drivers/bios_emulator/x86emu/debug.c - u-boot - Git at Google

 /****************************************************************************
 *
 *                       Realmode X86 Emulator Library
 *
 *               Copyright (C) 1991-2004 SciTech Software, Inc.
 *                    Copyright (C) David Mosberger-Tang
 *                      Copyright (C) 1999 Egbert Eich
 *
 *  ========================================================================
 *
 *  Permission to use, copy, modify, distribute, and sell this software and
 *  its documentation for any purpose is hereby granted without fee,
 *  provided that the above copyright notice appear in all copies and that
 *  both that copyright notice and this permission notice appear in
 *  supporting documentation, and that the name of the authors not be used
 *  in advertising or publicity pertaining to distribution of the software
 *  without specific, written prior permission.  The authors makes no
 *  representations about the suitability of this software for any purpose.
 *  It is provided "as is" without express or implied warranty.
 *
 *  THE AUTHORS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 *  INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 *  EVENT SHALL THE AUTHORS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 *  CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
 *  USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 *  OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 *  PERFORMANCE OF THIS SOFTWARE.
 *
 *  ========================================================================
 *
 * Language:     ANSI C
 * Environment:  Any
 * Developer:    Kendall Bennett
 *
 * Description:  This file contains the code to handle debugging of the
 *               emulator.
 *
 ****************************************************************************/

 #include <stdarg.h>
 #include <common.h>
 #include "x86emu/x86emui.h"

 /*----------------------------- Implementation ----------------------------*/

 #ifdef DEBUG

 static void print_encoded_bytes(u16 s, u16 o);
 static void print_decoded_instruction(void);
 static int x86emu_parse_line(char *s, int *ps, int *n);

 /* should look something like debug's output. */
 void X86EMU_trace_regs(void)
 {
 	if (DEBUG_TRACE()) {
 		x86emu_dump_regs();
 	}
 	if (DEBUG_DECODE() && !DEBUG_DECODE_NOPRINT()) {
 		printk("%04x:%04x ", M.x86.saved_cs, M.x86.saved_ip);
 		print_encoded_bytes(M.x86.saved_cs, M.x86.saved_ip);
 		print_decoded_instruction();
 	}
 }

 void X86EMU_trace_xregs(void)
 {
 	if (DEBUG_TRACE()) {
 		x86emu_dump_xregs();
 	}
 }

 void x86emu_just_disassemble(void)
 {
 	/*
 	 * This routine called if the flag DEBUG_DISASSEMBLE is set kind
 	 * of a hack!
 	 */
 	printk("%04x:%04x ", M.x86.saved_cs, M.x86.saved_ip);
 	print_encoded_bytes(M.x86.saved_cs, M.x86.saved_ip);
 	print_decoded_instruction();
 }

 static void disassemble_forward(u16 seg, u16 off, int n)
 {
 	X86EMU_sysEnv tregs;
 	int i;
 	u8 op1;
 	/*
 	 * hack, hack, hack.  What we do is use the exact machinery set up
 	 * for execution, except that now there is an additional state
 	 * flag associated with the "execution", and we are using a copy
 	 * of the register struct.  All the major opcodes, once fully
 	 * decoded, have the following two steps: TRACE_REGS(r,m);
 	 * SINGLE_STEP(r,m); which disappear if DEBUG is not defined to
 	 * the preprocessor.  The TRACE_REGS macro expands to:
 	 *
 	 * if (debug&DEBUG_DISASSEMBLE)
 	 *     {just_disassemble(); goto EndOfInstruction;}
 	 *     if (debug&DEBUG_TRACE) trace_regs(r,m);
 	 *
 	 * ......  and at the last line of the routine.
 	 *
 	 * EndOfInstruction: end_instr();
 	 *
 	 * Up to the point where TRACE_REG is expanded, NO modifications
 	 * are done to any register EXCEPT the IP register, for fetch and
 	 * decoding purposes.
 	 *
 	 * This was done for an entirely different reason, but makes a
 	 * nice way to get the system to help debug codes.
 	 */
 	tregs = M;
 	tregs.x86.R_IP = off;
 	tregs.x86.R_CS = seg;

