Date: Fri, 11 Aug 2000 11:41:54 -0700 (PDT) From: John Baldwin <jhb@pike.osd.bsdi.com> To: John Reynolds~ <jreynold@sedona.ch.intel.com> Cc: questions@FreeBSD.org Subject: Re: diff between fdisk, boot0cfg, and disklabel -B? (was Re: recompiling boot blocks & serial console) Message-ID: <200008111841.LAA22766@pike.osd.bsdi.com> In-Reply-To: <14740.12435.310805.691257@hip186.ch.intel.com> from John Reynolds~ at "Aug 11, 2000 09:57:55 am"
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John Reynolds~ wrote: > > > On Thu, 10 Aug 2000, Mike Smith wrote: > > > > You need to recompile the bootblocks to change the baudrate; set > > BOOT_COMCONSOLE_SPEED in /etc/make.conf, then do: > > > > # cd /sys/boot > > # make clean cleandepend > > # make depend && make && make install > > # disklabel -B <boot device> > > Good information! > > Question: What is the difference between the "-B" option of disklabel, fdisk, > and boot0cfg? They seem to do the same thing from reading the man pages but > recently I was not able to use "disklabel -B" when using the "fixit" > floppy. jhb said "use boot0cfg -B". I did and it worked. > > I'm just wondering why there are 3 programs with seemingly the same option and > if they are not the same, how do they differ? They don't all do the same thing. :) fdisk -B and boot0cfg -B do do the same thing in that they both install MBR boot loaders, which are only present on x86 machines. This is the code that chooses which slice to boot from. disklabel -B sets the FreeBSD boot loaders, which are inside the FreeBSD slice itself. Maybe this diagram can help: disk start disk end -------------------------------------------------------------------------- | MBR | FreeBSD slice | Windows slice | -------------------------------------------------------------------------- | boot0 | boot1 | FreeBSD data | FAT | Windows data | --------| disklabel | |------------------------------- | boot2 | | ----------------------------------- The reason that both boot0cfg and fdisk have -B, is that fdisk -B is a general tool for configuring the slice table in the MBR and installing MBR boot loaders. boot0cfg is a tool for installing and configuring boot0, which is a specific MBR boot loader. The -B option is the one place in which those two programs' functionality overlap. HTH. > Thanks, > > -Jr -- John Baldwin <jhb@bsdi.com> -- http://www.FreeBSD.org/~jhb/ PGP Key: http://www.cslab.vt.edu/~jobaldwi/pgpkey.asc "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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