AUTOCONF(4) BSD Programmer's Manual AUTOCONF(4)NAME
autoconf - diagnostics from the autoconfiguration code
DESCRIPTION
When the system bootstraps it probes the innards of the machine on which
it is running and locates controllers, drives, and other devices. Each
item found is recorded on the console. This procedure is driven by a
system configuration table which is processed by config(8) and compiled
into each kernel.
Devices are located by probing to see if their control-status registers
respond. If not, they are silently ignored. If the control status reg-
ister responds but the device cannot be made to interrupt, a diagnostic
warning may be printed on the console and either the device will not be
available to the system, or a default interrupt level will be assumed.
Alternatively, interrupt autoconfiguration may be bypassed by assigning a
fixed interrupt level (``irq'') in the kernel configuration file. The
configuration information may also include the location and size of de-
vice memory, which is also checked when probing the device, and/or a dma
channel (``drq''). Some configuration parameters must be set to agree
with the hardware configuration. Other parameters may cause the hardware
to be configured according to the kernel configuration. See the individ-
ual manual pages for the devices for configuration information.
Options are available to obtain additional information about the autocon-
figuration process and/or to avoid probing individual devices. This is
controlled by the -autodebug value given to the boot program (see
boot(8)). A value of 1 causes verbose output including each device and
location probed and the outcome. The autoconfiguration output is pagi-
nated in this mode, requiring a key to be pressed after each screen. A
value of 2 causes confirmation to be requested before probing each device
and location in addition to the verbose output. These options may be
useful in debugging failures during autoconfiguration.
Normally, the system uses the disk partition from which it was loaded as
the root filesystem. If the RB_DFLTROOT option is specified (see
reboot(2)), the system will instead use the pre-configured root device.
If a GENERIC system is booted with the RB_ASKNAME option, then the name
of the root device is read from the console terminal at boot time, and
any available device may be used.
DIAGNOSTICS
isa0 (root) The primary system bus is an ISA bus.
isa0 (root): eisa The primary system bus is an EISA bus.
%s%d at isa0 iobase 0x%x irq %d drq %d %s%d0 %s%d1 A device with the
specified i/o base address, interrupt level, dma request level and memory
mapped region was found. Fields that are meaningless for a particular
device are omitted.
Warning: probe of %s%d may have modified ports 0x%x - 0x%x, already in
use An attempt to probe a device failed because some of the ports re-
quired had already been claimed by a previous device. This could cause
problems in operation of the device owning the ports in the specified
range.
fd%d at fdc%d slave %d A floppy disk attached to the specified floppy
controller was found.
wd%d at wdc%d slave %d A winchester disk attached to the specified con-
troller was found.
%s%d at tg%d unit %d: inquiry-info A SCSI disk or tape was found at the
specified SCSI target number. The inquiry-info is the string returned by
the SCSI Inquiry command.
SEE ALSOintro(4), boot(8), config(8)HISTORY
The autoconf feature first appeared in 4.1BSD. The current version is
based on work done at Lawrence Berkeley Laboratory.
BSD/OS October 31, 1994 2