431 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			431 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
| /****************************************************************************
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| *
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| *						Realmode X86 Emulator Library
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| *
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| *            	Copyright (C) 1996-1999 SciTech Software, Inc.
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| * 				     Copyright (C) David Mosberger-Tang
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| * 					   Copyright (C) 1999 Egbert Eich
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| *
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| *  ========================================================================
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| *
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| *  Permission to use, copy, modify, distribute, and sell this software and
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| *  its documentation for any purpose is hereby granted without fee,
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| *  provided that the above copyright notice appear in all copies and that
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| *  both that copyright notice and this permission notice appear in
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| *  supporting documentation, and that the name of the authors not be used
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| *  in advertising or publicity pertaining to distribution of the software
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| *  without specific, written prior permission.  The authors makes no
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| *  representations about the suitability of this software for any purpose.
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| *  It is provided "as is" without express or implied warranty.
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| *
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| *  THE AUTHORS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
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| *  INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
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| *  EVENT SHALL THE AUTHORS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
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| *  CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
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| *  USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
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| *  OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
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| *  PERFORMANCE OF THIS SOFTWARE.
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| *
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| *  ========================================================================
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| *
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| * Language:		ANSI C
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| * Environment:	Any
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| * Developer:    Kendall Bennett
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| *
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| * Description:  This file contains the code to handle debugging of the
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| *				emulator.
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| *
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| ****************************************************************************/
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| 
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| #include "x86emu/x86emui.h"
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| #include <stdio.h>
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| #include <string.h>
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| #ifndef NO_SYS_HEADERS
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| #include <stdarg.h>
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| #include <stdlib.h>
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| #endif
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| 
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| /*----------------------------- Implementation ----------------------------*/
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| 
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| #ifdef DEBUG
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| 
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| static void     print_encoded_bytes (u16 s, u16 o);
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| static void     print_decoded_instruction (void);
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| static int      parse_line (char *s, int *ps, int *n);
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|   
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| /* should look something like debug's output. */
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| void X86EMU_trace_regs (void)
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| {
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| 	if (DEBUG_TRACE()) {
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| 		x86emu_dump_regs();
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|     }
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| 	if (DEBUG_DECODE() && ! DEBUG_DECODE_NOPRINT()) {
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| 		printk("%04x:%04x ",M.x86.saved_cs, M.x86.saved_ip);
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| 		print_encoded_bytes( M.x86.saved_cs, M.x86.saved_ip);
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| 		print_decoded_instruction();
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|     }
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| }
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| 
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| void X86EMU_trace_xregs (void)
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| {
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| 	if (DEBUG_TRACE()) {
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| 		x86emu_dump_xregs();
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|     }
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| }
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| 
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| void x86emu_just_disassemble (void)
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| {
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|     /*
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|      * This routine called if the flag DEBUG_DISASSEMBLE is set kind
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|      * of a hack!
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|      */
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| 	printk("%04x:%04x ",M.x86.saved_cs, M.x86.saved_ip);
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| 	print_encoded_bytes( M.x86.saved_cs, M.x86.saved_ip);
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| 	print_decoded_instruction();
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| }
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| 
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| static void disassemble_forward (u16 seg, u16 off, int n)
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| {
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| 	X86EMU_sysEnv tregs;
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| 	int i;
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| 	u8 op1;
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|     /*
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|      * hack, hack, hack.  What we do is use the exact machinery set up
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|      * for execution, except that now there is an additional state
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|      * flag associated with the "execution", and we are using a copy
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|      * of the register struct.  All the major opcodes, once fully
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|      * decoded, have the following two steps: TRACE_REGS(r,m);
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|      * SINGLE_STEP(r,m); which disappear if DEBUG is not defined to
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|      * the preprocessor.  The TRACE_REGS macro expands to:
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|      *
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|      * if (debug&DEBUG_DISASSEMBLE) 
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|      *     {just_disassemble(); goto EndOfInstruction;}
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|      *     if (debug&DEBUG_TRACE) trace_regs(r,m);
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|      *
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|      * ......  and at the last line of the routine. 
