bsnes/higan/processor/m68k/m68k.cpp

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Update to v100r02 release. byuu says: Sigh ... I'm really not a good person. I'm inherently selfish. My responsibility and obligation right now is to work on loki, and then on the Tengai Makyou Zero translation, and then on improving the Famicom emulation. And yet ... it's not what I really want to do. That shouldn't matter; I should work on my responsibilities first. Instead, I'm going to be a greedy, self-centered asshole, and work on what I really want to instead. I'm really sorry, guys. I'm sure this will make a few people happy, and probably upset even more people. I'm also making zero guarantees that this ever gets finished. As always, I wish I could keep these things secret, so if I fail / give up, I could just drop it with no shame. But I would have to cut everyone out of the WIP process completely to make it happen. So, here goes ... This WIP adds the initial skeleton for Sega Mega Drive / Genesis emulation. God help us. (minor note: apparently the new extension for Mega Drive games is .md, neat. That's what I chose for the folders too. I thought it was .smd, so that'll be fixed in icarus for the next WIP.) (aside: this is why I wanted to get v100 out. I didn't want this code in a skeleton state in v100's source. Nor did I want really broken emulation, which the first release is sure to be, tarring said release.) ... So, basically, I've been ruminating on the legacy I want to leave behind with higan. 3D systems are just plain out. I'm never going to support them. They're too complex for my abilities, and they would run too slowly with my design style. I'm not willing to compromise my design ideals. And I would never want to play a 3D game system at native 240p/480i resolution ... but 1080p+ upscaling is not accurate, so that's a conflict I want to avoid entirely. It's also never going to emulate computer systems (X68K, PC-98, FM-Towns, etc) because holy shit that would completely destroy me. It's also never going emulate arcade machines. So I think of higan as a collection of 2D emulators for consoles and handhelds. I've gone over every major 2D gaming system there is, looking for ones with games I actually care about and enjoy. And I basically have five of those systems supported already. Looking at the remaining list, I see only three systems left that I have any interest in whatsoever: PC-Engine, Master System, Mega Drive. Again, I'm not in any way committing to emulating any of these, but ... if I had all of those in higan, I think I'd be content to really, truly, finally stop writing more emulators for the rest of my life. And so I decided to tackle the most difficult system first. If I'm successful, the Z80 core should cover a lot of the work on the SMS. And the HuC6280 should land somewhere between the NES and SNES in terms of difficulty ... closer to the NES. The systems that just don't appeal to me at all, which I will never touch, include, but are not limited to: * Atari 2600/5200/7800 * Lynx * Jaguar * Vectrex * Colecovision * Commodore 64 * Neo-Geo * Neo-Geo Pocket / Color * Virtual Boy * Super A'can * 32X * CD-i * etc, etc, etc. And really, even if something were mildly interesting in there ... we have to stop. I can't scale infinitely. I'm already way past my limit, but I'm doing this anyway. Too many cores bloats everything and kills quality on everything. I don't want higan to become MESS v2. I don't know what I'll do about the Famicom Disk System, PC-Engine CD, and Mega CD. I don't think I'll be able to achieve 60fps emulating the Mega CD, even if I tried to. I don't know what's going to happen here with even the Mega Drive. Maybe I'll get driven crazy with the documentation and quit. Maybe it'll end up being too complicated and I'll quit. Maybe the emulation will end up way too slow and I'll give up. Maybe it'll take me seven years to get any games playable at all. Maybe Steve Snake, AamirM and Mike Pavone will pool money to hire a hitman to come after me. Who knows. But this is what I want to do, so ... here goes nothing.
