From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id 445DB13838B for ; Thu, 2 Oct 2014 21:39:12 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id E8BA7E084E; Thu, 2 Oct 2014 21:39:05 +0000 (UTC) Received: from smtp.gentoo.org (smtp.gentoo.org [140.211.166.183]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 59FC4E083B for ; Thu, 2 Oct 2014 21:39:04 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp.gentoo.org (Postfix) with ESMTP id 78653340393 for ; Thu, 2 Oct 2014 21:39:03 +0000 (UTC) X-Virus-Scanned: by amavisd-new using ClamAV at gentoo.org X-Spam-Flag: NO X-Spam-Score: -2.888 X-Spam-Level: X-Spam-Status: No, score=-2.888 tagged_above=-999 required=5.5 tests=[AWL=-0.188, BAYES_00=-1.9, DKIM_ADSP_CUSTOM_MED=0.001, FREEMAIL_FROM=0.001, NML_ADSP_CUSTOM_MED=0.9, RCVD_IN_DNSWL_LOW=-0.7, RP_MATCHES_RCVD=-1, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001] autolearn=no Received: from smtp.gentoo.org ([127.0.0.1]) by localhost (smtp.gentoo.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id vMchu9Ag_aTJ for ; Thu, 2 Oct 2014 21:38:57 +0000 (UTC) Received: from plane.gmane.org (plane.gmane.org [80.91.229.3]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.gentoo.org (Postfix) with ESMTPS id 7BD82340392 for ; Thu, 2 Oct 2014 21:38:56 +0000 (UTC) Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1XZo5L-0000C6-Mv for gentoo-user@gentoo.org; Thu, 02 Oct 2014 23:38:51 +0200 Received: from dsl.comtrol.com ([64.122.56.22]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 02 Oct 2014 23:38:51 +0200 Received: from grant.b.edwards by dsl.comtrol.com with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 02 Oct 2014 23:38:51 +0200 X-Injected-Via-Gmane: http://gmane.org/ To: gentoo-user@lists.gentoo.org From: Grant Edwards Subject: [gentoo-user] Re: [OT] Making a bootable USB flash drive from ISO image Date: Thu, 2 Oct 2014 21:38:36 +0000 (UTC) Message-ID: References: <20141002222412.6e07e903@hactar.digimed.co.uk> Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: dsl.comtrol.com User-Agent: slrn/1.0.1 (Linux) X-Archives-Salt: 82855711-5480-4d77-ae3c-94cefa9a1e61 X-Archives-Hash: e5293f362baffde20637d8a602ee3a64 On 2014-10-02, Neil Bothwick wrote: > On Thu, 2 Oct 2014 21:11:03 +0000 (UTC), Grant Edwards wrote: > >> What I'm wondering is why all the blog posts, wiki pages, and HOWTOs >> showing either the complicated command-line procedures or >> dependency-heavy "USB creator" apps? (Many of them quite recent.) > > There is no need for them. >> Did this work because the Xubuntu people do something special when >> creating the ISO image? (If so, then they have my thanks!) > > They did something, but it's not particularly special. All they did was > run isohybrid (from syslinux) on the ISO image. It uses unused space at > the start of the DVD ISO specification that is normally left blank to > hold a partition table so the image can be copied to a USB drive and > appear as a partitioned disk. There must be a little more to it than that. Does it also install along with a parition table some bootloader code that knows where/how to boot the ISO boot image? [After a little googling] It also installs MBR bootloader code that knows how to find/load isolinux.bin: http://www.syslinux.org/wiki/index.php/Isohybrid Interestingly, it also created a second EFI boot partition which exists inside the main parition. $ sudo fdisk -l /dev/sdd Disk /dev/sdd: 7.3 GiB, 7864320000 bytes, 15360000 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x19fabbe1 Device Boot Start End Blocks Id System /dev/sdd1 * 0 1904639 952320 0 Empty /dev/sdd2 14296 18967 2336 ef EFI (FAT-12/16/32) I can mount the sdd2 VFAT partition, and there are a couple files in there: sdd2 └── efi └── boot ├── bootx64.efi └── grubx64.efi -- Grant Edwards grant.b.edwards Yow! SHHHH!! I hear SIX at TATTOOED TRUCK-DRIVERS gmail.com tossing ENGINE BLOCKS into empty OIL DRUMS ...