Boot manager behavior questions

[Gary W. Swearingen]

Michael Dexter <dexter at ambidexter.com> writes:

> 1. Is there any equivalent to nextboot(8) for the boot manager such that a boot selection can be made prior to the boot
> sequence so that the choice can be made remotely instead of only at the console?

Read about "boot0cfg's -s".  And please shorten your lines.

> 2. Can anyone confirm that the "Default" behavior is simply F1 (first slice) the first time it is invoked and then any
> other choices become the next default?

The FreeBSD BMs don't behave that way.  /boot/mbr just boots the
active partition and doesn't change it.  The other is described in the
"boot0cfg" manpage.

> In theory, this should work and be the equivalent of choosing F4, right?:
>
> boot: 0:ad(0,4,a)/kernel
>
> BIOS drive 0, ata drive 0, slice 4, partition a, 5.x default boot of /kernel
>
> Alas, it only bells at me and gives me the same suggested syntax.

Wrong; it's not the equivalent.  Hitting F4 causes the bootstrap on
"s4" to run.  This normally starts /boot/loader but in some cases
produces your "boot:" prompt.  The handbook shows it in a "boot2
Screenshot".

I'm unsure why you can't get the "boot:" prompter to transfer you to
another slice.  Maybe it requires that you pass the kernel some
options.  You might have better luck asking it to start /boot/loader
which provides more gizmos for changing defaults, etc.

> Does anyone know the syntax to perform the boot-to-cd from the boot manager feat?

Not I.  And you're likely to confuse people if you use "boot manager"
like that.  FreeBSD docs call it the "stage-two bootstrap" or
something similar (even though it is seldom the second stage of the
bootstrap process).