2016-07-09 04:21:37 +00:00
#include <processor/processor.hpp>
#include "m68k.hpp"
namespace Processor {
enum : uint { Byte, Word, Long };
enum : bool { Reverse = 1 };
Update to v100r06 release. byuu says: Up to ten 68K instructions out of somewhere between 61 and 88, depending upon which PDF you look at. Of course, some of them aren't 100% completed yet, either. Lots of craziness with MOVEM, and BCC has a BSR variant that needs stack push/pop functions. This WIP actually took over eight hours to make, going through every possible permutation on how to design the core itself. The updated design now builds both the instruction decoder+dispatcher and the disassembler decoder into the same main loop during M68K's constructor. The special cases are also really psychotic on this processor, and I'm afraid of missing something via the fallthrough cases. So instead, I'm ordering the instructions alphabetically, and including exclusion cases to ignore binding invalid cases. If I end up remapping an existing register, then it'll throw a run-time assertion at program startup. I wanted very much to get rid of struct EA (EffectiveAddress), but it's too difficult to keep track of the internal effective address without it. So I split out the size to a separate parameter, since every opcode only has one size parameter, and otherwise it was getting duplicated in opcodes that take two EAs, and was also awkward with the flag testing. It's a bit more typing, but I feel it's more clean this way. Overall, I'm really worried this is going to be too slow. I don't want to turn the EA stuff into templates, because that will massively bloat out compilation times and object sizes, and will also need a special DSL preprocessor since C++ doesn't have a static for loop. I can definitely optimize a lot of EA's address/read/write functions away once the core is completed, but it's never going to hold a candle to a templatized 68K core. ---- Forgot to include the SA-1 regression fix. I always remember immediately after I upload and archive the WIP. Will try to get that in next time, I guess.
2016-07-16 08:39:44 +00:00
#include "registers.cpp"
#include "memory.cpp"
#include "effective-address.cpp"
#include "instructions.cpp"
#include "disassembler.cpp"
#include "instruction.cpp"
Update to v102r16 release. byuu says: Changelog: - Emulator::Stream now allows adding low-pass and high-pass filters dynamically - also accepts a pass# count; each pass is a second-order biquad butterworth IIR filter - Emulator::Stream no longer automatically filters out >20KHz frequencies for all streams - FC: added 20Hz high-pass filter; 20KHz low-pass filter - GB: removed simple 'magic constant' high-pass filter of unknown cutoff frequency (missed this one in the last WIP) - GB,SGB,GBC: added 20Hz high-pass filter; 20KHz low-pass filter - MS,GG,MD/PSG: added 20Hz high-pass filter; 20KHz low-pass filter - MD: added save state support (but it's completely broken for now; sorry) - MD/YM2612: fixed Voice#3 per-operator pitch support (fixes sound effects in Streets of Rage, etc) - PCE: added 20Hz high-pass filter; 20KHz low-pass filter - WS,WSC: added 20Hz high-pass filter; 20KHz low-pass filter So, the point of the low-pass filters is to remove frequencies above human hearing. If we don't do this, then resampling will introduce aliasing that results in sounds that are audible to the human ear. Which basically an annoying buzzing sound. You'll definitely hear the improvement from these in games like Mega Man 2 on the NES. Of course, these already existed before, so this WIP won't sound better than previous WIPs. The high-pass filters are a little more complicated. Their main role is to remove DC bias and help to center the audio stream. I don't understand how they do this at all, but ... that's what everyone who knows what they're talking about says, thus ... so be it. I have set all of the high-pass filters to 20Hz, which is below the limit of human hearing. Now this is where it gets really interesting ... technically, some of these systems actually cut off a lot of range. For instance, the GBA should technically use an 800Hz high-pass filter when output is done through the system's speakers. But of course, if you plug in headphones, you can hear the lower frequencies. Now 800Hz ... you definitely can hear. At that level, nearly all of the bass is stripped out and the audio is very tinny. Just like the real system. But for now, I don't want to emulate the audio being crushed that badly. I'm sticking with 20Hz everywhere since it won't negatively affect audio quality. In fact, you should not be able to hear any difference between this WIP and the previous WIP. But theoretically, DC bias should mostly be removed as a result of these new filters. It may be that we need to raise the values on some cores in the future, but I don't want to do that until we know for certain that we have to. What I can say is that compared to even older WIPs than r15 ... the removal of the simple one-pole low-pass and high-pass filters with the newer three-pass, second-order filters should result in much better attenuation (less distortion of audible frequencies.) Probably not enough to be noticeable in a blind test, though.
