From patchwork Fri Jan 17 10:44:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Shevchenko X-Patchwork-Id: 1224743 X-Patchwork-Delegate: trini@ti.com Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.denx.de (client-ip=85.214.62.61; helo=phobos.denx.de; envelope-from=u-boot-bounces@lists.denx.de; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.intel.com Received: from phobos.denx.de (phobos.denx.de [85.214.62.61]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 47zd4j40PFz9s29 for ; Fri, 17 Jan 2020 21:45:20 +1100 (AEDT) Received: from h2850616.stratoserver.net (localhost [IPv6:::1]) by phobos.denx.de (Postfix) with ESMTP id 3D8F681A3C; Fri, 17 Jan 2020 11:45:08 +0100 (CET) Authentication-Results: phobos.denx.de; dmarc=none (p=none dis=none) header.from=linux.intel.com Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=u-boot-bounces@lists.denx.de Received: by phobos.denx.de (Postfix, from userid 109) id D27E681A47; Fri, 17 Jan 2020 11:45:06 +0100 (CET) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on phobos.denx.de X-Spam-Level: X-Spam-Status: No, score=0.0 required=5.0 tests=SPF_HELO_NONE, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.2 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by phobos.denx.de (Postfix) with ESMTPS id A83D181A38 for ; Fri, 17 Jan 2020 11:44:58 +0100 (CET) Authentication-Results: phobos.denx.de; dmarc=none (p=none dis=none) header.from=linux.intel.com Authentication-Results: phobos.denx.de; spf=none smtp.mailfrom=andriy.shevchenko@linux.intel.com X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Jan 2020 02:44:55 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,329,1574150400"; d="scan'208";a="249192285" Received: from black.fi.intel.com ([10.237.72.28]) by fmsmga004.fm.intel.com with ESMTP; 17 Jan 2020 02:44:53 -0800 Received: by black.fi.intel.com (Postfix, from userid 1003) id 3FC17501; Fri, 17 Jan 2020 12:44:51 +0200 (EET) From: Andy Shevchenko To: AKASHI Takahiro , Heinrich Schuchardt , Tom Rini , U-Boot Mailing List , Simon Glass , Bin Meng Subject: [PATCH v1] doc: README.distro: Special case with Windows formatted disk Date: Fri, 17 Jan 2020 12:44:51 +0200 Message-Id: <20200117104451.62417-1-andriy.shevchenko@linux.intel.com> X-Mailer: git-send-email 2.24.1 MIME-Version: 1.0 X-BeenThere: u-boot@lists.denx.de X-Mailman-Version: 2.1.26 Precedence: list List-Id: U-Boot discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Andy Shevchenko Errors-To: u-boot-bounces@lists.denx.de Sender: "U-Boot" X-Virus-Scanned: clamav-milter 0.101.4 at phobos.denx.de X-Virus-Status: Clean If someone wants to use shared (by installed OS) eMMC partition to the Windows to boot from, it's not possible due to U-Boot limitations. Describe this case and possible workaround. Signed-off-by: Andy Shevchenko --- doc/README.distro | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/doc/README.distro b/doc/README.distro index ab6e6f4e74..807a82c910 100644 --- a/doc/README.distro +++ b/doc/README.distro @@ -405,3 +405,23 @@ of the boot environment and are not guaranteed to exist or work in the same way in future u-boot versions. In particular the _boot variables (e.g. mmc_boot, usb_boot) are a strictly internal implementation detail and must not be used as a public interface. + +Using a eMMC partition that has been formatted as a disk by Windows 10 +====================================================================== + +Let's assume we have an (embedded) board with U-Boot and Linux OS +installed on eMMC. Linux OS shares one of the eMMC partitions as +a disk via USB Mass Storage protocol. + +It may be useful to utilize that disk to copy bootable files from +Windows machine to the board in case someone doesn't want to erase +stock installation on it. + +Unfortunately, Windows 10 doesn't provide knobs and always formats +that disk as a whole, meaning that it creates a partition table on it +with requested (FAT) partition. As a result U-Boot may not see any +files on it due to nesting partition tables. + +The workaround may be in formatting the partition under Linux OS, +setting up a network connection between Linux OS and Windows 10 and +use it to copy files to the partition.