src/debug.js - emulators/v86 - Rivoreo Source Code Repositories

 "use strict";

 CPU.prototype.debug_init = function()
 {
     var cpu = this;
     var debug = {};
     this.debug = debug;

     /**
      * wheter or not in step mode
      * used for debugging
      * @type {boolean}
      */
     debug.step_mode = false;
     debug.ops = undefined;
     debug.all_ops = [];

     debug.trace_all = false;

     // "log" some information visually to the user.
     // Also in non-DEBUG modes
     debug.show = function(x)
     {
         if(typeof document !== "undefined")
         {
             var el = document.getElementById("log");

             if(el)
             {
                 el.textContent += x + "\n";
                 el.style.display = "block";
                 el.scrollTop = 1e9;
                 return;
             }
         }

         console.log(x);
     };

     debug.init = function()
     {
         if(!DEBUG) return;

         // used for debugging
         debug.ops = new CircularQueue(200000);

         if(cpu.io)
         {
             // write seabios debug output to console
             var seabios_debug = "";

             cpu.io.register_write(0x402, this, handle); // seabios
             cpu.io.register_write(0x500, this, handle); // vgabios
         }

         function handle(out_byte)
         {
             if(out_byte === 10)
             {
                 dbg_log(seabios_debug, LOG_BIOS);
                 seabios_debug = "";
             }
             else
             {
                 seabios_debug += String.fromCharCode(out_byte);
             }
         }
     };

     debug.dump_regs = dump_regs;
     debug.dump_instructions = dump_instructions;
     debug.get_instructions = get_instructions;
     debug.dump_regs_short = dump_regs_short;
     debug.dump_stack = dump_stack;

     debug.dump_page_directory = dump_page_directory;
     debug.dump_gdt_ldt = dump_gdt_ldt;
     debug.dump_idt = dump_idt;

     debug.get_memory_dump = get_memory_dump;
     debug.memory_hex_dump = memory_hex_dump;
     debug.used_memory_dump = used_memory_dump;

     debug.step = step;
     debug.run_until = run_until;

     debug.debugger = function()
     {
         if(DEBUG)
         {
             debugger;
         }
     }

     /**
      * @param {string=} msg
      */
     debug.unimpl = function(msg)
     {
         var s = "Unimplemented" + (msg ? ": " + msg : "");

         debug.show(s);

         if(DEBUG)
         {
             console.trace();
             return s;
         }
         else
         {
             debug.show("Execution stopped");
             return s;
         }
         //this.name = "Unimplemented";
     }

     function step()
     {
         if(!DEBUG) return;

         if(!cpu.running)
         {
             try
             {
                 cpu.cycle();
             }
             catch(e)
             {
                 cpu.exception_cleanup(e);
             }
         }

         dump_regs_short();
         var now = Date.now();

         cpu.devices.vga.timer(now);
         //this.pit.timer(now);
         //this.rtc.timer(now);

         cpu.running = false;
         dump_instructions();
     }

     function run_until()
     {
         if(!DEBUG) return;

         cpu.running = false;
         var a = parseInt(prompt("input hex", ""), 16);
         if(a) while(cpu.instruction_pointer != a) step();
         dump_regs();
     }

