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Re: badaddr() panics when TT is enabled

At Sat, 15 Apr 2023 17:19:55 +0900,
Izumi Tsutsui wrote:
> > Would you also try a case where badaddr() fires in TT area?
> > I don't know well about NEWS but how about this?
> It boots but si1 is also attached, i.e. looks no bus error.
> According to "md" command outputs on PROM monitor, whole 0xeXXXXXXX
> region doesn't cause bus error, but at least 0xf0000000 does.

Thanks!  This is interesting result.
nono should be updated...

> However, this means we should implememnt some proper probe routine
> for nono emulator that doesn't have si(4) SCSI.  Umm.

nono's news68k emulation is pretty incomplete quality (because
we authors don't know about NEWS hardware at all).  I prefer that
guest OS doesn't take care of such in-development emulators that
run differently from the real hardware.

On the other hand, in general, it's welcome to make our probe
routine more robust.

> Just because MC68030 USER'S MANUAL 9.7.4 says:
> >> The PTEST instruction searches either the ATC (PTEST with level 0) or
> >> the translation tables (PTEST with levels of 1-7) to determine status
> >> information about the translation of a specified logical address.
> (Ah, I misread "either" as "entire")

I see :)

> I.e.
> PTEST with level 0:       searches the ATC
> PTEST with levels of 1-7: searches the translation tables
>  ..to determine status information about the translation
> I guess "PTEST, level 0" is more explicit, per Table 9-3 ?

How about the following comment that spans in two lines?
(Both one and two space indentation seem to be used to represent
line continuation)

+	ptestr	%d0,%a0@,#0		| only PTEST #0 can detect transparent
+	pmove	%psr,%sp@		|   translation (TT0 or TT1).
+	movw	%sp@,%d1
+	btst	#6,%d1			| transparent (TT0 or TT1)?

> > Unfortunately, it's not possible to find spc0 and spc1 correctly
> > by only using current spc_mainbus_match() on LUNA due to its hard-
> > ware characteristics.
> As you pointed out actually it doesn't cause bus error.
> I'll add a machtype check and cleanup maimbus_attach_args later.

Nice.  (I prefer more strict way but it maybe excessive..)
Tetsuya Isaki <isaki%pastel-flower.jp@localhost / isaki%NetBSD.org@localhost>

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