/boot/ directory path

Barry Bouwsma freebsd-misuser at remove-NOSPAM-to-reply.NOSPAM.dyndns.dk
Mon Aug 9 15:28:32 PDT 2004

[drop direct replies to me for your convenience]

> > I'd like to change the path /boot/ under which all sorts of
> > things can be found to, well, something else like /dboot/ .
> > Why?  Because I'd like to work around BIOS limitations of

> Have you thought about mounting /boot from that disk directly and
> place a symbolic link (/boot/boot -> ..) into it? It should be enough
> to make loader(8) happy

I'm not sure that I understand.  In order to mount /boot, I
would already have needed to be booted into the OS, oder?
Or is this something that can be done as part of the boot
process, perhaps in loader?

If so, I believe that the boot0-2 and loader all depend on
the BIOS to do disk access.  In my present case, my system
drive is an external USB/firewire disk, and the BIOSen which
I have at hand, among which I swap system disks, require me to
settle for a lowest-common-denominator of CHS geometry, with
1024C limit.  At best I could access floppy, IDE drives, or
with controller, SCSI, but I don't have any hardware with
BIOS access to USB- or firewire-attached devices.

I'd be happy to know if what you are suggesting would in fact
be possible for me, but I'm pretty sure that I have a chicken-
and-egg problem, in that the BIOS support needed doesn't
cover the hardware I want to use, while as soon as loader
gets the kernel running, I have no problems accessing any
hardware the kernel supports.

>  , boot2 might not work though. But if you want
> > to use grub or so anyway, no problem. Try to avoid putting the whole
> > module directory on the disk, it's very big.

It's not so much that I *want* to use `grub', it's just
that I decided to try it for laughs, and it appears to offer
flexibility missing from the other bootloaders (though it
has a few things missing too).  Like booting me directly
into `memtest' from my FreeBSD partition.  As it bypasses
boot0-boot2 entirely and handles /boot/loader (or whatever
you tell it to as the kernel to boot) directly, that gave
me the hair-brained idea of trying different paths.

Of course, the only things I need on the disk where the
real loader is found, would be the modules loaded before
booting the kernel (interfaces and the like), while any
modules needed later (nullfs, unionfs, and so on) can
happily remain in the /boot or /dboot path on the mounted
system drive, where I think they can be happily loaded

Naturally, one has to keep the /dboot directory which
is used at boot by the internal drive in sync with the
/dboot or /boot directory on the actual root filesystem
that gets mounted later from the external (or whatever)

barry bouwsma

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