[haiku-commits] Re: r37068 - haiku/trunk/src/system/kernel/arch/x86

Ingo Weinhold <ingo_weinhold@xxxxxx> wrote:
> Drivers in our repository can be adjusted, of course, and, from what 
> I've 
> seen, quite a few have to be. I've also seen that some hardware only 
> seems 
> to support 32 bit physical addresses, which also has to be dealt with 
> somehow. These are tasks necessary for the x86_64 as well, BTW.

Apart from the earliest 64 bit machines, all of the current ones should 
have a dedicated MMU for PCI devices. If that isn't available, and the 
pages used lie outside the 4 GB range, a bounce buffer has to be used.
Our DMAResource implementation should be able to deliver this all one 
day, but it will have to be used by all drivers that need its 
functionality.

Bye,
   Axel.


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