This accounts for DMA stealing cycles from the CPU whenever the CPU
triggers a DMA (does not affect H/V blank or sound DMAs).
Works by moving the CPU to a PAUSED state where the cycles are accounted
for, reusing a similar mechanism for HALT/STOP.
Fixes a couple of games, notably GTA that has a DMA/IRQ race condition
(likely a bug really) if cycles are grossly miscalculated.
It should not happen since the magic value and version would normally
discard incompatible savestates, however it's preferrable to check
before loading the state (it's just some minor sanity check).
On a reset bios_swi_entrypoint can end up pointing to code over the
watermark, due to block_lookup_address_arm looking up the function
instead of translating it.
Fix it by making flush and init different functions (albeit similar).
Tested by running and resetting games automatically, causing ~10% of
games to crash.
This rewrites the way that CPU alerts work, making them a bitmap (since
multiple alerts can happen simultaneously, like SMC and IRQ). This
doesn't really fix many games but improves accuracy overall and improves
performance on some I/O writes (the ones without side effects).
The IRQ raising is now decoupled and explicitely called via a new
function (check_and_raise_interrupts) to avoid issues such as invalid
CPSR values (doesn't seem to bother most games!). There's more side
effects missing, so this just lays the ground for more fixes.
Whenever an interrupt is pending and interrupts are disabled (via
IME/IE), an IE/IME write that re-enables IRQs will fail to raise an IRQ.
This makes some games hang. Most games seem to use CPSR.IRQ to enable
and disable interruts, so they are not affected. However some others use
IME/IE (or all of them), causing these deadlocks and some race
conditions.
This fixes a bunch of games that did not crash but would "hang" in some
interesting ways.
This fixes ROM swapping for x86/64, arm32 and arm64. On top of that it
improves speed by removing unnecessary slow paths on small ROMs for
arm32 and mips. If the ROM can fit in RAM, it will emit more efficient
code that assumes the ROM is fully loaded.
For low-memory Linux platforms it would be better to use some mmap'ed
ROM, that way the OS would transparently handle page swapping, which is
perhaps faster. Will investigate and follow up on this in a separate
commit.
gpsp doesn't differentiate between USER and SYSTEM mode, most likely
cause it is not that important for most games. This implements the modes
correctly and adds checks for privileged operations. Still some
bugs/hacks but it mostly fixes CPSR/SPSR reads/writes.
To implement PSR writes we are using a more refined masks and force mode
bit num. 4 to always be one. Reserved bits are forced to zero (this
needs to be validated on a real device).
Converted the hack into another... hopefully better hack.
Check for IW/EWRAM addr bit and handle accesses to EWRAM by correcting
the base addr and the mirroring range.
Assumes that iwram and ewram buffers are at a distance multiple of 64KB
for speed (so that lw/sw offsets can be shared).
This fixes a variety of games that should have been present in
game_config.txt such as Ninja Cop, Star Wars JPB, Medal of Honor,
Spongebob, etc. Some of them were just missing regional versions of the
cart. It also fixes newer games and homebrew such as GoodBoy Galaxy.
This gets rid of the bloated memmap_win32.c in favour of a much simpler
wrapper. This will be needed in the future since the wrapper does not
support MAP_FIXED maps (necessary for some platforms)
This fixes a race condition that happens whenever the ROM cache is flushed but
the RAM one is not, causing any SWI calls (implemented as direct branches) to
jump to random instructions.
The fix could be to flush both caches at the same time (~expensive on
low mem platforms), use indirect jumps (a bit expensive) or emit the SWI
handler below the watermark to ensure it is never flushed. This is cheap
and effective, requires minimal changes.
This uses BSON as savestate format, to allow external tools to parse it
(so that we can add proper test of the states). The BSON is not 100%
correct according to spec (no ordered keys) but can be parsed by most
libraries.
This fixes also a bug in the savestate palette color recalculation that
was wrongly overwritting the original palette (which could cause some
problems on some games).
Also fixes some potential issues by serializing some more stuff and
cleans up unused stuff.
Testing shows that states look good and there's only minor differences
in audio ticks, related to buffer sizes (since buffer flushes are
de-synced from video frames due to different frequency).
Seems that using the __atribute__ magic for sections is not the best way
of doing this, since it injects some default atributtes that collide
with the user defined ones. Using assembly is far easier in this case.
Reworked definitions a bit to make it easier to import from assembly.
Also wrapped stuff around macros for easy and less verbose
implementation of the symbol prefix issue.
This saves a few cycles in MIPS and simplifies a bit the core.
Removed the write map, only affects interpreter performance very
minimally. Rewired ARM and x86 handlers to support direct access to
I/EWRAM (and VRAM on ARM) to compensate. Overall performance is slightly
better but code is cleaner and allows for further improvements in the
dynarecs.
Added a more thorough cache cleanup for reset/mode-change too.
Fixed the mmap initialization that ends up leaking memory.
Minor x86 asm fixes for Android.
This is not really necessary since it can share area with ROM.
Performance impact should be very minimal (haven't noticed it myself)
and could be compensated (even by a positive offset) if we bump the ROM
cache area size.
Tested with several dynarecs.
This allows us to emit the handlers directly in a more efficient manner.
At the same time it allows for an easy fix to emit PIC code, which is
necessary for libretro. This also enables more platform specific
optimizations and variations, perhaps even run-time multiplatform
support.
This removes libco and all the usages of it (+pthreads).
Rewired all dynarecs and interpreter to return after every frame so that
libretro can process events. This required to make dynarec re-entrant.
Dynarecs were updated to check for new frame on every update (IRQ, cycle
exhaustion, I/O write, etc). The performance impact of doing so should
be minimal (and definitely outweight the libco gains). While at it,
fixed small issues to get a bit more perf: arm dynarec was not idling
correctly, mips was using stack when not needed, etc.
Tested on PSP (mips), OGA (armv7), Linux (x86 and interpreter). Not
tested on Android though.
David Guillen Fandos
bmaupin
Francisco José García García
aliaspider
twinaphex
notaz