Bug 12655

The kernel build file  /usr/src/sys/i386/conf/GENERIC is a good way to configure the  kernel but lacks sufficent comments.  I have included a copy of my kernel config which is extensivly, though not totaly, commented.

Fix: 

#
# GENERIC -- Generic machine with WD/AHx/NCR/BTx family disks
#
# For more information read the handbook part System Administration -> 
# Configuring the FreeBSD Kernel -> The Configuration File. 
# The handbook is available in /usr/share/doc/handbook or online as
# latest version from the FreeBSD World Wide Web server 
# <URL:http://www.FreeBSD.ORG/>
#
# An exhaustive list of options and more detailed explanations of the 
# device lines is present in the ./LINT configuration file. If you are 
# in doubt as to the purpose or necessity of a line, check first in LINT.
#
#	$Id: GENERIC,v 1.143.2.2 1999/02/15 02:50:07 des Exp $

machine		"i386"		# Archetecture deffinition of a PC
cpu		"I386_CPU"	# Processor class delete as applicable
cpu		"I486_CPU"	#
cpu		"I586_CPU"      # e.g AMD K-6
cpu		"I686_CPU"      # e.g Pent II
ident		GENERIC		# define your kernel name
maxusers	32		# set process table limit

options		MATH_EMULATE		#Support for x87 emulation
options		INET			#InterNETworking
options		FFS			#Berkeley Fast Filesystem
options		FFS_ROOT		#FFS usable as root device [keep this!]
options		MFS			#Memory Filesystem
options		MFS_ROOT		#MFS usable as root device, "MFS" req'ed
options		NFS			#Network Filesystem
options		NFS_ROOT		#NFS usable as root device, "NFS" req'ed
options		MSDOSFS			#MSDOS Filesystem
options		"CD9660"		#ISO 9660 Filesystem
options		"CD9660_ROOT"		#CD-ROM usable as root. "CD9660" req'ed
options		PROCFS			#Process filesystem
options		"COMPAT_43"		#Compatible with BSD 4.3 [KEEP THIS!]
options		SCSI_DELAY=15000	#Be pessimistic about Joe SCSI device
options		UCONSOLE		#Allow users to grab the console
options		FAILSAFE		#Be conservative
options		USERCONFIG		#boot -c editor
options		VISUAL_USERCONFIG	#visual boot -c editor

config		kernel	root on wd0	#define the location of the kernel

# To make an SMP kernel, the next two are needed
#options	SMP			# Symmetric MultiProcessor Kernel
#options	APIC_IO			# Symmetric (APIC) I/O
# Optionally these may need tweaked, (defaults shown):
#options	NCPU=2			# number of CPUs
#options	NBUS=4			# number of busses
#options	NAPIC=1			# number of IO APICs
#options	NINTR=24		# number of INTs

controller	isa0	#Compulsary
controller	eisa0	#Problably compulsary
controller	pci0	#Include if you have a PCI motherboard

controller	fdc0	at isa? port "IO_FD1" bio irq 6 drq 2
disk		fd0	at fdc0 drive 0
disk		fd1	at fdc0 drive 1

options		"CMD640"	# work around CMD640 chip deficiency
controller	wdc0	at isa? port "IO_WD1" bio irq 14
disk		wd0	at wdc0 drive 0
disk		wd1	at wdc0 drive 1

controller	wdc1	at isa? port "IO_WD2" bio irq 15
disk		wd2	at wdc1 drive 0
disk		wd3	at wdc1 drive 1

options		ATAPI		#Enable ATAPI support for IDE bus
options		ATAPI_STATIC	#Don't do it as an LKM
device		acd0		#IDE CD-ROM
device		wfd0		#IDE Floppy (e.g. LS-120)

# A single entry for any of these controllers (ncr, ahb, ahc) is
# sufficient for any number of installed devices.
controller	ncr0	#NCR SCSI controller
controller	ahb0	#Adaptec 174x SCSI controller
controller	ahc0	#Adaptec 274x/284x/294x SCSI controller
controller	isp0	#Unknown SCSI controller

# This controller offers a number of configuration options, too many to
# document here  - see the LINT file in this directory and look up the
# dpt0 entry there for much fuller documentation on this.
controller      dpt0	#DPT RAID controller

controller	adv0	at isa? port ? cam irq ? # Unknown SCSI
controller	adw0	 # Unknown SCSI
controller	bt0	at isa? port ? cam irq ? # Buslogic SCSI
controller	aha0	at isa? port ? cam irq ? # Adaptec 154X SCSI
#controller	aic0	at isa? port 0x340 bio irq 11 #Adaptec sound card

controller	scbus0	#Include for SCSI support

device		da0	#Direct Access HDD

device		sa0	#Serial Access (SCSI Tape)

device		pass0	#CAM passthrough driver

device		cd0	#SCSI CD-ROM
#Only need one of these, the code dynamically grows

#Wangtec tape drive
device		wt0	at isa? port 0x300 bio irq 5 drq 1

#Mitsumi CD-ROM
device		mcd0	at isa? port 0x300 bio irq 10

#Matushita CD-ROM controller
controller	matcd0	at isa? port 0x230 bio

#Sony CDU31/33A CDROM
device		scd0	at isa? port 0x230 bio

# atkbdc0 controlls both the keyboard and the PS/2 mouse
controller	atkbdc0	at isa? port IO_KBD tty
device		atkbd0	at isa? tty irq 1
device		psm0	at isa? tty irq 12

