Split out core code

commands.lua

@@ -0,0 +1,608 @@
+local _p = emu.log
+local function print(data)
+  _p(data .. "")
+end
+
+return function(server)
+    local me = {}
+
+    local function responseCheckpointInfo(requestId, checkpt, hit)
+        local r = {}
+
+        r[#r+1] = server.uint32ToLittleEndian(checkpt.num)
+        r[#r+1] = server.boolToLittleEndian(hit)
+
+        r[#r+1] = server.uint16ToLittleEndian(checkpt.start)
+        r[#r+1] = server.uint16ToLittleEndian(checkpt.finish)
+        r[#r+1] = server.boolToLittleEndian(checkpt.stop)
+        r[#r+1] = server.boolToLittleEndian(checkpt.enabled)
+        r[#r+1] = server.uint8ToLittleEndian(checkpt.op)
+        r[#r+1] = server.boolToLittleEndian(checkpt.temp)
+
+        r[#r+1] = server.uint32ToLittleEndian(checkpt.hitCount)
+        r[#r+1] = server.uint32ToLittleEndian(checkpt.ignoreCount)
+        r[#r+1] = server.boolToLittleEndian(checkpt.condition ~= nil)
+        r[#r+1] = server.uint32ToLittleEndian(checkpt.memspace)
+
+        server.response(server.responseType.CHECKPOINT_INFO, server.errorType.OK, requestId, table.concat(r))
+    end
+
+    local regMeta = {
+        a =  { name = "A",  id = 0, size = 1 },
+        x =  { name = "X",  id = 1, size = 1 },
+        y =  { name = "Y",  id = 2, size = 1 },
+        pc = { name = "PC", id = 3, size = 2 },
+        sp =  { name = "SP", id = 4, size = 1 },
+        status =  { name = "FL", id = 5, size = 1 },
+    }
+
+    local function responseRegisterInfo(requestId)
+        if requestId == nil then
+            error("request id was nil", 2)
+        end
+
+        local r = {}
+        local regs = emu.getState().cpu
+
+        local count = 0
+        for name, meta in pairs(regMeta) do
+            count = count + 1
+        end
+
+        r[#r+1] = server.uint16ToLittleEndian(count)
+
+        local itemSize = 3
+        for name, meta in pairs(regMeta) do
+            r[#r+1] = server.uint8ToLittleEndian(itemSize)
+            r[#r+1] = server.uint8ToLittleEndian(meta.id)
+            r[#r+1] = server.uint16ToLittleEndian(regs[name])
+        end
+
+        server.response(server.responseType.REGISTER_INFO, server.errorType.OK, requestId, table.concat(r))
+    end
+
+    local function responseStopped()
+        local pc = emu.getState().cpu.pc
+
+        server.response(server.responseType.STOPPED, server.errorType.OK, server.EVENT_ID, server.uint16ToLittleEndian(pc))
+    end
+
+    local function responseResumed()
+        local pc = emu.getState().cpu.pc
+
+        server.response(server.responseType.RESUMED, server.errorType.OK, server.EVENT_ID, server.uint16ToLittleEndian(pc))
+    end
+
+    function me.monitorOpened()
+        print("Monitor opened")
+        responseRegisterInfo(server.EVENT_ID)
+        responseStopped(server.EVENT_ID)
+    end
+
+    function me.monitorClosed()
+        print("Monitor closed")
+        responseRegisterInfo(server.EVENT_ID)
+        responseResumed(server.EVENT_ID)
+    end
+
+    local function processAdvanceInstructions(command)
+        if command.length < 3 then
+            server.errorResponse(server.errorType.CMD_INVALID_LENGTH, command.requestId)
+            return
+        end
+
+        local stepOverSubroutines = server.readBool(command.body, 1)
+        local count = server.readUint16(command.body, 2)
+
+        server.stepping = true
+        if stepOverSubroutines then
+            -- FIXME
+            emu.execute(count, emu.executeCountType.cpuInstructions)
+        else
+            emu.execute(count, emu.executeCountType.cpuInstructions)
+        end
+
+        server.running = true
+
+        server.response(server.responseType.ADVANCE_INSTRUCTIONS, server.errorType.OK, command.requestId, nil)
+
+        me.monitorClosed()
+    end
+
+    local function processPing(command)
+        server.response(server.responseType.PING, server.errorType.OK, command.requestId, nil)
+    end
+
+    local function processExit(command)