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|      *
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|      * EndOfInstruction: end_instr();
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|      *
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|      * Up to the point where TRACE_REG is expanded, NO modifications
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|      * are done to any register EXCEPT the IP register, for fetch and
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|      * decoding purposes.
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|      *
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|      * This was done for an entirely different reason, but makes a
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|      * nice way to get the system to help debug codes.
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|      */
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| 	tregs = M;
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|     tregs.x86.R_IP = off;
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|     tregs.x86.R_CS = seg;
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|     
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|     /* reset the decoding buffers */
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|     tregs.x86.enc_str_pos = 0;
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|     tregs.x86.enc_pos = 0;
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|     
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|     /* turn on the "disassemble only, no execute" flag */
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|     tregs.x86.debug |= DEBUG_DISASSEMBLE_F;
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|  
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|     /* DUMP NEXT n instructions to screen in straight_line fashion */
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|     /*
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|      * This looks like the regular instruction fetch stream, except
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|      * that when this occurs, each fetched opcode, upon seeing the
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|      * DEBUG_DISASSEMBLE flag set, exits immediately after decoding
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|      * the instruction.  XXX --- CHECK THAT MEM IS NOT AFFECTED!!!
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|      * Note the use of a copy of the register structure...
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|      */
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|     for (i=0; i<n; i++) {
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| 		op1 = (*sys_rdb)(((u32)M.x86.R_CS<<4) + (M.x86.R_IP++));
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| 		(x86emu_optab[op1])(op1);
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|     }
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|     /* end major hack mode. */
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| }
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| 
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| void x86emu_check_ip_access (void)
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| {
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|     /* NULL as of now */
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| }
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| 
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| void x86emu_check_sp_access (void)
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| {
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| }
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| 
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| void x86emu_check_mem_access (u32 dummy)
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| {
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| 	/*  check bounds, etc */
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| }
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| 
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| void x86emu_check_data_access (uint dummy1, uint dummy2)
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| {
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| 	/*  check bounds, etc */
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| }
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| 
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| void x86emu_inc_decoded_inst_len (int x)
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| {
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| 	M.x86.enc_pos += x;
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| }
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| 
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| void x86emu_decode_printf (char *x)
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| {
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| 	sprintf(M.x86.decoded_buf+M.x86.enc_str_pos,"%s",x);
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| 	M.x86.enc_str_pos += strlen(x);
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| }
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| 
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| void x86emu_decode_printf2 (char *x, int y)
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| {
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| 	char temp[100];
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| 	sprintf(temp,x,y);
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| 	sprintf(M.x86.decoded_buf+M.x86.enc_str_pos,"%s",temp);
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| 	M.x86.enc_str_pos += strlen(temp);
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| }
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| 
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| void x86emu_end_instr (void)
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| {
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| 	M.x86.enc_str_pos = 0;
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| 	M.x86.enc_pos = 0;
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| }
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| 
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| static void print_encoded_bytes (u16 s, u16 o)
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| {
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|     int i;
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|     char buf1[64];
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| 	for (i=0; i< M.x86.enc_pos; i++) {
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| 		sprintf(buf1+2*i,"%02x", fetch_data_byte_abs(s,o+i));
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|     }
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| 	printk("%-20s",buf1);
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| }
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| 
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| static void print_decoded_instruction (void)
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| {
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| 	printk("%s", M.x86.decoded_buf);
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| }
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| 
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| void x86emu_print_int_vect (u16 iv)
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| {
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| 	u16 seg,off;
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| 
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| 	if (iv > 256) return;
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| 	seg   = fetch_data_word_abs(0,iv*4);
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| 	off   = fetch_data_word_abs(0,iv*4+2);
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| 	printk("%04x:%04x ", seg, off);
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| }
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| 
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| void X86EMU_dump_memory (u16 seg, u16 off, u32 amt)
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| {
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| 	u32 start = off & 0xfffffff0;
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| 	u32 end  = (off+16) & 0xfffffff0;
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| 	u32 i;
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| 	u32 current;
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| 
