mirror of https://github.com/bsnes-emu/bsnes.git
22 Commits
Author | SHA1 | Message | Date |
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Tim Allen | 55f19c3e0d |
Update to v103r32 release.
byuu says: Changelog: - Master System: merged Bus into CPU - Mega Drive: merged BusCPU into CPU; BusAPU into AU - Mega Drive: added TMSS emulation; disabled by default [hex\_usr] - VDP lockout not yet emulated - processor/arm7tdmi: renamed interrupt() to exception() - processor/arm7tdmi: CPSR.F (FIQ disable) flag is set on reset - processor/arm7tdmi: pipeline decode stage caches CPSR.T (THUMB mode) [MerryMage] - fixes `msr_tests.gba` test F - processor/arm7tdmi/disassembler: add PC address to left of currently executing instruction - processor/arm7tdmi: stop forcing CPSR.M (mode flags) bit 4 high (I don't know what really happens here) - processor/arm7tdmi: undefined instructions now generate Undefined 0x4 exception - processor/arm7tdmi: thumbInstructionAddRegister masks PC by &~3 instead of &~2 - hopefully this is correct; &~2 felt very wrong - processor/arm7tdmi: thumbInstructionStackMultiple can use sequential timing for PC/LR PUSH/POP [Cydrak] - systems/Mega Drive.sys: added tmss.rom; enable with cpu version=1 - tomoko: detect when a ruby video/audio/input driver crashes higan; disable it on next program startup v104 blockers: - Mega Drive: support 8-bit SRAM (even if we don't support 16-bit; don't force 8-bit to 16-bit) - Mega Drive: add region detection support to icarus - ruby: add default audio device information so certain drivers won't default to silence out of the box |
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Tim Allen | 3517d5c4a4 |
Update to v103r02 release.
byuu says: Changelog: - fc/apu: improved phase duty cycle emulation (mode 3 is 25% phase inverted; counter decrements) - md/apu: power/reset do not cancel 68K bus requests - md/apu: 68K is not granted bus access on Z80 power/reset - md/controller: replaced System::Peripherals with ControllerPort concept - md/controller: CTRL port is now read-write, maintains value across controller changes (and soon, soft resets) - md/psg: PSG sampling rate unintentionally modified¹ - processor/spc700: improve cycle timing of (indirect),y instructions [Overload] - processor/spc700: idle() cycles actually read from the program counter; much like the 6502 [Overload] - some of the idle() cycles should read from other addresses; this still needs to be supported - processor/spc700: various cleanups to instruction function naming - processor/z80: prefix state (HL→IX,IY override) can now be serialized - icarus: fix install rule for certain platforms (it wasn't buggy on FreeBSD, but was on Linux?) ¹: the clock speed of the PSG is oscillator/15. But I was setting the sampling rate to oscillator/15/16, which was around 223KHz. I am not sure whether the PSG should be outputting at 3MHz or 223KHz. Amazingly ... I don't really hear a difference either way `o_O` I didn't actually mean to make this change; I just noticed it after comparing the diff between r01 and r02. If this turns out to be wrong, set stream = Emulator::audio.createStream(1, frequency() / 16.0); in md/psg.cpp to revert this change. |
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Tim Allen | 82c58527c3 |
Update to v102r17 release.
