RAM 6.0 BUX II Series Betriebsanweisung PDF herunterladen (Seite 110)

VxWorks

BSP Developer’s Guide, 6.0

102

For more information about adding support for devices, refer to the VxWorks

Device Driver Developer’s Guide.

Generic Driver Introduction

This section provides guidelines for writing generic drivers for the handful of

devices that are common to most BSPs. Although BSPs can differ considerably in

detail, there are some needs that are common to almost all BSPs. For example, most

BSPs require a serial device driver or a timer driver. Ideally, the drivers for these

devices are generic enough to port to a new BSP with a simple recompilation. This

reuse of code reduces maintenance overhead and lets the developer focus on other

efforts.

To help you use generic drivers across multiple similar BSPs, your VxWorks

installation includes source for generic drivers located in the target/src/drv

directory. At compile time, sysLib.c (a file duplicated in every BSP) can include

generic drivers from the target/src/drv directory as needed. As you develop

drivers for your BSP, strive to create drivers that are generic enough to service

multiple BSPs. These drivers can be added to vendor-specific subdirectories in the

target/src/drv directory, as specified in the following note.

However, if you are dealing with atypical hardware or legacy code, it may not be

practical to use a generic driver. Certain hardware designs are just too unique to

work with a generic driver and, although it is sometimes possible to use a generic

driver with legacy code, reworking the BSP to use a generic driver may not be

worth the effort. This is especially true if you are only upgrading the BSP to a new

release of VxWorks. If you are unable to use a generic driver, you must create or

maintain a BSP-specific driver. This type of driver does not reside in the

target/src/drv directory but is kept in a BSP-specific directory (so that the BSP’s

sysLib.c can include the driver when needed).

NOTE: Wind River reserves the right to add files to the target/src/drv

subdirectories. However, if you write a generic driver for use with multiple BSPs,

you can create a company-specific common directory under target/src/drv, and

add your driver to that subdirectory. The name of the directory should include a

abbreviation for your company name (must be three letters or more), followed by

the word “Common”. For example, aswiCommon would be an appropriate

directory name for a company called Acme Software Incorporated.

1 2 ... 105 106 107 108 109 110 111 112 113 114 115 ... 188 189

Keine Kommentare

RAM 6.0 BUX II Series Betriebsanweisung Seite 110