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| 	current = start;
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| 	while (end <= off + amt) {
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| 		printk("%04x:%04x ", seg, start);
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| 		for (i=start; i< off; i++)
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| 		  printk("   ");
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| 		for (       ; i< end; i++)
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| 		  printk("%02x ", fetch_data_byte_abs(seg,i));
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| 		printk("\n");
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| 		start = end;
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| 		end = start + 16;
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| 	}
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| }
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| 
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| void x86emu_single_step (void)
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| {
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|     char s[1024];
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|     int ps[10];
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|     int ntok;
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|     int cmd;
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|     int done;
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| 		int segment;
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|     int offset;
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|     static int breakpoint;
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|     static int noDecode = 1;
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|     
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|     char *p;
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| 
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| 		if (DEBUG_BREAK()) {
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| 				if (M.x86.saved_ip != breakpoint) {
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| 						return;
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| 				} else {
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|  	          M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
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| 						M.x86.debug |= DEBUG_TRACE_F;
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| 						M.x86.debug &= ~DEBUG_BREAK_F;
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| 						print_decoded_instruction ();
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| 						X86EMU_trace_regs();
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| 				}
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| 		}
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|     done=0;
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| 	offset = M.x86.saved_ip;
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|     while (!done) {
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|         printk("-");
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|         p = fgets(s, 1023, stdin);
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|         cmd = parse_line(s, ps, &ntok);
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|         switch(cmd) {
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|           case 'u':
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| 			disassemble_forward(M.x86.saved_cs,(u16)offset,10);
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|             break;
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|           case 'd':  
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| 							if (ntok == 2) {
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| 									segment = M.x86.saved_cs;
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| 									offset = ps[1];
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| 									X86EMU_dump_memory(segment,(u16)offset,16);
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| 									offset += 16;
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| 							} else if (ntok == 3) {
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| 									segment = ps[1];
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| 									offset = ps[2];
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| 									X86EMU_dump_memory(segment,(u16)offset,16);
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| 									offset += 16;
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| 							} else {
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| 									segment = M.x86.saved_cs;
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| 									X86EMU_dump_memory(segment,(u16)offset,16);
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| 									offset += 16;
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| 							}
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|             break;
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|           case 'c':
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| 			M.x86.debug ^= DEBUG_TRACECALL_F;
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|             break;
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|           case 's':
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| 			M.x86.debug ^= DEBUG_SVC_F | DEBUG_SYS_F | DEBUG_SYSINT_F;
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|             break;
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|           case 'r':
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| 			X86EMU_trace_regs();
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|             break;
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|           case 'x':
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| 			X86EMU_trace_xregs();
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|             break;
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|           case 'g':
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|             if (ntok == 2) {
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|                 breakpoint = ps[1];
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| 		if (noDecode) {
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| 		                M.x86.debug |= DEBUG_DECODE_NOPRINT_F;
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| 		} else {
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| 		                M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
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| 		}
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| 		M.x86.debug &= ~DEBUG_TRACE_F;
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| 		M.x86.debug |= DEBUG_BREAK_F;
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| 		done = 1;
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|             }
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|             break;
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|           case 'q':
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|           M.x86.debug |= DEBUG_EXIT;
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|           return;
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| 	  case 'P':
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| 	      noDecode = (noDecode)?0:1;
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| 	      printk("Toggled decoding to %s\n",(noDecode)?"FALSE":"TRUE");
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| 	      break;
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|           case 't':
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| 	  case 0:
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|             done = 1;
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|             break;
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|         }   
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|     }
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| }
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| 
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| int X86EMU_trace_on(void)
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| {
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| 	return M.x86.debug |= DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F;
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| }
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| 
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| int X86EMU_trace_off(void)
