//      TITLE("Debug Support Functions")

// Copyright (c) 1993  IBM Corporation

// Module Name:
//    debug.s

// Abstract:
//    This module implements functions to support debugging NT.  Each
//    function executes a trap r31,r29,r0 instruction with a special value in
//    R31.  The simulator decodes this trap instruction and dispatches to the
//    correct piece of code in the simulator based on the value in R31.  See
//    the simscal.c source file in the simulator source directory.

// Author:
//    Chuck Bauman 12-Aug-1993

// Environment:
//    Any mode.

// Revision History:
//    Initial PowerPC port of NT product1 source 12-Aug-1993


#include "ksppc.h"


// VOID DbgBreakPoint()
// Routine Description:
//    This function executes a breakpoint instruction.  Useful for entering
//    the debugger under program control.  This breakpoint will always go to
//    the kernel debugger if one is installed, otherwise it will go to the debug subsystem.
// Arguments:
//    None.
// Return Value:
//    None.


        LEAF_ENTRY(DbgBreakPoint)

        twi     31,0,DEBUG_STOP_BREAKPOINT

        LEAF_EXIT(DbgBreakPoint)


// VOID DbgBreakPointWithStatus(IN ULONG Status)
// Routine Description:
//    This function executes a breakpoint instruction.  Useful for entering
//    the debugger under program control.  This breakpoint will always go to
//    the kernel debugger if one is installed, otherwise it will go to the
//    debug subsystem.  This function is identical to DbgBreakPoint, except
//    that it takes an argument which the debugger can see.
// Arguments:
//    None.
// Return Value:
//    None.

        LEAF_ENTRY(DbgBreakPointWithStatus)

        ALTERNATE_ENTRY(RtlpBreakWithStatusInstruction)
        twi     31,0,DEBUG_STOP_BREAKPOINT

        LEAF_EXIT(DbgBreakPointWithStatus)


// VOID DbgUserBreakPoint()
// Routine Description:
//    This function executes a breakpoint instruction.  Useful for entering
//    the debug subsystem under program control.  The kernel debug will ignore
//    this breakpoint since it will not find the instruction address in its breakpoint table.
// Arguments:
//    None.
// Return Value:
//    None.


        LEAF_ENTRY(DbgUserBreakPoint)

        twi     31,0,DEBUG_STOP_BREAKPOINT

        LEAF_EXIT(DbgUserBreakPoint)

// ULONG DebugPrompt(IN PSTRING Output, IN PSTRING Input)
// Routine Description:
//    This function executes a debug prompt breakpoint.
// Arguments:
//    Output (r.3) - Supplies a pointer to the output string descriptor.
//    Input (r.4) - Supplies a pointer to the input string descriptor.
// Return Value:
//    The length of the input string is returned as the function value.

#if DEVL

        LEAF_ENTRY(DebugPrompt)

        lhz     r.6,StrMaximumLength(r.4) // set maximum length of input string
        lwz     r.5,StrBuffer(r.4)        // set address of input string
        lhz     r.4,StrLength(r.3)        // set length of output string
        lwz     r.3,StrBuffer(r.3)        // set address of output string
        twi     31,0,DEBUG_PROMPT_BREAKPOINT  // execute a debug prompt breakpoint

        LEAF_EXIT(DebugPrompt)

#endif


// VOID DebugLoadImageSymbols(IN PSTRING ImagePathName, IN PKD_SYMBOLS_INFO SymbolInfo)
// Routine Description:
//    This function calls the kernel debugger to load the symbol
//    table for the specified image.
// Arguments:
//    ImagePathName - specifies the fully qualified path name of the image
//       file that has been loaded into an NT address space.

//    SymbolInfo - information captured from header of image file.
// Return Value:
//    None.

#if DEVL

        LEAF_ENTRY(DebugLoadImageSymbols)

        twi     31,0,DEBUG_LOAD_SYMBOLS_BREAKPOINT

        LEAF_EXIT(DebugLoadImageSymbols)

#endif


// VOID DebugUnLoadImageSymbols(IN PSTRING ImagePathName, IN PKD_SYMBOLS_INFO SymbolInfo)
// Routine Description:
//    This function calls the kernel debugger to unload the symbol table for the specified image.
// Arguments:
//    ImagePathName - specifies the fully qualified path name of the image file that has been unloaded from an NT address space.
//    SymbolInfo - information captured from header of image file.
// Return Value:
//    None.


#if DEVL

        LEAF_ENTRY(DebugUnLoadImageSymbols)

        twi     31,0,DEBUG_UNLOAD_SYMBOLS_BREAKPOINT

        LEAF_EXIT(DebugUnLoadImageSymbols)

#endif


// NTSTATUS DebugPrint(IN PSTRING Output)
// Routine Description:
//    This function executes a debug print breakpoint.
// Arguments:
//    Output (r.3) - Supplies a pointer to the output string descriptor.
// Return Value:
//    Status code.  STATUS_SUCCESS if debug print happened.
//    STATUS_BREAKPOINT if user typed a Control-C during print.
//    STATUS_DEVICE_NOT_CONNECTED if kernel debugger not present.


#if DEVL

        LEAF_ENTRY(DebugPrint)

        lhz     r.4,StrLength(r.3)      // set length of output string
        lwz     r.3,StrBuffer(r.3)      // set address of output string
        twi     31,0,DEBUG_PRINT_BREAKPOINT  // execute a debug print breakpoint

        LEAF_EXIT(DebugPrint)

#endif