From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nils Faerber Subject: Re: ACPI for x-scale Date: Mon, 09 May 2005 21:31:31 +0200 Message-ID: <427FBA93.1060309@kernelconcepts.de> References: <6EF58BF68042DF4AA46A54994117D64F035A1C81@mercury.mtctech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <6EF58BF68042DF4AA46A54994117D64F035A1C81-x6Fv9fcoW1YgtwCHe4clqUEOCMrvLtNR@public.gmane.org> Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: "Williams, Richard" Cc: acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-acpi@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Williams, Richard wrote: > Hi, Hi! > I'm a newbie to the ACPI world. > Has anyone ported the Linux 2.6 kernel ACPI to the ARM processors - > specifically an Intel X-scale, PXA-270 ? ROTFL ;) Sorry... couldn't resist... > Is this appropriate for an embedded single board computer ? No, it isn't. It starts with the "problem" that the usual ARM/StrongARM/XScale device do not own a BIOS as it is known on x86 PCs. For most embedded platforms implementing huge systems like APM or ACPI is simply a waste of time - you simply do it yourself in the specific kernel you are using on your platform anyway. IMHO ACPI and APM are used as a generic approach, i.e. for situation where you do not know specifics of the system you are running on. Then ACPI offers for example a method to suspend, resume or power throttle a device (put to standby, suspend, ...). The more complex systems became the more complex those sophisticated system became with ACPI being its current culprit. The current embedded Linux flavours all do power management to various degrees by themselves, expecially using the current Linux device model and power state siganlling, i.e. the device drivers have to do their own power management. Or to make it short: No, you do not want to implement ACPI for embedded platforms. > Thanks, > Rich CU nils faerber - -- kernel concepts Tel: +49-271-771091-12 Dreisbachstr. 24 Fax: +49-271-771091-19 D-57250 Netphen Mob: +49-176-21024535 - -- -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFCf7qTJXeIURG1qHgRAlZrAJ0cbKE2ZeckBf2o7qKHQyxAUDsGHwCfcip9 4+HZrQQfFW8BZW2/RjPK/F0= =v0io -----END PGP SIGNATURE----- ------------------------------------------------------- This SF.Net email is sponsored by: NEC IT Guy Games. Get your fingers limbered up and give it your best shot. 4 great events, 4 opportunities to win big! Highest score wins.NEC IT Guy Games. Play to win an NEC 61 plasma display. Visit http://www.necitguy.com/?r=20