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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 A02C4C433EF for ; Sat, 18 Sep 2021 06:55:10 +0000 (UTC) Received: from phobos.denx.de (phobos.denx.de [85.214.62.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A432061260 for ; Sat, 18 Sep 2021 06:55:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org A432061260 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.denx.de Received: from h2850616.stratoserver.net (localhost [IPv6:::1]) by phobos.denx.de (Postfix) with ESMTP id 56BFD83246; Sat, 18 Sep 2021 08:55:07 +0200 (CEST) Authentication-Results: phobos.denx.de; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=u-boot-bounces@lists.denx.de Authentication-Results: phobos.denx.de; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=linaro.org header.i=@linaro.org header.b="KpxIjFFq"; dkim-atps=neutral Received: by phobos.denx.de (Postfix, from userid 109) id 94BDC83246; Sat, 18 Sep 2021 08:55:05 +0200 (CEST) Received: from mail-ed1-x530.google.com (mail-ed1-x530.google.com [IPv6:2a00:1450:4864:20::530]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) by phobos.denx.de (Postfix) with ESMTPS id 6489D82DA1 for ; Sat, 18 Sep 2021 08:55:00 +0200 (CEST) Authentication-Results: phobos.denx.de; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=francois.ozog@linaro.org Received: by mail-ed1-x530.google.com with SMTP id q3so38512728edt.5 for ; Fri, 17 Sep 2021 23:55:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Qee6lq+9xyPrwuFXFcuI3efDZKBnA87tr8Wml31DAk8=; b=KpxIjFFqa8WjcpG6jbQQq69ClecNAfNHdx2+50G91NHTuFJSsr2wto+YG0aV4hSsYS nJzZovlIxrTdrA2JyYaukIi6e+OKzXEpRmHmBUhmS67T7VRuX6ejT3xDwldmT1RhqYwQ fujgkUQrviIXMwvhJ5Y0hipnHup0/fQc0NsHqaPVqgt9uUR7WbxLdWhyAlta8ABtwJ6E Lp1RS91f3DSwpele1lidtI41DNzi8IN7AO3/FKVYgaCyW8DJNWt+ssZ6UlTOmd5tdN1r mPGVLGHlwKk+Q/DGAtrN2HHG//0aQ2klCojR7SYyvAx4i7kPifwNRl39aRK5U/7ipKGi 3Umw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Qee6lq+9xyPrwuFXFcuI3efDZKBnA87tr8Wml31DAk8=; b=zQ9NuWf6G7Le+1mphlm4Uk/2knmvTbp9Xm2Laob6A3y32Nv31VGkdW2YBPrNtIz+g8 XeihusOfIQo/2hAtRs/XJ+FQzUyyhXqb+RsTPS2hU3py92+F9ZSXAkYHFVRg7XtYM4by XfKBwh6eFnXayg9hpCdXQ5AhHaAXT8gYcWCG6t70CZDn6ypic8mP1eI3dyv9cyvqUp0I kwDD34ORP4Ot8lWnUNGs3Zo2wjV6eZf9avgJY0Mqmq8rfw9kQXv4UYAbmgBbUX05ZYeq kPec3x5dgcHa+irQkv86+gScgH5SLTeKYC8nH+g8ch/ij187OlR2hP5+sFmHPgLomy41 jHMw== X-Gm-Message-State: AOAM533nJ09wYN8yFvr8hiIdrZK4A/vFsRUWZ37WE1bbZF7Ak08xhbXY rsVTmJE+7n0NSTOFZvf1f3eD50QR+47ltoPtryEckw== X-Google-Smtp-Source: ABdhPJw+SoKgUwLZMPcl3muDYk2O1Zyt7YGGMoEbuYHs3ev3Z7vyrG1ehP6Nwfs8HzqFt8xXjbgDWpcMS9JtabjyDdk= X-Received: by 2002:a05:6402:6d6:: with SMTP id n22mr10007996edy.257.1631948099979; Fri, 17 Sep 2021 23:54:59 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: =?UTF-8?Q?Fran=C3=A7ois_Ozog?= Date: Sat, 18 Sep 2021 08:54:49 +0200 Message-ID: Subject: Re: Question about extension board used in U-boot To: "Ying-Chun Liu (PaulLiu)" Cc: Bill Mills , Boot Architecture Mailman List , u-boot Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.34 X-BeenThere: u-boot@lists.denx.de X-Mailman-Version: 2.1.34 Precedence: list List-Id: U-Boot discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: u-boot-bounces@lists.denx.de Sender: "U-Boot" X-Virus-Scanned: clamav-milter 0.103.2 at phobos.denx.de X-Virus-Status: Clean Le sam. 18 sept. 2021 =C3=A0 08:49, Fran=C3=A7ois Ozog a =C3=A9crit : > Hi Paul > > Too posting because I think we also need to address this at a higher leve= l. > > i think we discussed this topic quite a while back. I may be wrong but it > may be Bill Mills who proposed to have an eeprom on the extensions that t= he > carrier board can use to detect and fetch proper overlay. Another way wou= ld > be that the contract between the extension board and the carrier board > includes an i2c accessible storage to fetch an overlay that would identif= y > the board and give all details. > i just forgot to state that the mode is well known: SPD for DIMMs. > Bottom line, a software only solution seems not entirely satisfying. > In that suboptimal case, U-Boot shall be able to assemble a DT for itself > and another for OS (may be same in some cases) through scripting. And in > this case, come your questions below > > . > > Le sam. 18 sept. 2021 =C3=A0 01:21, Ying-Chun Liu (PaulLiu) > a =C3=A9crit : > >> Hi all, >> >> >> I have some questions about how to implement extension board usage. >> My case is on imx8mm-cl-iot-gate. It can add three different types of >> extension boards. >> One of the extension boards is SPI extension which have 3 empty slots. >> And you can add >> some small boards onto it. One of them is a "TPM2" module. >> >> >> My first question is if I want to use tpm2 in U-boot for measured boot. >> How to implement this right? Currently I just modify the dts used by >> U-boot to let it drive >> the extension board. And let it drive the TPM. But it is not good for >> upstreaming because >> when other types of extension boards installed then it is not working. >> Where to implement this? What is the best practice of this? > > >> The second question is about extension manager. >> I have read the extension.rst. I think I'll implement this anyway >> because then >> I can have a command to query what type of extension boards I have. >> And if the extension board is the 3 slots one. I can then detect which >> slot is the TPM. >> I'll implement this anyway because the "extension" command is convenient >> for users. >> But it seems to me that it only solves the problem for Linux kernel. >> It can apply a DTB Overlay to Linux DTB to let Linux knows we have that >> extension board. >> But it is too late for U-boot itself, right? >> >> >> The third question is I'm also dong SystemReady IR certificate. That mea= ns >> the dtb for Linux is directly provided by U-boot. We use U-boot dtb >> directly to Linux >> kernel. In this case, how to modify that dts dynamically to feed to the >> Linux kernel by >> the extension manager? >> What is the best practice if I want to use U-boot dts for Linux in >> implementation? >> >> >> Thanks a lot. >> >> >> Yours, >> Paul >> >> >> -- > Fran=C3=A7ois-Fr=C3=A9d=C3=A9ric Ozog | *Director Business Development* > T: +33.67221.6485 > francois.ozog@linaro.org | Skype: ffozog > > -- Fran=C3=A7ois-Fr=C3=A9d=C3=A9ric Ozog | *Director Business Development* T: +33.67221.6485 francois.ozog@linaro.org | Skype: ffozog