[openbeos] Re: mmap, vm2 and you

  • From: cdegea@xxxxxxxxxxxxxxxx (Cedric Degea)
  • To: openbeos@xxxxxxxxxxxxx
  • Date: Sat, 07 Sep 2002 17:41:17 CEST

=?ISO-8859-1?Q?Fran=E7ois_Revol?= <revol@xxxxxxx> wrote:
> En réponse à Cedric Degea <cdegea@xxxxxxxxxxxxxxxx>:
> > Kernel newbie question: what will the kernelland counterpart
> > to userland mmap() be called? (the BeOS current map_memory()
> > call used by accelerant's drivers I mean).
> > 
> > At any rate, that one will definitely need the "straight forward"
> > version of mapping, in the context of accelerants (ie in the context
> > of mapping "memory" to memory), no funky copy-on-write feature there.
> > 
> I think you mean map_physical_memory() ?

It's the one, I think, yes. Spotted that in Mark Watson's excellent
Gxxx driver.

> This should still be provided, and isn't really exactly the same
> (even if QNX does what map_physical_memory() with mmap() and a special 
> flag, but this is for userland stuff).

Ok, gotta update my ranting script (!) to take that difference
into account when ranting about how kicking OBOS in graphics mode
needs more not-yet-coded syscalls in order to compile and run the accelerant
and driver :-)...   So, it's map_physical_memory(), ok.

(all assuming that OBOS R1 will have the same -- or similar -- accelerant
driver model as BeOS R5 had).

PGP key: http://cdegea.free.fr/degea_kagi_pubkey.txt | BeDev E-16870
"What's oil got to do, got to do with it" -- F02 Chorus

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