# The video card driver.
device		vga0	at isa? port ? conflicts

# splash screen/screen saver
pseudo-device	splash

# syscons is the default console driver, resembling an SCO console
device		sc0	at isa? tty

# Enable this and PCVT_FREEBSD for pcvt vt220 compatible console driver
#device		vt0	at isa? tty
#options		XSERVER			# support for X server
#options		FAT_CURSOR		# start with block cursor
# If you have a ThinkPAD, uncomment this along with the rest of the PCVT lines
#options		PCVT_SCANSET=2		# IBM keyboards are non-std

#Math co-processer REQUIRED!!
device		npx0	at isa? port IO_NPX irq 13

#
# Laptop support (see LINT for more options)
# Advanced power management
device		apm0    at isa?	disable	flags 0x31 # Advanced Power Management

# PCCARD (PCMCIA) support
#controller	card0
#device		pcic0	at card?
#device		pcic1	at card?

#Serial com's port
device		sio0	at isa? port "IO_COM1" flags 0x10 tty irq 4
device		sio1	at isa? port "IO_COM2" tty irq 3
device		sio2	at isa? disable port "IO_COM3" tty irq 5
device		sio3	at isa? disable port "IO_COM4" tty irq 9

# Parallel port
device		ppc0	at isa? port? net irq 7
controller	ppbus0
device		nlpt0	at ppbus?
device		plip0	at ppbus?
device		ppi0	at ppbus?
#controller	vpo0	at ppbus?

# Order is important here due to intrusive probes, do *not* alphabetize
# this list of network interfaces until the probes have been fixed.
# Right now it appears that the ie0 must be probed before ep0. See
# revision 1.20 of this file.
device ax0	# Unknown PCI NIC
device de0	# Digital Equipment NIC
device fxp0	# Intel EtherExpress Pro/100B
device mx0	# Unknown PCI NIC
device pn0	# Unknown PCI NIC
device rl0	# Unknown PCI NIC
device tl0	# Unknown PCI NIC
device tx0	# Unknown PCI NIC
device vr0	# Unknown PCI NIC
device vx0	# 3Com 3C590 and 3C595 (buggy) 
device wb0	# Unknown PCI NIC
device xl0	# 3com 3C905B and related

device ed0 at isa? port 0x280 net irq 10 iomem 0xd8000
#Many common ISA Novell 3com HP and Western Digital

device ie0 at isa? port 0x300 net irq 10 iomem 0xd0000
#AT&T StarLAN 10 and EN100; 3Com 3C507; unknown NI5210; Intel
#EtherExpress 16 

device ep0 at isa? port 0x300 net irq 10
#3Com 3C509 (buggy)

device ex0 at isa? port? net irq?
#Unknown NIC

device fe0 at isa? port 0x300 net irq ?
#Fujitsu MB86960A/MB86965A Ethernet 

device le0 at isa? port 0x300 net irq 5 iomem 0xd0000
#Digital Equipment EtherWorks 2 and EtherWorks 3

device lnc0 at isa? port 0x280 net irq 10 drq 0
#Lance/PCnet cards (Isolan, Novell NE2100, NE32-VL) 

device ze0 at isa? port 0x300 net irq 10 iomem 0xd8000
#IBM/National Semiconductor PCMCIA ethernet controller. 

device zp0 at isa? port 0x300 net irq 10 iomem 0xd8000
#3Com PCMCIA Etherlink III 

device cs0 at isa? port 0x300 net irq ?
#Unknown ISA NIC

pseudo-device	loop		#generic loopback device for TCP/IP
pseudo-device	ether		#only needed if you have an Ethernet card
pseudo-device	sl	1	#Unknown
pseudo-device	ppp	1	#Kernel PPP
pseudo-device	tun	1	#Kernel tunnel driver (PPP)
pseudo-device	pty	16	#limit the number of simultaneous remote logins
pseudo-device	gzip		# Exec gzipped a.out's

# KTRACE enables the system-call tracing facility ktrace(2).
# This adds 4 KB bloat to your kernel, and slightly increases
# the costs of each syscall.
options		KTRACE		#kernel tracing

# This provides support for System V shared memory and message queues.
#
options		SYSVSHM
options		SYSVMSG

#  The `bpfilter' pseudo-device enables the Berkeley Packet Filter.  Be
#  aware of the legal and administrative consequences of enabling this
#  option.  The number of devices determines the maximum number of
#  simultaneous BPF clients programs runnable.
#pseudo-device	bpfilter 4	#Berkeley packet filter


# USB support
#controller    uhci0
#controller    ohci0
#controller    usb0
#
# for the moment we have to specify the priorities of the device
# drivers explicitly by the ordering in the list below. This will
# be changed in the future.
#
#device        ums0
#device        ukbd0
#device        ulpt0
#device        uhub0
#device        ucom0
#device        umodem0
#device        hid0
#device        ugen0

#
#options       USB_DEBUG
#options       USBVERBOSE
How-To-Repeat: Not applicable, though to understand the problem you need to hav tried to produce a realy leen kernel.