+        server.running = true
+
+        server.response(server.responseType.EXIT, server.errorType.OK, command.requestId, nil)
+
+        me.monitorClosed()
+    end
+
+    local function processReset(command)
+        server.running = true
+        emu.reset()
+
+        server.response(server.responseType.RESET, server.errorType.OK, command.requestId, nil)
+
+        me.monitorClosed()
+    end
+
+    local memspaces = {
+        MAIN = 0,
+        INVALID = -1,
+    }
+
+    local function getRequestedMemspace(requestedMemspace)
+        if requestedMemspace == 0 then
+            return memspaces.MAIN
+        else
+            return memspaces.INVALID
+        end
+    end
+
+    local banks = {
+        default = 0,
+        cpu = 1,
+        ppu = 2,
+        palette = 3,
+        oam = 4,
+        secondaryOam = 5
+    }
+
+    local function validateBanknum(memspace, banknum)
+        return memspace == memspaces.MAIN and banknum >= banks.default and banknum <= banks.secondaryOam
+    end
+
+    local function processMemorySet(command)
+        local newSidefx = server.readBool(command.body, 1)
+
+        local startAddress = server.readUint16(command.body, 2)
+        local endAddress = server.readUint16(command.body, 4)
+
+        if startAddress > endAddress then
+            server.errorResponse(server.errorType.INVALID_PARAMETER, command.requestId)
+            return
+        end
+
+        local length = endAddress - startAddress + 1
+
+        if command.length < length + 8 then
+            server.errorResponse(server.errorType.CMD_INVALID_LENGTH, command.requestId)
+            return
+        end
+
+        local requestedMemspace = server.readUint8(command.body, 6)
+        local requestedBanknum = server.readUint16(command.body, 7)
+
+        local memspace = getRequestedMemspace(requestedMemspace)
+
+        if memspace == memspaces.INVALID then
+            server.errorResponse(server.errorType.INVALID_MEMSPACE, command.requestId)
+            return
+        end
+
+        if not validateBanknum(memspace, requestedBanknum) then
+            server.errorResponse(server.errorType.INVALID_PARAMETER, command.requestId)
+            return
+        end
+
+        local banknum = requestedBanknum
+
+        if banknum == banks.default then
+            banknum = banks.cpu
+        end
+
+        if not newSidefx and ( banknum == banks.cpu or banknum == banks.ppu ) then
+            banknum = banknum + 0x100
+        end
+
+        banknum = banknum - 1
+
+        for i = 0,length - 1,1 do
+            local val = command.body:byte(8 + i + 1)
+            print(val)
+            emu.write(startAddress + i, val, banknum)
+        end
+
+        server.response(server.responseType.MEM_SET, server.errorType.OK, command.requestId, nil)
+    end
+
+    local function processMemoryGet(command)
+        if command.length < 8 then
+            server.errorResponse(server.errorType.CMD_INVALID_LENGTH, command.requestId)
+            return
+        end
+
+        local newSidefx = server.readBool(command.body, 1)
+
+        local startAddress = server.readUint16(command.body, 2)
+        local endAddress = server.readUint16(command.body, 4)
+
+        if startAddress > endAddress then
+            server.errorResponse(server.errorType.INVALID_PARAMETER, command.requestId)
+            return
+        end
+
+        local requestedMemspace = server.readUint8(command.body, 6)
+        local memspace = getRequestedMemspace(requestedMemspace)
+
+        if memspace == memspaces.INVALID then
+            server.errorResponse(server.errorType.INVALID_MEMSPACE, command.requestId)
+            return
+        end
+
+        local length = endAddress - startAddress + 1
+
+        local requestedBanknum = server.readUint16(command.body, 7)
+
+        if not validateBanknum(memspace, requestedBanknum) then
+            server.errorResponse(server.errorType.INVALID_PARAMETER, command.requestId)
+            return
+        end
