sysbus(4) File Formats sysbus(4)NAME
sysbus, isa - device tree properties for ISA bus device drivers
DESCRIPTION
Solaris for x86 supports the ISA bus as the system bus. Drivers for
devices on this buse use the device tree built by the booting system to
retrieve the necessary system resources used by the driver. These
resources include device I/O port addresses, any interrupt capabilities
that the device can have, any DMA channels it can require, and any mem‐
ory-mapped addresses it can occupy.
Configuration files for ISA device drivers are only necessary to
describe properties used by a particular driver that are not part of
the standard properties found in the device tree. See driver.conf(4)
for further details of configuration file syntax.
The ISA nexus drivers all belong to class sysbus. All bus drivers of
class sysbus recognize the following properties:
interrupts An arbitrary-length array where each element of the
array represents a hardware interrupt (IRQ) that is
used by the device. In general, this array only has
one entry unless a particular device uses more than one
IRQ.
Solaris defaults all ISA interrupts to IPL 5. This
interrupt priority can be overridden by placing an
interrupt-priorities property in a .conf file for the
driver. Each entry in the array of integers for the
interrupt-priorities property is matched one-to-one
with the elements in the interrupts property to specify
the IPL value that is used by the system for this
interrupt in this driver. This is the priority that
this device's interrupt handler receives relative to
the interrupt handlers of other drivers. The priority
is an integer from 1 to 16. Generally, disks are
assigned a priority of 5, while mice and printers are
lower, and serial communication devices are higher,
typically 7. 10 is reserved by the system and must not
be used. Priorities 11 and greater are high level pri‐
orities and are generally not recommended (see
ddi_intr_hilevel(9F)).
The driver can refer to the elements of this array by
index using ddi_add_intr(9F). The index into the array
is passed as the inumber argument of ddi_add_intr().
Only devices that generate interrupts have an inter‐
rupts property.
reg An arbitrary-length array where each element of the
array consists of a 3-tuple of integers. Each array
element describes a contiguous memory address range
associated with the device on the bus.
The first integer of the tuple specifies the memory
type, 0 specifies a memory range and 1 specifies an I/O
range. The second integer specifies the base address of
the memory range. The third integer of each 3-tuple
specifies the size, in bytes, of the mappable region.
The driver can refer to the elements of this array by
index, and construct kernel mappings to these addresses
using ddi_map_regs(9F). The index into the array is
passed as the rnumber argument of ddi_map_regs().
All sysbus devices have reg properties. The first
tuple of this property is used to construct the
address part of the device name under /devices. In the
case of Plug and Play ISA devices, the first tuple is a
special tuple that does not denote a memory range, but
is used by the system only to create the address part
of the device name. This special tuple can be recog‐
nized by determining if the top bit of the first inte‐
ger is set to a one.
The order of the tuples in the reg property is deter‐
mined by the boot system probe code and depends on the
characteristics of each particular device. However,
the reg property maintains the same order of entries
from system boot to system boot. The recommended way
to determine the reg property for a particular device
is to use the prtconf(1M) command after installing the
particular device. The output of the prtconf command
can be examined to determine the reg property for any
installed device.
You can use the ddi_get* and ddi_put* family of func‐
tions to access register space from a high-level inter‐
rupt context.
dma-channels A list of integers that specifies the DMA channels used
by this device. Only devices that use DMA channels have
a dma-channels property.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Architecture │x86 │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOprtconf(1M), driver.conf(4), scsi(4), attributes(5), ddi_add_intr(9F),
ddi_intr_hilevel(9F), ddi_map_regs(9F), ddi_prop_op(9F)
Writing Device Drivers
SunOS 5.10 18 Nov 2004 sysbus(4)
