BC (short for Backwards Compatibility) is a bootloader similar to boot1. It is responsible for lowering the Broadway's clock speed, then verifying and loading boot2, which will load MIOS after it detects the lowered clock speed. It is run when a GameCube game is launched from the Disc Channel. It is unknown why Nintendo did not simply place all of the GameCube compatibility code in MIOS.
BC can be launched by calling ES_LaunchBC
in /dev/es, or by launching title 1-256 through the standard title launching mechanism.
Version history
version
|
length
|
build tag / date
|
notes
|
0
|
0x41be
|
Aug 11, 2006*
|
corresponds with boot1a?
|
1
|
0x412a
|
Sep 2, 2006*
|
corresponds with boot1b?
|
2
|
0x414c
|
bc.0611021443
|
|
4
|
0x4d8c
|
bc.0803040819
|
corresponds with boot1c? Fixes the signing bug.
|
5
|
0x4f08
|
bc.0806101038
|
|
6
|
0x502c
|
bc.0908240243
|
corresponds with boot1d?
|
* No build tags are included with early versions of BC, so approximate dates are listed from corresponding MIOS. These dates are likely very close (If not identical) to the actual BC build dates.