 	/* reset the decoding buffers */
 	tregs.x86.enc_str_pos = 0;
 	tregs.x86.enc_pos = 0;

 	/* turn on the "disassemble only, no execute" flag */
 	tregs.x86.debug |= DEBUG_DISASSEMBLE_F;

 	/* DUMP NEXT n instructions to screen in straight_line fashion */
 	/*
 	 * This looks like the regular instruction fetch stream, except
 	 * that when this occurs, each fetched opcode, upon seeing the
 	 * DEBUG_DISASSEMBLE flag set, exits immediately after decoding
 	 * the instruction.  XXX --- CHECK THAT MEM IS NOT AFFECTED!!!
 	 * Note the use of a copy of the register structure...
 	 */
 	for (i = 0; i < n; i++) {
 		op1 = (*sys_rdb) (((u32) M.x86.R_CS << 4) + (M.x86.R_IP++));
 		(x86emu_optab[op1]) (op1);
 	}
 	/* end major hack mode. */
 }

 void x86emu_check_ip_access(void)
 {
 	/* NULL as of now */
 }

 void x86emu_check_sp_access(void)
 {
 }

 void x86emu_check_mem_access(u32 dummy)
 {
 	/*  check bounds, etc */
 }

 void x86emu_check_data_access(uint dummy1, uint dummy2)
 {
 	/*  check bounds, etc */
 }

 void x86emu_inc_decoded_inst_len(int x)
 {
 	M.x86.enc_pos += x;
 }

 void x86emu_decode_printf(char *x)
 {
 	sprintf(M.x86.decoded_buf + M.x86.enc_str_pos, "%s", x);
 	M.x86.enc_str_pos += strlen(x);
 }

 void x86emu_decode_printf2(char *x, int y)
 {
 	char temp[100];
 	sprintf(temp, x, y);
 	sprintf(M.x86.decoded_buf + M.x86.enc_str_pos, "%s", temp);
 	M.x86.enc_str_pos += strlen(temp);
 }

 void x86emu_end_instr(void)
 {
 	M.x86.enc_str_pos = 0;
 	M.x86.enc_pos = 0;
 }

 static void print_encoded_bytes(u16 s, u16 o)
 {
 	int i;
 	char buf1[64];
 	for (i = 0; i < M.x86.enc_pos; i++) {
 		sprintf(buf1 + 2 * i, "%02x", fetch_data_byte_abs(s, o + i));
 	}
 	printk("%-20s", buf1);
 }

 static void print_decoded_instruction(void)
 {
 	printk("%s", M.x86.decoded_buf);
 }

 void x86emu_print_int_vect(u16 iv)
 {
 	u16 seg, off;

 	if (iv > 256)
 		return;
 	seg = fetch_data_word_abs(0, iv * 4);
 	off = fetch_data_word_abs(0, iv * 4 + 2);
 	printk("%04x:%04x ", seg, off);
 }

 void X86EMU_dump_memory(u16 seg, u16 off, u32 amt)
 {
 	u32 start = off & 0xfffffff0;
 	u32 end = (off + 16) & 0xfffffff0;
 	u32 i;
 	u32 current;

 	current = start;
 	while (end <= off + amt) {
 		printk("%04x:%04x ", seg, start);
 		for (i = start; i < off; i++)
 			printk("   ");
 		for (; i < end; i++)
 			printk("%02x ", fetch_data_byte_abs(seg, i));
 		printk("\n");
 		start = end;
 		end = start + 16;
 	}
 }

 void x86emu_single_step(void)
 {
 	char s[1024];
 	int ps[10];
 	int ntok;
 	int cmd;
 	int done;
 	int segment;
 	int offset;
 	static int breakpoint;
 	static int noDecode = 1;

 	char *p;

