Dreamcast mvc2 crashing at stage 2

tackett1980

Pi3b
Retropie newest version
Reicast newest version
Dragon rise usb encoders

Everything on this works halfway decent except arcade mode. The game crashes upon entering stage 2.

It was suggested my overclock was the issue, which it is indeed grossly overclocked.

Things I have tried:

The game does not crash with flycast, though the game functions much worse, eventually running at about 10fps I can get through to stage 2 no crashing

I deleted my overclock
Game functions horrible about 12-15fps but it still crashes with reicast.

I tried a new rom
Same result, crash on entering stage 2.

I was googling and came across this, I will link it here please don’t call in an orbital strike on me if for some reason these links are not allowed.

I found this:
https://github.com/reicast/reicast-emulator/issues/1658

Which links to this, as the solution:
https://github.com/reicast/reicast-emulator/pull/1684

The problem is that I’m too ignorant to decipher what it is that is being discussed. Can someone look at this and tell me what it is I need to be doing according to what is posted in these links?

Edit:
From what I can tell with further googling is that this is a bug in the dynarec cpu. Using interpreter it does not crash, but then again it isn’t playable this way.

Darksavior

@tackett1980 You can try flycast, but honestly, get a pi4 and use redream for ~full speed dreamcast emulation.

rejesterd

@tackett1980 said in Dreamcast mvc2 crashing at stage 2:

The game does not crash with flycast, though the game functions much worse

In comparing the cpu/gpu specs between a pi3 and pi4, it seems that you should easily be able to overclock the pi3 to get to the same values (1500/500 MHz cpu/gpu) as the pi4 has without any overclocking.. and I can confirm that with no overclocking, the pi4 can run mvc2 in flycast pretty well. It's not as good as redream, but it's playable.

Can you run..

top -i -b -n 10 > topout.txt

..and post the resulting topout.txt? That will take about 30 seconds to run.

Also..

vmstat -n 1 > vmstat.txt

Run both of those while you're observing the slowness when playing the game in flycast.

I'm just wondering if your troubles are related to swapping, as opposed to insufficient cpu/gpu resources.

rejesterd

Also, regarding the links you posted.. it just seems like there was a defect in reicast that was fixed back in July.

However, I just tested this and I can confirm the same behavior with reicast at stage 2. So I would say this is not yet fixed. I'll try fiddling with the reicast settings a bit to see if that changes things. I assume the fix from July is in the current build provided by retropie.. that's something else to check on.

rejesterd

Just noting that I couldn't make the bad behavior go away in reicast by changing the settings. However, I also noticed that redream crashes with the game as well, but not until I reach level 3.. so it just takes longer with redream.

Maybe flycast will last longer.. might test that tomorrow. But it certainly looks like this game is tough for the emulators, and these issues should be reported.

Again, I have decent performance in flycast, so I'd be interested in your top & vmstat output.

Darksavior

I forgot..there is a ~10fps speed increase if you use the naomi version of mvc2 with flycast on a pi4. I haven't tested this on a pi3b+. I highly recommend you get a pi4, though. This hobby doesn't break the bank.

tackett1980

@rejesterd

I will take a look at this and post results tommorrow.

I’d love to have a pi4, but there is no retropie install for it at the moment.

Edit:

My pi3, (not3b+) is overclocked to 1.5ghz.

And for fear of sounding really stupid...umm, how exactly step by step do I accomplish what you are asking me to do?

For a person trying to do this I’m totally computer illiterate. I’m kind of out of my element here.

rejesterd

@tackett1980 Sure, I can give you exact steps. Do you have another computer besides the pi? If so, let me know what kind it is (Windows/Mac/etc.). The instructions will be different depending.