     // http://ref.x86asm.net/x86reference.xml
     // for debuggin" purposes
     var opcode_map = [
         "ADD", "ADD", "ADD", "ADD", "ADD", "ADD", "PUSH", "POP",
         "OR", "OR", "OR", "OR", "OR", "OR", "PUSH", "0F:",
         "ADC", "ADC", "ADC", "ADC", "ADC", "ADC", "PUSH", "POP",
         "SBB", "SBB", "SBB", "SBB", "SBB", "SBB", "PUSH", "POP",
         "AND", "AND", "AND", "AND", "AND", "AND", "ES", "DAA",
         "SUB", "SUB", "SUB", "SUB", "SUB", "SUB", "CS", "DAS",
         "XOR", "XOR", "XOR", "XOR", "XOR", "XOR", "SS", "AAA",
         "CMP", "CMP", "CMP", "CMP", "CMP", "CMP", "DS", "AAS",
         "INC", "INC", "INC", "INC", "INC", "INC", "INC", "INC",
         "DEC", "DEC", "DEC", "DEC", "DEC", "DEC", "DEC", "DEC",
         "PUSH", "PUSH", "PUSH", "PUSH", "PUSH", "PUSH", "PUSH", "PUSH",
         "POP", "POP", "POP", "POP", "POP", "POP", "POP", "POP",
         "PUSHA", "POPA", "BOUND", "ARPL", "FS", "GS", "none", "none",
         "PUSH", "IMUL", "PUSH", "IMUL", "INS", "INS", "OUTS", "OUTS",
         "JO", "JNO", "JB", "JNB", "JZ", "JNZ", "JBE", "JNBE",
         "JS", "JNS", "JP", "JNP", "JL", "JNL", "JLE", "JNLE",
         "ADD", "ADD", "ADD", "ADD", "TEST", "TEST", "XCHG", "XCHG",
         "MOV", "MOV", "MOV", "MOV", "MOV", "LEA", "MOV", "POP",
         "NOP", "XCHG", "XCHG", "XCHG", "XCHG", "XCHG", "XCHG", "XCHG",
         "CBW", "CWD", "CALLF", "FWAIT", "PUSHF", "POPF", "SAHF", "LAHF",
         "MOV", "MOV", "MOV", "MOV", "MOVS", "MOVS", "CMPS", "CMPS",
         "TEST", "TEST", "STOS", "STOS", "LODS", "LODS", "SCAS", "SCAS",
         "MOV", "MOV", "MOV", "MOV", "MOV", "MOV", "MOV", "MOV",
         "MOV", "MOV", "MOV", "MOV", "MOV", "MOV", "MOV", "MOV",
         "ROL", "ROL", "RETN", "RETN", "LES", "LDS", "MOV", "MOV",
         "ENTER", "LEAVE", "RETF", "RETF", "INT", "INT", "INTO", "IRET",
         "ROL", "ROL", "ROL", "ROL", "AAM", "AAD", "none", "XLAT",
         "FADD", "FLD", "FIADD", "FILD", "FADD", "FLD", "FIADD", "FILD",
         "LOOPNZ", "LOOPZ", "LOOP", "JCXZ", "IN", "IN", "OUT", "OUT",
         "CALL", "JMP", "JMPF", "JMP", "IN", "IN", "OUT", "OUT",
         "LOCK", "none", "REPNZ", "REPZ", "HLT", "CMC", "TEST", "TEST",
         "CLC", "STC", "CLI", "STI", "CLD", "STD", "INC", "INC"
     ];

     debug.logop = function(_ip, op)
     {
         if(!DEBUG || !debug.step_mode)
         {
             return;
         }

         if(debug.trace_all && debug.all_ops)
         {
             debug.all_ops.push(_ip, op);
         }
         else if(debug.ops)
         {
             debug.ops.add(_ip);
             debug.ops.add(op);
         }
     }

     function dump_stack(start, end)
     {
         if(!DEBUG) return;

         var esp = cpu.reg32[reg_esp];
         dbg_log("========= STACK ==========");

         if(end >= start || end === undefined)
         {
             start = 5;
             end = -5;
         }

         for(var i = start; i > end; i--)
         {
             var line = "    ";

             if(!i) line = "=>  ";

             line += h(i, 2) + " | ";

             dbg_log(line + h(esp + 4 * i, 8) + " | " + h(cpu.memory.read32s(esp + 4 * i) >>> 0));
         }
     }

     function dump_regs_short()
     {
         if(!DEBUG) return;

         var
             r32 = { "eax": reg_eax, "ecx": reg_ecx, "edx": reg_edx, "ebx": reg_ebx,
                     "esp": reg_esp, "ebp": reg_ebp, "esi": reg_esi, "edi": reg_edi },
             r32_names = ["eax", "ecx", "edx", "ebx", "esp", "ebp", "esi", "edi"],
             s = { "cs": reg_cs, "ds": reg_ds, "es": reg_es, "fs": reg_fs, "gs": reg_gs, "ss": reg_ss },
             line1 = "",
             line2 = "";


         for(var i = 0; i < 4; i++)
         {
             line1 += r32_names[i] + "="  + h(cpu.reg32[r32[r32_names[i]]], 8) + " ";
             line2 += r32_names[i+4] + "="  + h(cpu.reg32[r32[r32_names[i+4]]], 8) + " ";
         }

         line1 += " eip=" + h(cpu.get_real_eip() >>> 0, 8);
         line2 += " flg=" + h(cpu.get_eflags(), 8);

         line1 += "  ds=" + h(cpu.sreg[reg_ds], 4) + " es=" + h(cpu.sreg[reg_es], 4) + "  fs=" + h(cpu.sreg[reg_fs], 4);
         line2 += "  gs=" + h(cpu.sreg[reg_gs], 4) + " cs=" + h(cpu.sreg[reg_cs], 4) + "  ss=" + h(cpu.sreg[reg_ss], 4);

         dbg_log(line1, LOG_CPU);
         dbg_log(line2, LOG_CPU);
     }

     function dump_regs()
     {
         if(!DEBUG) return;

         var
             r32 = { "eax": reg_eax, "ecx": reg_ecx, "edx": reg_edx, "ebx": reg_ebx,
                     "esp": reg_esp, "ebp": reg_ebp, "esi": reg_esi, "edi": reg_edi },

