[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]
Re: CAS and 020 bus error (was: Amiga 3000 video strangeness - next thing)
Michael van Elst wrote:
> frank%phoenix.owl.de@localhost (Frank Wille) writes:
>> I guess it gets into trouble when running into a bus-fault
>> (MMU-exception) while executing CAS. I don't know if the exception
>> handler is prepared to emulate the entire read-modify-write cycle of this
> The 68020 (unlike the 68040) is supposed to rerun the complete
That explains it. Code for this special case is obviously missing.
I made a test and compiled sys/arch/m68k/m68k/lock_stubs.s for 68010, and
the kernel booted without problems!
So we have these options:
- add the missing 020-support in the exception handler for CAS and TAS
- make the 68010-code in lock_stubs.s compile for 68020 as well
There are certainly more 020-based systems than my A2500 (some Suns?).
Crossposting to port-m68k because of that.
_ Frank Wille (frank%phoenix.owl.de@localhost)
_ // http://sun.hasenbraten.de/~frank/
\X/ Phx @ #AmigaGer
Main Index |
Thread Index |