Re: Finding bugs in 8086-80386 emulation core?

Posted on 2018-01-05, 11:21

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by superfury

in PC Emulation

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It´s odd that, even though the math instructions should be working according to the test386.asm testsuite (https://github.com/barotto/test386.asm), with most jumps/call instructions verified as well, the Windows 95 setup still produces a Bound Exception when it's unexpected(it's handled by the BIOS, …

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Re: Windows 3.0/EMM386.SYS/EXE(MS-DOS 6.22) issues when booting (Windows in standard mode)?

Posted on 2018-01-05, 02:15

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by superfury

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Just tried the Supersoft/Landmark AT BIOS again(using 80286 cycle-accurate emulation). It seems to work, except (after fixing CGA/MDA memory to be shadowed and copied back on VGA memory mode changes, fixing CGA memory bugs it reported, while increasing CGA/MDA compatibility) the U keyboard chip, …

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Re: Windows 3.0/EMM386.SYS/EXE(MS-DOS 6.22) issues when booting (Windows in standard mode)?

Posted on 2018-01-04, 22:41

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by superfury

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It's strange that after all the VM monitor is crashing. The test386.asm testsuite (https://github.com/barotto/test386.asm) checks out correctly, so basic operation should be flawless(at least math instructions). Basic jumps should also work(since they're so simple). Protected mode stuff should also …

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Re: Windows 3.0/EMM386.SYS/EXE(MS-DOS 6.22) issues when booting (Windows in standard mode)?

Posted on 2018-01-04, 13:38

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by superfury

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One thing I notice when the invalid jump happens is that ECX contains 0xFF? It contains 0x06 all other times, which runs fine, but 0xFF is probably out of some table's range? It's also an unalligned address, so probably some invalid jump anyway? It seems to happen between the last device driver(VIDE …

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Touch events cause lots of screen updates for every event(press and finger movement)?

Posted on 2018-01-02, 21:40

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by superfury

in PC Emulation

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I'm using SDL2 for touch/finger events, but each event, Android's debugging tools indicates the screen to be updating completely(indicated by app execution speed lowering a lot as well)? It's basically multiple layers, which update only when a parent layer is updated with different pixels(parents …

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Re: Issues with seperated .o directory and .. paths?

Posted on 2018-01-01, 18:50

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by superfury

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After fixing some stuff, it now compiles properly again(adding .d.o dummy ruke for those).

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Re: Issues with seperated .o directory and .. paths?

Posted on 2018-01-01, 14:34

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by superfury

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This is the unmodified Makefile for Windows(MinGW(64)): https://bitbucket.org/superfury/unipcemu/src/64e7422a2445f1f0fb74ab23dd0b734467f6648c/UniPCemu/Makefile.win?at=master Anyone can see what's going wrong with the path adjustments in my previous post? Edit: Removing the part that replaces :%.c …

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Issues with seperated .o directory and .. paths?

Posted on 2018-01-01, 01:33

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by superfury

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I'm having the unipcemu directory within the repo store project-specific .c-files, while ../../projects_build(BUILD_DIR variable) contains the compiled(.o, .exe, .pbp etc.) files. This worked fine up till now, but I now have split part of the repo in a subrepository(../commonemuframework). Now the …

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Re: How to slow down real-time

Posted on 2017-12-31, 21:30

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by superfury

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Theoretically, only slowing down the reported time reported TO windows will solve all cases? But it requires a custom driver and control software to direct the driver to do so(although slowing down all other software as well?)?

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Re: How to slow down real-time

Posted on 2017-12-31, 11:13

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by superfury

in PC Emulation

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In some cases it might even require some or all of those five devices to slowdown relatively to the base clock. Like audio processing(non-PIT, e.g. Sound Blaster, Game Blaster) and video processing(VGA/CGA/MDA) combined with the CPU clock. Like in 8088 MPH, which uses both the PIT, CPU and Video …

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Re: How to slow down real-time

Posted on 2017-12-30, 22:58

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by superfury

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Afaik this isn't directly possible with most emulators without changing source code and recompilation(and even then there's the problem of the system clock used for CMOS time). So, in general, it's at least 5 possible sources: - CPU clock(Hz or IPS). - Timer(PIT). - CMOS(Maybe Windows/Linux clock, …

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Re: Windows 3.0/EMM386.SYS/EXE(MS-DOS 6.22) issues when booting (Windows in standard mode)?

