From owner-svn-doc-all@FreeBSD.ORG Mon Apr 21 21:29:57 2014 Return-Path: Delivered-To: svn-doc-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id BA7C4801; Mon, 21 Apr 2014 21:29:57 +0000 (UTC) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id A66521917; Mon, 21 Apr 2014 21:29:57 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.8/8.14.8) with ESMTP id s3LLTvGM040809; Mon, 21 Apr 2014 21:29:57 GMT (envelope-from dru@svn.freebsd.org) Received: (from dru@localhost) by svn.freebsd.org (8.14.8/8.14.8/Submit) id s3LLTvZ5040808; Mon, 21 Apr 2014 21:29:57 GMT (envelope-from dru@svn.freebsd.org) Message-Id: <201404212129.s3LLTvZ5040808@svn.freebsd.org> From: Dru Lavigne Date: Mon, 21 Apr 2014 21:29:57 +0000 (UTC) To: doc-committers@freebsd.org, svn-doc-all@freebsd.org, svn-doc-head@freebsd.org Subject: svn commit: r44622 - head/en_US.ISO8859-1/books/handbook/boot X-SVN-Group: doc-head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-doc-all@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: "SVN commit messages for the entire doc trees \(except for " user" , " projects" , and " translations" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 21 Apr 2014 21:29:57 -0000 Author: dru Date: Mon Apr 21 21:29:57 2014 New Revision: 44622 URL: http://svnweb.freebsd.org/changeset/doc/44622 Log: Prep work for boot chapter. Add missing items from what is covered in this chapter list. Add note about GPT and EFI/UEFI. Some shuffling of headings to improve flow. More commits to come. Sponsored by: iXsystems Modified: head/en_US.ISO8859-1/books/handbook/boot/chapter.xml Modified: head/en_US.ISO8859-1/books/handbook/boot/chapter.xml ============================================================================== --- head/en_US.ISO8859-1/books/handbook/boot/chapter.xml Mon Apr 21 21:16:02 2014 (r44621) +++ head/en_US.ISO8859-1/books/handbook/boot/chapter.xml Mon Apr 21 21:29:57 2014 (r44622) @@ -19,7 +19,7 @@ The process of starting a computer and loading the operating system is referred to as the bootstrap process, - or simply booting. &os;'s boot process provides + or booting. &os;'s boot process provides a great deal of flexibility in customizing what happens when the system starts, including the ability to select from different operating systems installed on the same computer, @@ -47,18 +47,27 @@ - The basics of &man.device.hints.5;. + How to configure a customized boot splash screen. + + + + The basics of setting device hints. + + + + How to boot into single- and multi-user mode and how to + properly shutdown a &os; system. This chapter only describes the boot process for &os; - running on Intel x86 systems. + running on x86 and amd64 systems. - The Booting Problem + &os; Boot Process Turning on a computer and starting the operating system poses an interesting dilemma. By definition, the computer does @@ -71,7 +80,7 @@ This problem parallels one in the book The Adventures of Baron Munchausen. A character had fallen part way down a manhole, and pulled himself - out by grabbing his bootstraps, and lifting. In the early days + out by grabbing his bootstraps and lifting. In the early days of computing the term bootstrap was applied to the mechanism used to load the operating system, which has become shortened to booting. @@ -81,9 +90,9 @@ Basic Input/Output SystemBIOS - On x86 hardware the Basic Input/Output System + On x86 hardware, the Basic Input/Output System (BIOS) is responsible for loading the - operating system. To do this, the BIOS + operating system. The BIOS looks on the hard disk for the Master Boot Record (MBR), which must be located in a specific place on the disk. The BIOS has enough @@ -91,6 +100,19 @@ assumes that the MBR can then carry out the rest of the tasks involved in loading the operating system, possibly with the help of the BIOS. + + + amd64 hardware is backward compatible as it understands + BIOS instructions. Newer hardware uses + a GUID Partition Table (GPT) instead of a + MBR. &os; can boot from a + MBR or GPT partition. + When booting from GPT, &os; can boot from + either a legacy BIOS or an Extensible + Firmware Interface (EFI). Work is in + progress to provide Unified Extensible Firmware Interface + (UEFI) support. + Master Boot Record MBR) @@ -101,60 +123,50 @@ The code within the MBR is usually referred to as a boot manager, especially - when it interacts with the user. In this case, the boot + when it interacts with the user. The boot manager usually has more code in the first - track of the disk or within the file - system of some operating systems. A boot manager is sometimes - also called a boot loader, but &os; uses - that term for a later stage of booting. Popular boot managers - include boot0, also called - Boot Easy, the standard &os; boot - manager, Grub, - GAG, and - LILO. Only - boot0 fits within the - MBR. + track of the disk or within the file + system. Examples of boot managers + include the standard &os; boot + manager boot0, also called + Boot Easy, and Grub, + which is used by many &linux; distributions. - If only one operating system is installed, a standard PC - MBR will suffice. This + If only one operating system is installed, the MBR searches for the first bootable (active) slice on the disk, and then runs the code on that slice to load - the remainder of the operating system. By default, the - MBR installed by &man.fdisk.8; is such an - MBR and is based on - /boot/mbr. - - If multiple operating systems are present, a different boot + the remainder of the operating system. If multiple operating + systems are present, a different boot manager can be installed which displays the list of operating - systems so that the user can choose which one to boot from. Two - boot managers are discussed in the next subsection. + systems so that the user can choose which one to boot from. The remainder of the &os; bootstrap system is divided into - three stages. The first stage is run by the - MBR, which knows just enough to get the + three stages. The first stage knows just enough to get the computer into a specific state and run the second stage. The second stage can do a little bit more, before running the third stage. The third stage finishes the task of loading the operating system. The work is split into three stages because - PC standards put limits on the size of the programs that can be + the MBR puts limits on the size of the programs that can be run at stages one and two. Chaining the tasks together allows &os; to provide a more flexible loader. kernel &man.init.8; - The kernel is then started and it begins to probe for + The kernel is then started and begins to probe for devices and initialize them for use. Once the kernel boot process is finished, the kernel passes control to the user - process &man.init.8;, which then makes sure the disks are in a - usable state. &man.init.8; then starts the user-level resource + process &man.init.8;, which makes sure the disks are in a + usable state, starts the user-level resource configuration which mounts file systems, sets up network cards to communicate on the network, and starts the processes which - have been configured to run on a &os; system at startup. - + have been configured to run at startup. + + This section describes these stages in more detail and + demonstrates how to interact with the &os; boot process. - - The Boot Manager and Boot Stages + + The Boot Manager Boot Manager @@ -232,6 +244,7 @@ label=FreeBSD run /sbin/lilo -v to commit the new changes. Verify these are correct by checking the screen messages. + Stage One and Stage Two @@ -605,6 +618,7 @@ boot: boot flags. + - + Configuring Boot Time Splash Screens @@ -766,7 +780,6 @@ bitmap_name="/boot/splash.b For more information, refer to &man.splash.4;, &man.loader.conf.5;, and &man.vga.4;. -