From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49960) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YDEJW-0007sR-68 for qemu-devel@nongnu.org; Mon, 19 Jan 2015 10:32:27 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YDEJV-0002Gi-DC for qemu-devel@nongnu.org; Mon, 19 Jan 2015 10:32:26 -0500 Message-ID: <54BD236E.1040200@redhat.com> Date: Mon, 19 Jan 2015 16:31:58 +0100 From: Paolo Bonzini 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: 7bit 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 , =?UTF-8?B?QW5kcmVhcyBGw6RyYmVy?= Cc: qemu-ppc@nongnu.org, =?UTF-8?B?SGVydsOpIA==?= =?UTF-8?B?UG91c3NpbmVhdQ==?= , Mark Cave-Ayland , qemu-devel , Alexander Graf On 19/01/2015 16:22, Artyom Tarasenko wrote: >>> >> >>> >> 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? > Ask Paolo. :-) For me it's only important to have a MMIO device in the > proper address range. The reason I asked is simply because ISA devices never do MMIO (apart for the VGA window). >> > I previously discussed with Mark that it should be an EBusDevice, not an >> > ISADevice or SysBusDevice. > Interesting. I can't find this discussion in the list archive. 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? Is there a description of EBus and the sun4u memory map somewhere? Is there an "EBus bridge" PCI device similar to the PCI-to-ISA bridge? Paolo