Edit: also wanted to mention that I couldn't get it to crash using redream with a CDI version of the game. But it still consistently crashes every time using reicast. Flycast has frozen on me a couple times, but it hasn't crashed yet like the others.

tackett1980

@rejesterd

Using an ancient PC.

quicksilver

@rejesterd said in Dreamcast mvc2 crashing at stage 2:

In comparing the cpu/gpu specs between a pi3 and pi4, it seems that you should easily be able to overclock the pi3 to get to the same values (1500/500 MHz cpu/gpu) as the pi4 has without any overclocking

This is incorrect. There may be 1% of pi3s that can boot at 1500mhz and also be stable, the ARM Cortex-A53 on the pi3 is already "overclocked" from the factory and has very little headroom for CPU overclocking. Remember also that the pi4 is a completely different CPU (ARM Cortex-A72). Even if you underclocked the pi 4 to 1200mhz to match the pi 3 it would still be considerably faster than the pi3. The GPU on the pi 4 is a Videocore VI while the pi 3 is a videocore IV, the performance difference is immense, again even if you set them both to the same clock speed. You'll never be able to make the pi 3 match a pi 4's performance by overclocking.

rejesterd

So after all my fiddling and observations so far, I really think this crashing issue is related to saving data to the VMU file. When you reach a new level in the game, it seems the emulator tries to write to the vmu and is unsuccessful.

For instance, if I launch the game with flycast, select a memory card slot, then go and delete the vmu files under ~/RetroPie/BIOS/dc/, the game will crash right after I select my characters and am about to play stage 1. Of course that's expected to happen for any game using a vmu, but the timing of the crash (and where in the game it happens) is very similar to the case where I don't mess with the vmus and simply reach stage 2 or 3 (depending on which emulator is being used).

I still need to collect more data before reporting it, but that my take on it so far.

quicksilver

My pi3 has an older version of reicast and I was able to make it to the 2nd stage without crashing. You might be able to take my reicast binary and swap it out on your pi.

https://mega.nz/#!9ZBBjSCZ!DEetDT-HYLEdByt5o2xYcv5uW3kb8HiiuO7yApzgX6U

Place it in:

/opt/retropie/emulators/reicast/bin/

I would recommend backing up your reicast binary first before replacing.

rejesterd

@quicksilver Good to know.. when I was reviewing the specs last night, my tired eyes couldn't tell the difference between Roman numerals VI and IV lol.

@tackett1980 I think we can forget the tests I mentioned, as I seriously doubt you are swapping. Plus, I don't think the results from those tests would guide you to a configuration that avoids this particular crash.

rejesterd

@quicksilver btw I did test with your binary, but it won't launch the game. In the runcommand log, I get..

Parameters: 
Executing: /opt/retropie/emulators/reicast/bin/reicast.sh alsa "/home/pi/RetroPie/roms/dreamcast/Marvel vs. Capcom 2.chd" 640 480
Virtual cfg config:homedir=/home/pi
Virtual cfg x11:fullscreen=1
Virtual cfg x11:width=640
Virtual cfg x11:height=480
Virtual cfg audio:backend=alsa
Virtual cfg audio:disable=0
Virtual cfg config:image=/home/pi/RetroPie/roms/dreamcast/Marvel vs. Capcom 2.chd

Config dir is: /home/pi/.reicast/
Data dir is:   /home/pi/.reicast/
Personality: 00C00000
Updated personality: 00800000
found libbcm_host
rpi2: bcm_init
ARM VFP-Run Fast (NFP) enabled !
Linux paging: 4096 00001000 00000FFF
MAP 00800000 w/ 25165824
MAP 20000000 w/ 25165824
MAP 04000000 w/ 16777216

quicksilver

@rejesterd what version of raspbian is your pi 3 on? Or you using an old image?

rejesterd

@quicksilver I'm on a pi4.. very recent image from about a month ago.

inolen

@rejesterd do you have any more info about the crash? I've not heard of a crash from this game in ages, but would love to see the stdout after it crashes if you can snag it. To note, I pushed a fix a few nights ago that addresses a silly shader compilation error (literally, a typo) that'd been hanging around for a few weeks and effected some games with fog.

mitu

@rejesterd said in Dreamcast mvc2 crashing at stage 2:

@quicksilver I'm on a pi4.. very recent image from about a month ago.

Then a binary compiled for the 3b model won't work, since it uses the legacy video drivers.

tackett1980

@inolen

I’m on the way home from work I can try to get the information you need if someone can walk me through how to obtain it.

quicksilver

@tackett1980 he's referring to the crashing behavior on redream not reicast.