From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f52.google.com (mail-ej1-f52.google.com [209.85.218.52]) by mx.groups.io with SMTP id smtpd.web11.3695.1618538769446633844 for ; Thu, 15 Apr 2021 19:06:09 -0700 Authentication-Results: mx.groups.io; dkim=pass header.i=@gmail.com header.s=20161025 header.b=A0wVWq21; spf=pass (domain: gmail.com, ip: 209.85.218.52, mailfrom: harlydavidsen@gmail.com) Received: by mail-ej1-f52.google.com with SMTP id w23so23975423ejb.9 for ; Thu, 15 Apr 2021 19:06:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=QYCvA7BK7RG6GDYPTvi5pziymb/Dg116beaqMUWUQok=; b=A0wVWq21ZJfJYOCI4EUszRX1CkywmxoF4Z8qNVb8GLboavei3q9igAfSEMLzUMEdhM wLU5emSFm8r5vp/QCZzkGz3y087SWY/HPbOJQK0FwLYFmOSTp3mHjQNpEmf3kithny2i ipZcMhffxwCzprWiepbAFWGHtzjlbOYvDV1Y9JE7ndtQJTEvfbKvsvLgPDGUSJpjhelK TCjV5KM8RoPojDIvtSerMfWY+Hoyc6u8DigD49IXTVglQx8eXLrVXzg9s5f8eLIU7ufn koE/tR47BxGYdZq2lJOpIaT4tCGJijIH67th2YMQZezG1oB8wwQE04jZVv+8xaCnTd6r ncWg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=QYCvA7BK7RG6GDYPTvi5pziymb/Dg116beaqMUWUQok=; b=XzsuvU4a/bgjz6y2+rgMpvGEqBwOux6xkImJBysPv2Fl13NT68k1IXKaEneRQagJCj mAoXMZDCbxF9B3qGQk54MoFg5eoo7MniFdQAej0xux7tQ3lt69MfN/PQFjb1Uytfd2TM 2UbBWP3IdHkzw59HEsw2GCszpqLTGRlGvHUxUZzzLFkuzFlG+TcD++wcUlkU7wm8b00i X5voKmnC843Q5C/wt+OpZmK7Q/+s2LLOJJJZEVotxboGnKywuRFf4uvDX9txp9L7lPJO 1mDQ+tMPBFUkh8x6sAtsk+vFpC78CmyWPl2C/dSpExHZxjvjhSRfgfv2heO1rO7R4fWd cdEw== X-Gm-Message-State: AOAM530kyucR6TZLJ5ZwS5PyUcrSofadFymYEQgfKBpfZLM6LRF5VPP+ yAvV+Y4eK2V5rtzar8fCUpN7fKITZxc+GM3Y2/4= X-Google-Smtp-Source: ABdhPJy4Vn0Q27YfpBBShC4Y5QXxkQwoMO60cmftUdTbN6vGqvOCkI8EMKAyZvmErgl5likNCVB6m7JpwfQokTLaMog= X-Received: by 2002:a17:906:130a:: with SMTP id w10mr6212395ejb.71.1618538767940; Thu, 15 Apr 2021 19:06:07 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:ab4:9a0a:0:0:0:0:0 with HTTP; Thu, 15 Apr 2021 19:06:07 -0700 (PDT) In-Reply-To: <4f029f76-0f11-f229-af04-2407ac80308b@ipxe.org> References: <16758FB6436B1195.32393@groups.io> <4AEC1784-99AF-47EF-B7DD-77F91EA3D7E9@apple.com> <309cc5ca-2ecd-79dd-b183-eec0572ea982@ipxe.org> <16762C957671127A.12361@groups.io> <4f029f76-0f11-f229-af04-2407ac80308b@ipxe.org> From: "Ethin Probst" Date: Thu, 15 Apr 2021 21:06:07 -0500 Message-ID: Subject: Re: [edk2-devel] VirtIO Sound Driver (GSoC 2021) To: Michael Brown Cc: devel@edk2.groups.io, Andrew Fish , Mike Kinney , Leif Lindholm , Laszlo Ersek , "Desimone, Nathaniel L" , Rafael Rodrigues Machado , Gerd Hoffmann Content-Type: text/plain; charset="UTF-8" Oh, okay, thank you. On 4/15/21, Michael Brown wrote: > On 16/04/2021 01:59, Ethin Probst wrote: >> Also, I'm a bit confused. I've looked at several VirtIO devices now >> and have seen things like this: >> #define VIRTIO_PCI_DEVICE_SIGNATURE SIGNATURE_32 ('V', 'P', 'C', 'I') >> // ... >> UINT32 Signature; >> I'm quite confused because I can't seem to find this anywhere in the >> VirtIO specification. The spec says nothing about signature values >> anywhere, just the magic value of 0x74726976. So where does this come >> from? > > From a quick look at the code, it seems to be a private signature value > applied to a software-only data structure used by the UEFI driver, and > is used solely for sanity checking that a pointer is pointing to the > right kind of object. > > Michael > -- Signed, Ethin D. Probst