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> Wii games don't have to do any of this - they have full access to the 64MB of MEM2. This means that Dolphin doesn't have to worry about MMU emulation in gener

by cwyers 8y ago

> Wii games don't have to do any of this - they have full access to the 64MB of MEM2. This means that Dolphin doesn't have to worry about MMU emulation in general. As with any great rule, there are some exceptions, such as games that are purposefully trying to break Dolphin. Those games will be covered in another article as they seem to particular target Dolphin's weaknesses and thus some of their behaviors doesn't actually make sense for the source hardware. Boy I want to read that article

phant0mas 8y ago
Where these games actually developed with this purpose? Did doplhin existed back during the game's dev cycle and the developers say "we don't want our game on the dolphin emulator"? Or it just happens that they use an approach that is problematic to begin with?
- wtallis 8y ago
  Since Dolphin emulates two generations of console, it definitely was around and well-known for the development cycle of later games. The first version of Dolphin was released in 2003, and the Wii was released in 2006.
- jimmyspice 8y ago
  it is worth noting that the three titles mentioned in the article are all Disney properties (Cars, Toy Story and Disney Infinity).
jsheard 8y ago
Those games were briefly covered in this older article: https://dolphin-emu.org/blog/2017/02/01/dolphin-progress-report-january-2017/ https://dolphin-emu.org/blog/2017/02/01/dolphin-progress-rep... > In basic terms, Disney Infinity and Cars 2 do a very specific amount of writes to lower MEM1, where a lot of really important data is stored. But, it writes just enough that the CPU doesn't flush it to MEM1; it remains in the CPU L1/L2 caches. It then tells the CPU, nevermind and invalidates the CPU cache. Thus, even on a hacked Wii this would do exactly nothing; it's specifically targeting a weakness in emulators. > Emulating the CPU cache in Dolphin would likely slow-down Dolphin by a factor of ten or more. While we prefer not using hacks to "fix" games, we found it to be permissable in this case due to how specialized of an issue it is. Even if the L1/L2 caches are implemented in the future (which is definitely a possibility,) it will likely be something only used for testing, and thus this hack would remain so that people could actually play these two games. It's a compromise, one that no one is entirely happy with, but the game behavior necessitated it in this case.
- vanderZwan 8y ago
  Given that they know this, couldn't they patch the games themselves instead?

by cwyers 8y ago

phant0mas 8y ago

Where these games actually developed with this purpose? Did doplhin existed back during the game's dev cycle and the developers say "we don't want our game on the dolphin emulator"? Or it just happens that they use an approach that is problematic to begin with?

wtallis 8y ago
Since Dolphin emulates two generations of console, it definitely was around and well-known for the development cycle of later games. The first version of Dolphin was released in 2003, and the Wii was released in 2006.
jimmyspice 8y ago
it is worth noting that the three titles mentioned in the article are all Disney properties (Cars, Toy Story and Disney Infinity).

jsheard 8y ago

Those games were briefly covered in this older article: https://dolphin-emu.org/blog/2017/02/01/dolphin-progress-report-january-2017/ https://dolphin-emu.org/blog/2017/02/01/dolphin-progress-rep... > In basic terms, Disney Infinity and Cars 2 do a very specific amount of writes to lower MEM1, where a lot of really important data is stored. But, it writes just enough that the CPU doesn't flush it to MEM1; it remains in the CPU L1/L2 caches. It then tells the CPU, nevermind and invalidates the CPU cache. Thus, even on a hacked Wii this would do exactly nothing; it's specifically targeting a weakness in emulators. > Emulating the CPU cache in Dolphin would likely slow-down Dolphin by a factor of ten or more. While we prefer not using hacks to "fix" games, we found it to be permissable in this case due to how specialized of an issue it is. Even if the L1/L2 caches are implemented in the future (which is definitely a possibility,) it will likely be something only used for testing, and thus this hack would remain so that people could actually play these two games. It's a compromise, one that no one is entirely happy with, but the game behavior necessitated it in this case.

vanderZwan 8y ago
Given that they know this, couldn't they patch the games themselves instead?