| |
Paulko64
Registered: Jul 2010
Posts: 24 |
Reverse debugging in emulator?
Hi all,
I'm currently working on a game-project that has high irregular CPU load during each frame. I've coded everything in such a way that all this irregular code is ran during a mainloop and starting of the routines is regulated during raster-irqs (besides the multiplexor and music calls).
Now this all works perfectly except for once in a few minutes my game crashes (CPU-jam), because it apparently jumped to a strange adres (ZP in my case). I'm not sure what happened but maybe I didn't end the irqs well enough, or perhaps I used the same ZP-adres for indirect adressing in both main and irq-code, which then screws up code if an irq fires at exactly the right (wrong!) moment...
Anyhow, this proves to be very hard to troubleshoot. So I thought, isn't there an emulater that supports some kind of "reverse debugging"? I.e. when I get a CPU-jam can I trace back what instructions were used just before? Or maybe an emulator that supports writing all instructions executed to a textfile which I can then trace back? Although this last option will probably generate a HUGE trace-file.
Does anybody know how to accomplish something like this?
Thanks,
PaulKo64 |
|
... 11 posts hidden. Click here to view all posts....
|
| |
Zyron
Registered: Jan 2002
Posts: 2381 |
The VICE monitor have a backtrace command which might be helpful. |
| |
chatGPZ
Registered: Dec 2001
Posts: 11386 |
configure/compile VICE with --memmap ... this enables the cpu-history feature in the monitor (chist) which does exactly what you want (prints the last 1000 or so executed instructions) |
| |
Mr. SID
Registered: Jan 2003
Posts: 424 |
Why isn't that compiled in by default? |
| |
chatGPZ
Registered: Dec 2001
Posts: 11386 |
because it slows down the emulator quite a bit, and most people dont need it :) |
| |
Paulko64
Registered: Jul 2010
Posts: 24 |
Thanks for the suggestions!
The memmap option in VICE sounds like the best option.
Before going through all the trouble of trying to compile VICE, I don't suppose anyone already has a win32 compiled version of VICE with this option included? |
| |
Angel of Death
Registered: Apr 2008
Posts: 211 |
Micro64 1.00.2012.05.28 Build 669 has an in-build real-time monitor. (needs a powerful PC, though) |
| |
MagerValp
Registered: Dec 2001
Posts: 1078 |
Yeah I had a bug exactly like this a while back, where the stack was corrupted and the code died with a CPU JAM in a completely bizarre location. I ended up installing a Ubuntu VM just to compile vice with --enable-memmap, since compiling the Mac sources was pretty much impossible... |
| |
Martin Piper
Registered: Nov 2007
Posts: 722 |
This version of VICE contains some of my extra tweaks for debugging.
http://www.wellytop.com/VICEMyTweaks.zip
The source for the tweaks can be downloaded from: http://www.wellytop.com/C64.html
The monitor command "chis" will display the state of the registers for each instruction.
If you have labels loaded then the disassembly and memory dump windows will also include those.
Let me know when you've got it so I can nuke it from the server.
|
| |
JackAsser
Registered: Jun 2002
Posts: 2014 |
Quote: Yeah I had a bug exactly like this a while back, where the stack was corrupted and the code died with a CPU JAM in a completely bizarre location. I ended up installing a Ubuntu VM just to compile vice with --enable-memmap, since compiling the Mac sources was pretty much impossible...
Hmms.. configure && make worked quite nicely for me on Mac OS Mountain Lion. Although I have all the dev tools installed from xcode etc... perhaps that was your issue? |
| |
chatGPZ
Registered: Dec 2001
Posts: 11386 |
afaik only outdated OSX are affected...
martin: where are the sources to these tweaks exactly?
|
| Previous - 1 | 2 | 3 - Next |