+
+        local banknum = requestedBanknum
+
+        local r = {}
+
+        r[#r+1] = server.uint16ToLittleEndian(length)
+
+        if banknum == banks.default then
+            banknum = banks.cpu
+        end
+
+        if not newSidefx and ( banknum == banks.cpu or banknum == banks.ppu ) then
+            banknum = banknum + 0x100
+        end
+
+        banknum = banknum - 1
+
+        local remainingByte = length % 2 ~= 0
+        for addr=startAddress,endAddress-1,2 do
+            r[#r+1] = server.uint16ToLittleEndian(emu.readWord(addr, banknum))
+        end
+        if remainingByte then
+            r[#r+1] = server.uint8ToLittleEndian(emu.read(addr, banknum))
+        end
+
+        server.response(server.responseType.MEM_GET, server.errorType.OK, command.requestId, table.concat(r))
+    end
+
+    nextTrap = 1
+    traps = {}
+    local operation = {
+        READ  = 0x01,
+        WRITE = 0x02,
+        EXEC  = 0x04,
+    }
+
+    local trapHandle
+
+    local function addCheckpoint(start, finish, stop, enabled, op, temp)
+        local num = nextTrap
+        nextTrap = nextTrap+1
+        local trap = {
+            start = start,
+            finish = finish,
+            stop = stop,
+            enabled = enabled,
+            op = op,
+            temp = temp,
+            hitCount = 0,
+            ignoreCount = 0,
+            condition = nil,
+            memspace = 0,
+            num = num,
+        }
+        traps[#traps+1] = trap
+
+        if trap.op & operation.EXEC ~= 0 then
+            trap.execRegistration = emu.addMemoryCallback(function()
+                if trap.enabled then
+                    trapHandle(trap)
+                end
+            end, emu.memCallbackType.cpuExec, trap.start, trap.finish)
+        end
+        if trap.op & operation.READ ~= 0 then
+            trap.readRegistration = emu.addMemoryCallback(function()
+                if trap.enabled then
+                    trapHandle(trap)
+                end
+            end, emu.memCallbackType.cpuRead, trap.start, trap.finish)
+        end
+        if trap.op & operation.WRITE ~= 0 then
+            trap.writeRegistration = emu.addMemoryCallback(function()
+                if trap.enabled then
+                    trapHandle(trap)
+                end
+            end, emu.memCallbackType.cpuRead, trap.start, trap.finish)
+        end
+        return trap
+    end
+
+    local function removeCheckpoint(num)
+        local trap
+        for i=#traps,1,-1 do
+            trap = traps[i]
+            if trap.num == num then
+                table.remove(traps, i)
+                break
+            end
+            trap = nil
+        end
+
+        if trap == nil then
+            return false
+        end
+
+        if trap.execRegistration ~= nil then
+            emu.removeMemoryCallback(trap.execRegistration, emu.memCallbackType.cpuExec, trap.start, trap.finish)
+        end
+        if trap.readRegistration ~= nil then
+            emu.removeMemoryCallback(trap.readRegistration, emu.memCallbackType.cpuRead, trap.start, trap.finish)
+        end
+        if trap.writeRegistration ~= nil then
+            emu.removeMemoryCallback(trap.writeRegistration, emu.memCallbackType.cpuWrite, trap.start, trap.finish)
+        end
+
+        return true
+    end
+
+    local function toggleCheckpoint(enable, num)
+        for i=#traps,1,-1 do
+            trap = traps[i]
+            if trap.num == num then
+                break
+            end
+            trap = nil
+        end
+
+        if trap == nil then
+            return false
+        end
+
+        trap.enabled = enable
+
+        return true
+    end
+
+    local function processCheckpointGet(command)
+        if command.length < 4 then
+            server.errorResponse(server.errorType.CMD_INVALID_LENGTH, command.requestId)
+            return
+        end
+
+        local num = server.readUint32(command.body, 1)
+
+        for i=#traps,1,-1 do
