1Boot Manager Selection:
2-----------------------
3
4If you wish to switch between multiple operating systems on your
5machine, or if you are trying to install FreeBSD on a drive other than
6your 1st drive, then you must install a boot manager.  In the case
7where you wish to boot off an alternate drive, it should also be noted
8that you still need to install a boot manager on the FIRST drive!
9Even if you do not intend to create a FreeBSD partition on that drive
10(e.g. it's being wholly used by something else), the boot manager
11still needs to reside on the first disk in order to function as a
12"redirector" for the boot process.
13
14To do this, simply select your 1st drive in the drive selection menu
15and when the partition editor comes up, don't make any changes - just
16(Q)uit.  At the boot manager menu which follows, select the first
17option (install a boot manager) and then proceed to setup the other
18drive(s) for FreeBSD as normal.
19
20It should also be noted that "operating systems" such as Windows 95
21will completely overwrite your boot manager without so much as a
22polite "may I please destroy your boot manager?" prompt if you make
23the mistake of installing them second.  If this happens to you after
24FreeBSD is already installed, all is not lost!  Simply revisit your
25FreeBSD distribution directory and look for a tools/ subdirectory, in
26which you'll find "bootinst.exe" and "boot.bin".  To reinstall, simply
27say "bootinst boot.bin" while in the tools/ subdirectory.
28
29
30If you see the boot manager displaying ``F?'' when you try to come up
31for the first time and it refuses to change, no matter how often you
32whap on the function key assigned to FreeBSD, then you have a geometry
33mismatch problem and you should read the next section for important
34information on how to prevent that exact problem from happening!
35
36
37Geometry Translation / Sharing the disk(s) with another OS:
38----------------------------------------------------------
39
40If you are going to actually install some portion of FreeBSD on a
41drive then PLEASE BE VERY CERTAIN that the Geometry reported in the
42Partition Editor is the correct one for your drive and controller
43combination!
44
45IDE drives often have a certain geometry set during the PC BIOS setup,
46or (in the case of larger IDE drives) have their geometry "translated"
47by either the IDE controller or a special boot-sector translation
48utility such as that by OnTrack Systems.  In these cases, knowing the
49correct geometry gets even more complicated as it's not something you
50can easily tell by looking at the drive or the PC BIOS setup.  The
51best way of verifying that your geometry is being correctly calculated
52in such situations is to boot DOS (from the hard disk, not a floppy!)
53and run the ``pfdisk'' utility provided in the tools/ subdirectory of
54the FreeBSD CDROM or FTP site.  It will report the geometry that DOS
55sees, which is generally the correct one.
56
57If you have no DOS partition sharing the disk at all, then you may
58find that you have better luck with Geometry detection if you create a
59very small DOS partition first, before installing FreeBSD.  Once
60FreeBSD is installed you can always delete it again if you need the
61space.
62
63It's actually not a bad idea (believe it or not) to have a small
64bootable DOS partition on your FreeBSD machine anyway: Should the
65machine become unstable or exhibit strange behavior at some point in
66the future (which is not uncommon behavior for PC hardware!) you can
67then at least use DOS for installing and running one of the
68commercially available system diagnostic utilities.
69
70IMPORTANT NOTE:
71
72Any root partition you try to boot from must also reside below the
731024th cylinder.  If you're using a translated geometry then this is
74probably not a problem, but if you are using a native disk geometry
75which exceeds 1024 cylinders then you could have a failure to boot if
76you end up installing a root partition (or even just the kernel file
77in a root partition) out past cylinder 1024.  If you are trying to
78share your first disk with FreeBSD and another OS which was installed
79previously, you are particularly susceptible to this problem and should
80check your disk addresses very carefully.
81
82If you find that you have insufficient space below cylinder 1024 to
83make a root partition for FreeBSD (and again, this ONLY applies to the
84root partition - once FreeBSD's kernel is loaded, it doesn't care
85about the geometry issues) then you will probably need to install on a
86completely different disk (see the boot manager section above) or
87resize your existing partitions so that both operating systems can
88have boot partitions below cylinder 1024.
89
90You may blame IBM for the limitations of a 10 bit cylinder address.
91"No one will have a disk with more than 1024 cylinders." I'm sure
92someone said.
93