 	if (DEBUG_BREAK()) {
 		if (M.x86.saved_ip != breakpoint) {
 			return;
 		} else {
 			M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
 			M.x86.debug |= DEBUG_TRACE_F;
 			M.x86.debug &= ~DEBUG_BREAK_F;
 			print_decoded_instruction();
 			X86EMU_trace_regs();
 		}
 	}
 	done = 0;
 	offset = M.x86.saved_ip;
 	while (!done) {
 		printk("-");
 		cmd = x86emu_parse_line(s, ps, &ntok);
 		switch (cmd) {
 		case 'u':
 			disassemble_forward(M.x86.saved_cs, (u16) offset, 10);
 			break;
 		case 'd':
 			if (ntok == 2) {
 				segment = M.x86.saved_cs;
 				offset = ps[1];
 				X86EMU_dump_memory(segment, (u16) offset, 16);
 				offset += 16;
 			} else if (ntok == 3) {
 				segment = ps[1];
 				offset = ps[2];
 				X86EMU_dump_memory(segment, (u16) offset, 16);
 				offset += 16;
 			} else {
 				segment = M.x86.saved_cs;
 				X86EMU_dump_memory(segment, (u16) offset, 16);
 				offset += 16;
 			}
 			break;
 		case 'c':
 			M.x86.debug ^= DEBUG_TRACECALL_F;
 			break;
 		case 's':
 			M.x86.debug ^=
 			    DEBUG_SVC_F | DEBUG_SYS_F | DEBUG_SYSINT_F;
 			break;
 		case 'r':
 			X86EMU_trace_regs();
 			break;
 		case 'x':
 			X86EMU_trace_xregs();
 			break;
 		case 'g':
 			if (ntok == 2) {
 				breakpoint = ps[1];
 				if (noDecode) {
 					M.x86.debug |= DEBUG_DECODE_NOPRINT_F;
 				} else {
 					M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
 				}
 				M.x86.debug &= ~DEBUG_TRACE_F;
 				M.x86.debug |= DEBUG_BREAK_F;
 				done = 1;
 			}
 			break;
 		case 'q':
 			M.x86.debug |= DEBUG_EXIT;
 			return;
 		case 'P':
 			noDecode = (noDecode) ? 0 : 1;
 			printk("Toggled decoding to %s\n",
 			       (noDecode) ? "FALSE" : "TRUE");
 			break;
 		case 't':
 		case 0:
 			done = 1;
 			break;
 		}
 	}
 }

 int X86EMU_trace_on(void)
 {
 	return M.x86.debug |= DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F;
 }

 int X86EMU_trace_off(void)
 {
 	return M.x86.debug &= ~(DEBUG_STEP_F | DEBUG_DECODE_F | DEBUG_TRACE_F);
 }

 static int x86emu_parse_line(char *s, int *ps, int *n)
 {
 	int cmd;

 	*n = 0;
 	while (*s == ' ' || *s == '\t')
 		s++;
 	ps[*n] = *s;
 	switch (*s) {
 	case '\n':
 		*n += 1;
 		return 0;
 	default:
 		cmd = *s;
 		*n += 1;
 	}

 	while (1) {
 		while (*s != ' ' && *s != '\t' && *s != '\n')
 			s++;

 		if (*s == '\n')
 			return cmd;

 		while (*s == ' ' || *s == '\t')
 			s++;

 		*n += 1;
 	}
 }

 #endif				/* DEBUG */

 void x86emu_dump_regs(void)
 {
 	printk("\tAX=%04x  ", M.x86.R_AX);
 	printk("BX=%04x  ", M.x86.R_BX);
 	printk("CX=%04x  ", M.x86.R_CX);
 	printk("DX=%04x  ", M.x86.R_DX);
 	printk("SP=%04x  ", M.x86.R_SP);
 	printk("BP=%04x  ", M.x86.R_BP);
 	printk("SI=%04x  ", M.x86.R_SI);
 	printk("DI=%04x\n", M.x86.R_DI);
 	printk("\tDS=%04x  ", M.x86.R_DS);
 	printk("ES=%04x  ", M.x86.R_ES);
 	printk("SS=%04x  ", M.x86.R_SS);
 	printk("CS=%04x  ", M.x86.R_CS);
 	printk("IP=%04x   ", M.x86.R_IP);
 	if (ACCESS_FLAG(F_OF))
 		printk("OV ");	/* CHECKED... */
 	else
 		printk("NV ");
 	if (ACCESS_FLAG(F_DF))
 		printk("DN ");
 	else
 		printk("UP ");
 	if (ACCESS_FLAG(F_IF))
 		printk("EI ");
 	else
 		printk("DI ");
 	if (ACCESS_FLAG(F_SF))
 		printk("NG ");
 	else
 		printk("PL ");
 	if (ACCESS_FLAG(F_ZF))
 		printk("ZR ");
 	else
 		printk("NZ ");
 	if (ACCESS_FLAG(F_AF))
 		printk("AC ");
 	else
 		printk("NA ");
 	if (ACCESS_FLAG(F_PF))
 		printk("PE ");
 	else
 		printk("PO ");
 	if (ACCESS_FLAG(F_CF))
 		printk("CY ");
 	else
 		printk("NC ");
 	printk("\n");
 }

