SCO OpenServer

halt(D2oddi)

halt -- device-specific shutdown processing

Synopsis

   void prefixhalt(void);

Description

The halt( ) entry point routine is called at system shutdown time to do any cleanup that is necessary before the kernel shutdown occurs.

Arguments

None

Return values

None

Usage

Use the halt( ) routine to set or clear device registers so that devices are ready for initialization after a warm boot. Be sure that all hardware and hardware controllers are reset as they would be by a power cycle. halt( ) is also commonly used to flush the cache on the controller hardware for block I/O operations.

Context and synchronization

Blockable context. The driver can block but cannot do operations such as copyout(D3) that require access to the requesting process's address space.

Hardware applicability

All

Version applicability

oddi: 1, 2, 2mp, 3, 3mp, 4, 4mp, 5, 5mp, 6, 6mp

SVR5 DDI compatibility

The halt(D2) entry point routine for DDI versions prior to version 8 is identical to the ODDI entry point routine. For DDI 8 and later versions, replace halt( ) with a call to the CFG_SUSPEND and CFG_REMOVE subfunctions of the config(D2) entry point routine.

External dependencies

Drivers that contain a halt( ) routine must have a h in the function list of the mdevice(F) file. The halt( ) routine is accessed through the haltsw switch table that is created at system configuration time to list all configured halt( ) routines.