Nintendo Game Cube Linux - Modchip Influence

Modchip Influence

The kernels produced by the project originally booted their root file system over NFS, though this was later extended to allow booting over a network block device. Ironically, however, one of the major developments came about due to piracy. A modchip called the "Viper" was released, quickly followed by a BIOS from another team, who were unaffiliated to the Viper team and yet were able to encrypt the BIOS specially for the modchip, which permitted the booting of pirate games from standard DVDs. (The GameCube could only read the first 1.4GB, but because the original games were produced on these discs, that was sufficient). However, after the reverse engineering work by the 'utopia' group, an assembly language recode of the trick used by the cobra BIOS was released. Essentially, a debug command is sent to the GameCube's DVD drive which allowed its firmware to be rewritten in memory (in this case in order to allow it to read from a standard DVD+/-R). However, as soon as the drive is again reset, these changes are lost, meaning one had to use either the cobra BIOS or the asm recode every time.

These debug commands were implemented in the Nintendo GameCube Linux kernel as the 'cactus firmware extension'. Essentially, this allowed it to read the first 1.4GB of any standard DVD. However, the GameCube's laser is fairly picky resulting in some disc read errors. Nevertheless, this opened some very interesting opportunities. For example a completely standalone Media Player Frontend ("MFE") distro was produced—a fully functioning Linux distribution booting entirely without computer networking.