From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: None (no SPF record) identity=mailfrom; client-ip=68.230.241.216; helo=eastrmfepo201.cox.net; envelope-from=rodsmith@rodsbooks.com; receiver=edk2-devel@lists.01.org Received: from eastrmfepo201.cox.net (eastrmfepo201.cox.net [68.230.241.216]) by ml01.01.org (Postfix) with ESMTP id C6758210D83CF for ; Fri, 15 Jun 2018 13:11:25 -0700 (PDT) Received: from eastrmimpo109.cox.net ([68.230.241.222]) by eastrmfepo201.cox.net (InterMail vM.8.01.05.28 201-2260-151-171-20160122) with ESMTP id <20180615201125.YGIY1466.eastrmfepo201.cox.net@eastrmimpo109.cox.net> for ; Fri, 15 Jun 2018 16:11:25 -0400 Received: from [192.168.1.2] ([98.182.36.110]) by eastrmimpo109.cox.net with cox id z8BQ1x00d2Nb5V6018BQ9Z; Fri, 15 Jun 2018 16:11:24 -0400 X-Authority-Analysis: v=2.2 cv=faTd8wYF c=1 sm=1 tr=0 a=fGEtHzg9pACwwgu90N25OA==:117 a=fGEtHzg9pACwwgu90N25OA==:17 a=N659UExz7-8A:10 a=DfuHEfYujLMA:10 a=28bguoTQAAAA:8 a=PHhwTPayP-FmZA7kt-AA:9 a=pILNOxqGKmIA:10 a=voRV_PY5qW-4FQMV9MBC:22 X-CM-Score: 0.00 Authentication-Results: cox.net; auth=pass (PLAIN) smtp.auth=rodericksmith2@cox.net To: edk2-devel@lists.01.org References: <6a7f5c2c-3dfc-c0ba-6223-30b837898258@rodsbooks.com> <7EBBED81-A368-4878-819F-2ECB0252F9CC@apple.com> From: Rod Smith Openpgp: preference=signencrypt Autocrypt: addr=rodsmith@rodsbooks.com; prefer-encrypt=mutual; keydata= xsBNBFZgoQEBCADBB16LbVAopSIiVn6n8CN4soC5VVseWEQJiut4NkfPtctD4xofvDZeW0sP h3iXS55hftP9EXOTT2IeNDFI0gwZe55aSaG3hUQMMimpP7OyJHrV8J4jyKr5Qk7IYa+qGjFK InfeGSgzVkMA5x62Nm/QwmP/45LqFZN/CLDpdgGIUbTKQvoojIHoytd0EB77RfkJG95EMcBv t7xF318M8dxolE7yZVQy19id7uiM7idZHV0v6nAp80uFWlkcJqzCKvGB0eOjZ8JMzPN4UJKV 0mn6PLggBlf9+qazH+2H/5IOBDr97zd5dYcEzVrvybX1YMy5WV9CEgEnFS3epPTgN7WLABEB AAHNIlJvZCBTbWl0aCA8cm9kc21pdGhAcm9kc2Jvb2tzLmNvbT7CwHgEEwECACIFAlZgoQEC GwMGCwkIBwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEP5hb1BFxoQhSSoIAI2UxPSYY2dUDRFP kA4KhvmkVK08hODPrwh26Rhs8cHVOHcM9HfuDeUi8g/d3tULhRxxF3dphldRqSD0s9sBwsSD yujxp1iwWN8mYXw0cD9+g391R3G2Dwd2yr4KFZ2mab8hTUT3dmeUXUXMx/s0IY9JHQdzumbY O0Xna60WL/IgiE4ykljU8FilX6pWmdsKRB+ZO21Evski7mRxsMwovTcxUSk0Arr8a2tCP3l3 ckJeUNJzV6TPEq7rCBH+DyNgg7uqlZNXN8KL67Xw6YaT+yMbP6VHL8yCrRBaJIaDKkk809N+ TegU+ENRhz5FFBGicPaVCWtXX4Oc35WeJk0/EtHOwE0EVmChAQEIAJ6kKtOd29bBf1/xLADc 6LbLvnASrKGxbG7UiFEpFEkSGaD5bLR96RaFItrPs4ntrWIrFfN+93w5aMH8W4SlTPemaPVx YHUOw6fylWobKA3UApAnVJV5KyFdc+5jK+1SziBSIdNkp8f2H4kImuEhvzVER2abJPm61270 E0qnu0cazyZC9E3YwSAqmFFvdo7H3AF4bfShHu7QTtSWp4HmihUsdVTEYjYB0GQIYrTeX2gh TLfgmo5wfpxdQIIL19oPA9GAFl5j7x2h93Y+5skCIfP/x2oOKumscbxVdxN2feuyLsbEvPAP FUnwIfA1Biv8syE8d9LPizadtagcZCCDFf0AEQEAAcLAXwQYAQIACQUCVmChAQIbDAAKCRD+ YW9QRcaEIdK9CAC34qKJTC9gHESxqpPmnMmR39icrQ1o4u4xHE1wAax2oB/3Y0BBUgvOnykf RVIgf1r0TxTap0dFBX2TnAgb8fDG33Ef6x1E6asSoOTpUfOcwgeAkOk+FW9zdW6FTclhlKsi vsa2vlUda4dj0nirGLorX59yfABVdpTTUGh75qjyBNJGFulbDDAh3ca2Tj46Ew1VRvqDix+Y 