Custom kernel config questions for Linux user

Giorgos Keramidas keramida at
Thu Jun 23 01:25:38 GMT 2005

On 2005-06-22 18:04, Garrett Cooper <youshi10 at> wrote:
> Hello,
>    I was wondering if anyone could provide me an answer to the
> following questions. Please keep in mind that by default I learned Unix
> on a Linux system, so... please no flames :(.

That's ok.  I was also a Linux user for a long time before I switched
exclusively to FreeBSD somewhere around 1999.

>    1) Is there any sort of configuration interface (ncurses, X, etc),
> or am I 'stuck' with 'manually configuring' a textfile?

Yes.  It may seem daunting or "primitive" at first, but eventually you
may start enjoying the fact that you don't constantly have to fight with
multilevel, deeply nested, ever changing manu hierarchies to find that
particular option that you know exists somewhere, but for the life of
you can't right now remember where :-)

Being able to just fire up your favorite editor and search using common
"search" operations for strings like "disk", or "usb" (possibly
repeating the search within the rest of the file with a single
keystroke), is actually very very cool, once you get the hang of it.

>    2) Is there a complete list of features which can be enabled for the
> kernel, other what was in the GENERIC configuration file?

The GENERIC configuration file is just, well, a "generic" configuration
file that is used as the kernel configuration when preparing the FreeBSD
release CD-ROMs.  It also serves as a common reference point for
troubleshooting, which is a lot easier when there is a single "reference
config" instead of a billion, custom, personalized configuration sets.

Note that I'm not arguing that Linux *does*, in fact, use ``a billion,
custom, personalized configuration sets''.  Just that this is one of the
roles GENERIC fulfills.

In general, modern versions of FreeBSD include at least the following too:


The first is the complete set of machine & architecture-independent
options that the kernel supports.

The files described by the second set are currently:

% # ls -l /usr/src/sys/*/conf/NOTES
% -rw-r--r--  1 root  wheel   2160 Nov 11  2004 /usr/src/sys/alpha/conf/NOTES
% -rw-r--r--  1 root  wheel  15923 Jun 16 01:53 /usr/src/sys/amd64/conf/NOTES
% -rw-r--r--  1 root  wheel  33439 Jun 23 04:18 /usr/src/sys/i386/conf/NOTES
% -rw-r--r--  1 root  wheel   1781 Feb 26 10:33 /usr/src/sys/ia64/conf/NOTES
% -rw-r--r--  1 root  wheel  24728 May 27 02:06 /usr/src/sys/pc98/conf/NOTES
% -rw-r--r--  1 root  wheel   3344 Jun 11 03:26 /usr/src/sys/sparc64/conf/NOTES

and they contain architecture-dependent options for the specific

>    3) What is needed for the FreeBSD kernel and what modules need to be
> compiled in order to use IDE CD-burning. In linux previous to kernel
> version 2.6.8 I know that SCSI was required, but now they are doing
> proper IDE emulation.

Look up the descriptions of the following options:

% device          scbus           # SCSI bus (required for SCSI)
% device          cd              # CD
% device          pass            # Passthrough device (direct SCSI access)
% device          atapicam        # emulate ATAPI devices as SCSI ditto via CAM
%                                 # needs CAM to be present (scbus & pass)

This should get you started for now.  This list exists specifically for
asking questions about FreeBSD, what it is, how it works, etc.  Please,
if you need to, feel free to ask any questions.

Welcome to FreeBSD :-)

- Giorgos

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