yuzu-emu/yuzu

[Feature Request] Add support for Skyline modding framework

jam1garner opened this issue · 25 comments

jam1garner commented

Spinning this off from #6076 as it's unspecific and doesn't provided any technical details about what it'd entail.

Motivation

Skyline, for those who aren't familiar, is a framework for modifying the code of games. It acts as a subsdk (overriding subsdk9, as no current game uses it) and uses a plugin system in order to allow users to load their own code, and provides an API for users to patch existing game code in order to redirect into user re-implementations of functions.

It's desirable to support due to its usage across a variety of games, most notably Smash Ultimate, which requires it to do any serious patching of game files, but it is also the framework used for moveset edits among other things. It's also been used some in the {Animal Crossing New Horizon, Pokemon SwSh/BdSp, Spelunky, etc} modding scenes, and other developers seem to be showing interest in it. (For example Pokemon Mystery Dungeon has shown interest but needs emulator support first: tech-ticks/hyperbeam#3 (comment))

Outstanding Issues

  • SVC Support
    • Support MapProcessMemory SVC
      • Implementation status: #7519
    • Support UnmapProcessMemory SVC
      • Implementation status: #7519
    • Support CreateCodeMemory SVC
      • Implementation status: #7519
    • Support ControlCodeMemory SVC
      • Implementation status: #7519
    • Support SetProcessMemoryPermission SVC
      • Implementation status: #7394
  • CPU Emulation Level Support
    • Support Instruction Cache Clearing
      • Seems to be mostly implemented as it's implemented in dynarmic (See merryhime/dynarmic#562), just requires a InstructionCacheOperationRaised callback be implemented for yuzu's DynarmicCallbacks64 to actually handle the cache clear, which shouldn't be too hard as parent.InvalidateCacheRange(...) should do the trick.
      • Implementation status: #7407
  • IPC Service Support
    • Atmosphere's pm:info extension, notably AtmosphereGetProcessId
      • This is decently easy, and such an implementation could effectively just return a constant due to the application being the only real concept of a process under yuzu. The only input actually of interest to Skyline is 0xFFFF8001, Atmosphere's Program ID assigned for getting the current process' Process ID. The hardcoded process ID it could return for the application should then be usable with the SVCs mentioned before (MapProcessMemory, UnmapProcessMemory, SetProcessMemoryPermission)
      • Implementation status: #7393
    • Atmosphere's pm:dmnt extension's AtmosphereGetProcessInfo
      • Similar to GetProcessId, Skyline only cares about the special 0xFFFF8001 handle, which is used to the process info for the current process. Skyline uses this to get a handle to the current process.
      • Implementation status: #7847
  • Loader
    • Load subsdks properly (e.g. support subsdk8 and subsdk9)
      • Implementation status: #7523
  • Misc
    • Debugging Skyline and ensuring no other functionality is missing/dysfunctional in Yuzu
      • Status: Blocked on yuzu debugging, see comment by tech-ticks below undocumented memory issue
      • Note: may result in finding additional issues to be added above

Next Steps

I'm willing to provide some development time to help with the above implementation, but would appreciate guidance/thoughts first, in order to avoid submitting non-trivial PRs without being sure they'd be excepted.

I'm also willing to provide help for any Yuzu developers on the Skyline end of things, as I'm certainly not asking for Yuzu devs to have to debug skyline code.

Update: I do not have time or resources to dedicate at this time. I'm doing my best to keep this thread updated but my organizational/PR help is done for the time being.

FernandoS27 commented

@jam1garner hi jam if you need help with this we can do this tomorrow. feel free to contact me on discord:

@Morph1984 has implemented some so you have a base guideline on how to proceed.

you can contact me at: Blinkhawk#2544 on discord

TheHomerOfSteel commented

I hope you will finish this
I'm too excited to play all the mods on yuzu :)

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Applemaster21 commented

I just want to say thank you for doing this. Even if this never sees the light of day or isn't ever completed fully, taking the time out of your day to do something like this is amazing. Everyone who contributed to this project is awesome :)

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Rafario448 commented

I really wish success to this project, I wish I knew how to help.

Having skyline on emulators will be revolutionary to smash bros modding, specially as hacked switches are getting harder to get each day.

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kir-alt commented

I really hope this can be finished! Modding SSBU on a emulator would be cool.

NiQR1 commented

I really hope this can be finished! Modding SSBU on a emulator would be cool.

tech-ticks commented

All the prerequisites are now implemented, but Skyline hits an access violation in the memset in KCodeMemory::Initialize() (it passes address 0x00000295f6d84000 and size 0x1000, the device memory backing base pointer is 0x0000028576680000). The crash happens when Skyline calls svcCreateCodeMemory with an address from memalign (see https://github.com/skyline-dev/skyline/blob/master/source/skyline/nx/kernel/detect.c#L64). I'm not familiar enough with Yuzu internals to debug this, but let me know if you have any ideas.

NiQR1 commented

you guys got this good job! I cant wait too mod smash ultimate!

JulesBarbe commented

I am in no way a good enough programmer to help with this project, but I'm following your with the utmost curiosity. The potential of eventually having access to the training mod on yuzu could completely change the competitive scene for the better.

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cykeswiki commented

Any further updates on this? I noticed that most (if not all, according to tech-ticks' post) of the prerequisites are ready to go, so is it just a matter of backend testing we're not privy to?

Ketoro commented

this is amazing. ive been wanting this for awhile now

PrinceBubloo commented

Any further updates on this? I noticed that most (if not all, according to tech-ticks' post) of the prerequisites are ready to go, so is it just a matter of backend testing we're not privy to?

@bunnei is looking into it, so its in good hands.
It will be done soon hopefully

rings2006 commented

i hope this all works out, good luck to everyone

NicholasR18 commented

Hey so if you can send me the stuff you have been working on I can have my dad help he's worked at Microsoft for 20 years now and codes daily I think I can get him to help

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Ruther92 commented

Hi! Is there any update?

nsragow commented

I'd be happy to contribute, want to get this done

JoeBudson commented

Any updates on this?

Wfree86 commented

Hey folks if you need someone to test this let us know. If someone wrote up a test case I'm willing to help out.

FerLuisxd commented

Hello? Any updates on this?

p-victor commented

Everything for skyline seems ready I think. Is it time to close this issue @bunnei @tech-ticks ?
#8090 (comment) Seems to confirm it is working right.

PrinceBubloo commented

Which comment, last comment is 7 months old

p-victor commented

Yes and the comment states that the previous issue (which if I understand correctly is the last remaining) is no longer an issue for skyline.

jam1garner commented

Yes and the comment states that the previous issue (which if I understand correctly is the last remaining) is no longer an issue for skyline.

"Skyline loads but is not working" doesn't tell one anything except that loading non-sequential subsdks works, not anything regarding skyline itself working.