diff options
author | Tobias Weingartner <weingart@cvs.openbsd.org> | 1997-09-05 21:25:17 +0000 |
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committer | Tobias Weingartner <weingart@cvs.openbsd.org> | 1997-09-05 21:25:17 +0000 |
commit | 0cda81d504a905ab5b6a4e6c3baacf2733b7e42d (patch) | |
tree | b9f062a47abdaad80e7a3465bc2190c0c86d52a8 /sys/arch/i386/stand/biosboot/biosboot.8 | |
parent | b2122dc141c0f564a99477ddb15cdd9e5e457814 (diff) |
Finishing? touches.
Diffstat (limited to 'sys/arch/i386/stand/biosboot/biosboot.8')
-rw-r--r-- | sys/arch/i386/stand/biosboot/biosboot.8 | 82 |
1 files changed, 50 insertions, 32 deletions
diff --git a/sys/arch/i386/stand/biosboot/biosboot.8 b/sys/arch/i386/stand/biosboot/biosboot.8 index 638a9ce275f..6c841d96cbf 100644 --- a/sys/arch/i386/stand/biosboot/biosboot.8 +++ b/sys/arch/i386/stand/biosboot/biosboot.8 @@ -1,4 +1,4 @@ -.\" $OpenBSD: biosboot.8,v 1.3 1997/09/05 17:59:27 mickey Exp $ +.\" $OpenBSD: biosboot.8,v 1.4 1997/09/05 21:25:15 weingart Exp $ .\" .\" Copyright (c) 1997 Michael Shalayeff .\" All rights reserved. @@ -31,54 +31,73 @@ .\" .Dd September 1, 1997 .Dt BIOSBOOT 8 i386 -.Os +.Os OpenBSD 2.1 .Sh NAME .Nm biosboot .Nd primary system bootstrap program .Sh DESCRIPTION -This small program (about of 256 bytes of code) is responsible for -loading second stage +This small program (roughly 256 bytes of code) is responsible for +loading the second stage .Xr boot 8 program, which in turn, will load the kernel. -It is small, robust and takes neither input nor options. -Location of the +It is a small piece of code that takes no input or options. +.Pp +The location of the .Xr boot 8 -program is stored in the block table inside of the +program that +.Nm +loads, is stored in a block table inside the .Nm -by the +program. The .Xr installboot 8 -program, and is very machine dependant. So, you have to run +program is used to fill this table with the location of the +.Nm +program. This location is BIOS dependant, so you have to run the .Xr installboot 8 -program every time you are moving your disk between machines and/or -controllers. +program to update this table every time you move your disk between +machines and/or controllers. .Pp -When it receives control from either BIOS or MBR it will print message: +When +.Nm +receives control from either the BIOS or the MBR it will print the message: .Pp .Dl loading /boot .Pp followed by a dot for every successfully loaded block, -and then put cursor on the next line right before switching into the +and then put cursor on the next line right before switching into protected mode and transferring control to the just loaded /boot program. .Sh DIAGNOSTICS Diagnostics consist of two error messages: .Bl -tag -width read_error_ .It Er Read error Some kind of error returned by the BIOS read call. This might be -any media error. +any media error, including bad sectors (common on floppy disks), +and invalid sectors (can occur with messed up geometry translations). .It Er Bad magic -Just loaded /boot image contains bad magic in it's header. -This might indicate some kind of hardware problem. -This may also means that +The just loaded /boot image contains a bad magic in it's header. This +might indicate some kind of hardware problem, or it may mean that the .Ar boot -argument for +argument to the .Xr installboot 8 -program was actually not a valid /boot program. +command was not a valid /boot program. .El -Other common reason for those errors to appear is a wrong BIOS geometry -had been used in +.Pp +Other common reasons for these errors to appear is that a wrong BIOS geometry +has been used in .Xr installboot 8 for the device you are booting from. +.Sh NOTES +The practice of making OpenBSD use the whole disk (ie: having +.Nm +as the MBR) has been depreciated, and will not work on certain BIOS versions. +There is a lot of strange behaviour with different BIOS's, one of well +known lobotomy cases is that the BIOS does not pass the right boot drive +number to the +.Nm +program. This is one of the main reasons that having +.Nm +as the MBR has been depreciated. .Sh FILES .Bl -tag -width /usr/mdec/biosbootxx -compact .It Pa /usr/mdec/mbr @@ -86,7 +105,7 @@ Master Boot Record block .It Pa /usr/mdec/biosboot primary bootstrap .It Pa /boot -system bootstrap +secondary bootstrap .It Pa /bsd system code .El @@ -96,21 +115,20 @@ system code .Xr installboot 8 , .Xr boot 8 . .Sh BUGS -It contains fake fdisk table and the stuff, that it should not. +It contains a fake partition table and associated things that it should not. .Pp -It should check checksum over the loaded /boot image. -.Pp -There is neither BIOS error number reported nor the error location. +It should do a checksum over the loaded /boot image, and check that against +a value that +.Xr installboot 8 +has precomputed. .Pp -There is a lot of strange behaviour with different BIOSes, the one of well -known lobotomy cases is a wrong boot drive number passed to boot program -by BIOS. +There is no BIOS error number reported nor is the location of the error +reported. .Pp You can pick your motherboard, and you can pick your BIOS, but you can't pick your motherboard's BIOS. .Sh HISTORY -This program was written by Michael Shalayeff for -.Ox 2.1 . +This program was written by Michael Shalayeff for OpenBSD. However it's based on bootstrap code from older versions of this operating system, other operating systems, other programs, and -other people's works. +other people's work. |