JitArm64: Allow DoJit at address 0 (fix launching Wii titles) #9618
+0
−6
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
JitArm64::DoJit contains a check where it prints a warning and tries to pause emulation if instructed to compile code at address 0. I'm assuming this was done in order to provide a nicer error behavior in cases where PC was accidentally set to null. Unfortunately, it has started causing us problems recently, as 688bd61 writes and runs some code at address 0 to simulate the PPC being held in reset. What makes this worse is that calling Core::SetState from the CPU thread is actually not allowed and will cause a deadlock instead of the intended behavior. I don't believe there is anything on a real console that would stop you from executing code at address 0 (as long as the MMU has been set up to allow it), and Jit64::DoJit doesn't contain any check like this, so let's remove the check.
leoetlino
approved these changes
Apr 1, 2021
|
0x0 is a valid memory address, both with IR=0 and (maybe) IR=1. |
Honestly, that is completely understandable. JitArm64 is just as cursed as ES_Launch :) |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
JitArm64::DoJitcontains a check where it prints a warning and tries to pause emulation if instructed to compile code at address 0. I'm assuming this was done in order to provide a nicer error behavior in cases where PC was accidentally set to null. Unfortunately, it has started causing us problems recently, as 688bd61 writes and runs some code at address 0 to simulate the PPC being held in reset. What makes this worse is that callingCore::SetStatefrom the CPU thread is actually not allowed and will cause a deadlock instead of the intended behavior. I don't believe there is anything on a real console that would stop you from executing code at address 0 (as long as the MMU has been set up to allow it), andJit64::DoJitdoesn't contain any check like this, so let's remove the check.