mirror of https://github.com/bsnes-emu/bsnes.git
5 Commits
| Author | SHA1 | Message | Date |
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Tim Allen
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c50723ef61 |
Update to v100r15 release.
byuu wrote: Aforementioned scheduler changes added. Longer explanation of why here: http://hastebin.com/raw/toxedenece Again, we really need to test this as thoroughly as possible for regressions :/ This is a really major change that affects absolutely everything: all emulation cores, all coprocessors, etc. Also added ADDX and SUB to the 68K core, which brings us just barely above 50% of the instruction encoding space completed. [Editor's note: The "aformentioned scheduler changes" were described in a previous forum post: Unfortunately, 64-bits just wasn't enough precision (we were getting misalignments ~230 times a second on 21/24MHz clocks), so I had to move to 128-bit counters. This of course doesn't exist on 32-bit architectures (and probably not on all 64-bit ones either), so for now ... higan's only going to compile on 64-bit machines until we figure something out. Maybe we offer a "lower precision" fallback for machines that lack uint128_t or something. Using the booth algorithm would be way too slow. Anyway, the precision is now 2^-96, which is roughly 10^-29. That puts us far beyond the yoctosecond. Suck it, MAME :P I'm jokingly referring to it as the byuusecond. The other 32-bits of precision allows a 1Hz clock to run up to one full second before all clocks need to be normalized to prevent overflow. I fixed a serious wobbling issue where I was using clock > other.clock for synchronization instead of clock >= other.clock; and also another aliasing issue when two threads share a common frequency, but don't run in lock-step. The latter I don't even fully understand, but I did observe it in testing. nall/serialization.hpp has been extended to support 128-bit integers, but without explicitly naming them (yay generic code), so nall will still compile on 32-bit platforms for all other applications. Speed is basically a wash now. FC's a bit slower, SFC's a bit faster. The "longer explanation" in the linked hastebin is: Okay, so the idea is that we can have an arbitrary number of oscillators. Take the SNES: - CPU/PPU clock = 21477272.727272hz - SMP/DSP clock = 24576000hz - Cartridge DSP1 clock = 8000000hz - Cartridge MSU1 clock = 44100hz - Controller Port 1 modem controller clock = 57600hz - Controller Port 2 barcode battler clock = 115200hz - Expansion Port exercise bike clock = 192000hz Is this a pathological case? Of course it is, but it's possible. The first four do exist in the wild already: see Rockman X2 MSU1 patch. Manifest files with higan let you specify any frequency you want for any component. The old trick higan used was to hold an int64 counter for each thread:thread synchronization, and adjust it like so: - if thread A steps X clocks; then clock += X * threadB.frequency - if clock >= 0; switch to threadB - if thread B steps X clocks; then clock -= X * threadA.frequency - if clock < 0; switch to threadA But there are also system configurations where one processor has to synchronize with more than one other processor. Take the Genesis: - the 68K has to sync with the Z80 and PSG and YM2612 and VDP - the Z80 has to sync with the 68K and PSG and YM2612 - the PSG has to sync with the 68K and Z80 and YM2612 Now I could do this by having an int64 clock value for every association. But these clock values would have to be outside the individual Thread class objects, and we would have to update every relationship's clock value. So the 68K would have to update the Z80, PSG, YM2612 and VDP clocks. That's four expensive 64-bit multiply-adds per clock step event instead of one. As such, we have to account for both possibilities. The only way to do this is with a single time base. We do this like so: - setup: scalar = timeBase / frequency - step: clock += scalar * clocks Once per second, we look at every thread, find the smallest clock value. Then subtract that value from all threads. This prevents the clock counters from overflowing. Unfortunately, these oscillator values are psychotic, unpredictable, and often times repeating fractions. Even with a timeBase of 1,000,000,000,000,000,000 (one attosecond); we get rounding errors every ~16,300 synchronizations. Specifically, this happens with a CPU running at 21477273hz (rounded) and SMP running at 24576000hz. That may be good enough for most emulators, but ... you know how I am. Plus, even at the attosecond level, we're really pushing against the limits of 64-bit integers. Given the reciprocal inverse, a frequency of 1Hz (which does exist in higan!) would have a scalar that consumes 1/18th of the entire range of a uint64 on every single step. Yes, I could raise the frequency, and then step by that amount, I know. But I don't want to have weird gotchas like that in the scheduler core. Until I increase the accuracy to about 100 times greater than a yoctosecond, the rounding errors are too great. And since the only choice above 64-bit values is 128-bit values; we might as well use all the extra headroom. 