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.
Init cannot be called more than once because it registers the
CoreTiming callbacks, that trips the assertions and will cause
anyone with PanicAlerts disabled to crash.
CoreTiming gets restored before ExpansionInterface so CoreTiming
events need to already be registered before the save state loading
begins. This means that the callbacks must be registered
unconditionally instead of on-demand.
Chris Burgener
Scott MansellandGitHub
Markus WickandGitHub
degasus
magumaguanddegasus
EmptyChaos
aldelaro5
Jasper St. Pierre
Mat MandGitHub