Re: PCI support

[Marco Gerards <mgerards@xs4all.nl>]

Robert Millan <rmh@aybabtu.com> writes:

> On Wed, Jan 30, 2008 at 11:17:49PM +0100, Marco Gerards wrote:
>> >> IO addresses are Intel only, AFAIK.  Almost all architectures have
>> >> mmapped IO.  It's really arch specific.
>> >
>> > Are you sure that makes grub_inl / grub_outl arch-specific ?  They can't be
>> > implemented as wrappers for direct memory access?
>> 
>> No, AFAIK that is not possible.  However, PCI gives you the mmapped IO
>> addresses we can use, for example for the ATA driver.
>
> Why not?
>
> What's wrong with:
>
> grub_uint32_t
> grub_inl (grub_uint32_t *addr)
> {
>   return *addr;
> }

Nothing, except the missing volatile I guess.  This just isn't an IO
port.  So you can't use IO port 0x60 to access the keyboard or so.
But sure, we need an abstraction.


--
Marco