 void x86emu_dump_xregs(void)
 {
 	printk("\tEAX=%08x  ", M.x86.R_EAX);
 	printk("EBX=%08x  ", M.x86.R_EBX);
 	printk("ECX=%08x  ", M.x86.R_ECX);
 	printk("EDX=%08x  \n", M.x86.R_EDX);
 	printk("\tESP=%08x  ", M.x86.R_ESP);
 	printk("EBP=%08x  ", M.x86.R_EBP);
 	printk("ESI=%08x  ", M.x86.R_ESI);
 	printk("EDI=%08x\n", M.x86.R_EDI);
 	printk("\tDS=%04x  ", M.x86.R_DS);
 	printk("ES=%04x  ", M.x86.R_ES);
 	printk("SS=%04x  ", M.x86.R_SS);
 	printk("CS=%04x  ", M.x86.R_CS);
 	printk("EIP=%08x\n\t", M.x86.R_EIP);
 	if (ACCESS_FLAG(F_OF))
 		printk("OV ");	/* CHECKED... */
 	else
 		printk("NV ");
 	if (ACCESS_FLAG(F_DF))
 		printk("DN ");
 	else
 		printk("UP ");
 	if (ACCESS_FLAG(F_IF))
 		printk("EI ");
 	else
 		printk("DI ");
 	if (ACCESS_FLAG(F_SF))
 		printk("NG ");
 	else
 		printk("PL ");
 	if (ACCESS_FLAG(F_ZF))
 		printk("ZR ");
 	else
 		printk("NZ ");
 	if (ACCESS_FLAG(F_AF))
 		printk("AC ");
 	else
 		printk("NA ");
 	if (ACCESS_FLAG(F_PF))
 		printk("PE ");
 	else
 		printk("PO ");
 	if (ACCESS_FLAG(F_CF))
 		printk("CY ");
 	else
 		printk("NC ");
 	printk("\n");
 }
	/****************************************************************************
	*
	* Realmode X86 Emulator Library
	*
	* Copyright (C) 1991-2004 SciTech Software, Inc.
	* Copyright (C) David Mosberger-Tang
	* Copyright (C) 1999 Egbert Eich
	*
	* ========================================================================
	*
	* Permission to use, copy, modify, distribute, and sell this software and
	* its documentation for any purpose is hereby granted without fee,
	* provided that the above copyright notice appear in all copies and that
	* both that copyright notice and this permission notice appear in
	* supporting documentation, and that the name of the authors not be used
	* in advertising or publicity pertaining to distribution of the software
	* without specific, written prior permission. The authors makes no
	* representations about the suitability of this software for any purpose.
	* It is provided "as is" without express or implied warranty.
	*
	* THE AUTHORS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
	* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
	* EVENT SHALL THE AUTHORS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
	* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
	* USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
	* OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
	* PERFORMANCE OF THIS SOFTWARE.
	*
	* ========================================================================
	*
	* Language: ANSI C
	* Environment: Any
	* Developer: Kendall Bennett
	*
	* Description: This file contains the code to handle debugging of the
	* emulator.
	*
	****************************************************************************/

	#include <stdarg.h>
	#include <common.h>
	#include "x86emu/x86emui.h"

	/----------------------------- Implementation ----------------------------/

	#ifdef DEBUG

	static void print_encoded_bytes(u16 s, u16 o);
	static void print_decoded_instruction(void);
	static int x86emu_parse_line(char s, int ps, int *n);