             s = { "cs": reg_cs, "ds": reg_ds, "es": reg_es,
                   "fs": reg_fs, "gs": reg_gs, "ss": reg_ss },

             out;


         dbg_log("----- DUMP (ip = " + h(cpu.instruction_pointer >>> 0) + ") ----------")
         dbg_log("protected mode: " + cpu.protected_mode);

         for(var i in r32)
         {
             dbg_log(i + " =  " + h(cpu.reg32[r32[i]], 8));
         }
         dbg_log("eip =  " + h(cpu.get_real_eip() >>> 0, 8));

         for(i in s)
         {
             dbg_log(i + "  =  " + h(cpu.sreg[s[i]], 4));
         }

         out = "";

         var flg = { "cf": cpu.getcf, "pf": cpu.getpf, "zf": cpu.getzf,  "sf": cpu.getsf,
                     "of": cpu.getof, "df": flag_direction, "if": flag_interrupt };

         for(var i in flg)
         {
             if(+flg[i])
             {
                 out += i + "=" + Number(!!(cpu.flags & flg[i])) + " | ";
             }
             else
             {
                 out += i + "=" + Number(!!flg[i]()) + " | ";
             }
         }
         out += "iopl=" + cpu.getiopl();
         dbg_log(out);


         //dbg_log("last operation: " + h(last_op1 | 0) + ", " +  h(last_op2 | 0) + " = " +
                 //h(last_result | 0) + " (" + last_op_size + " bit)")

     }

     function get_instructions()
     {
         if(!DEBUG) return;

         debug.step_mode = true;

         function add(ip, op)
         {
             out += h(ip, 8)  + ":        " +
                 v86util.pads(opcode_map[op] || "unkown", 20) + h(op, 2) + "\n";
         }

         var opcodes;
         var out = "";

         if(debug.trace_all && debug.all_ops)
         {
             opcodes = debug.all_ops;
         }
         else if(debug.ops)
         {
             opcodes = debug.ops.toArray();
         }

         if(!opcodes)
         {
             return "";
         }

         for(var i = 0; i < opcodes.length; i += 2)
         {
             add(opcodes[i], opcodes[i + 1]);
         }

         debug.ops.clear();
         debug.all_ops = [];

         return out;
     }

     function dump_instructions()
     {
         if(!DEBUG) return;

         debug.show(get_instructions());
     }

     function dump_gdt_ldt()
     {
         if(!DEBUG) return;

         dbg_log("gdt: (len = " + h(cpu.gdtr_size) + ")");
         dump_table(cpu.translate_address_read(cpu.gdtr_offset), cpu.gdtr_size);

         dbg_log("\nldt: (len = " + h(cpu.segment_limits[reg_ldtr]) + ")");
         dump_table(cpu.translate_address_read(cpu.segment_offsets[reg_ldtr]), cpu.segment_limits[reg_ldtr]);

         function dump_table(addr, size)
         {
             for(var i = 0; i < size; i += 8, addr += 8)
             {
                 var base = cpu.memory.read16(addr + 2) |
                         cpu.memory.read8(addr + 4) << 16 |
                         cpu.memory.read8(addr + 7) << 24,

                     limit = cpu.memory.read16(addr) | (cpu.memory.read8(addr + 6) & 0xF) << 16,
                     access = cpu.memory.read8(addr + 5),
                     flags = cpu.memory.read8(addr + 6) >> 4,
                     flags_str = "",
                     dpl = access >> 5 & 3;

                 if(!(access & 128))
                 {
                     // present bit not set
                     //continue;
                     flags_str += "NP ";
                 }
                 else
                 {
                     flags_str += " P ";
                 }

                 if(access & 16)
                 {
                     if(flags & 4)
                     {
                         flags_str += "32b ";
                     }
                     else
                     {
                         flags_str += "16b ";
                     }

                     if(access & 8)
                     {
                         // executable
                         flags_str += "X ";

                         if(access & 4)
                         {
                             flags_str += "C ";
                         }
                     }
                     else
                     {
                         // data
                         flags_str += "R ";
                     }
                 }
                 else
                 {
                     // system
                     flags_str += "sys: " + h(access & 15);
                 }

                 if(flags & 8)
                 {
                     limit = limit << 12 | 0xFFF;
                 }

                 dbg_log(h(i & ~7, 4) + " " + h(base >>> 0, 8) + " (" + h(limit >>> 0, 8) + " bytes) " +
                         flags_str + ";  dpl = " + dpl + ", a = " + access.toString(2) +
                         ", f = " + flags.toString(2));
             }
         }
     }

     function dump_idt()
     {
         if(!DEBUG) return;

