Re: [Q] How can I transfer data from hard disk to PCI device'smemory

Re: [Q] How can I transfer data from hard disk to PCI device'smemory

[Cho, joon-woo]

Not to PCI device's register, but to PCI device's SDRAM memory.

In detail after I modify kernel, I want to transfer data

from HDD controller's data register (IDE controller case)

to another PCI's SDRAM memory with the help of kernel

( I think Direct I/O(using O_DIRECT flag) )

Is this impossible?


----- Original Message -----
From: "wa moua" <wmatlus@yahoo.com>
To: "Cho, joon-woo" <jwc@core.kaist.ac.kr>
Sent: Friday, August 08, 2003 1:19 AM
Subject: Re: [Q] How can I transfer data from hard disk to PCI
device'smemory


> Are you trying to transfer data from one PCI register
> to another PCI register? Could you please rephrase
> your problem. PCI is a bus not a system storage.
>
> --- "Cho, joon-woo" <jwc@core.kaist.ac.kr> wrote:
> > Thank you for your reply, and I am very pleasant to
> > talk with you. ^^
> >
> > But english is not mother tongue, so I am little
> > confused about your
> > sentence.
> >
> > > The O_DIRECT I/O handling
> > > needs to know about stuff like page reference
> > counts that PCI space
> > > doesn't have lots of older (and some current)
> > hardware has real problems
> > > with PCI PCI transfers.
> >
> > At above sentence, you mean that
> >
> > 'To handle O_DIRECT I/O, stuff like page reference
> > is needed.
> >
> > But some HW(expecially old HW) doesn't have PCI
> > space,
> >
> > so that it needs much additional work to add a
> > PCI-PCI transferring.'
> >
> > Do I understand right?
> >
> >
> > Please reply, thanks.
> >
> >
> >
> > > So its a non trivial project, although doable

Re: [Q] How can I transfer data from hard disk to PCI device'smemory

[Cho, joon-woo]

Thank you for your reply, and I am very pleasant to talk with you. ^^

But english is not mother tongue, so I am little confused about your
sentence.

> The O_DIRECT I/O handling
> needs to know about stuff like page reference counts that PCI space
> doesn't have lots of older (and some current) hardware has real problems
> with PCI PCI transfers.

At above sentence, you mean that

'To handle O_DIRECT I/O, stuff like page reference is needed.

But some HW(expecially old HW) doesn't have PCI space,

so that it needs much additional work to add a PCI-PCI transferring.'

Do I understand right?


Please reply, thanks.



> So its a non trivial project, although doable