2^-96 as a timebase gives me the ability to have both a 1Hz and 4GHz clock; and run them both for a full second; before an overflow event would occur. Another hastebin includes demonstration code: #include <libco/libco.h> #include <nall/nall.hpp> using namespace nall; // cothread_t mainThread = nullptr; const uint iterations = 100'000'000; const uint cpuFreq = 21477272.727272 + 0.5; const uint smpFreq = 24576000.000000 + 0.5; const uint cpuStep = 4; const uint smpStep = 5; // struct ThreadA { cothread_t handle = nullptr; uint64 frequency = 0; int64 clock = 0; auto create(auto (*entrypoint)() -> void, uint frequency) { this->handle = co_create(65536, entrypoint); this->frequency = frequency; this->clock = 0; } }; struct CPUA : ThreadA { static auto Enter() -> void; auto main() -> void; CPUA() { create(&CPUA::Enter, cpuFreq); } } cpuA; struct SMPA : ThreadA { static auto Enter() -> void; auto main() -> void; SMPA() { create(&SMPA::Enter, smpFreq); } } smpA; uint8 queueA[iterations]; uint offsetA; cothread_t resumeA = cpuA.handle; auto EnterA() -> void { offsetA = 0; co_switch(resumeA); } auto QueueA(uint value) -> void { queueA[offsetA++] = value; if(offsetA >= iterations) { resumeA = co_active(); co_switch(mainThread); } } auto CPUA::Enter() -> void { while(true) cpuA.main(); } auto CPUA::main() -> void { QueueA(1); smpA.clock -= cpuStep * smpA.frequency; if(smpA.clock < 0) co_switch(smpA.handle); } auto SMPA::Enter() -> void { while(true) smpA.main(); } auto SMPA::main() -> void { QueueA(2); smpA.clock += smpStep * cpuA.frequency; if(smpA.clock >= 0) co_switch(cpuA.handle); } // struct ThreadB { cothread_t handle = nullptr; uint128_t scalar = 0; uint128_t clock = 0; auto print128(uint128_t value) { string s; while(value) { s.append((char)('0' + value % 10)); value /= 10; } s.reverse(); print(s, "\n"); } //femtosecond (10^15) = 16306 //attosecond (10^18) = 688838 //zeptosecond (10^21) = 13712691 //yoctosecond (10^24) = 13712691 (hitting a dead-end on a rounding error causing a wobble) //byuusecond? ( 2^96) = (perfect? 79,228 times more precise than a yoctosecond) auto create(auto (*entrypoint)() -> void, uint128_t frequency) { this->handle = co_create(65536, entrypoint); uint128_t unitOfTime = 1; //for(uint n : range(29)) unitOfTime *= 10; unitOfTime <<= 96; //2^96 time units ... this->scalar = unitOfTime / frequency; print128(this->scalar); this->clock = 0; } auto step(uint128_t clocks) -> void { clock += clocks * scalar; } auto synchronize(ThreadB& thread) -> void { if(clock >= thread.clock) co_switch(thread.handle); } }; struct CPUB : ThreadB { static auto Enter() -> void; auto main() -> void; CPUB() { create(&CPUB::Enter, cpuFreq); } } cpuB; struct SMPB : ThreadB { static auto Enter() -> void; auto main() -> void; SMPB() { create(&SMPB::Enter, smpFreq); clock = 1; } } smpB; auto correct() -> void { auto minimum = min(cpuB.clock, smpB.clock); cpuB.clock -= minimum; smpB.clock -= minimum; } uint8 queueB[iterations]; uint offsetB; cothread_t resumeB = cpuB.handle; auto EnterB() -> void { correct(); offsetB = 0; co_switch(resumeB); } auto QueueB(uint value) -> void { queueB[offsetB++] = value; if(offsetB >= iterations) { resumeB = co_active(); co_switch(mainThread); } } auto CPUB::Enter() -> void { while(true) cpuB.main(); } auto CPUB::main() -> void { QueueB(1); step(cpuStep); synchronize(smpB); } auto SMPB::Enter() -> void { while(true) smpB.main(); } auto SMPB::main() -> void { QueueB(2); step(smpStep); synchronize(cpuB); } // #include <nall/main.hpp> auto nall::main(string_vector) -> void { mainThread = co_active(); uint masterCounter = 0; while(true) { print(masterCounter++, " ...\n"); auto A = clock(); EnterA(); auto B = clock(); print((double)(B - A) / CLOCKS_PER_SEC, "s\n"); auto C = clock(); EnterB(); auto D = clock(); print((double)(D - C) / CLOCKS_PER_SEC, "s\n"); for(uint n : range(iterations)) { if(queueA[n] != queueB[n]) return print("fail at ", n, "\n"); } } } ...and that's everything.] |
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Tim Allen
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ca277cd5e8 |
Update to v100r14 release.
