From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56281) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YDIYB-0005hT-10 for qemu-devel@nongnu.org; Mon, 19 Jan 2015 15:03:55 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YDIY4-0002bP-70 for qemu-devel@nongnu.org; Mon, 19 Jan 2015 15:03:50 -0500 Message-ID: <54BD631C.8070409@suse.de> Date: Mon, 19 Jan 2015 21:03:40 +0100 From: =?UTF-8?B?QW5kcmVhcyBGw6RyYmVy?= MIME-Version: 1.0 References: <1421667328-11800-1-git-send-email-mark.cave-ayland@ilande.co.uk> <1421667328-11800-3-git-send-email-mark.cave-ayland@ilande.co.uk> <54BCFC57.3010709@redhat.com> <54BD1C2D.9070603@suse.de> In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH 2/2] m48t59: add mem_base value to m48t59_init_isa() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Artyom Tarasenko Cc: Mark Cave-Ayland , qemu-devel , Alexander Graf , qemu-ppc@nongnu.org, Paolo Bonzini , =?UTF-8?B?SGVydsOpIFBvdXNzaW5lYXU=?= Am 19.01.2015 um 16:22 schrieb Artyom Tarasenko: > On Mon, Jan 19, 2015 at 4:01 PM, Andreas F=C3=A4rber = wrote: >> Am 19.01.2015 um 13:57 schrieb Artyom Tarasenko: >>> On Mon, Jan 19, 2015 at 1:45 PM, Paolo Bonzini = wrote: >>>> On 19/01/2015 12:35, Mark Cave-Ayland wrote: >>>>> Similar to m48t59_init(), add a mem_base value so that NVRAM can be= mapped via >>>>> MMIO rather than ioport if required. >>>>> >>>>> Signed-off-by: Mark Cave-Ayland >>>>> --- >>>> >>>> Is it really ISA if it's MMIO? In other words, why can't this be a >>>> sysbus device? >>> >>> On physical machines it's EBus, which is pretty much like 8-bit ISA. >>> So, I think modelling it as ISA is closer to to the reality. >>> But out of curiosity, would it be possible to have a sysbus device >>> somewhere in a middle of PCI space? [...] >> >> Why would you want to use a SysBusDevice in the first place? >=20 > Ask Paolo. :-) For me it's only important to have a MMIO device in the > proper address range. >=20 >> I previously discussed with Mark that it should be an EBusDevice, not = an >> ISADevice or SysBusDevice. >=20 > Interesting. I can't find this discussion in the list archive. Hm, am I mixing that up with SBus then? There were some helper functions related to ROM loading being added as context to my suggestion that I thought could become class fields. > Do you suggest to > create EBusDevices for all ISA devices (serial, parallel, keyboard, > floppy) used in sun4u, or only for m48t59? > What would be the advantage of using EBusDevice over ISADevice? For all devices that are in fact EBus devices. The general idea is encapsulation and abstraction - hiding the implementation detail of whether it is internally an ISADevice or something else. Such a patch should be quite trivial. Similarly it gives helper functions and potential class methods a natural place to live. Andreas --=20 SUSE Linux GmbH, Maxfeldstr. 5, 90409 N=C3=BCrnberg, Germany GF: Felix Imend=C3=B6rffer, Jane Smithard, Jennifer Guild, Dilip Upmanyu, Graham Norton; HRB 21284 (AG N=C3=BCrnberg)