BSP Developer's Guide

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Implementing a MUX-Based Network Interface Driver
H.2.3 Executing Calls Waiting in the Network Job Queue
The tNetTask task sleeps on an incoming work queue. In response to an incoming
packet, your interrupt service routine calls netJobAdd( ). As parameters to
netJobAdd( ), your interrupt service routine specifies your driver’s entry point for
handling task-level packet reception. The netJobAdd( ) call adds this entry point
to tNetTask’s work queue. The netJobAdd( ) call also automatically gives the
appropriate semaphore for awakening tNetTask.
Upon awakening, tNetTask dequeues function calls and associated arguments
from its work queue. It then executes these functions in its context. The tNetTask
task runs as long as there is work on its queue. When the queue is empty and all
packets have been successfully handed off to the MUX, tNetTask goes back to
sleep on the queue.
H.2.4 Adding Your Network Interface Driver to VxWorks
Adding your driver to the target VxWorks system is much like adding any other
application. The first step is to compile and include the driver code in the VxWorks
image. For a description of the general procedures, see the Tornado User’s Guide.It
tells you how to compile source code to produce target-suitable object code.
Including most software modules in the VxWorks image is usually just a matter of
setting a few #define statements. Adding a network interface driver does not
require much more. However, because VxWorks allows you to create more than
one network device, you must also set up a table that groups the #define
statements into device-specific groups. This table is defined in
target/src/config/BSP/configNet.h where BSP is the name of your Board Support
Package, such as mv162, pc486, and the like.
For example, if you wanted VxWorks to create two network devices, one that
supported buffer loaning and one that did not, you would first edit configNet.h to
include the following statements:
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/* Parameters for loading the driver supporting buffer loaning. */
#define LOAD_FUNC_0 ln7990EndLoad
#define LOAD_STRING_0 "0xfffffe0:0xffffffe2:0:1:1"
#define BSP_0 NULL
/* Parameters for loading the driver NOT supporting buffer loaning. */
#define LOAD_FUNC_1 LOAD_FUNC_0
#define LOAD_STRING_1 "0xffffee0:0xfffffee2:4:1:1"
#define BSP_1 NULL
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