"options atapicam" and/or "device ATA_CAM" in kernel config?

[b. f.]

> > > What is the role of "options atapicam" and "device ATA_CAM" in kernel config file?
>
> > > Are they redundant?  Kernel will build with both these options, but will it make things go awry?  Is ATA_CAM deprecated?

They are redundant and incompatible.  atapicam is deprecated, and
ATA_CAM is the new default on FreeBSD 9 and 10. Unless you have some
special requirements, you should use ATA_CAM on recent versions of
FreeBSD, because it usually performs better than the old ATA code, and
has added functionality.

>
> Lowell Gilbert <freebsd-questions-local at be-well.ilk.org> responds:
>
> > As far as I can see, ATA_CAM isn't currently documented.
> > Just ignore it.

This is bad advice, for the reasons mentioned above.  It is briefly
documented in /usr/src/sys/conf/NOTES, and you can find more
information about it in the commit logs of the source repository, and
the mailing lists. For example:

http://svnweb.FreeBSD.org/base?view=revision&revision=195534
...
http://svnweb.FreeBSD.org/base?view=revision&revision=200171
http://svnweb.FreeBSD.org/base?view=revision&revision=220982
http://svnweb.FreeBSD.org/base?view=revision&revision=216088
http://lists.freebsd.org/pipermail/freebsd-current/2009-June/008574.html
http://lists.freebsd.org/pipermail/freebsd-current/2011-April/024110.html
...

>
> So I can say good riddance to ATA_CAM.  According to burncd man page, ATA_CAM is incompatible with burncd, also burncd was deprecated in FreeBSD 9.0.

As I wrote above, you probably do _not_ want to discard ATA_CAM on
recent versions of FreeBSD.  burncd is deprecated because it does not
work with ATA_CAM, and no one has volunteered to rewrite it yet.  You
can use a port like sysutils/cdrtools or sysutils/cdrtools-devel
instead.

> > > I am trying to burn a CD (or DVD) on a SATA DVD-RW drive, but cdrtools don't work.

Why not? Specifically, what fails?  Does your kernel include the
necessary bits, like ATA_CAM?  Have you asked the cdrtools port
maintainer for help, and sent him a verbose listing of any errors you
encounter?  There were some recent CAM changes that broke some ports
like audio/cdparanoia, but these ports will probably be fixed soon.

...

> > > Also, how do I build and install a kernel to some name other than /boot/kernel, and not build all modules in duplicate?

I think we answered these questions in the other recent thread.

...

> I don't want to upgrade FreeBSD on older computer because of shortage of disk space and only 256 MB RAM.  Portupgrading everything would be too gruesomely slow, in addition to likely running short of disk space.

You can use a faster computer to build packages for your slower
computer, or use packages from the FreeBSD mirrors.  You can also use
tools like devel/ccache to speed builds, although this requires more
disk space.  Building ports in a swap-backed memory file system like
mdmfs or tmpfs can also help, although you have to be careful when RAM
is limited.  You could work around your disk space limitations by
using a removable drive for builds, or a network-based files system
like nfs.  And if you have a number of slower computers of the same
type, you can speed up builds by having the computers work together,
with something like devel/distcc.

b.