (Waikiki); it is unknown if this is used in retail system production or not.
See also: Data Check and Log Check
122E is a disc which has a game partition and an update partition; the game partition installs the title "0002" from the SD card (with filename "DataChk.wad"), and the update partition contains the final set of retail Wii System Menu/IOS/Channel data for production.
0002 (DATA CHECK & LOG CHECK) is a program which checks the results of 121J to ensure that diagnostics passed and data was written correctly. While this program is meant to be deleted before the process finishes, for unknown reasons it is still present intact on some Wiis and versions 1.5.0 and 1.5.1 have been recovered.