         for(var i = 0; i < cpu.idtr_size; i += 8)
         {
             var addr = cpu.translate_address_system_read(cpu.idtr_offset + i),
                 base = cpu.memory.read16(addr) | cpu.memory.read16(addr + 6) << 16,
                 selector = cpu.memory.read16(addr + 2),
                 type = cpu.memory.read8(addr + 5),
                 line,
                 dpl = type >> 5 & 3;

             if((type & 31) === 5)
             {
                 line = "task gate ";
             }
             else if((type & 31) === 14)
             {
                 line = "intr gate ";
             }
             else if((type & 31) === 15)
             {
                 line = "trap gate ";
             }
             else
             {
                 line = "invalid   ";
             }


             if(type & 128)
             {
                 line += " P";
             }
             else
             {
                 // present bit not set
                 //continue;
                 line += "NP";
             }


             dbg_log(h(i >> 3, 4) + " " + h(base >>> 0, 8) + ", " +
                     h(selector, 4) + "; " + line + ";  dpl = " + dpl + ", t = " + type.toString(2));
         }
     }

     function load_page_entry(dword_entry, is_directory)
     {
         if(!DEBUG) return;

         if(!(dword_entry & 1))
         {
             // present bit not set
             return false;
         }

         var size = (dword_entry & 128) === 128,
             address;

         if(size && !is_directory)
         {
             address = dword_entry & 0xFFC00000;
         }
         else
         {
             address = dword_entry & 0xFFFFF000;
         }

         return {
             size: size,
             global: (dword_entry & 256) === 256,
             accessed: (dword_entry & 0x20) === 0x20,
             dirty: (dword_entry & 0x40) === 0x40,
             cache_disable : (dword_entry & 16) === 16,
             user : (dword_entry & 4) === 4,
             read_write : (dword_entry & 2) === 2,
             address : address >>> 0
         };
     }

     function dump_page_directory()
     {
         if(!DEBUG) return;

         for(var i = 0; i < 1024; i++)
         {
             var dword = cpu.memory.read32s(cpu.cr[3] + 4 * i),
                 entry = load_page_entry(dword, true);

             if(!entry)
             {
                 continue;
             }

             var flags = "";

             flags += entry.size ? "S " : "  ";
             flags += entry.accessed ? "A " : "  ";
             flags += entry.cache_disable ? "Cd " : "  ";
             flags += entry.user ? "U " : "  ";
             flags += entry.read_write ? "Rw " : "   ";

             if(entry.size)
             {
                 dbg_log("=== " + h((i << 22) >>> 0, 8) + " -> " + h(entry.address >>> 0, 8) + " | " + flags);
                 continue;
             }
             else
             {
                 dbg_log("=== " + h((i << 22) >>> 0, 8) + " | " + flags);
             }

             for(var j = 0; j < 1024; j++)
             {
                 dword = cpu.memory.read32s(entry.address + 4 * j);

                 var subentry = load_page_entry(dword, false);

                 if(subentry)
                 {
                     flags = "";

                     flags += subentry.cache_disable ? "Cd " : "   ";
                     flags += subentry.user ? "U " : "  ";
                     flags += subentry.read_write ? "Rw " : "   ";
                     flags += subentry.global ? "G " : "  ";
                     flags += subentry.accessed ? "A " : "  ";
                     flags += subentry.dirty ? "Di " : "   ";

                     dbg_log("# " + h((i << 22 | j << 12) >>> 0, 8) + " -> " +
                             h(subentry.address, 8) + " | " + flags);
                 }
             }
         }
     }


     function get_memory_dump(start, count)
     {
         if(!DEBUG) return;

         if(start === undefined)
         {
             start = 0;
             count = cpu.memory_size;
         }
         else if(count === undefined)
         {
             count = start;
             start = 0;
         }

         return cpu.memory.mem8.slice(start, start + count).buffer;
     }


     function memory_hex_dump(addr, length)
     {
         if(!DEBUG) return;

         length = length || 4 * 0x10;
         var line, byt;

         for(var i = 0; i < length >> 4; i++)
         {
             line = h(addr + (i << 4), 5) + "   ";

             for(var j = 0; j < 0x10; j++)
             {
                 byt = cpu.memory.read8(addr + (i << 4) + j);
                 line += h(byt, 2) + " ";
             }

             line += "  ";

             for(j = 0; j < 0x10; j++)
             {
                 byt = cpu.memory.read8(addr + (i << 4) + j);
                 line += (byt < 33 || byt > 126) ? "." : String.fromCharCode(byt);
             }

             dbg_log(line);
         }
     }

     function used_memory_dump()
     {
         if(!DEBUG) return;

         var width = 0x80,
             height = 0x10,
             block_size = cpu.memory_size / width / height | 0,
             row;

         for(var i = 0; i < height; i++)
         {
             row = h(i * width * block_size, 8) + " | ";

             for(var j = 0; j < width; j++)
             {
                 var used = cpu.memory.mem32s[(i * width + j) * block_size] > 0;

                 row += used ? "X" : " ";
             }

             dbg_log(row);
         }
     };