2017-03-08 20:20:40 +00:00
#include "serialization.cpp"
auto M68K::power() -> void {
for(auto& dr : r.d) dr = 0;
for(auto& ar : r.a) ar = 0;
r.sp = 0;
r.pc = 0;
r.c = 0;
r.v = 0;
r.z = 0;
r.n = 0;
r.x = 0;
r.i = 7;
r.s = 1;
r.t = 0;
r.stop = false;
r.reset = false;
}
auto M68K::supervisor() -> bool {
if(r.s) return true;
r.pc -= 2;
exception(Exception::Unprivileged, Vector::Unprivileged);
return false;
}
auto M68K::exception(uint exception, uint vector, uint priority) -> void {
Update to v101r07 release. byuu says: Added VDP sprite rendering. Can't get any games far enough in to see if it actually works. So in other words, it doesn't work at all and is 100% completely broken. Also added 68K exceptions and interrupts. So far only the VDP interrupt is present. It definitely seems to be firing in commercial games, so that's promising. But the implementation is almost certainly completely wrong. There is fuck all of nothing for documentation on how interrupts actually work. I had to find out the interrupt vector numbers from reading the comments from the Sonic the Hedgehog disassembly. I have literally no fucking clue what I0-I2 (3-bit integer priority value in the status register) is supposed to do. I know that Vblank=6, Hblank=4, Ext(gamepad)=2. I know that at reset, SR.I=7. I don't know if I'm supposed to block interrupts when I is >, >=, <, <= to the interrupt level. I don't know what level CPU exceptions are supposed to be. Also implemented VDP regular DMA. No idea if it works correctly since none of the commercial games run far enough to use it. So again, it's horribly broken for usre. Also improved VDP fill mode. But I don't understand how it takes byte-lengths when the bus is 16-bit. The transfer times indicate it's actually transferring at the same speed as the 68K->VDP copy, strongly suggesting it's actually doing 16-bit transfers at a time. In which case, what happens when you set an odd transfer length? Also, both DMA modes can now target VRAM, VSRAM, CRAM. Supposedly there's all kinds of weird shit going on when you target VSRAM, CRAM with VDP fill/copy modes, but whatever. Get to that later. Also implemented a very lazy preliminary wait mechanism to to stall out a processor while another processor exerts control over the bus. This one's going to be a major work in progress. For one, it totally breaks the model I use to do save states with libco. For another, I don't know if a 68K->VDP DMA instantly locks the CPU, or if it the CPU could actually keep running if it was executing out of RAM when it started the DMA transfer from ROM (eg it's a bus busy stall, not a hard chip stall.) That'll greatly change how I handle the waiting. Also, the OSS driver now supports Audio::Latency. Sound should be even lower latency now. On FreeBSD when set to 0ms, it's absolutely incredible. Cannot detect latency whatsoever. The Mario jump sound seems to happen at the very instant I hear my cherry blue keyswitch activate.
