This is achieved by using a priiloader hack to tell the disc channel to load... another channel instead of a disc. There are 2 versions I have made, one that loads a specified channel every time, and another that loads a different channel depending on whether you try to boot a WIi or GC disc.
So far, the hack has only been made for 4.3E ATM, but I will port to 4.3, 4.3U, and 4.3K soon (then to 4.1 and 4.2, and MAYBE 3.xx versions).
Single Channel priiloader hack:
[Disc Channel - NeoGamma (HNCA)] version=514 offset=0x816956B8,0x816956BC,0x816956C0,0x816956C4 ,0x816956C8,0x8137C6BC,0x8137C6C0,0x8137C70C,0x813 7C710,0x8137C75C,0x8137C760,0x8137BFC0,0x8137C6AC value=0x3F200001,0x3B390008,0x3F00484E,0x3B184341, 0x4E800020,0x7F04C378,0x7F23CB78,0x7F04C378,0x7F23 CB78,0x7F04C378,0x7F23CB78,0x483196F9,0x4831900D
Dual Channel priiloader hack:
[Disc Channel - Wii - HNCA GC - HCLA] version=514 offset=0x816956B8,0x816956BC,0x816956C0,0x816956C4 ,0x816956C8,0x816956CC,0x816956D0,0x816956D4,0x816 956D8,0x816956DC, 0x8137C6BC,0x8137C6C0,0x8137C70C,0x8137C710,0x8137 C75C,0x8137C760,0x8137BFC0,0x8137C6AC value=0x3F200001,0x3B390008,0x3F00484E,0x3B184341, 0x4E800020,0x3F200001,0x3B390008,0x3F004843,0x3B18 4C41,0x4E800020, 0x7F04C378,0x7F23CB78,0x7F04C378,0x7F23CB78,0x7F04 C378,0x7F23CB78,0x483196F9,0x48319021
It works by patching the part where the System Menu checks to see the IOS a disc wants, and then loads that IOS's Title ID. Instead of getting the Title ID for an IOS, the hack gives it a Title ID at it specifies. Normally, the sysmenu only uses 2 ASM commands to get the IOS's ID, but for a full channel Title ID, the hack had to use 4 ASM commands. So instead of just patching over the top of the existing 2 commands, the hack puts the 4 commands (plus a blr to return back) in an empty (value is all "00") part of the dol, then branch to that offset. And then for the GC part, the value had to be patch a few times, so I had to use a few more patches to copy the loaded Title ID over to those few areas too.
So, like I said, by default, those are the 2 channels that the hacks boot, but you can change them to any full Title ID you have installed on your Wii, and the Disc Channel will boot it.
Here is an example pack containing:
- the 2 example hidden channel Wads (both made with HideandSeek v0.9
- a hacks.ini with the 2 hacks for 4.3E already put into it (plus the regular hacks for sysmenus 4.1, 4.2, and 4.3)
- and a modified priiloader 0.8 beta 2 (this version does seems to run stable under IOS249 unlike v0.7 and lower, allowing for backups to be loaded) NeoGamma_via_DiscChannel_PoC_Pack.zip
Now to get this working on your own Wii
1. System Menu specifically version 4.3E installed (only 4.3E for now, will add support for other sysmenus soon)
2. Ability to run homebrew (HBC installed) from SD card
3. Ability to install fakesigned wads
4. The above PoC pack
5. (optional) cIOS249 to load backups
1. grab the PoC pack linked to above, and extract it to the root of your SD card.
2. load up your favorite wad managing app, and use it to install the example sd:\wad\HNCA.wad (and optionally HCLA.wad if you want to test out the Dual Channel hack)
3. if you have priiloader already, then you can skip this step if you do not want to overwrite the version you currently have. Load up the "priiloader v0.8b2" installer, and use it to install priiloader v0.8 beta 2. The installer should also copy the hacks.ini over to your Wii too.
4. Now boot into priiloader by resetting or switching on the wii, but while holding down RESET button as you boot it up, to access priiloader menu. When in the menu, go to "Settings", and then set "Use Classic hacks.ini" to "on". Save settings. If you are using certain versions of priiloader (v0.6 and v0.7 AFAIK), it might not find the hacks.ini on sd root. To get these versions of priiloader to read it, move it from sd:\hacks.ini to sd:\apps\priiliader\hacks.ini
5. Now go back to priiloader's main menu, and select "System Menu Hacks". Enable hacks you may like (such as region free everything, and block disc updates), then enable the "Disc Channel - NeoGamma (HNCA)" to test out the Single Channel hack (or "Disc Channel - Wii - HNCA GC - HCLA" if you want to test the Dual Channel hack, but never enable both of these hacks at the same time!). Save settings.
This will now allow the Disc Channel to load HNCA (NeoGamma) when you boot a disc (or HNCA for WIi discs and HCLA (CFG USB Loader MOD with DML support) for GC discs if you are testing out the Dual Channel hack).
6. (optional step - Only do this if you are using specifically the above linked priiloader v0.8beta2 MOD! Using any other version priiloader and doing this will make priiloader lock up!)
- Load up priiloader once more, and go to Settings. Change the "Use System Menu IOS" to "off", then change "IOS to use for SM:" to "249". Save settings. This little extra, combined with loading the hidden autoboot NeoGamma, will allow you to load backup discs via the Disc Channel without cIOSCORP/DARKCORP! So it is not just retail games that benefit from this hack, backups can be loaded with this too.