	/* should look something like debug's output. */
	void X86EMU_trace_regs(void)
	{
	if (DEBUG_TRACE()) {
	x86emu_dump_regs();
	}
	if (DEBUG_DECODE() && !DEBUG_DECODE_NOPRINT()) {
	printk("%04x:%04x ", M.x86.saved_cs, M.x86.saved_ip);
	print_encoded_bytes(M.x86.saved_cs, M.x86.saved_ip);
	print_decoded_instruction();
	}
	}

	void X86EMU_trace_xregs(void)
	{
	if (DEBUG_TRACE()) {
	x86emu_dump_xregs();
	}
	}

	void x86emu_just_disassemble(void)
	{
	/*
	* This routine called if the flag DEBUG_DISASSEMBLE is set kind
	* of a hack!
	*/
	printk("%04x:%04x ", M.x86.saved_cs, M.x86.saved_ip);
	print_encoded_bytes(M.x86.saved_cs, M.x86.saved_ip);
	print_decoded_instruction();
	}

	static void disassemble_forward(u16 seg, u16 off, int n)
	{
	X86EMU_sysEnv tregs;
	int i;
	u8 op1;
	/*
	* hack, hack, hack. What we do is use the exact machinery set up
	* for execution, except that now there is an additional state
	* flag associated with the "execution", and we are using a copy
	* of the register struct. All the major opcodes, once fully
	* decoded, have the following two steps: TRACE_REGS(r,m);
	* SINGLE_STEP(r,m); which disappear if DEBUG is not defined to
	* the preprocessor. The TRACE_REGS macro expands to:
	*
	* if (debug&DEBUG_DISASSEMBLE)
	* {just_disassemble(); goto EndOfInstruction;}
	* if (debug&DEBUG_TRACE) trace_regs(r,m);
	*
	* ...... and at the last line of the routine.
	*
	* EndOfInstruction: end_instr();
	*
	* Up to the point where TRACE_REG is expanded, NO modifications
	* are done to any register EXCEPT the IP register, for fetch and
	* decoding purposes.
	*
	* This was done for an entirely different reason, but makes a
	* nice way to get the system to help debug codes.
	*/
	tregs = M;
	tregs.x86.R_IP = off;
	tregs.x86.R_CS = seg;

	/* reset the decoding buffers */
	tregs.x86.enc_str_pos = 0;
	tregs.x86.enc_pos = 0;

	/* turn on the "disassemble only, no execute" flag */
	tregs.x86.debug \|= DEBUG_DISASSEMBLE_F;

	/* DUMP NEXT n instructions to screen in straight_line fashion */
	/*
	* This looks like the regular instruction fetch stream, except
	* that when this occurs, each fetched opcode, upon seeing the
	* DEBUG_DISASSEMBLE flag set, exits immediately after decoding
	* the instruction. XXX --- CHECK THAT MEM IS NOT AFFECTED!!!
	* Note the use of a copy of the register structure...
	*/
	for (i = 0; i < n; i++) {
	op1 = (*sys_rdb) (((u32) M.x86.R_CS << 4) + (M.x86.R_IP++));
	(x86emu_optab[op1]) (op1);
	}
	/* end major hack mode. */
	}

	void x86emu_check_ip_access(void)
	{
	/* NULL as of now */
	}

	void x86emu_check_sp_access(void)
	{
	}

	void x86emu_check_mem_access(u32 dummy)
	{
	/* check bounds, etc */
	}

	void x86emu_check_data_access(uint dummy1, uint dummy2)
	{
	/* check bounds, etc */
	}

	void x86emu_inc_decoded_inst_len(int x)
	{
	M.x86.enc_pos += x;
	}

	void x86emu_decode_printf(char *x)
	{
	sprintf(M.x86.decoded_buf + M.x86.enc_str_pos, "%s", x);
	M.x86.enc_str_pos += strlen(x);
	}

	void x86emu_decode_printf2(char *x, int y)
	{
	char temp[100];
	sprintf(temp, x, y);
	sprintf(M.x86.decoded_buf + M.x86.enc_str_pos, "%s", temp);
	M.x86.enc_str_pos += strlen(temp);
	}