2016-08-15 04:56:38 +00:00
auto pc = r.pc;
auto sr = readSR();
Update to v104r07 release. byuu says: Changelog: - md/vdp: added VIP bit to status register; fixes Cliffhanger - processor/m68k/disassembler: added modes 7 and 8 to LEA address disassembly - processor/m68k/disassembler: enhanced ILLEGAL to display LINEA/LINEF $xxx variants - processor/m68k: ILLEGAL/LINEA/LINEF do not modify the stack register; fixes Caeser no Yabou II - icarus/sfc: request sgb1.boot.rom and sgb2.boot.rom separately; as they are different - icarus/sfc: removed support for external firmware when loading ROM images The hack to run Mega Drive Ballz 3D isn't in place, as I don't know if it's correct, and the graphics were corrupted anyway. The SGB boot ROM change is going to require updating the icarus database as well. I will add that in when I start dumping more cartridges here soon. Finally ... I explained this already, but I'll do so here as well: I removed icarus' support for loading SNES coprocessor firmware games with external firmware files (eg dsp1.program.rom + dsp1.data.rom in the same path as supermariokart.sfc, for example.) I realize most are going to see this as an antagonizing/stubborn move given the recent No-Intro discussion, and I won't deny that said thread is why this came to the forefront of my mind. But on my word, I honestly believe this was an ineffective solution for many reasons not related to our disagreements: 1. No-Intro distributes SNES coprocessor firmware as a merged file, eg "DSP1 (World).zip/DSP1 (World).bin" -- icarus can't possibly know about every ROM distribution set's naming conventions for firmware. (Right now, it appears GoodSNES and NSRT are mostly dead; but there may be more DATs in the future -- including my own.) 2. Even if the user obtains the firmware and tries to rename it, it won't work: icarus parses manifests generated by the heuristics module and sees two ROM files: dsp1.program.rom and dsp1.data.rom. icarus cannot identify a file named dsp1.rom as containing both of these sub-files. Users are going to have to know how to split files, which there is no way to do on stock Windows. Merging files, however, can be done via `copy /b supermariokart.sfc+dsp1.rom supermariokartdsp.sfc`; - and dsp1.rom can be named whatever now. I am not saying this will be easy for the average user, but it's easier than splitting files. 3. Separate firmware breaks icarus' database lookup. If you have pilotwings.sfc but without firmware, icarus will not find a match for it in the database lookup phase. It will then fall back on heuristics. The heuristics will pick DSP1B for compatibility with Ballz 3D which requires it. And so it will try to pull in the wrong firmware, and the game's intro will not work correctly. Furthermore, the database information will be unavailable, resulting in inaccurate mirroring. So for these reasons, I have removed said support. You must now load SNES coprocessor games into higan in one of two ways: 1) game paks with split files; or 2) SFC images with merged firmware. If and when No-Intro deploys a method I can actually use, I give you all my word I will give it a fair shot and if it's reasonable, I'll support it in icarus.
2017-08-28 12:46:14 +00:00
if(exception != Exception::Illegal) {
if(!r.s) swap(r.a[7], r.sp);
r.i = priority;
r.s = 1;
r.t = 0;
}
Update to v101r07 release. byuu says: Added VDP sprite rendering. Can't get any games far enough in to see if it actually works. So in other words, it doesn't work at all and is 100% completely broken. Also added 68K exceptions and interrupts. So far only the VDP interrupt is present. It definitely seems to be firing in commercial games, so that's promising. But the implementation is almost certainly completely wrong. There is fuck all of nothing for documentation on how interrupts actually work. I had to find out the interrupt vector numbers from reading the comments from the Sonic the Hedgehog disassembly. I have literally no fucking clue what I0-I2 (3-bit integer priority value in the status register) is supposed to do. I know that Vblank=6, Hblank=4, Ext(gamepad)=2. I know that at reset, SR.I=7. I don't know if I'm supposed to block interrupts when I is >, >=, <, <= to the interrupt level. I don't know what level CPU exceptions are supposed to be. Also implemented VDP regular DMA. No idea if it works correctly since none of the commercial games run far enough to use it. So again, it's horribly broken for usre. Also improved VDP fill mode. But I don't understand how it takes byte-lengths when the bus is 16-bit. The transfer times indicate it's actually transferring at the same speed as the 68K->VDP copy, strongly suggesting it's actually doing 16-bit transfers at a time. In which case, what happens when you set an odd transfer length? Also, both DMA modes can now target VRAM, VSRAM, CRAM. Supposedly there's all kinds of weird shit going on when you target VSRAM, CRAM with VDP fill/copy modes, but whatever. Get to that later. Also implemented a very lazy preliminary wait mechanism to to stall out a processor while another processor exerts control over the bus. This one's going to be a major work in progress. For one, it totally breaks the model I use to do save states with libco. For another, I don't know if a 68K->VDP DMA instantly locks the CPU, or if it the CPU could actually keep running if it was executing out of RAM when it started the DMA transfer from ROM (eg it's a bus busy stall, not a hard chip stall.) That'll greatly change how I handle the waiting. Also, the OSS driver now supports Audio::Latency. Sound should be even lower latency now. On FreeBSD when set to 0ms, it's absolutely incredible. Cannot detect latency whatsoever. The Mario jump sound seems to happen at the very instant I hear my cherry blue keyswitch activate.
