From: "Mike Sweeney" <msweeney77@gmail.com>
To: ecos-discuss@ecos.sourceware.org
Subject: Re: [ECOS] Re: Device driver implementation questions
Date: Fri, 15 Jun 2007 09:43:00 -0000 [thread overview]
Message-ID: <70d4f620706141821k534b1157kbb2c3fdd15bdeb3c@mail.gmail.com> (raw)
In-Reply-To: <f4shtm$phe$1@sea.gmane.org>
On 6/14/07, Grant Edwards <grante@visi.com> wrote:
> On 2007-06-14, Mike Sweeney <msweeney77@gmail.com> wrote:
>
> > I am finding the way device drivers are implemented in eCos to be
> > slightly confusing so was looking for some help. The main source of my
> > confusion is the need for some sort of interface under the io package
> > and then another part of the driver in the devs package. I have looked
> > at examples like the serial driver and understand how it works in that
> > context, but am having trouble seeing the bigger picture. Should
> > drivers for all types of devices follow this split implementation
> > design? Furthermore, can someone provide me an analogy between the
> > eCos driver model and Linux, for example? I don't see this two layer
> > method in Linux so am hoping someone can clarify this.
>
> Linux has almost the exact same two layer method for many
> drivers:
>
> Serial drivers: There is a line-discipline layer which
> provides the application with open/close/read/write calls.
> That corresponds to the "io" stuff in eCos. The
> line-discipline layer then calls lower-level
> hardware-specific drivers for different sorts of serial
> ports. That corresponds to the "dev" stuff in eCos.
>
> SCSI drivers: Pretty much the same -- there's a generic layer
> that provides an API to the user and then a lower layer that
> talks to individual SCSI controllers (or other hardware).
>
> There are probably other examples (VFS on top of the individual
> filesystem modules, 80211 on top of various card drivers).
>
> --
> Grant Edwards grante Yow! FUN is never having to
> at say you're SUSHI!!
> visi.com
Thanks for the information, that clarifies things for me.
--
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prev parent reply other threads:[~2007-06-15 1:21 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-06-15 1:21 [ECOS] " Mike Sweeney
2007-06-15 8:43 ` [ECOS] " Grant Edwards
2007-06-15 9:43 ` Mike Sweeney [this message]
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