byuu says: Changelog: - GBA: process audio at 2MHz instead of 32KHz¹ - MD: do not allow the 68K to stop the Z80, unless it has been granted bus access first - MD: do not reset bus requested/granted signals when the 68K resets the Z80 - the above two fix The Lost Vikings - MD: clean up the bus address decoding to be more readable - MD: add support for a13000-a130ff (#TIME) region; pass to cartridge I/O² - MD: emulate SRAM mapping used by >16mbit games; bank mapping used by >32mbit games³ - MD: add 'reset pending' flag so that loading save states won't reload 68K PC, SP registers - this fixes save state support ... mostly⁴ - MD: if DMA is not enabled, do not allow CD5 to be set [Cydrak] - this fixes in-game graphics for Ristar. Title screen still corrupted on first run - MD: detect and break sprite lists that form an infinite loop [Cydrak] - this fixes the emulator from dead-locking on certain games - MD: add DC offset to sign DAC PCM samples [Cydrak] - this improves audio in Sonic 3 - MD: 68K TAS has a hardware bug that prevents writing the result back to RAM - this fixes Gargoyles - MD: 68K TRAP should not change CPU interrupt level - this fixes Shining Force II, Shining in the Darkness, etc - icarus: better SRAM heuristics for Mega Drive games Todo: - need to serialize the new cartridge ramEnable, ramWritable, bank variables ¹: so technically, the GBA has its FIFO queue (raw PCM), plus a GB chipset. The GB audio runs at 2MHz. However, I was being lazy and running the sequencer 64 times in a row, thus decimating the audio to 32KHz. But simply discarding 63 out of every 64 samples resorts in muddier sound with more static in it. However ... increasing the audio thread processing intensity 64-fold, and requiring heavy-duty three-chain lowpass and highpass filters is not cheap. For this bump in sound quality, we're eating a loss of about 30% of previous performance. Also note that the GB audio emulation in the GBA core still lacks many of the improvements made to the GB core. I was hoping to complete the GB enhancements, but it seems like I'm never going to pass blargg's psychotic edge case tests. So, first I want to clean up the GB audio to my current coding standards, and then I'll port that over to the GBA, which should further increase sound quality. At that point, it sound exceed mGBA's audio quality (due to the ridiculously high sampling rate and strong-attenuation audio filtering.) ²: word writes are probably not handled correctly ... but games are only supposed to do byte writes here. ³: the SRAM mapping is used by games like "Story of Thor" and "Phantasy Star IV." Unfortunately, the former wasn't released in the US and is region protected. So you'll need to change the NTSU to NTSCJ in md/system/system.cpp in order to boot it. But it does work nicely now. The write protection bit is cleared in the game, and then it fails to write to SRAM (soooooooo many games with SRAM write protection do this), so for now I've had to disable checking that bit. Phantasy Star IV has a US release, but sadly the game doesn't boot yet. Hitting some other bug. The bank mapping is pretty much just for the 40mbit Super Street Fighter game. It shows the Sega and Capcom logos now, but is hitting yet another bug and deadlocking. For now, I emulate the SRAM/bank mapping registers on all cartridges, and set sane defaults. So long as games don't write to $a130XX, they should all continue to work. But obviously, we need to get to a point where higan/icarus can selectively enable these registers on a per-game basis. ⁴: so, the Mega Drive has various ways to lock a chip until another chip releases it. The VDP can lock the 68K, the 68K can lock the Z80, etc. If this happens when you save a state, it'll dead-lock the emulator. So that's obviously a problem that needs to be fixed. The fix will be nasty ... basically, bypassing the dead-lock, creating a miniature, one-instruction-long race condition. Extremely unlikely to cause any issues in practice (it's only a little worse than the SNES CPU/SMP desync), but ... there's nothing I can do about it. So you'll have to take it or leave it. But yeah, for now, save states may lock up the emulator. I need to add code to break the loops when in the process of creating a save state still. |
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Tim Allen | 04072b278b |
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. |
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Tim Allen | bdc100e123 |
Update to v102r02 release.
byuu says: Changelog: - I caved on the `samples[] = {0.0}` thing, but I'm very unhappy about it - if it's really invalid C++, then GCC needs to stop accepting it in strict `-std=c++14` mode - Emulator::Interface::Information::resettable is gone - Emulator::Interface::reset() is gone - FC, SFC, MD cores updated to remove soft reset behavior - split GameBoy::Interface into GameBoyInterface, GameBoyColorInterface - split WonderSwan::Interface into WonderSwanInterface, WonderSwanColorInterface - PCE: fixed off-by-one scanline error [hex_usr] - PCE: temporary hack to prevent crashing when VDS is set to < 2 - hiro: Cocoa: removed (u)int(#) constants; converted (u)int(#) types to (u)int_(#)t types - icarus: replaced usage of unique with strip instead (so we don't mess up frameworks on macOS) - libco: added macOS-specific section marker [Ryphecha] So ... the major news this time is the removal of the soft reset behavior. This is a major!! change that results in a 100KiB diff file, and it's very prone to accidental mistakes!! If anyone is up for testing, or even better -- looking over the code changes between v102r01 and v102r02 and looking for any issues, please do so. Ideally we'll want to test every NES mapper type and every SNES coprocessor type by loading said games and power cycling to make sure the games are all cleanly resetting. It's too big of a change for me to cover there not being any issues on my own, but this is truly critical code, so yeah ... please help if you can. We technically lose a bit of hardware documentation here. The soft reset events do all kinds of interesting things in all kinds of different chips -- or at least they do on the SNES. This is obviously not ideal. But in the process of removing these portions of code, I found a few mistakes I had made previously. It simplifies resetting the system state a lot when not trying to have all the power() functions call the reset() functions to share partial functionality. In the future, the goal will be to come up with a way to add back in the soft reset behavior via keyboard binding as with the Master System core. What's going to have to happen is that the key binding will have to send a "reset pulse" to every emulated chip, and those chips are going to have to act independently to power() instead of reusing functionality. We'll get there eventually, but there's many things of vastly greater importance to work on right now, so it'll be a while. The information isn't lost ... we'll just have to pull it out of v102 when we are ready. Note that I left the SNES reset vector simulation code in, even though it's not possible to trigger, for the time being. Also ... the Super Game Boy core is still disconnected. To be honest, it totally slipped my mind when I released v102 that it wasn't connected again yet. This one's going to be pretty tricky to be honest. I'm thinking about making a third GameBoy::Interface class just for SGB, and coming up with some way of bypassing platform-> calls when in this mode. |
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Tim Allen | 4c3f58150c |
Update to v101r15 release.