byuu says:
(Windows: compile with -fpermissive to silence an annoying error. I'll
fix it in the next WIP.)
I completely replaced the time management system in higan and overhauled
the scheduler.
Before, processor threads would have "int64 clock"; and there would
be a 1:1 relationship between two threads. When thread A ran for X
cycles, it'd subtract X * B.Frequency from clock; and when thread B ran
for Y cycles, it'd add Y * A.Frequency from clock. This worked well
and allowed perfect precision; but it doesn't work when you have more
complicated relationships: eg the 68K can sync to the Z80 and PSG; the
Z80 to the 68K and PSG; so the PSG needs two counters.
The new system instead uses a "uint64 clock" variable that represents
time in attoseconds. Every time the scheduler exits, it subtracts
the smallest clock count from all threads, to prevent an overflow
scenario. The only real downside is that rounding errors mean that
roughly every 20 minutes, we have a rounding error of one clock cycle
(one 20,000,000th of a second.) However, this only applies to systems
with multiple oscillators, like the SNES. And when you're in that
situation ... there's no such thing as a perfect oscillator anyway. A
real SNES will be thousands of times less out of spec than 1hz per 20
minutes.
The advantages are pretty immense. First, we obviously can now support
more complex relationships between threads. Second, we can build a
much more abstracted scheduler. All of libco is now abstracted away
completely, which may permit a state-machine / coroutine version of
Thread in the future. We've basically gone from this:
auto SMP::step(uint clocks) -> void {
clock += clocks * (uint64)cpu.frequency;
dsp.clock -= clocks;
if(dsp.clock < 0 && !scheduler.synchronizing()) co_switch(dsp.thread);
if(clock >= 0 && !scheduler.synchronizing()) co_switch(cpu.thread);
}
To this:
auto SMP::step(uint clocks) -> void {
Thread::step(clocks);
synchronize(dsp);
synchronize(cpu);
}
As you can see, we don't have to do multiple clock adjustments anymore.
This is a huge win for the SNES CPU that had to update the SMP, DSP, all
peripherals and all coprocessors. Likewise, we don't have to synchronize
all coprocessors when one runs, now we can just synchronize the active
one to the CPU.
Third, when changing the frequencies of threads (think SGB speed setting
modes, GBC double-speed mode, etc), it no longer causes the "int64
clock" value to be erroneous.
Fourth, this results in a fairly decent speedup, mostly across the
board. Aside from the GBA being mostly a wash (for unknown reasons),
it's about an 8% - 12% speedup in every other emulation core.
Now, all of this said ... this was an unbelievably massive change, so
... you know what that means >_> If anyone can help test all types of
SNES coprocessors, and some other system games, it'd be appreciated.
----
Lastly, we have a bitchin' new about screen. It unfortunately adds
~200KiB onto the binary size, because the PNG->C++ header file
transformation doesn't compress very well, and I want to keep the
original resource files in with the higan archive. I might try some
things to work around this file size increase in the future, but for now
... yeah, slightly larger archive sizes, sorry.
The logo's a bit busted on Windows (the Label control's background
transparency and alignment settings aren't working), but works well on
GTK. I'll have to fix Windows before the next official release. For now,
look on my Twitter feed if you want to see what it's supposed to look
like.
