diff --git a/sbin/reboot/boot_i386.8 b/sbin/reboot/boot_i386.8 index 321fe8f5746c..c8cac5b4e4ca 100644 --- a/sbin/reboot/boot_i386.8 +++ b/sbin/reboot/boot_i386.8 @@ -36,7 +36,7 @@ .\" .\" @(#)boot_i386.8 8.2 (Berkeley) 4/19/94 .\" -.\" $Id: boot_i386.8,v 1.13 1998/07/15 06:51:35 charnier Exp $ +.\" $Id: boot_i386.8,v 1.14 1998/09/23 06:54:14 yokota Exp $ .\" .Dd April 19, 1994 .Dt BOOT 8 i386 @@ -60,11 +60,42 @@ drive 0 (otherwise known as drive C:, or (confusingly) hard disk drive 1, or drive 0x80 in the BIOS). Some BIOSes let you change this default sequence or may include a CD-ROM drive as a boot device. +.Pp +By default, a three-stage bootstrap is employed, and control is +automatically passed from the boot blocks (bootstrap stages one and +two) to a separate third-stage bootstrap program, +.Pa /boot/loader . +This third stage provides considerably more sophisticated control +over the booting process than it is possible to achieve in the boot +blocks, which are constrained by occupying limited fixed space on a +given disk or slice. +.Pp +However, it is possible to dispense with the third stage altogether, +either by specifying a kernel name in the boot block parameter +file, +.Pa /boot.config , +or by hitting a key during a brief pause (while one of the characters +.Dv - , +.Dv \e , +.Dv \&| , +or +.Dv / +is displayed) before +.Pa /boot/loader +is invoked. Booting will also be attempted at stage two, if the +third stage cannot be loaded. +.Pp +The remainder of this subsection deals only with the boot blocks. +At present, documentation of the third stage is chiefly +available though online help in the +.Pa /boot/loader +program itself. +.Pp After the boot blocks have been loaded, you should see a prompt similar to the following: .Bd -literal ->> FreeBSD BOOT @ 0x10000: 640/7168 k of memory, internal console -Boot default: 0:wd(0,a)kernel +>> FreeBSD/i386 BOOT +Default: 0:wd(0,a)/kernel boot: .Ed @@ -83,7 +114,10 @@ prompt. At this time, the following input will be accepted: .Bl -tag -width 10x .It \&? Give a short listing of the files in the root directory of the default -boot device, as a hint about available boot files. +boot device, as a hint about available boot files. (A +.Dv \&? +may also be specified as the last segment of a path, in which case +the listing will be of the relevant subdirectory.) .It Op bios_drive:interface(unit,part) Op filename Op Fl aCcDdghPrsv Specify boot file and flags. .Bl -tag -width 10x -compact @@ -117,12 +151,12 @@ By convention, only partition .Ql a contains a bootable image. If sliced disks are used .Pq Dq fdisk partitions , -only the first BSD slice can be used to boot from. The partition -letter always refers to the first slice. +any slice can be booted from, with the default being the active slice +or, otherwise, the first slice. .It filename The pathname of the file to boot (relative to the root directory on the specified partition). Defaults to -.Pa kernel . +.Pa /kernel . Symbolic links are not supported (hard links are). .It Fl acCdDghPrsv Boot flags: @@ -206,19 +240,15 @@ prompt. .Sh FILES .Bl -tag -width /kernel.old.config -compact .It Pa /boot.config -parameters for the boot loader (optional) +parameters for the boot blocks (optional) .It Pa /boot.help -help messages +help messages (optional) +.It Pa /boot/loader +third-stage bootstrap .It Pa /kernel default kernel -.It Pa /kernel.config -parameters for default kernel (optional) .It Pa /kernel.old typical non-default kernel (optional) -.It Pa /kernel.old.config -parameters for non-default kernel (optional) -.\" .It Pa /boot -.\" system bootstrap .El .Sh SEE ALSO .Xr ddb 4 , @@ -234,5 +264,4 @@ The disklabel format used by this version of is quite different from that of other architectures. .Pp -The boot flags are not very self-explanatory, and the alphabet has -too few characters to implement every potentially useful boot option. +Some features are, as yet, undocumented.