Adding MMU state values to state

[john-peterson]

Adding MMU state values to state

Problem

State loading before CCPU::Run() in

• F-Zero and Rouge Leader and potentially other programs that use the options TLBHack or MMU

result in a DSI interrupt because these values start at 0 which is the wrong value

Solution

Save the MMU state values

Discussion

The problem hasn't been fixed before because it's not noticed when loading a state

• during a running emulation if the values for the current state is correct which they often are because the values are set at boot and not changed after that
• after a terminated emulation (that doesn't reset the values) for the same ISO the state is for and the last values are right

These values are used for page trable translation discussed at Terms and Acronyms

MMU PPC Memory Management Unit. Translates virtual address to physical. MMU has two translation mechanisms: block address translation and page table translation

Shutdown

Problem

It's not clear which values are state values

Solution

Adding the values to shutdown because that makes it clear that they're part of the system state

Fake VMEM

Problem

A state saved with "TLBHack" doesn't work if it's changed to "MMU" because fake VMEM isn't saved if "TLBHack" isn't used because

• it's 32 MB which makes the state larger without benefit when its not used

  Solution

Fake VMEM should be saved regardless of the TLBHack setting because

• the state can be loaded with "MMU" (instead of "TLBHack") because fake VMEM is ignored and unnecessary
• its size is only 152 KB (,005 larger than the compressed size 27 MB) when it's empty because the state is compressed

truncate -s 32M file.bin
lzop -fo file.lzo file.bin
du -h file.lzo
152K   file.lzo