 }
	"use strict";

	CPU.prototype.debug_init = function()
	{
	var cpu = this;
	var debug = {};
	this.debug = debug;

	/**
	* wheter or not in step mode
	* used for debugging
	* @type {boolean}
	*/
	debug.step_mode = false;
	debug.ops = undefined;
	debug.all_ops = [];

	debug.trace_all = false;

	// "log" some information visually to the user.
	// Also in non-DEBUG modes
	debug.show = function(x)
	{
	if(typeof document !== "undefined")
	{
	var el = document.getElementById("log");

	if(el)
	{
	el.textContent += x + "\n";
	el.style.display = "block";
	el.scrollTop = 1e9;
	return;
	}
	}

	console.log(x);
	};

	debug.init = function()
	{
	if(!DEBUG) return;

	// used for debugging
	debug.ops = new CircularQueue(200000);

	if(cpu.io)
	{
	// write seabios debug output to console
	var seabios_debug = "";

	cpu.io.register_write(0x402, this, handle); // seabios
	cpu.io.register_write(0x500, this, handle); // vgabios
	}

	function handle(out_byte)
	{
	if(out_byte === 10)
	{
	dbg_log(seabios_debug, LOG_BIOS);
	seabios_debug = "";
	}
	else
	{
	seabios_debug += String.fromCharCode(out_byte);
	}
	}
	};

	debug.dump_regs = dump_regs;
	debug.dump_instructions = dump_instructions;
	debug.get_instructions = get_instructions;
	debug.dump_regs_short = dump_regs_short;
	debug.dump_stack = dump_stack;

	debug.dump_page_directory = dump_page_directory;
	debug.dump_gdt_ldt = dump_gdt_ldt;
	debug.dump_idt = dump_idt;

	debug.get_memory_dump = get_memory_dump;
	debug.memory_hex_dump = memory_hex_dump;
	debug.used_memory_dump = used_memory_dump;

	debug.step = step;
	debug.run_until = run_until;

	debug.debugger = function()
	{
	if(DEBUG)
	{
	debugger;
	}
	}

	/**
	* @param {string=} msg
	*/
	debug.unimpl = function(msg)
	{
	var s = "Unimplemented" + (msg ? ": " + msg : "");

	debug.show(s);

	if(DEBUG)
	{
	console.trace();
	return s;
	}
	else
	{
	debug.show("Execution stopped");
	return s;
	}
	//this.name = "Unimplemented";
	}

	function step()
	{
	if(!DEBUG) return;

	if(!cpu.running)
	{
	try
	{
	cpu.cycle();
	}
	catch(e)
	{
	cpu.exception_cleanup(e);
	}
	}

	dump_regs_short();
	var now = Date.now();

	cpu.devices.vga.timer(now);
	//this.pit.timer(now);
	//this.rtc.timer(now);

	cpu.running = false;
	dump_instructions();
	}

	function run_until()
	{
	if(!DEBUG) return;

	cpu.running = false;
	var a = parseInt(prompt("input hex", ""), 16);
	if(a) while(cpu.instruction_pointer != a) step();
	dump_regs();
	}

