SVR5

init(D2)

init -- initialize a static device driver

Synopsis (Not in current DDI version)

   void prefixinit(void);

Description

The driver's init( ) entry point routine is called during system initialization to initialize the driver and the devices it controls. init( ) is a named entry point and must be defined as a global symbol.

Return values

None

Usage

This entry point is optional. It is never called for dynamically loadable drivers.

Although init( ) and start( ) routines both perform initialization tasks, they execute at different times during system start-up. For this reason, they should be used to handle different types of initialization tasks.

init( ) routines:

execute during system initialization
handle any driver and device setup and initialization that must take place before system services are initialized (for example, perform any setup and initialization that must be done before device interrupts are enabled)
may only call the kernel functions listed below

start( ) routines:

execute after system services are initialized
handle all driver and device setup and initialization that can take place after system services are initialized (most driver setup and initialization tasks can be performed at this time, using a start routine)
handle any driver and device setup and initialization that can only take place after system services are initialized (for example, perform any setup and initialization that must be done after device interrupts are enabled)

Types of activities performed by the init( ) routine include initializing data structures, allocating memory for private data, mapping the device into virtual address space, and initializing hardware. The init( ) routine can only call kernel functions that are can run in initialization context in HDK Technical Reference. Context information is provided on the manual page for each kernel function.

init( ) routines for dynamically loadable modules are not called during system start-up as they are for statically linked modules. A loadable module's initialization is performed by its _load(D2) routine, which is called each time the module is loaded into a running system. However, if the processing done by a module's init( ) routine when the module is configured as a statically linked module can also be used when the module is configured as a loadable module, the module can call its init( ) routine from its load( ) routine.

Context and synchronization

Initialization context. Most system facilities are not available and interrupt detection is not enabled.

Hardware applicability

All

Version applicability

ddi: 1, 2, 3, 4, 5, 5mp, 6, 6mp, 7, 7mp, 7.1, 7.1mp

Differences between versions

Starting with DDI version 8, the init( ) entry point routine is no longer supported. Instead, _load(D2) is always called to initialize drivers.

External dependencies

Named entry point routines must be declared in the driver's Master(DSP/4dsp) file. The declaration for this entry point is $entry init.

References

_load(D2), start(D2)