Posted on 2017-12-30, 18:40

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by superfury

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I've implemented the pseudo V86 (int 12/13h) for #GP(0) and #SS(0). It's still reaching the LOCK HLT? Anyone? Current CPU emulation: https://bitbucket.org/superfury/unipcemu/src/ … /cpu/?at=master Anyone can see what's going wrong?

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Re: Windows 3.0/EMM386.SYS issues when booting (Windows in standard mode)?

Posted on 2017-12-29, 01:56

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by superfury

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One thing I notice now, after modifying and simplifying the EMM386 parameters and MS-DOS 6.22(Previously 5.0a)/EMM386(.EXE from MS-DOS 6.22 instead of the .SYS from Windows 3.0) being loaded in the correct format(UniPCemu compatible geometry, only NOEMS parameter), that it seems to crash. It now …

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Re: Windows 3.0/EMM386.SYS issues when booting (Windows in standard mode)?

Posted on 2017-12-28, 20:36

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by superfury

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Well, somewhere directly after that(probably first DMA I/O port being accessed and faulting because of the TSS blocking the ports by default(all cleared entries afaik)), it starts the Virtual 8086 monitor, which somehow goes REALLY WRONG and somehow corrupts some/most registers with invalid values(I …

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Re: Windows 3.0/EMM386.SYS strange subroutine when booting (Windows in standard mode)?

Posted on 2017-12-28, 01:22

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by superfury

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Just modified the #GP(0) and #SS(0) (as well as #NP for non-present descriptors of data segmemts that are allowed to be loaded with cleared value(e.g. mov es,0)) to be according to the manual. Booting works, until reaching virtual 8086 mode address 2AA:DCA9, which tries to access an offset(32-bit …

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Re: Windows 3.0/EMM386.SYS strange subroutine when booting (Windows in standard mode)?

Posted on 2017-12-27, 22:09

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by superfury

in PC Emulation

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One little question: some #SS and #GP faults say #SS(0) and #GP(0) in the 80386 user reference, but that would mean the EXT bit is cleared. But the EXT bit is supposed to be set for exceptions(these cases) and external interrupts? So is it supposed to be set or cleared with the #SS(0) and #GP(0) in …

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Re: Windows 3.0/EMM386.SYS strange subroutine when booting (Windows in standard mode)?

Posted on 2017-12-26, 13:09

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by superfury

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After stepping through the code, I notice the V86 monitor is executing a loop, while ECX contains a ridiculously(0x2XXXXXXX loaded in ECX) large loop, causing the CPU to appear hanging?

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Re: Windows 3.0/EMM386.SYS strange subroutine when booting (Windows in standard mode)?

Posted on 2017-12-24, 18:35

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by superfury

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I see it keeps reading port 20h and acessing port 2XXXh whuch traps to the VM monitor? VIDE-CDD.SYS seems to have completed it's detection of the drives(and succeeded). It now seems to hang on the port OUT faulting(because of i/o rights fault to the unknown port)?

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Re: 86box produces farting noises and lags on an i7 PC

Posted on 2017-12-24, 00:20

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by superfury

in PC Emulation

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Probaby some minimal setup with least accuracy, dynarec CPU emulation and as much hardware as possible disabled? It's as they say: accuracy takes power. So decrease most settings to their minimal values(CPU clock speed, IPS instead of cycle-accurate, minimum hardware emulation/accuracy). All little …

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Re: 86box produces farting noises and lags on an i7 PC

Posted on 2017-12-23, 21:52

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by superfury

in PC Emulation

in PC Emulation

The difficult part of such heavier OSes is mostly emulating them at full speed. PCem and other emulators that use full CPU emulation(cycle-accurate or not) instead of dynamic recompilation won't easily run at 100% realtime speed. Since it's not running at 100% speed, sound produced is below 100% as …

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