----
EDIT: forgot about ICD2::Enter. It's doing some weird inverse
run-to-save thing that I need to implement support for somehow. So, save
states on the SGB core probably won't work with this WIP.
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Tim Allen
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3a9c7c6843 |
Update to v099r09 release.
byuu says:
Changelog:
- Emulator::Interface::Medium::bootable removed
- Emulator::Interface::load(bool required) argument removed
[File::Required makes no sense on a folder]
- Super Famicom.sys now has user-configurable properties (CPU,PPU1,PPU2
version; PPU1 VRAM size, Region override)
- old nall/property removed completely
- volatile flags supported on coprocessor RAM files now (still not in
icarus, though)
- (hopefully) fixed SNES Multitap support (needs testing)
- fixed an OAM tiledata range clipping limit in 128KiB VRAM mode (doesn't
fix Yoshi's Island, sadly)
- (hopefully, again) fixed the input polling bug hex_usr reported
- re-added dialog box for when File::Required files are missing
- really cool: if you're missing a boot ROM, BIOS ROM, or IPL ROM,
it warns you immediately
- you don't have to select a game before seeing the error message
anymore
- fixed cheats.bml load/save location
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Tim Allen
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f48b332c83 |
Update to v099r08 release.
byuu says:
Changelog:
- nall/vfs work 100% completed; even SGB games load now
- emulation cores now call load() for the base cartridges as well
- updated port/device handling; portmask is gone; device ID bug should
be resolved now
- SNES controller port 1 multitap option was removed
- added support for 128KiB SNES PPU VRAM (for now, edit sfc/ppu/ppu.hpp
VRAM::size=0x10000; to enable)
Overall, nall/vfs was a huge success!! We've substantially reduced
the amount of boilerplate code everywhere, while still allowing (even
easier than before) support for RAM-based game loading/saving. All of
nall/stream is dead and buried.
I am considering removing Emulator::Interface::Medium::id and/or
bootable flag. Or at least, doing something different with it. The
values for the non-bootable GB/BS/ST entries duplicate the ID that is
supposed to be unique. They are for GB/GBC and WS/WSC. Maybe I'll use
this as the hardware revision selection ID, and then gut non-bootable
options. There's really no reason for that to be there. I think at one
point I was using it to generate library tabs for non-bootable systems,
but we don't do that anymore anyway.
Emulator::Interface::load() may not need the required flag anymore ... it
doesn't really do anything right now anyway.
I have a few reasons for having the cores load the base cartridge. Most
importantly, it is going to enable a special mode for the WonderSwan /
WonderSwan Color in the future. If we ever get the IPLROMs dumped ... it's
possible to boot these systems with no games inserted to set user profile
information and such. There are also other systems that may accept being
booted without a cartridge. To reach this state, you would load a game and
then cancel the load dialog. Right now, this results in games not loading.
The second reason is this prevents nasty crashes when loading fails. So
if you're missing a required manifest, the emulator won't die a violent
death anymore. It's able to back out at any point.
The third reason is consistency: loading the base cartridge works the
same as the slot cartridges.
The fourth reason is Emulator::Interface::open(uint pathID)
values. Before, the GB, SB, GBC modes were IDs 1,2,3 respectively. This
complicated things because you had to pass the correct ID. But now
instead, Emulator::Interface::load() returns maybe<uint> that is nothing
when no game is selected, and a pathID for a valid game. And now open()
can take this ID to access this game's folder contents.
The downside, which is temporary, is that command-line loading is
currently broken. But I do intend on restoring it. In fact, I want to do
better than before and allow multi-cart booting from the command-line by
specifying the base cartridge and then slot cartridges. The idea should
be pretty simple: keep a queue of pending filenames that we fill from
the command-line and/or drag-and-drop operations on the main window,
and then empty out the queue or prompt for load dialogs from the UI
when booting a system. This also might be a bit more unorthodox compared
to the traditional emulator design of "loadGame(filename)", but ... oh
well. It's easy enough still.
The port/device changes are fun. We simplified things quite a bit. The
portmask stuff is gone entirely. While ports and devices keep IDs,
this is really just sugar-coating so UIs can use for(auto& port :
emulator->ports) and access port.id; rather than having to use for(auto
n : range(emulator->ports)) { auto& port = emulator->ports[n]; ... };
but they should otherwise generally be identical to the order they appear
in their respective ranges. Still, don't rely on that.
