member in the driver’s
probe
interface to the media state constant that
identifies the state for the media.
You can set the
lan_media
member to the same constants that are
listed for the
lan_media_mode
member in item 2.
3.4 Defining the Base Register
The base register in a network driver’s
softc
data structure is a member
that represents the base register of the device. The following code shows
the declaration of the base register in the
if_el
device driver’s
el_softc
data structure. Most network device drivers declare a variable to store the
device’s base register.
vm_offset_t basereg;
1
1
Declares a base register member and calls it
basereg
.
3.5 Defining Multicast Table Information
All multicast address information in a network driver’s
softc
data structure
is encapsulated in the
lan_multi
data structure. The following code shows
the declaration of the
lan_multi
data structure in the
if_el
device driver’s
el_softc
data structure. Most network device drivers declare this data
structure in their
softc
data structure.
struct lan_multi is_multi;
1
1
Declares a
lan_multi
data structure and calls it
is_multi
.
3.6 Defining the Interrupt Handler ID
The interrupt handler ID in a network driver’s
softc
data structure is a
variable that stores the interrupt handler ID that the
handler_add( )
routine returns. The following code shows the declaration of the interrupt
handler ID in the
if_el
device driver’s
el_softc
data structure. Make
sure that the interrupt handler ID part of your
softc
data structure has
a similar declaration.
ihandler_id_t *hid;
1
1
Declares a pointer to an ID that deregisters the interrupt handlers.
3.7 Defining CSR Pointer Information
The control and status register (CSR) addresses in a network driver’s
softc
data structure consist of specific adapter register addresses. These
registers generally consist of the base register plus some offset, as defined
by the network adapter’s hardware specification. Make sure that you never
3–6 Defining the softc Data Structure