	// http://ref.x86asm.net/x86reference.xml
	// for debuggin" purposes
	var opcode_map = [
	"ADD", "ADD", "ADD", "ADD", "ADD", "ADD", "PUSH", "POP",
	"OR", "OR", "OR", "OR", "OR", "OR", "PUSH", "0F:",
	"ADC", "ADC", "ADC", "ADC", "ADC", "ADC", "PUSH", "POP",
	"SBB", "SBB", "SBB", "SBB", "SBB", "SBB", "PUSH", "POP",
	"AND", "AND", "AND", "AND", "AND", "AND", "ES", "DAA",
	"SUB", "SUB", "SUB", "SUB", "SUB", "SUB", "CS", "DAS",
	"XOR", "XOR", "XOR", "XOR", "XOR", "XOR", "SS", "AAA",
	"CMP", "CMP", "CMP", "CMP", "CMP", "CMP", "DS", "AAS",
	"INC", "INC", "INC", "INC", "INC", "INC", "INC", "INC",
	"DEC", "DEC", "DEC", "DEC", "DEC", "DEC", "DEC", "DEC",
	"PUSH", "PUSH", "PUSH", "PUSH", "PUSH", "PUSH", "PUSH", "PUSH",
	"POP", "POP", "POP", "POP", "POP", "POP", "POP", "POP",
	"PUSHA", "POPA", "BOUND", "ARPL", "FS", "GS", "none", "none",
	"PUSH", "IMUL", "PUSH", "IMUL", "INS", "INS", "OUTS", "OUTS",
	"JO", "JNO", "JB", "JNB", "JZ", "JNZ", "JBE", "JNBE",
	"JS", "JNS", "JP", "JNP", "JL", "JNL", "JLE", "JNLE",
	"ADD", "ADD", "ADD", "ADD", "TEST", "TEST", "XCHG", "XCHG",
	"MOV", "MOV", "MOV", "MOV", "MOV", "LEA", "MOV", "POP",
	"NOP", "XCHG", "XCHG", "XCHG", "XCHG", "XCHG", "XCHG", "XCHG",
	"CBW", "CWD", "CALLF", "FWAIT", "PUSHF", "POPF", "SAHF", "LAHF",
	"MOV", "MOV", "MOV", "MOV", "MOVS", "MOVS", "CMPS", "CMPS",
	"TEST", "TEST", "STOS", "STOS", "LODS", "LODS", "SCAS", "SCAS",
	"MOV", "MOV", "MOV", "MOV", "MOV", "MOV", "MOV", "MOV",
	"MOV", "MOV", "MOV", "MOV", "MOV", "MOV", "MOV", "MOV",
	"ROL", "ROL", "RETN", "RETN", "LES", "LDS", "MOV", "MOV",
	"ENTER", "LEAVE", "RETF", "RETF", "INT", "INT", "INTO", "IRET",
	"ROL", "ROL", "ROL", "ROL", "AAM", "AAD", "none", "XLAT",
	"FADD", "FLD", "FIADD", "FILD", "FADD", "FLD", "FIADD", "FILD",
	"LOOPNZ", "LOOPZ", "LOOP", "JCXZ", "IN", "IN", "OUT", "OUT",
	"CALL", "JMP", "JMPF", "JMP", "IN", "IN", "OUT", "OUT",
	"LOCK", "none", "REPNZ", "REPZ", "HLT", "CMC", "TEST", "TEST",
	"CLC", "STC", "CLI", "STI", "CLD", "STD", "INC", "INC"
	];

	debug.logop = function(_ip, op)
	{
	if(!DEBUG \|\| !debug.step_mode)
	{
	return;
	}

	if(debug.trace_all && debug.all_ops)
	{
	debug.all_ops.push(_ip, op);
	}
	else if(debug.ops)
	{
	debug.ops.add(_ip);
	debug.ops.add(op);
	}
	}

	function dump_stack(start, end)
	{
	if(!DEBUG) return;

	var esp = cpu.reg32[reg_esp];
	dbg_log("========= STACK ==========");

	if(end >= start \|\| end === undefined)
	{
	start = 5;
	end = -5;
	}

	for(var i = start; i > end; i--)
	{
	var line = " ";

	if(!i) line = "=> ";

	line += h(i, 2) + " \| ";

	dbg_log(line + h(esp + 4 * i, 8) + " \| " + h(cpu.memory.read32s(esp + 4 * i) >>> 0));
	}
	}

	function dump_regs_short()
	{
	if(!DEBUG) return;

	var
	r32 = { "eax": reg_eax, "ecx": reg_ecx, "edx": reg_edx, "ebx": reg_ebx,
	"esp": reg_esp, "ebp": reg_ebp, "esi": reg_esi, "edi": reg_edi },
	r32_names = ["eax", "ecx", "edx", "ebx", "esp", "ebp", "esi", "edi"],
	s = { "cs": reg_cs, "ds": reg_ds, "es": reg_es, "fs": reg_fs, "gs": reg_gs, "ss": reg_ss },
	line1 = "",
	line2 = "";



	for(var i = 0; i < 4; i++)
	{
	line1 += r32_names[i] + "=" + h(cpu.reg32[r32[r32_names[i]]], 8) + " ";
	line2 += r32_names[i+4] + "=" + h(cpu.reg32[r32[r32_names[i+4]]], 8) + " ";
	}

	line1 += " eip=" + h(cpu.get_real_eip() >>> 0, 8);
	line2 += " flg=" + h(cpu.get_eflags(), 8);

	line1 += " ds=" + h(cpu.sreg[reg_ds], 4) + " es=" + h(cpu.sreg[reg_es], 4) + " fs=" + h(cpu.sreg[reg_fs], 4);
	line2 += " gs=" + h(cpu.sreg[reg_gs], 4) + " cs=" + h(cpu.sreg[reg_cs], 4) + " ss=" + h(cpu.sreg[reg_ss], 4);

	dbg_log(line1, LOG_CPU);
	dbg_log(line2, LOG_CPU);
	}

	function dump_regs()
	{
	if(!DEBUG) return;

	var
	r32 = { "eax": reg_eax, "ecx": reg_ecx, "edx": reg_edx, "ebx": reg_ebx,
	"esp": reg_esp, "ebp": reg_ebp, "esi": reg_esi, "edi": reg_edi },