Input::id is gone. There was no point since we also got rid of the nasty
Input::order vector. Since I was in here, I went ahead and caved on the
pedantics and renamed Input::guid to Input::userData.
I removed the SNES controller port 1 multitap option. Basically, the only
game that uses this is N-warp Daisakusen and, no offense to d4s, it's
not really a good game anyway. It's just a quick demo to show 8-players
on the SNES. But in the UI, all it does is confuse people into wasting
time mapping a controller they're never going to use, and they're going
to wonder which port to use. If more compelling use cases for 8-players
comes about, we can reconsider this. I left all the code to support this
in place, so all you have to do is uncomment one line to enable it again.
We now have dsnes emulation! :D
If you change PPU::VRAM::size to 0x10000 (words), then you should now
have 128KiB of VRAM. Even better, it serializes the used-VRAM size,
so your save states shouldn't crash on you if you swap between the two
(though if you try this, you're nuts.)
Note that this option does break commercial software. Yoshi's Island in
particular. This game is setting A15 on some PPU register writes, but
not on others. The end result of this is things break horribly in-game.
Also, this option is causing a very tiny speed hit for obvious reasons
with the variable masking value (I'm even using size-1 for now.) Given
how niche this is, I may just leave it a compile-time constant to avoid
the overhead cost. Otherwise, if we keep the option, then it'll go into
Super Famicom.sys/manifest.bml ... I'll flesh that out in the near-future.
----
Finally, some fun for my OCD ... my monitor suddenly cut out on me
in the middle of working on this WIP, about six hours in of non-stop
work. Had to hit a bunch of ctrl+alt+fN commands (among other things)
and trying to log in headless on another TTY to do issue commands,
trying to recover the display. Finally power cycled the monitor and it
came back up. So all my typing ended up going to who knows where.
Usually this sort of thing terrifies me enough that I scrap a WIP and
start over to ensure I didn't screw anything up during the crashed screen
when hitting keys randomly.
Obviously, everything compiles and appears to work fine. And I know
it's extremely paranoid, but OCD isn't logical, so ... I'm going
to go over every line of the 100KiB r07->r08 diff looking for any
corruption/errors/whatever.
----
Review finished.
r08 diff review notes:
- fc/controller/gamepad/gamepad.cpp:
use uint device = ID::Device::Gamepad; not id = ...;
- gb/cartridge/cartridge.hpp:
remove redundant uint _pathID; (in Information::pathID already)
- gb/cartridge/cartridge.hpp:
pull sha256 inside Information
- sfc/cartridge/load/cpp:
add " - Slot (A,B)" to interface->load("Sufami Turbo"); to be more
descriptive
- sfc/controller/gamepad/gamepad.cpp:
use uint device = ID::Device::Gamepad; not id = ...;
- sfc/interface/interface.cpp:
remove n variable from the Multitap device input generation loop
(now unused)
- sfc/interface/interface.hpp:
put struct Port above struct Device like the other classes
- ui-tomoko:
cheats.bml is reading from/writing to mediumPaths(0) [system folder
instead of game folder]
- ui-tomoko:
instead of mediumPaths(1) - call emulator->metadataPathID() or something
like that
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Tim Allen
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40abcfc4a5 |
Update to v099r04 release.
byuu says: Changelog: - lots of code cleanups to processor/r6502 (the switch.cpp file is only halfway done ...) - lots of code cleanups to fc/cpu - removed fc/input - implemented fc/controller hex_usr, you may not like this, but I want to keep the controller port and expansion port interface separate, like I do with the SNES. I realize the NES' is used more for controllers, and the SNES' more for hardware expansions, but ... they're not compatible pinouts and you can't really connect one to the other. Right now, I've only implemented the controller portion. I'll have to get to the peripheral portion later. Also, the gamepad implementation there now may be wrong. It's based off the Super Famicom version obviously. I'm not sure if the Famicom has different behavior with latching $4016 writes, or not. But, it works in Mega Man II, so it's a start. Everyone, be sure to remap your controls, and then set port 1 -> gamepad after loading your first Famicom game with the new WIP. |