BHA(4) BSD Programmer's Manual BHA(4)NAMEbha - BusLogic 32 bit SCSI host adapter driver
SYNOPSIS
bha0 at pci*
bha0 at isa0 port 0x330
DESCRIPTION
The bha driver is a software interface to the BusLogic line of 32-bit
host adapters for the Small Computer Systems Interface (X3.131-1992) bus.
The software interface to the 32-bit BusLogic adapters is very similar to
the interface for the Adaptec AHA-1542B (see aha(4)), with extensions to
support full 32 bit addressing. This eliminates the need for bounce
buffers on systems with more than 16 megabytes of physical memory.
CONFIGURATION
Older Buslogic PCI controllers are not fully PCI compliant and have to be
configured at a port on the ISA bus.
bha0 at isa0 port 0x330
Newer controllers are fully PCI compliant and can be configured on the
PCI bus.
bha0 at pci*
The newer controllers have a compatability mode which allows them to also
be found on the ISA bus. Prior to BSD/OS 3.1 this was the only way these
boards could be operated. In this mode the boards show up both on the ISA
and PCI bus. These boards must be found on the PCI bus first to avoid
them being found on both the PCI and ISA bus. In order to do this the PCI
config line
bha0 at pci*
must precede the ISA config line
bha0 at isa0 port 0x330
in the configuration file.
BOOT PARAMETERS
There are now parameters which are configurable from boot(8) with the
-parm command. Typically these commands would be added to boot.default(5)
though they can be set at the ``boot:'' prompt.
Many of the parameters take as an argument one or more target ids. The
following are permissible arguments to these parameters:
t0 target 0.
target0 target 0.
t1 target 1.
target1 target 1.
t2 target 2.
target2 target 2.
.
.
.
t14 target 14
target14 target 14
t15 target 15
target15 target 15
all targets 0 through 15
none no targets
The following parameters take a list of target specifiers as an argu-
ment(s):
single_lun
For these targets only look at lun 0.
-parm bha* single_lun=none #default
-parm bha* single_lun=all
tags These targets will use tag queueing if supported by the
target. See sd(4) for caveats on its use. Examples:
-parm bha* tags=none #default
-parm bha1 tags=all-t1 #all but target 1
-parm bha0 tags=t0,t1,t2 #targets 0, 1 and 2.
The following parameter takes a numeric value as an argument:
reset_delay
This is used to control the number of seconds of delay
which is inserted after the SCSI bus is reset at boot time.
-parm bha* reset_delay=5 #default
-parm bha* reset_delay=1 #1 second reset delay
-parm bha* reset_delay=0 #no delay after reset
SEE ALSOaha(4), sd(4), sg(4), st(4)BUGS
Some versions of BusLogic firmware return error codes which are not docu-
mented. It is unclear if these are even errors.
Many users have experience problems with the BT946 on systems with any-
thing but the best of cabling.
BSDI BSD/OS August 8, 1997 2