byuu says: Changelog: - added (poorly-named) castable<To, With> template - Z80 debugger rewritten to make declaring instructions much simpler - Z80 has more instructions implemented; supports displacement on (IX), (IY) now - added `Processor::M68K::Bus` to mirror `Processor::Z80::Bus` - it does add a pointer indirection; so I'm not sure if I want to do this for all of my emulator cores ... |
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Tim Allen | 5df717ff2a |
Update to v101r12 release.
byuu says: Changelog: - new md/bus/ module for bus reads/writes - abstracts byte/word accesses wherever possible (everything but RAM; forces all but I/O to word, I/O to byte) - holds the system RAM since that's technically not part of the CPU anyway - added md/controller and md/system/peripherals - added emulation of gamepads - added stub PSG audio output (silent) to cap the framerate at 60fps with audio sync enabled - fixed VSRAM reads for plane vertical scrolling (two bugs here: add instead of sub; interlave plane A/B) - mask nametable read offsets (can't exceed 8192-byte nametables apparently) - emulated VRAM/VSRAM/CRAM reads from VDP data port - fixed sprite width/height size calculations - added partial emulation of 40-tile per scanline limitation (enough to fix Sonic's title screen) - fixed off-by-one sprite range testing - fixed sprite tile indexing - Vblank happens at Y=224 with overscan disabled - unsure what happens when you toggle it between Y=224 and Y=240 ... probably bad things - fixed reading of address register for ADDA, CMPA, SUBA - fixed sign extension for MOVEA effect address reads - updated MOVEM to increment the read addresses (but not writeback) for (aN) mode With all of that out of the way, we finally have Sonic the Hedgehog (fully?) playable. I played to stage 1-2 and through the special stage, at least. EDIT: yeah, we probably need HIRQs for Labyrinth Zone. Not much else works, of course. Most games hang waiting on the Z80, and those that don't (like Altered Beast) are still royally screwed. Tons of features still missing; including all of the Z80/PSG/YM2612. A note on the perihperals this time around: the Mega Drive EXT port is basically identical to the regular controller ports. So unlike with the Famicom and Super Famicom, I'm inheriting the exension port from the controller class. |
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Tim Allen | f7ddbfc462 |
Update to v101r11 release.
byuu says: Changelog: - 68K: fixed NEG/NEGX operand order - 68K: fixed bug in disassembler that was breaking trace logging - VDP: improved sprite rendering (still 100% broken) - VDP: added horizontal/vertical scrolling (90% broken) Forgot: - 68K: fix extension word sign bit on indexed modes for disassembler as well - 68K: emulate STOP properly (use r.stop flag; clear on IRQs firing) I'm really wearing out fast here. The Genesis documentation is somehow even worse than Game Boy documentation, but this is a far more complex system. It's a massive time sink to sit here banging away at every possible combination of how things could work, only to see no positive improvements. Nothing I do seems to get sprites to do a goddamn thing. squee says the sprite Y field is 10-bits, X field is 9-bits. genvdp says they're both 10-bits. BlastEm treats them like they're both 10-bits, then masks off the upper bit so it's effectively 9-bits anyway. Nothing ever bothers to tell you whether the horizontal scroll values are supposed to add or subtract from the current X position. Probably the most basic detail you could imagine for explaining horizontal scrolling and yet ... nope. Nothing. I can't even begin to understand how the VDP FIFO functionality works, or what the fuck is meant by "slots". I'm completely at a loss as how how in the holy hell the 68K works with 8-bit accesses. I don't know whether I need byte/word handlers for every device, or if I can just hook it right into the 68K core itself. This one's probably the most major design detail. I need to know this before I go and implement the PSG/YM2612/IO ports-\>gamepads/Z80/etc. Trying to debug the 68K is murder because basically every game likes to start with a 20,000,000-instruction reset phase of checksumming entire games, and clearing out the memory as agonizingly slowly as humanly possible. And like the ARM, there's too many registers so I'd need three widescreen monitors to comfortably view the entire debugger output lines onscreen. I can't get any test ROMs to debug functionality outside of full games because every **goddamned** test ROM coder thinks it's acceptable to tell people to go fetch some toolchain from a link that died in the late '90s and only works on MS-DOS 6.22 to build their fucking shit, because god forbid you include a 32KiB assembled ROM image in your fucking archives. ... I may have to take a break for a while. We'll see. |
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Tim Allen | 0b70a01b47 |
Update to v101r10 release.
