On Tue, 8 Jun 1999, Martin [iso-8859-1] S�fke wrote:
> Alistair MacDonald schrieb:
> > That said, *I* didn't understand *exactly* what you were asking because
> > *you* didn't provide any details of the source and target of the transfer.
> Ok... the DMA is supposed to transfer 625kb/s on 16 bit DMA #5 from a
> satellite receiver card to memory.
> If it is emuated, I see that it won't transfer data from that receiver
> hardware.
> Would there be any way to get that DMA work ?
Only in the same way that you could get *any* DMA to work. You have to get
the kernel to give a user space program (eg DOSEMU) rights to manipulate
the DMA registers (and to prevent problems, the kernel tables that go with
it).
I *DID* receive a patch that provided a series of *devices* which enabled
*ANY* application to pick & manipulate the IRQs & DMA channels. *However*
the only security hole *bigger* than this would be having just a single
user on a machine (root) and having all processess run/owned by this user
(and, of course, logging in as this user all the time). Oh - and for good
measure you would probably want the root password to be an empty string
....
In case that last paragraph *didn't* frighten you enough, I'll put it a
different way. Allowing arbitrary software access to control & manipulate
your IRQs & DMA channels allows *any* process to trash your OS, Disks and
(virtually) anything else you care to mention.
This will *never* become part of DOSEMU *unless* this issue can be
resolved.
Alistair
