Adjust notes to describe new boot floppy scheme.

This commit is contained in:
Jordan K. Hubbard 1999-01-31 12:55:08 +00:00
parent 50156effd9
commit c49127f127
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=43470

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@ -1,57 +1,59 @@
For a normal CDROM or network installation, all you need to copy onto an
actual floppy from this directory is the boot.flp image (for 1.44MB floppies).
For a normal CDROM or network installation, all you need to copy onto
actual floppies from this directory are the kern.flp and mfsroot.flp
images (for 1.44MB floppies).
If you're on the ALPHA then the boot.flp image is probably larger
than any kind of floppy you have available and you will need to
either netboot it, load it from some other type of media (such
as a jaz drive) or use the kern.flp image described below.
This release still uses only one installation floppy, the boot.flp
image. For convenience (and for the DEC ALPHA architecture, on which
binaries are quite a bit larger), however, we also provide the
functionality of boot.flp now "decoupled" into a kern.flp image,
which contains just the boot kernel, and mfsroot.flp, which contains
the compressed MFS root image that is normally stored as part of
the kernel itself on the boot.flp image. This allows you to boot
from kern.flp, which will fit on a 1.44MB floppy even on the alpha,
and then use mfsroot.flp from a 2nd floppy. This also allows you
to easily make your own boot or MFS floppies should you need to customize
some aspect of the installation process. As long as the kernel is compiled
with ``options MFS'' and ``options MFS_ROOT'', it will properly look for
and boot an mfsroot.flp image when run. The mfsroot.flp image is simply
a gzip'd filesystem image, something which can be made rather
easily using vnconfig(8). If none of this makes any sense to you,
don't worry about it - just use the boot.flp image as always; nothing
has changed there.
NOTE: The *.flp images are NOT DOS files! You cannot simply copy them
to a DOS or UFS floppy as regular files, you need to *image* copy them
to the floppy with fdimage.exe under DOS or `dd' under UNIX.
Get two blank, freshly formatted floppies and image copy kern.flp
onto one and mfsroot.flp onto the other. These images are NOT DOS
files! You cannot simply copy them to a DOS or UFS floppy as
regular files, you need to "image" copy them to the floppy with
fdimage.exe under DOS (see the tools/ directory on your CDROM or
FreeBSD FTP mirror) or the `dd' command in UNIX.
For example:
To create the boot floppy image from DOS, you'd do something like
To create the kern floppy image from DOS, you'd do something like
this:
C> fdimage boot.flp a:
Assuming that you'd copied fdimage.exe and boot.flp into a directory
somewhere. If you were doing this from the base of a CD distribution,
then the *exact* command would be:
E> tools\fdimage floppies\boot.flp a:
C> fdimage kern.flp a:
Assuming that you'd copied fdimage.exe and kern.flp into a directory
somewhere. You would do the same for mfsroot.flp, of course.
If you're creating the boot floppy from a UNIX machine, you may find
that:
dd if=floppies/boot.flp of=/dev/rfd0
dd if=floppies/kern.flp of=/dev/rfd0
or
dd if=floppies/boot.flp of=/dev/floppy
dd if=floppies/kern.flp of=/dev/floppy
work well, depending on your hardware and operating system environment
(different versions of UNIX have totally different names for the
floppy drive - neat, huh? :-).
If you're on an ALPHA machine which netboots its floppy images or
you have a 2.88MB or LS-120 floppy capable of taking a 2.88MB image
on an x86 machine, you may still wish to use the older (but now
twice as large) boot.flp image which we also provide. That contains
the contents of kern.flp and mfsroot.flp on a single floppy,
essentially, and can be used in all of the above scenarios as well
as a handy boot image for those mastering "El Torito" bootable CD
images. See the mkisofs(1) command for more information.
Going to two installation boot floppies is a step we definitely
would have rather avoided but we simply no longer could due to
general code bloat and FreeBSD's many new device drivers in GENERIC.
One positive side-effect of this new organizational scheme, however,
is that it also allows one to easily make one's own kern or MFS
floppies should a need to customize some aspect of the installation
process or use a custom kernel for an otherwise unsupported piece of
hardware arise. As long as the kernel is compiled with
``options MFS'' and ``options MFS_ROOT'', it will properly look for
and boot an mfsroot.flp image in memory when run (see how the
/boot/loader.rc file in kern.flp does its thing). The mfsroot.flp
image is also just a gzip'd filesystem image which is used as root,
something which can be made rather easily using vnconfig(8).
If none of that makes any sense to you then don't worry about it -
just use the kern.flp and mfsroot.flp images as described above.