Fundamentally, all this does is enforce the invariant that we always
translate effective addresses based on the current BAT registers and
page table before we do anything else with them.
This change can be logically divided into three parts. The first part is
creating a table to represent the current BAT state, and keeping it up to
date (PowerPC::IBATUpdated, PowerPC::DBATUpdated, etc.). This does
nothing by itself, but it's necessary for the other parts.
The second part (mostly in MMU.cpp) is simply removing all the hardcoded
checks for specific untranslated addresses, and consistently translating
addresses using the current BAT configuration. Very straightforward, but a
lot of code changes because we hardcoded assumptions all over the place.
The third part (mostly in Memmap.cpp) is making the fastmem arena reflect
the current BAT configuration. We do this by redoing the mapping (calling
memmap()) based on the BAT table whenever it changes.
One additional minor change is that translation can fail in two ways:
either the segment is a direct store segment, or page table lookup failed.
The difference doesn't usually matter, but the difference affects cache
instructions, like dcbz.
The PowerPC CPU has bits in MSR (DR and IR) which control whether
addresses are translated. We should respect these instead of mixing
physical addresses and translated addresses into the same address space.
This is mostly mass-renaming calls to memory accesses APIs from places
which expect address translation to use a different version from those
which do not expect address translation.
This does very little on its own, but it's the first step to a correct BAT
implementation.
When we cleaned up the code to calculate the shm_position and total_mem
in one step, we sometimes skipped over certain views because they were
Wii-only. When looking at the total memory, we'd look at the last field,
whether or not it was skipped. Since Wii-only fields are the last view,
this meant that the shm_position was 0, since it was skipped, causing us
to map a 0-sized field. Fix this by explicitly returning the total size
from MemoryMap_InitializeViews.
Additionally, the shm_position was being calculated incorrectly because
it was adding up the shm_position *before* the mirror, rather than after
it. Fix this by adopting a scheme similar to what we had before.
The code to calculate the offsets into the SHM file wasn't properly
respecting the skip flags, causing it to calculate offsets beyond
the end of the SHM file.
This code was ported from out_ptr, which was a double-pointer, and
wanted to double-check that the proper arena was actually allocated.
When I ported it to store the pointer directly in the view regardless
of whether out_ptr was non-NULL, I got confused here and instead
caused the code to only free the arena if the first byte was non-zero.
This code originally tried to map the "low space" for the Gamecube's
memory layout, but since has expanded to mapping all of the easily
mappable memory on the system. Change the name to "GrabSHMSegment" to
indicate that we're looking for a shared memory segment we can map into
our process space.
These are effectively unused, since the memmap already maps them in one
place. For 32-bit, they might have some slight advantage, but we already
special-case the regular "high-mem" pointer for 32-bit, so just use the
one we already have...
Our defines were never clear between what meant 64bit or x86_64
This makes a clear cut between bitness and architecture.
This commit also has the side effect of bringing up aarch64 compiling support.
- remove unused variables
- reduce the scope where it makes sense
- correct limits (did you know that strcat()'s last parameter does not
include the \0 that is always added?)
- set some free()'d pointers to NULL
JosJuice