2KPAVq7wtDSugITZS+P0kac3uIzGUPDC9nYLj1i+/ODIvNaS65Y3x7jA8k8YRekM3URJVL7B I4TiMOnwwxuXgFNaLnQ0iUOsfhv8x2Rtwnf9L/0C5ZqGc+jlteh5XLI6RCb7Sh373CZf Message-ID: <50cac78a-a686-14d6-3c1a-8c727b18ddd3@rodsbooks.com> Date: Fri, 15 Jun 2018 16:11:24 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <7EBBED81-A368-4878-819F-2ECB0252F9CC@apple.com> Subject: Re: Creating EFI System Partition X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 15 Jun 2018 20:11:26 -0000 Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 8bit On 06/15/2018 11:01 AM, Andrew Fish wrote: > >> On Jun 15, 2018, at 6:17 AM, Rod Smith > > wrote: >> >> but AFAIK, any common tool for creating a FAT32 filesystem should >> work. I generally do it with mkdosfs in Linux, but equivalent tools >> in macOS, Windows, or the BSDs also work. In practice, FAT16 and >> FAT12 usually work, too, although the EFI spec does explicitly say >> at one point that the filesystem should be FAT32, and I know of at >> least one implementation that gets a little flaky with FAT16, so >> I'd stick with FAT32. >> > > I seem to remember that the FAT32 spec also defined FAT16 and FAT12. > it also defines when FAT32, FAT16, or FAT12 should be used for > media. > > If the edk2 FAT driver has an issue with media that conform to the > FAT32 spec we should fix that. If the issue is non conferment, then > we need to decide if the fix can be made that will follow the FAT > Spec. See that CYA was useful after all :). No, I didn't mean to imply that the EDK2 FAT driver gets flaky with 12- or 16-bit FAT filesystems. The EFI in question was an early EFI-over-BIOS implementation on a Gigabyte motherboard from 2011 or 2012. That thing was a horror, and I wrote up my experiences at the time: http://www.rodsbooks.com/gb-hybrid-efi/ I no longer have that motherboard, so I can't do any more tests with it or double-check my findings from 2012. From that page, though: : A FAT-16 ESP, on the other hand, seems problematic. Ubuntu 11.04 (and : 11.10) in EFI mode creates a dinky FAT-16 ESP, and after my test : install of Ubuntu 11.04, the board hung on reboot until I reworked : the ESP as FAT-32. Thus, if you plan to install Ubuntu, or any other : OS that creates a FAT-16 ESP, be prepared to fix it, preferably : before the system reboots! Note that Ubuntu no longer creates a "dinky FAT-16 ESP;" it now creates a 512MiB FAT-32 ESP. The experience remains a relevant cautionary tale, though, for anybody who's trying to write an OS installer, particularly if the system must be installable on some random computer -- systems from that period are still in use today, so a FAT-16 ESP could cause problems in the real world. That said, I've not encountered this problem on any modern (say, 2014 or later) EFI. -- Rod Smith rodsmith@rodsbooks.com http://www.rodsbooks.com