Unknown GPU Registers

[NeoTheLynx]

We have tried one a few torque games and they are missing a lot GPU related, which is causing rendering bugs and possible cases where the player falls through the floor.

https://www.youtube.com/watch?v=ovwUd-PoYuY

We have tools that can mod the game, we will give them to you upon request if you are needing them.

For Marble Blast Ultra, here is some of the missing registers.

• [ ] 0004
• [ ] 0007
• [ ] 0081
• [x] 045e (Callback Acknowledgement)
• [x] 1838
• [x] 1844 (Frontbuffer ptr)
• [x] 1852

---

AVIVO_D1***

• [x] 1921
• [x] 1922
• [x] 1925
• [x] 1927
• [x] 1930
• [x] 1964
• [x] 1973

---

• [ ] 1e4e (AVIVOTMDSA???)

My friend found those, dont know where, but all torque games are like that.

[Razzile]

marble blast runs absolutely fine for me. Oh and hey @neolightning!

EDIT: I do remember falling through the floor however in some levels like mentioned

[NeoTheLynx]

@Razzile How is it working?

[hekar]

@neolightning That's on the OpenGL renderer (with an AMD card)? I'd wait until AMD is supported in Vulkan and give it another test.

It might make sense to close this issue and merge your findings with: https://github.com/xenia-project/game-compatibility/issues/47

[NeoTheLynx]

OpenGL With AMD Radeon R7 360.

[DrChat]

708 Adds definitions for most of the unknown registers. They should be able to be safely ignored.

[ghost]

00000004 GPU: Write to unknown register (045E = 00000004) This one is still a problem, do you know what that does?

[DrChat]

@tmccaff That's the callback acknowledgement register, which we can safely ignore.

[ghost]

@DrChat I also found in some games Write to unknown register 1924 and also 0081, 0082. I am trying to figure out what those are.

[raynebc]

The game Bandfuse uses two additional registers not listed here or in #708 (or its pull request): 00000004 GPU: Write to unknown register (0E00 = 00000001) 00000004 GPU: Write to unknown register (0E40 = 00000001)

[DrChat]

@tmccaff If you want to examine some libxenon code - multiply those register indexes by 4 and then look for them here.

For context - I'm mostly ignoring registers < 0x2000, as they're less important.

Range	Type
0x0000 - 0x1FFF	Setup
0x2000 - 0x2400	Graphics
0x4000 - 0x5000	Shader Constants

[ghost]

@DrChat for example I have w> 00000004 GPU: Write to unknown register (1973 = 00010000) so are you saying multiply 00010000 x 4? I am new to this and want to help. Thanks

[ghost]

thanks DrChat and parkerlamb for explaining this..

[ghost]

722 Added GPU register 0x1924

[Sleepy93]

GPU reads from unk. register:

!> 00000028 GPU: Read from unknown register (044B)

GPU writes to unk. register

w> 00000004 GPU: Write to unknown register (0081 = 80010000) w> 00000004 GPU: Write to unknown register (0082 = 00000000) w> 00000004 GPU: Write to unknown register (0E00 = 00000001) w> 00000004 GPU: Write to unknown register (0E40 = 00000001) w> 00000004 GPU: Write to unknown register (1E4E = 00000000)

refs from GameCompatiblity: #229 #357 #795 #796 #797

[Sleepy93]

I think we have another two unknown registers :)

• 074C
• 0388

Ref - 434D0839 - Bodycount | #221