byuu says: Changelog: - 68K: MOVEQ is 8-bit signed - 68K: disassembler was print EOR for OR instructions - 68K: address/program-counter indexed mode had the signed-word/long bit backward - 68K: ADDQ/SUBQ #n,aN always works in long mode; regardless of size - 68K→VDP DMA needs to use `mode.bit(0)<<22|dmaSource`; increment by one instead of two - Z80: added registers and initial two instructions - MS: hooked up enough to load and start running games - Sonic the Hedgehog can execute exactly one instruction... whoo. |
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Tim Allen | 043f6a8b33 |
Update to v101r08 release.
byuu says: Changelog: - 68K: fixed read-modify-write instructions - 68K: fixed ADDX bug (using wrong target) - 68K: fixed major bug with SUB using wrong argument ordering - 68K: fixed sign extension when reading address registers from effective addressing - 68K: fixed sign extension on CMPA, SUBA instructions - VDP: improved OAM sprite attribute table caching behavior - VDP: improved DMA fill operation behavior - added Master System / Game Gear stubs (needed for developing the Z80 core) |
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Tim Allen | ffd150735b |
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. |
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Tim Allen | ac2d0ba1cf |
Update to v101r05 release.
byuu says: Changelog: - 68K: fixed bug that affected BSR return address - VDP: added very preliminary emulation of planes A, B, W (W is entirely broken though) - VDP: added command/address stuff so you can write to VRAM, CRAM, VSRAM - VDP: added VRAM fill DMA I would be really surprised if any commercial games showed anything at all, so I'd probably recommend against wasting your time trying, unless you're really bored :P Also, I wanted to add: I am accepting patches\! So if anyone wants to look over the 68K core for bugs, that would save me untold amounts of time in the near future :D |
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Tim Allen | 1df2549d18 |
Update to v101r04 release.
byuu says: Changelog: - pulled the (u)intN type aliases into higan instead of leaving them in nall - added 68K LINEA, LINEF hooks for illegal instructions - filled the rest of the 68K lambda table with generic instance of ILLEGAL - completed the 68K disassembler effective addressing modes - still unsure whether I should use An to decode absolute addresses or not - pro: way easier to read where accesses are taking place - con: requires An to be valid; so as a disassembler it does a poor job - making it optional: too much work; ick - added I/O decoding for the VDP command-port registers - added skeleton timing to all five processor cores - output at 1280x480 (needed for mixed 256/320 widths; and to handle interlace modes) The VDP, PSG, Z80, YM2612 are all stepping one clock at a time and syncing; which is the pathological worst case for libco. But they also have no logic inside of them. With all the above, I'm averaging around 250fps with just the 68K core actually functional, and the VDP doing a dumb "draw white pixels" loop. Still way too early to tell how this emulator is going to perform. Also, the 320x240 mode of the Genesis means that we don't need an aspect correction ratio. But we do need to ensure the output window is a multiple 320x240 so that the scale values work correctly. I was hard-coding aspect correction to stretch the window an additional \*8/7. But that won't work anymore so ... the main higan window is now 640x480, 960x720, or 1280x960. Toggling aspect correction only changes the video width inside the window. It's a bit jarring ... the window is a lot wider, more black space now for most modes. But for now, it is what it is. |
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Tim Allen | 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 | f230d144b5 |
Update to v100r12 release.
byuu says: All of the above fixes, plus I added all 24 variations on the shift opcodes, plus SUBQ, plus fixes to the BCC instruction. I can now run 851,767 instructions into Sonic the Hedgehog before hitting an unimplemented instruction (SUB). The 68K core is probably only ~35% complete, and yet it's already within 4KiB of being the largest CPU core, code size wise, in all of higan. Fuck this chip. |
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Tim Allen | 7ccfbe0206 |
Update to v100r11 release.