2016-08-15 04:56:38 +00:00
push<Long>(pc);
push<Word>(sr);
r.pc = read<Long>(vector << 2);
}
Update to v100r02 release. byuu says: Sigh ... I'm really not a good person. I'm inherently selfish. My responsibility and obligation right now is to work on loki, and then on the Tengai Makyou Zero translation, and then on improving the Famicom emulation. And yet ... it's not what I really want to do. That shouldn't matter; I should work on my responsibilities first. Instead, I'm going to be a greedy, self-centered asshole, and work on what I really want to instead. I'm really sorry, guys. I'm sure this will make a few people happy, and probably upset even more people. I'm also making zero guarantees that this ever gets finished. As always, I wish I could keep these things secret, so if I fail / give up, I could just drop it with no shame. But I would have to cut everyone out of the WIP process completely to make it happen. So, here goes ... This WIP adds the initial skeleton for Sega Mega Drive / Genesis emulation. God help us. (minor note: apparently the new extension for Mega Drive games is .md, neat. That's what I chose for the folders too. I thought it was .smd, so that'll be fixed in icarus for the next WIP.) (aside: this is why I wanted to get v100 out. I didn't want this code in a skeleton state in v100's source. Nor did I want really broken emulation, which the first release is sure to be, tarring said release.) ... So, basically, I've been ruminating on the legacy I want to leave behind with higan. 3D systems are just plain out. I'm never going to support them. They're too complex for my abilities, and they would run too slowly with my design style. I'm not willing to compromise my design ideals. And I would never want to play a 3D game system at native 240p/480i resolution ... but 1080p+ upscaling is not accurate, so that's a conflict I want to avoid entirely. It's also never going to emulate computer systems (X68K, PC-98, FM-Towns, etc) because holy shit that would completely destroy me. It's also never going emulate arcade machines. So I think of higan as a collection of 2D emulators for consoles and handhelds. I've gone over every major 2D gaming system there is, looking for ones with games I actually care about and enjoy. And I basically have five of those systems supported already. Looking at the remaining list, I see only three systems left that I have any interest in whatsoever: PC-Engine, Master System, Mega Drive. Again, I'm not in any way committing to emulating any of these, but ... if I had all of those in higan, I think I'd be content to really, truly, finally stop writing more emulators for the rest of my life. And so I decided to tackle the most difficult system first. If I'm successful, the Z80 core should cover a lot of the work on the SMS. And the HuC6280 should land somewhere between the NES and SNES in terms of difficulty ... closer to the NES. The systems that just don't appeal to me at all, which I will never touch, include, but are not limited to: * Atari 2600/5200/7800 * Lynx * Jaguar * Vectrex * Colecovision * Commodore 64 * Neo-Geo * Neo-Geo Pocket / Color * Virtual Boy * Super A'can * 32X * CD-i * etc, etc, etc. And really, even if something were mildly interesting in there ... we have to stop. I can't scale infinitely. I'm already way past my limit, but I'm doing this anyway. Too many cores bloats everything and kills quality on everything. I don't want higan to become MESS v2. I don't know what I'll do about the Famicom Disk System, PC-Engine CD, and Mega CD. I don't think I'll be able to achieve 60fps emulating the Mega CD, even if I tried to. I don't know what's going to happen here with even the Mega Drive. Maybe I'll get driven crazy with the documentation and quit. Maybe it'll end up being too complicated and I'll quit. Maybe the emulation will end up way too slow and I'll give up. Maybe it'll take me seven years to get any games playable at all. Maybe Steve Snake, AamirM and Mike Pavone will pool money to hire a hitman to come after me. Who knows. But this is what I want to do, so ... here goes nothing.
2016-07-09 04:21:37 +00:00
}