466 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			466 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
| /****************************************************************************
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| *
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| *                       Realmode X86 Emulator Library
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| *
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| *               Copyright (C) 1991-2004 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 <stdarg.h>
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| 
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| #if defined(CONFIG_BIOSEMU)
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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)
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| 		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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| 		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 ^=
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| 			    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",
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| 			       (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')
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| 		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')
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| 			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')
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| 			s++;
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| 
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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))
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| 		printk("OV ");	/* CHECKED... */
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| 	else
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| 		printk("NV ");
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| 	if (ACCESS_FLAG(F_DF))
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| 		printk("DN ");
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| 	else
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| 		printk("UP ");
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| 	if (ACCESS_FLAG(F_IF))
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| 		printk("EI ");
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| 	else
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| 		printk("DI ");
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| 	if (ACCESS_FLAG(F_SF))
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| 		printk("NG ");
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| 	else
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| 		printk("PL ");
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| 	if (ACCESS_FLAG(F_ZF))
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| 		printk("ZR ");
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| 	else
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| 		printk("NZ ");
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| 	if (ACCESS_FLAG(F_AF))
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| 		printk("AC ");
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| 	else
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| 		printk("NA ");
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| 	if (ACCESS_FLAG(F_PF))
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| 		printk("PE ");
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| 	else
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| 		printk("PO ");
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| 	if (ACCESS_FLAG(F_CF))
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| 		printk("CY ");
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| 	else
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| 		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))
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| 		printk("OV ");	/* CHECKED... */
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| 	else
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| 		printk("NV ");
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| 	if (ACCESS_FLAG(F_DF))
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| 		printk("DN ");
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| 	else
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| 		printk("UP ");
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| 	if (ACCESS_FLAG(F_IF))
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| 		printk("EI ");
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| 	else
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| 		printk("DI ");
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| 	if (ACCESS_FLAG(F_SF))
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| 		printk("NG ");
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| 	else
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| 		printk("PL ");
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| 	if (ACCESS_FLAG(F_ZF))
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| 		printk("ZR ");
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| 	else
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| 		printk("NZ ");
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| 	if (ACCESS_FLAG(F_AF))
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| 		printk("AC ");
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| 	else
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| 		printk("NA ");
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| 	if (ACCESS_FLAG(F_PF))
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| 		printk("PE ");
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| 	else
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| 		printk("PO ");
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| 	if (ACCESS_FLAG(F_CF))
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| 		printk("CY ");
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| 	else
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| 		printk("NC ");
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| 	printk("\n");
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| }
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| 
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| #endif
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