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Inside Macintosh: Devices /

Chapter 2 - Slot Manager / Slot Manager Reference

Slot Manager Routines / Loading Drivers and Executing Code From sResources

SExec

You can use the SExec function to execute code stored in an sExecBlock data structure.

FUNCTION SExec (spBlkPtr: SpBlockPtr): OSErr;

spBlkPtr

A pointer to a Slot Manager parameter block.

-->	spsPointer	Ptr	A pointer to an sResource (described in "The sResource," beginning on page 2-7).
-->	spsExecPBlk	Ptr	A pointer to the SEBlock.
-->	spID	SignedByte	The ID of the sExecBlock entry in the sResource.
X	spResult	LongInt

DESCRIPTION

The SExec function loads sExecBlock code from an sResource into the current heap zone, checks its revision level, and executes the code.

You specify the sExecBlock by providing a pointer to the sResource in the spsPointer field and the ID of the sExecBlock entry in the spID field. You must also provide in the spsExecPBlk field a pointer to a slot execution parameter block. The SEBlock structure allows you to provide information about the execution of the sExecBlock code.

The SExec function passes the sExecBlock code a pointer to the SEBlock structure in register A0.

SPECIAL CONSIDERATIONS

The SExec function allocates memory; your application should not call this function at interrupt time.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for the SExec function are

Trap macro	Selector
_SlotManager	$0023

You must set up register D0 with the routine selector and register A0 with the address of the Slot Manager parameter block. When _SlotManager returns, register D0 contains the result code.

Registers on entry
A0	Address of the parameter block
D0	$0023

Registers on exit
D0	Result code

RESULT CODES

noErr	0	No error
smCodeRevErr	-333	The revision of the code to be executed by sExec was wrong
smCPUErr	-334	The CPU field of the code to be executed by sExec was wrong
smNoMoresRsrcs	-344	Requested sResource not found

SEE ALSO

For more information about the sExecBlock data structure, see page 2-9.