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Inside Macintosh: Memory /

Chapter 3 - Virtual Memory Manager / Virtual Memory Manager Reference

Routines / Virtual Memory Debugger Support Routines

DebuggerGetMax

The Memory Manager includes a special routine that debuggers use, instead of the Gestalt function, to determine which debugger functions are present.

FUNCTION DebuggerGetMax: LongInt;

DESCRIPTION

The DebuggerGetMax function returns the highest selector number of the debugger routines that are defined in terms of the _DebugUtil trap. The numbers correspond to the following routines:

Selector	Routine
$0000	DebuggerGetMax
$0001	DebuggerEnter
$0002	DebuggerExit
$0003	DebuggerPoll
$0004	GetPageState
$0005	PageFaultFatal
$0006	DebuggerLockMemory
$0007	DebuggerUnlockMemory
$0008	EnterSupervisorMode

Of course, you should use the Gestalt function to check whether virtual memory
is available at all before you call the DebuggerGetMax function.

ASSEMBLY-LANGUAGE INFORMATION

The trap macro and routine selector for the DebuggerGetMax function are

Trap macro	Selector
_DebugUtil	$0000

The registers on entry and exit for this routine are

Registers on entry
D0	Selector code

Registers on exit
D0	Highest available selector