This implements MIOS's PPC bootstrapping functionality, which enables
users to start a GameCube game from the Wii System Menu.
Because we aren't doing Starlet LLE (and don't have a boot1), we can
just jump to MIOS when the emulated software does an ES_LAUNCH or uses
ioctlv 0x25 to launch BC.
Note that the process is more complex on a real Wii and goes through
several more steps before getting to MIOS:
* The System Menu detects a GameCube disc and launches BC (1-100)
instead of the game. [Dolphin does this too.]
* BC, which is reportedly very similar to boot1, lowers the Hollywood
clock speed to the Flipper's and then launches boot2.
* boot2 sees the lowered clock speed and launches MIOS (1-101) instead
of the System Menu.
MIOS runs instead of IOS in GC mode and has an embedded GC IPL (which
is the code actually responsible for loading the disc game) and a PPC
bootstrap code. To get things working properly, we simply need to load
both to memory, then jump to the bootstrap code at 0x3400.
Obviously, because of the way this works, a real MIOS is required.
Instead of needing different switch cases for
converting countries to regions in multiple places,
we now only need a single country-to-region switch case
(in DiscIO/Enums.cpp), and we get a nice Region type.
At first there weren't many enums in Volume.h, but the number has been
growing, and I'm planning to add one more for regions. To not make
Volume.h too large, and to avoid needing to include Volume.h in code
that doesn't use volume objects, I'm moving the enums to a new file.
I'm also turning them into enum classes while I'm at it.
It was previously an important part of DVDInterface,
but since its usage there was replaced with DVDThread,
the only remaining uses of it are in Boot and Boot_BS2Emu.
Replaces them with forward declarations of used types, or removes them entirely if they aren't used at all. This also replaces certain Common headers with less inclusive ones (in terms of definitions they pull in).
* The file already exsists, otherwise we wouldn't have gotten
this far in the boot.
* We have already checked if it's a Wii or GameCube elf,
besides, it's too late to change our minds now anyway.
* On Wii - Don't call EmulatedBS2, it can never succeed as
it knows nothing about booting elfs. Just call the
SetupWiiMemory directly if needed.
* On GameCube - We still call EmulatedBS2_GC, but we stop
it from running Apploader, which might boot something
unexpected from the default iso or DVD root folder.
BhaaL