From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0AA88C433EF for ; Tue, 21 Sep 2021 07:26:41 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 80F6A61131 for ; Tue, 21 Sep 2021 07:26:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 80F6A61131 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ilande.co.uk Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:52226 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mSaAn-0002nU-P1 for qemu-devel@archiver.kernel.org; Tue, 21 Sep 2021 03:26:39 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57602) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mSa8o-0001Jq-7D for qemu-devel@nongnu.org; Tue, 21 Sep 2021 03:24:34 -0400 Received: from mail.ilande.co.uk ([2001:41c9:1:41f::167]:45668 helo=mail.default.ilande.bv.iomart.io) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mSa8m-0003Du-Da for qemu-devel@nongnu.org; Tue, 21 Sep 2021 03:24:33 -0400 Received: from [2a00:23c4:8b9d:4100:5d98:71b5:90ca:dad1] by mail.default.ilande.bv.iomart.io with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1mSa8d-000CDR-Re; Tue, 21 Sep 2021 08:24:24 +0100 To: =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , qemu-devel@nongnu.org, laurent@vivier.eu References: <20210916100554.10963-1-mark.cave-ayland@ilande.co.uk> <20210916100554.10963-11-mark.cave-ayland@ilande.co.uk> From: Mark Cave-Ayland Message-ID: <02ddb11c-c84b-2738-7ba9-6eba147bdbfa@ilande.co.uk> Date: Tue, 21 Sep 2021 08:24:24 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2a00:23c4:8b9d:4100:5d98:71b5:90ca:dad1 X-SA-Exim-Mail-From: mark.cave-ayland@ilande.co.uk Subject: Re: [PATCH v3 10/20] nubus-device: remove nubus_register_rom() and nubus_register_format_block() X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on mail.default.ilande.bv.iomart.io) Received-SPF: pass client-ip=2001:41c9:1:41f::167; envelope-from=mark.cave-ayland@ilande.co.uk; helo=mail.default.ilande.bv.iomart.io X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, NICE_REPLY_A=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 19/09/2021 22:10, Philippe Mathieu-Daudé wrote: > On 9/16/21 12:05, Mark Cave-Ayland wrote: >> Since there is no need to generate a dummy declaration ROM, remove both >> nubus_register_rom() and nubus_register_format_block(). These will shortly be >> replaced with a mechanism to optionally load a declaration ROM from disk to >> allow real images to be used within QEMU. > > Nubus neophyte question: is it OK to load a device without > optional ROM nor dummy? Yes, since the physical existence of the card is determined by whether the card accesses generate a bus fault, as per the Apple documentation, which is fixed in patch 8. The macfb device is an example of this since at least for the Quadra ROM its resources are not on the card itself, but stored in the MacOS toolbox ROM (normally referenced as slot 0xf). Having said that, without a declaration ROM being present then your driver would have to be able to identify the card the hard way, and at least Linux attempts to parse the MacOS resources during enumeration. So I'd expect declaration ROMs to be required for nubus devices that don't have corresponding drivers included in a standard MacOS toolbox ROM which is likely to be the majority of cases. ATB, Mark.