byuu says: I split the Register class and read/write handlers into DataRegister and AddressRegister, given that they have different behaviors on byte/word accesses (data tends to preserve the upper bits; address tends to sign-extend things.) I expanded EA to EffectiveAddress. No sense in abbreviating things to death. I've now implemented 26 instructions. But the new ones are just all the stupid from/to ccr/sr instructions. Ryphecha confirmed that you can't set the undefined bits, so I don't think the BitField concept is appropriate for the CCR/SR. Instead, I'm just storing direct flags and have (read,write)(CCR,SR) instead. This isn't like the 65816 where you have subroutines that push and pop the flag register. It's much more common to access individual flags. Doesn't match the consistency angle of the other CPU cores, but ... I think this is the right thing to for the 68K specifically. |
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Tim Allen | 4b897ba791 |
Update to v100r10 release.
byuu says: Redesigned the handling of reading/writing registers to be about eight times faster than the old system. More work may be needed ... it seems data registers tend to preserve their upper bits upon assignment; whereas address registers tend to sign-extend values into them. It may make sense to have DataRegister and AddressRegister classes with separate read/write handlers. I'd have to hold two Register objects inside the EffectiveAddress (EA) class if we do that. Implemented 19 opcodes now (out of somewhere between 60 and 90.) That gets the first ~530,000 instructions in Sonic the Hedgehog running (though probably wrong. But we can run a lot thanks to large initialization loops.) If I force the core to loop back to the reset vector on an invalid opcode, I'm getting about 1500fps with a dumb 320x240 blit 60 times a second and just the 68K running alone (no Z80, PSG, VDP, YM2612.) I don't know if that's good or not. I guess we'll find out. I had to stop tonight because the final opcode I execute is an RTS (return from subroutine) that's branching back to address 0; which is invalid ... meaning something went terribly wrong and the system crashed. |
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Tim Allen | be3f6ac0d5 |
Update to v100r09 release.
byuu says: Another six hours in ... I have all of the opcodes, memory access functions, disassembler mnemonics and table building converted over to the new template<uint Size> format. Certainly, it would be quite easy for this nightmare chip to throw me another curveball, but so far I can handle: - MOVE (EA to, EA from) case - read(from) has to update register index for +/-(aN) mode - MOVEM (EA from) case - when using +/-(aN), RA can't actually be updated until the transfer is completed - LEA (EA from) case - doesn't actually perform the final read; just returns the address to be read from - ANDI (EA from-and-to) case - same EA has to be read from and written to - for -(aN), the read has to come from aN-2, but can't update aN yet; so that the write also goes to aN-2 - no opcode can ever fetch the extension words more than once - manually control the order of extension word fetching order for proper opcode decoding To do all of that without a whole lot of duplicated code (or really bloating out every single instruction with red tape), I had to bring back the "bool valid / uint32 address" variables inside the EA struct =( If weird exceptions creep in like timing constraints only on certain opcodes, I can use template flags to the EA read/write functions to handle that. |
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Tim Allen | 059347e575 |
Update to v100r07 release.
byuu says: Four and a half hours of work and ... zero new opcodes implemented. This was the best job I could do refining the effective address computations. Should have all twelve 68000 modes implemented now. Still have a billion questions about when and how I'm supposed to perform certain edge case operations, though. |
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Tim Allen | 1c0ef793fe |
Update to v100r04 release.
byuu says: I now have enough of three instructions implemented to get through the first four instructions in Sonic the Hedgehog. But they're far from complete. The very first instruction uses EA addressing, which is similar to x86's ModRM in terms of how disgustingly complex it is. And it also accesses Z80 control registers, which obviously isn't going to do anything yet. The slow speed was me being stupid again. It's not 7.6MHz per frame, it's 7.67MHz per second. So yeah, speed is so far acceptable again. But we'll see how things go as I keep emulating more. The 68K decode is not pretty at all. |
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Tim Allen | 76a8ecd32a |
Update to v100r03 release.
byuu says: Changelog: - moved Thread, Scheduler, Cheat functionality into emulator/ for all cores - start of actual Mega Drive emulation (two 68K instructions) I'm going to be rather terse on MD emulation, as it's too early for any meaningful dialogue here. |
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Tim Allen | 3dd1aa9c1b |
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. |