//      TITLE("Debug Support Functions")

// Copyright (c) 1990  Microsoft 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:
//    Steven R. Wood (stevewo) 3-Aug-1989

// Environment:
//    Any mode.


#include "ksmips.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)

        break   DEBUG_STOP_BREAKPOINT
        j       ra

        .end    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)
        break   DEBUG_STOP_BREAKPOINT
        j       ra

        .end    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)

        break   DEBUG_STOP_BREAKPOINT
        j       ra

        .end    DbgUserBreakPoint

// ULONG DebugPrompt(IN PSTRING Output, IN PSTRING Input)
// Routine Description:
//    This function executes a debug prompt breakpoint.
// Arguments:
//    Output (a0) - Supplies a pointer to the output string descriptor.
//    Input (a1) - 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)

        lhu     a3,StrMaximumLength(a1) // set maximum length of input string
        lw      a2,StrBuffer(a1)        // set address of input string
        lhu     a1,StrLength(a0)        // set length of output string
        lw      a0,StrBuffer(a0)        // set address of output string
        break   DEBUG_PROMPT_BREAKPOINT  // execute a debug prompt breakpoint
        j       ra                      // return

        .end    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)

        break   DEBUG_LOAD_SYMBOLS_BREAKPOINT
        j       ra

        .end    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)

        break   DEBUG_UNLOAD_SYMBOLS_BREAKPOINT
        j       ra

        .end    DebugUnLoadImageSymbols

#endif

// NTSTATUS DebugPrint(IN PSTRING Output)
// Routine Description:
//    This function executes a debug print breakpoint.
// Arguments:
//    Output (a0) - 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)

        lhu     a1,StrLength(a0)        // set length of output string
        lw      a0,StrBuffer(a0)        // set address of output string
        break   DEBUG_PRINT_BREAKPOINT  // execute a debug print breakpoint
        j       ra                      // return

        .end    DebugPrint

#endif