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Old 14 May 2019, 00:27   #34
FrodeSolheim
FS-UAE Developer

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Join Date: Dec 2011
Location: Førde, Norway
Age: 40
Posts: 3,752
A short progress report.. I've been silent for a couple if days while I've been working on the filesys problem. The good news is that I'm quite near figuring out what the problem is. Long story short, after adding code to do an instruction-level comparison between FS-UAE and WinUAE running the same setup, I've narrowed the problem down to the following events during the emulation of the 107th frame:

Code:
PC=00FC0EC0 OP=00004E73 D0=00000000 D1=00000000 D2=00000113 D3=00000024 D4=00FE5052 D5=00FE4FF6 D6=00FE4F5E D7=00000000 A0=00C00276 A1=00C02488 A2=00C02B24 A3=00C02B24 A4=00C80000 A5=00FC0240 A6=00C02460 XX=00C7FFFA 
XX-XXX [106 000-011]: PC <- 00FE4FBA (m68k_setpci_j)
XX-XXX [106 021-011]: PC <- 00FC0CE2 (m68k_setpc) <- This only happens in FS-UAE
For some reason, FS-UAE overwrites the program counter at this point, changing PC for a second time. Winuae continues here:
Code:
XX-XXX [106 004-011]: PC=00FE4FBA OP=00002C5F D0=00000000 D1=00000000 D2=00000113 D3=00000024 D4=00FE5052 D5=00FE4FF6 D6=00FE4F5E D7=00000000 A0=00C00276 A1=00C02488 A2=00C02B24 A3=00C02B24 A4=00C80000 A5=00FC0240 A6=00C02460 XX=00C01518
While FS-UAE continues here:
Code:
XX-XXX [106 026-011]: PC=00FC0CE2 OP=000048E7 D0=00000000 D1=00000000 D2=00000113 D3=00000024 D4=00FE5052 D5=00FE4FF6 D6=00FE4F5E D7=00000000 A0=00C00276 A1=00C02488 A2=00C02B24 A3=00C02B24 A4=00C80000 A5=00FC0240 A6=00C02460 XX=00C7FFFA
So, should be able to dig further and find the cause of this within a reasonable amount of time

Edit: The PC change is due to a interrupt (identical to an earlier interrupt which happens in both FS-UAE/WinUAE):
Code:
XX-XXX [106 004-011]: do_interrupt 2
XX-XXX [106 004-011]: Exception 26
XX-XXX [106 004-011]: Exception_ce000 26
XX-XXX [106 021-011]: PC <- 00FC0CE2 (m68k_setpc)
Next step is to find out why this fires again in (only) FS-UAE.

EDIT: I found the bug in FS-UAE causing filesys boot to fail Fix coming tomorrow, probably.

Last edited by FrodeSolheim; 14 May 2019 at 13:40.
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