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| {
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| 	return M.x86.debug &= ~(DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F);
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| }
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| 
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| static int parse_line (char *s, int *ps, int *n)
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| {
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|     int cmd;
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| 
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|     *n = 0;
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|     while(*s == ' ' || *s == '\t') s++;
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|     ps[*n] = *s;
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|     switch (*s) {
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|       case '\n':
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|         *n += 1;
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|         return 0;
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|       default:
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|         cmd = *s;
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|         *n += 1;
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|     }
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| 
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| 	while (1) {
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| 		while (*s != ' ' && *s != '\t' && *s != '\n')  s++;
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| 		
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| 		if (*s == '\n')
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| 			return cmd;
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| 		
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| 		while(*s == ' ' || *s == '\t') s++;
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| 		
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| 		sscanf(s,"%x",&ps[*n]);
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| 		*n += 1;
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| 	}
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| }
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| 
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| #endif /* DEBUG */
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| 
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| void x86emu_dump_regs (void)
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| {
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| 	printk("\tAX=%04x  ", M.x86.R_AX );
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| 	printk("BX=%04x  ", M.x86.R_BX );
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| 	printk("CX=%04x  ", M.x86.R_CX );
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| 	printk("DX=%04x  ", M.x86.R_DX );
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| 	printk("SP=%04x  ", M.x86.R_SP );
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| 	printk("BP=%04x  ", M.x86.R_BP );
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| 	printk("SI=%04x  ", M.x86.R_SI );
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| 	printk("DI=%04x\n", M.x86.R_DI );
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| 	printk("\tDS=%04x  ", M.x86.R_DS );
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| 	printk("ES=%04x  ", M.x86.R_ES );
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| 	printk("SS=%04x  ", M.x86.R_SS );
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| 	printk("CS=%04x  ", M.x86.R_CS );
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| 	printk("IP=%04x   ", M.x86.R_IP );
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| 	if (ACCESS_FLAG(F_OF))    printk("OV ");     /* CHECKED... */
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| 	else                        printk("NV ");
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| 	if (ACCESS_FLAG(F_DF))    printk("DN ");
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| 	else                        printk("UP ");
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| 	if (ACCESS_FLAG(F_IF))    printk("EI ");
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| 	else                        printk("DI ");
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| 	if (ACCESS_FLAG(F_SF))    printk("NG ");
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| 	else                        printk("PL ");
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| 	if (ACCESS_FLAG(F_ZF))    printk("ZR ");
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| 	else                        printk("NZ ");
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| 	if (ACCESS_FLAG(F_AF))    printk("AC ");
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| 	else                        printk("NA ");
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| 	if (ACCESS_FLAG(F_PF))    printk("PE ");
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| 	else                        printk("PO ");
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| 	if (ACCESS_FLAG(F_CF))    printk("CY ");
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| 	else                        printk("NC ");
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| 	printk("\n");
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| }
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| 
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| void x86emu_dump_xregs (void)
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| {
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| 	printk("\tEAX=%08x  ", M.x86.R_EAX );
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| 	printk("EBX=%08x  ", M.x86.R_EBX );
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| 	printk("ECX=%08x  ", M.x86.R_ECX );
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| 	printk("EDX=%08x  \n", M.x86.R_EDX );
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| 	printk("\tESP=%08x  ", M.x86.R_ESP );
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| 	printk("EBP=%08x  ", M.x86.R_EBP );
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| 	printk("ESI=%08x  ", M.x86.R_ESI );
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| 	printk("EDI=%08x\n", M.x86.R_EDI );
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| 	printk("\tDS=%04x  ", M.x86.R_DS );
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| 	printk("ES=%04x  ", M.x86.R_ES );
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| 	printk("SS=%04x  ", M.x86.R_SS );
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| 	printk("CS=%04x  ", M.x86.R_CS );
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| 	printk("EIP=%08x\n\t", M.x86.R_EIP );
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| 	if (ACCESS_FLAG(F_OF))    printk("OV ");     /* CHECKED... */
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| 	else                        printk("NV ");
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| 	if (ACCESS_FLAG(F_DF))    printk("DN ");
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| 	else                        printk("UP ");
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| 	if (ACCESS_FLAG(F_IF))    printk("EI ");
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| 	else                        printk("DI ");
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| 	if (ACCESS_FLAG(F_SF))    printk("NG ");
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| 	else                        printk("PL ");
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| 	if (ACCESS_FLAG(F_ZF))    printk("ZR ");
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| 	else                        printk("NZ ");
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| 	if (ACCESS_FLAG(F_AF))    printk("AC ");
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| 	else                        printk("NA ");
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| 	if (ACCESS_FLAG(F_PF))    printk("PE ");
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| 	else                        printk("PO ");
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| 	if (ACCESS_FLAG(F_CF))    printk("CY ");
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| 	else                        printk("NC ");
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| 	printk("\n");
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| }
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