From 403d96e991072240c183689f0702ea6ed8739d59 Mon Sep 17 00:00:00 2001 From: Nik Clayton Date: Thu, 30 Dec 1999 22:06:51 +0000 Subject: [PATCH] Remove PHK's existing documentation about the boot process (out of date) and refer the reader to boot(8) and loader(8). Reviewed by: phk --- .../books/handbook/internals/chapter.sgml | 229 +----------------- 1 file changed, 3 insertions(+), 226 deletions(-) diff --git a/en_US.ISO_8859-1/books/handbook/internals/chapter.sgml b/en_US.ISO_8859-1/books/handbook/internals/chapter.sgml index 0942b7c0d5..467da85b31 100644 --- a/en_US.ISO_8859-1/books/handbook/internals/chapter.sgml +++ b/en_US.ISO_8859-1/books/handbook/internals/chapter.sgml @@ -1,7 +1,7 @@ @@ -10,231 +10,8 @@ The FreeBSD Booting Process - Contributed by &a.phk;. v1.1, April - 26th. - - Booting FreeBSD is essentially a three step process: load the - kernel, determine the root filesystem and initialize user-land things. - This leads to some interesting possibilities shown below. - - - Loading a kernel - - We presently have three basic mechanisms for loading the kernel as - described below: they all pass some information to the kernel to help - the kernel decide what to do next. - - - - Biosboot - - - Biosboot is our “bootblocks”. It consists of - two files which will be installed in the first 8Kbytes of the - floppy or hard-disk slice to be booted from. - - Biosboot can load a kernel from a FreeBSD filesystem. - - - - - Dosboot - - - Dosboot was written by DI. Christian Gusenbauer, and is - unfortunately at this time one of the few pieces of code that - will not compile under FreeBSD itself because it is written for - Microsoft compilers. - - Dosboot will boot the kernel from a MS-DOS file or from a - FreeBSD filesystem partition on the disk. It attempts to - negotiate with the various and strange kinds of memory manglers - that lurk in high memory on MS/DOS systems and usually wins them - for its case. - - - - - Netboot - - - Netboot will try to find a supported Ethernet card, and use - BOOTP, TFTP and NFS to find a kernel file to boot. - - - - - - - Determine the root filesystem - - Once the kernel is loaded and the boot-code jumps to it, the - kernel will initialize itself, trying to determine what hardware is - present and so on; it then needs to find a root filesystem. - - Presently we support the following types of root - filesystems: - - - - UFS - - - This is the most normal type of root filesystem. It can - reside on a floppy or on hard disk. - - - - - MSDOS - - - While this is technically possible, it is not particular - useful because of the FAT filesystem's - inability to deal with links, device nodes and other such - “UNIXisms”. - - - - - MFS - - - This is actually a UFS filesystem which has been compiled - into the kernel. That means that the kernel does not really - need any hard disks, floppies or other hardware to - function. - - - - - CD9660 - - - This is for using a CD-ROM as root filesystem. - - - - - NFS - - - This is for using a fileserver as root filesystem, basically - making it a diskless machine. - - - - - - - Initialize user-land things - - To get the user-land going, the kernel, when it has finished - initialization, will create a process with pid == 1 - and execute a program on the root filesystem; this program is normally - /sbin/init. - - You can substitute any program for /sbin/init, - as long as you keep in mind that: - - there is no stdin/out/err unless you open it yourself. If you - exit, the machine panics. Signal handling is special for pid - == 1. - - An example of this is the /stand/sysinstall - program on the installation floppy. - - - - Interesting combinations - - Boot a kernel with a MFS in it with a special - /sbin/init which... - - - - A — Using DOS - - - - - mounts your C: as - /C: - - - - Attaches C:/freebsd.fs on - /dev/vn0 - - - - mounts /dev/vn0 as - /rootfs - - - - makes symlinks - /rootfs/bin -> - /bin - /rootfs/etc -> - /etc - /rootfs/sbin -> - /sbin (etc...) - - - - Now you are running FreeBSD without repartitioning your hard - disk... - - - - - B — Using NFS - - - NFS mounts your server:~you/FreeBSD as - /nfs, chroots to /nfs - and executes /sbin/init there - - Now you are running FreeBSD diskless, even though you do not - control the NFS server... - - - - - C — Start an X-server - - - Now you have an X-terminal, which is better than that dingy - X-under-windows-so-slow-you-can-see-what-it-does thing that your - boss insist is better than forking out money on hardware. - - - - - D — Using a tape - - - Takes a copy of /dev/rwd0 and writes it - to a remote tape station or fileserver. - - Now you finally get that backup you should have made a year - ago... - - - - - E — Acts as a firewall/web-server/what do I - know... - - - This is particularly interesting since you can boot from a - write- protected floppy, but still write to your root - filesystem... - - - - + The FreeBSD booting process is described in the &man.boot.8; and + &man.loader.8; manual pages.