Re: [hatari-devel] [REGRESSION] Access to non-existant IDE slave crashes Hatari

[ Thread Index | Date Index | More lists.tuxfamily.org/hatari-devel Archives ]


Nicolas Pomarède schrieb:

> that's interesting ; does it mean that the MMU has a global test for
> supervisor mode for any access between FF8000 and FFFFFF but that
> there's no such test for the F0xxxx space ? (similar to the fact that a
> user program can read the TOS space)

I cannot answer this with certainty for the Falcon (because I don't have
one). But in the STbook, IDE address decoding is not done inside the
GLUE/MCU but with a bunch of discrete gates. One can therefore easily
see that the access is not restricted to supervisor mode, because
supervisor/user state (FC2) is not even an input to these gates:
https://docs.dev-docs.org/htm/search.php?find=Atari+STBook+Schematic

The same goes for many add-on IDE boards, e.g. for the ST.

Regards
Christian
--
Christian Zietz  -  CHZ-Soft  -  czietz@xxxxxxx
WWW: https://www.chzsoft.de/
PGP/GnuPG-Key-ID: 0x52CB97F66DA025CA / 0x6DA025CA



Mail converted by MHonArc 2.6.19+ http://listengine.tuxfamily.org/