Implementing The Initialization Section; Implementing The El_Init Routine; Setting Up The El_Init Routine - Compaq Tru64 UNIX Installation Manual

Implementing the Initialization Section

The initialization section prepares the network interface to transmit and
receive data packets. It can also allocate mbuf data structures for the
receive ring.
The if_el device driver implements the following routines in its
initialization section:
• el_init (Section 8.1)
• el_init_locked (Section 8.2)

8.1 Implementing the el_init Routine

The el_init( ) routine is a jacket routine that performs the following tasks:
• Determines whether the PCMCIA card is in the slot (Section 8.1.2)
• Sets the IPL and obtains the simple lock (Section 8.1.3)
• Calls the el_init_locked( ) routine to perform the initialization
(Section 8.1.4)
• Releases the simple lock and resets the IPL (Section 8.1.5)
• Returns the status from el_init_locked( ) (Section 8.1.6)

8.1.1 Setting Up the el_init Routine

The following code shows how to set up the el_init( ) routine:
static int el_init(int unit) 1
{
register struct el_softc *sc = el_softc[unit];
register struct ifnet *ifp = &sc->is_if;
int i, s; 4
Specifies the unit number of the network interface as the only argument
1
to el_init( ).
Declares a pointer to the el_softc data structure called sc and
2
initializes it to the el_softc data structure for this device. The
controller number (which is stored in the unit variable) is used as an
index into the array of el_softc data structures to determine which
el_softc data structure is for this device.
2
3
Implementing the Initialization Section 8–1
8