	void x86emu_end_instr(void)
	{
	M.x86.enc_str_pos = 0;
	M.x86.enc_pos = 0;
	}

	static void print_encoded_bytes(u16 s, u16 o)
	{
	int i;
	char buf1[64];
	for (i = 0; i < M.x86.enc_pos; i++) {
	sprintf(buf1 + 2 * i, "%02x", fetch_data_byte_abs(s, o + i));
	}
	printk("%-20s", buf1);
	}

	static void print_decoded_instruction(void)
	{
	printk("%s", M.x86.decoded_buf);
	}

	void x86emu_print_int_vect(u16 iv)
	{
	u16 seg, off;

	if (iv > 256)
	return;
	seg = fetch_data_word_abs(0, iv * 4);
	off = fetch_data_word_abs(0, iv * 4 + 2);
	printk("%04x:%04x ", seg, off);
	}

	void X86EMU_dump_memory(u16 seg, u16 off, u32 amt)
	{
	u32 start = off & 0xfffffff0;
	u32 end = (off + 16) & 0xfffffff0;
	u32 i;
	u32 current;

	current = start;
	while (end <= off + amt) {
	printk("%04x:%04x ", seg, start);
	for (i = start; i < off; i++)
	printk(" ");
	for (; i < end; i++)
	printk("%02x ", fetch_data_byte_abs(seg, i));
	printk("\n");
	start = end;
	end = start + 16;
	}
	}

	void x86emu_single_step(void)
	{
	char s[1024];
	int ps[10];
	int ntok;
	int cmd;
	int done;
	int segment;
	int offset;
	static int breakpoint;
	static int noDecode = 1;

	char *p;

	if (DEBUG_BREAK()) {
	if (M.x86.saved_ip != breakpoint) {
	return;
	} else {
	M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
	M.x86.debug \|= DEBUG_TRACE_F;
	M.x86.debug &= ~DEBUG_BREAK_F;
	print_decoded_instruction();
	X86EMU_trace_regs();
	}
	}
	done = 0;
	offset = M.x86.saved_ip;
	while (!done) {
	printk("-");
	cmd = x86emu_parse_line(s, ps, &ntok);
	switch (cmd) {
	case 'u':
	disassemble_forward(M.x86.saved_cs, (u16) offset, 10);
	break;
	case 'd':
	if (ntok == 2) {
	segment = M.x86.saved_cs;
	offset = ps[1];
	X86EMU_dump_memory(segment, (u16) offset, 16);
	offset += 16;
	} else if (ntok == 3) {
	segment = ps[1];
	offset = ps[2];
	X86EMU_dump_memory(segment, (u16) offset, 16);
	offset += 16;
	} else {
	segment = M.x86.saved_cs;
	X86EMU_dump_memory(segment, (u16) offset, 16);
	offset += 16;
	}
	break;
	case 'c':
	M.x86.debug ^= DEBUG_TRACECALL_F;
	break;
	case 's':
	M.x86.debug ^=
	DEBUG_SVC_F \| DEBUG_SYS_F \| DEBUG_SYSINT_F;
	break;
	case 'r':
	X86EMU_trace_regs();
	break;
	case 'x':
	X86EMU_trace_xregs();
	break;
	case 'g':
	if (ntok == 2) {
	breakpoint = ps[1];
	if (noDecode) {
	M.x86.debug \|= DEBUG_DECODE_NOPRINT_F;
	} else {
	M.x86.debug &= ~DEBUG_DECODE_NOPRINT_F;
	}
	M.x86.debug &= ~DEBUG_TRACE_F;
	M.x86.debug \|= DEBUG_BREAK_F;
	done = 1;
	}
	break;
	case 'q':
	M.x86.debug \|= DEBUG_EXIT;
	return;
	case 'P':
	noDecode = (noDecode) ? 0 : 1;
	printk("Toggled decoding to %s\n",
	(noDecode) ? "FALSE" : "TRUE");
	break;
	case 't':
	case 0:
	done = 1;
	break;
	}
	}
	}

	int X86EMU_trace_on(void)
	{
	return M.x86.debug \|= DEBUG_STEP_F \| DEBUG_DECODE_F \| DEBUG_TRACE_F;
	}

	int X86EMU_trace_off(void)
	{
	return M.x86.debug &= ~(DEBUG_STEP_F \| DEBUG_DECODE_F \| DEBUG_TRACE_F);
	}

	static int x86emu_parse_line(char s, int ps, int *n)
	{
	int cmd;