	s = { "cs": reg_cs, "ds": reg_ds, "es": reg_es,
	"fs": reg_fs, "gs": reg_gs, "ss": reg_ss },

	out;


	dbg_log("----- DUMP (ip = " + h(cpu.instruction_pointer >>> 0) + ") ----------")
	dbg_log("protected mode: " + cpu.protected_mode);

	for(var i in r32)
	{
	dbg_log(i + " = " + h(cpu.reg32[r32[i]], 8));
	}
	dbg_log("eip = " + h(cpu.get_real_eip() >>> 0, 8));

	for(i in s)
	{
	dbg_log(i + " = " + h(cpu.sreg[s[i]], 4));
	}

	out = "";

	var flg = { "cf": cpu.getcf, "pf": cpu.getpf, "zf": cpu.getzf, "sf": cpu.getsf,
	"of": cpu.getof, "df": flag_direction, "if": flag_interrupt };

	for(var i in flg)
	{
	if(+flg[i])
	{
	out += i + "=" + Number(!!(cpu.flags & flg[i])) + " \| ";
	}
	else
	{
	out += i + "=" + Number(!!flg[i]()) + " \| ";
	}
	}
	out += "iopl=" + cpu.getiopl();
	dbg_log(out);


	//dbg_log("last operation: " + h(last_op1 \| 0) + ", " + h(last_op2 \| 0) + " = " +
	//h(last_result \| 0) + " (" + last_op_size + " bit)")

	}

	function get_instructions()
	{
	if(!DEBUG) return;

	debug.step_mode = true;

	function add(ip, op)
	{
	out += h(ip, 8) + ": " +
	v86util.pads(opcode_map[op] \|\| "unkown", 20) + h(op, 2) + "\n";
	}

	var opcodes;
	var out = "";

	if(debug.trace_all && debug.all_ops)
	{
	opcodes = debug.all_ops;
	}
	else if(debug.ops)
	{
	opcodes = debug.ops.toArray();
	}

	if(!opcodes)
	{
	return "";
	}

	for(var i = 0; i < opcodes.length; i += 2)
	{
	add(opcodes[i], opcodes[i + 1]);
	}

	debug.ops.clear();
	debug.all_ops = [];

	return out;
	}

	function dump_instructions()
	{
	if(!DEBUG) return;

	debug.show(get_instructions());
	}

	function dump_gdt_ldt()
	{
	if(!DEBUG) return;

	dbg_log("gdt: (len = " + h(cpu.gdtr_size) + ")");
	dump_table(cpu.translate_address_read(cpu.gdtr_offset), cpu.gdtr_size);

	dbg_log("\nldt: (len = " + h(cpu.segment_limits[reg_ldtr]) + ")");
	dump_table(cpu.translate_address_read(cpu.segment_offsets[reg_ldtr]), cpu.segment_limits[reg_ldtr]);

	function dump_table(addr, size)
	{
	for(var i = 0; i < size; i += 8, addr += 8)
	{
	var base = cpu.memory.read16(addr + 2) \|
	cpu.memory.read8(addr + 4) << 16 \|
	cpu.memory.read8(addr + 7) << 24,

	limit = cpu.memory.read16(addr) \| (cpu.memory.read8(addr + 6) & 0xF) << 16,
	access = cpu.memory.read8(addr + 5),
	flags = cpu.memory.read8(addr + 6) >> 4,
	flags_str = "",
	dpl = access >> 5 & 3;

	if(!(access & 128))
	{
	// present bit not set
	//continue;
	flags_str += "NP ";
	}
	else
	{
	flags_str += " P ";
	}

	if(access & 16)
	{
	if(flags & 4)
	{
	flags_str += "32b ";
	}
	else
	{
	flags_str += "16b ";
	}

	if(access & 8)
	{
	// executable
	flags_str += "X ";

	if(access & 4)
	{
	flags_str += "C ";
	}
	}
	else
	{
	// data
	flags_str += "R ";
	}
	}
	else
	{
	// system
	flags_str += "sys: " + h(access & 15);
	}

	if(flags & 8)
	{
	limit = limit << 12 \| 0xFFF;
	}

	dbg_log(h(i & ~7, 4) + " " + h(base >>> 0, 8) + " (" + h(limit >>> 0, 8) + " bytes) " +
	flags_str + "; dpl = " + dpl + ", a = " + access.toString(2) +
	", f = " + flags.toString(2));
	}
	}
	}

	function dump_idt()
	{
	if(!DEBUG) return;

	for(var i = 0; i < cpu.idtr_size; i += 8)
	{
	var addr = cpu.translate_address_system_read(cpu.idtr_offset + i),
	base = cpu.memory.read16(addr) \| cpu.memory.read16(addr + 6) << 16,
	selector = cpu.memory.read16(addr + 2),
	type = cpu.memory.read8(addr + 5),
	line,
	dpl = type >> 5 & 3;