	*n = 0;
	while (s == ' ' \|\| s == '\t')
	s++;
	ps[n] = s;
	switch (*s) {
	case '\n':
	*n += 1;
	return 0;
	default:
	cmd = *s;
	*n += 1;
	}

	while (1) {
	while (s != ' ' && s != '\t' && *s != '\n')
	s++;

	if (*s == '\n')
	return cmd;

	while (s == ' ' \|\| s == '\t')
	s++;

	*n += 1;
	}
	}

	#endif /* DEBUG */

	void x86emu_dump_regs(void)
	{
	printk("\tAX=%04x ", M.x86.R_AX);
	printk("BX=%04x ", M.x86.R_BX);
	printk("CX=%04x ", M.x86.R_CX);
	printk("DX=%04x ", M.x86.R_DX);
	printk("SP=%04x ", M.x86.R_SP);
	printk("BP=%04x ", M.x86.R_BP);
	printk("SI=%04x ", M.x86.R_SI);
	printk("DI=%04x\n", M.x86.R_DI);
	printk("\tDS=%04x ", M.x86.R_DS);
	printk("ES=%04x ", M.x86.R_ES);
	printk("SS=%04x ", M.x86.R_SS);
	printk("CS=%04x ", M.x86.R_CS);
	printk("IP=%04x ", M.x86.R_IP);
	if (ACCESS_FLAG(F_OF))
	printk("OV "); /* CHECKED... */
	else
	printk("NV ");
	if (ACCESS_FLAG(F_DF))
	printk("DN ");
	else
	printk("UP ");
	if (ACCESS_FLAG(F_IF))
	printk("EI ");
	else
	printk("DI ");
	if (ACCESS_FLAG(F_SF))
	printk("NG ");
	else
	printk("PL ");
	if (ACCESS_FLAG(F_ZF))
	printk("ZR ");
	else
	printk("NZ ");
	if (ACCESS_FLAG(F_AF))
	printk("AC ");
	else
	printk("NA ");
	if (ACCESS_FLAG(F_PF))
	printk("PE ");
	else
	printk("PO ");
	if (ACCESS_FLAG(F_CF))
	printk("CY ");
	else
	printk("NC ");
	printk("\n");
	}

	void x86emu_dump_xregs(void)
	{
	printk("\tEAX=%08x ", M.x86.R_EAX);
	printk("EBX=%08x ", M.x86.R_EBX);
	printk("ECX=%08x ", M.x86.R_ECX);
	printk("EDX=%08x \n", M.x86.R_EDX);
	printk("\tESP=%08x ", M.x86.R_ESP);
	printk("EBP=%08x ", M.x86.R_EBP);
	printk("ESI=%08x ", M.x86.R_ESI);
	printk("EDI=%08x\n", M.x86.R_EDI);
	printk("\tDS=%04x ", M.x86.R_DS);
	printk("ES=%04x ", M.x86.R_ES);
	printk("SS=%04x ", M.x86.R_SS);
	printk("CS=%04x ", M.x86.R_CS);
	printk("EIP=%08x\n\t", M.x86.R_EIP);
	if (ACCESS_FLAG(F_OF))
	printk("OV "); /* CHECKED... */
	else
	printk("NV ");
	if (ACCESS_FLAG(F_DF))
	printk("DN ");
	else
	printk("UP ");
	if (ACCESS_FLAG(F_IF))
	printk("EI ");
	else
	printk("DI ");
	if (ACCESS_FLAG(F_SF))
	printk("NG ");
	else
	printk("PL ");
	if (ACCESS_FLAG(F_ZF))
	printk("ZR ");
	else
	printk("NZ ");
	if (ACCESS_FLAG(F_AF))
	printk("AC ");
	else
	printk("NA ");
	if (ACCESS_FLAG(F_PF))
	printk("PE ");
	else
	printk("PO ");
	if (ACCESS_FLAG(F_CF))
	printk("CY ");
	else
	printk("NC ");
	printk("\n");
	}