	if((type & 31) === 5)
	{
	line = "task gate ";
	}
	else if((type & 31) === 14)
	{
	line = "intr gate ";
	}
	else if((type & 31) === 15)
	{
	line = "trap gate ";
	}
	else
	{
	line = "invalid ";
	}


	if(type & 128)
	{
	line += " P";
	}
	else
	{
	// present bit not set
	//continue;
	line += "NP";
	}


	dbg_log(h(i >> 3, 4) + " " + h(base >>> 0, 8) + ", " +
	h(selector, 4) + "; " + line + "; dpl = " + dpl + ", t = " + type.toString(2));
	}
	}

	function load_page_entry(dword_entry, is_directory)
	{
	if(!DEBUG) return;

	if(!(dword_entry & 1))
	{
	// present bit not set
	return false;
	}

	var size = (dword_entry & 128) === 128,
	address;

	if(size && !is_directory)
	{
	address = dword_entry & 0xFFC00000;
	}
	else
	{
	address = dword_entry & 0xFFFFF000;
	}

	return {
	size: size,
	global: (dword_entry & 256) === 256,
	accessed: (dword_entry & 0x20) === 0x20,
	dirty: (dword_entry & 0x40) === 0x40,
	cache_disable : (dword_entry & 16) === 16,
	user : (dword_entry & 4) === 4,
	read_write : (dword_entry & 2) === 2,
	address : address >>> 0
	};
	}

	function dump_page_directory()
	{
	if(!DEBUG) return;

	for(var i = 0; i < 1024; i++)
	{
	var dword = cpu.memory.read32s(cpu.cr[3] + 4 * i),
	entry = load_page_entry(dword, true);

	if(!entry)
	{
	continue;
	}

	var flags = "";

	flags += entry.size ? "S " : " ";
	flags += entry.accessed ? "A " : " ";
	flags += entry.cache_disable ? "Cd " : " ";
	flags += entry.user ? "U " : " ";
	flags += entry.read_write ? "Rw " : " ";

	if(entry.size)
	{
	dbg_log("=== " + h((i << 22) >>> 0, 8) + " -> " + h(entry.address >>> 0, 8) + " \| " + flags);
	continue;
	}
	else
	{
	dbg_log("=== " + h((i << 22) >>> 0, 8) + " \| " + flags);
	}

	for(var j = 0; j < 1024; j++)
	{
	dword = cpu.memory.read32s(entry.address + 4 * j);

	var subentry = load_page_entry(dword, false);

	if(subentry)
	{
	flags = "";

	flags += subentry.cache_disable ? "Cd " : " ";
	flags += subentry.user ? "U " : " ";
	flags += subentry.read_write ? "Rw " : " ";
	flags += subentry.global ? "G " : " ";
	flags += subentry.accessed ? "A " : " ";
	flags += subentry.dirty ? "Di " : " ";

	dbg_log("# " + h((i << 22 \| j << 12) >>> 0, 8) + " -> " +
	h(subentry.address, 8) + " \| " + flags);
	}
	}
	}
	}


	function get_memory_dump(start, count)
	{
	if(!DEBUG) return;

	if(start === undefined)
	{
	start = 0;
	count = cpu.memory_size;
	}
	else if(count === undefined)
	{
	count = start;
	start = 0;
	}

	return cpu.memory.mem8.slice(start, start + count).buffer;
	}


	function memory_hex_dump(addr, length)
	{
	if(!DEBUG) return;

	length = length \|\| 4 * 0x10;
	var line, byt;

	for(var i = 0; i < length >> 4; i++)
	{
	line = h(addr + (i << 4), 5) + " ";

	for(var j = 0; j < 0x10; j++)
	{
	byt = cpu.memory.read8(addr + (i << 4) + j);
	line += h(byt, 2) + " ";
	}

	line += " ";

	for(j = 0; j < 0x10; j++)
	{
	byt = cpu.memory.read8(addr + (i << 4) + j);
	line += (byt < 33 \|\| byt > 126) ? "." : String.fromCharCode(byt);
	}

	dbg_log(line);
	}
	}

	function used_memory_dump()
	{
	if(!DEBUG) return;

	var width = 0x80,
	height = 0x10,
	block_size = cpu.memory_size / width / height \| 0,
	row;

	for(var i = 0; i < height; i++)
	{
	row = h(i * width * block_size, 8) + " \| ";

	for(var j = 0; j < width; j++)
	{
	var used = cpu.memory.mem32s[(i * width + j) * block_size] > 0;

	row += used ? "X" : " ";
	}

	dbg_log(row);
	}
	};

	}