+            trap = traps[i]
+            if trap.num == num then
+                break
+            end
+            trap = nil
+        end
+
+        if not trap then
+            server.errorResponse(server.errorType.OBJECT_MISSING, command.requestId)
+            return
+        end
+
+        responseCheckpointInfo(command.requestId, trap, false)
+    end
+
+    local function processCheckpointSet(command)
+        if command.length < 8 then
+            server.errorResponse(server.errorType.CMD_INVALID_LENGTH, command.requestId)
+            return
+        end
+
+        -- Ignore the memspace - byte 9
+        local checkpt = addCheckpoint(
+            server.readUint16(command.body, 1),
+            server.readUint16(command.body, 3),
+            server.readBool(command.body, 5),
+            server.readBool(command.body, 6),
+            server.readUint8(command.body, 7),
+            server.readBool(command.body, 8)
+        )
+
+        responseCheckpointInfo(command.requestId, checkpt, 0)
+    end
+
+    local function processCheckpointDelete(command)
+        if command.length < 4 then
+            server.errorResponse(server.errorType.CMD_INVALID_LENGTH, command.requestId)
+            return
+        end
+        
+        local brkNum = server.readUint32(command.body, 1)
+        local success = removeCheckpoint(brkNum)
+
+        if not success then
+            server.errorResponse(server.errorType.OBJECT_MISSING, command.requestId)
+            return
+        end
+
+        server.response(server.responseType.CHECKPOINT_DELETE, server.errorType.OK, command.requestId, nil)
+    end
+
+    local function processCheckpointList(command)
+        for i = 1,#traps,1 do
+            responseCheckpointInfo(command.requestId, traps[i], false)
+        end
+
+        local r = server.uint32ToLittleEndian(#traps)
+
+        server.response(server.responseType.CHECKPOINT_LIST, server.errorType.OK, command.requestId, r)
+    end
+
+    local function processCheckpointToggle(command)
+        if command.length < 5 then
+            server.errorResponse(server.errorType.CMD_INVALID_LENGTH, command.requestId)
+            return
+        end
+
+        local num = server.readUint32(command.body, 1)
+        local enable = server.readBool(command.body, 5)
+        
+        if not toggleCheckpoint(enable, num) then
+            server.errorResponse(server.errorType.OBJECT_MISSING, command.requestId)
+            return
+        end
+
+        server.response(server.responseType.CHECKPOINT_TOGGLE, server.errorType.OK, command.requestId, nil)
+    end
+
+    local function validateRegister(memspace, regId)
+        return memspace == memspaces.MAIN and regId >= regMeta.a.id and regId <= regMeta.status.id
+    end
+
+    local function processRegistersGet(command)
+        if command.length < 1 then
+            server.errorResponse(server.errorType.CMD_INVALID_LENGTH, command.requestId)
+            return
+        end
+
+        local requestedMemspace = server.readUint8(command.body, 1)
+        local memspace = getRequestedMemspace(requestedMemspace)
+
+        if memspace == memspaces.INVALID then
+            server.errorResponse(server.errorType.INVALID_MEMSPACE, command.requestId)
+            return
+        end
+
+        responseRegisterInfo(command.requestId, memspace)
+    end
+
+    local function processRegistersSet(command)
+        local headerSize = 3
+        local count = server.readUint16(command.body, 2)
+
+        if command.length < headerSize + count * (3 + 1) then
+            server.errorResponse(server.errorType.CMD_INVALID_LENGTH, command.requestId)
+            return
+        end
+
+        local requestedMemspace = server.readUint8(command.body, 1)
+        local memspace = getRequestedMemspace(requestedMemspace)
+
+        if memspace == memspaces.INVALID then
+            server.errorResponse(server.errorType.INVALID_MEMSPACE, command.requestId)
+            return
+        end
+
+        local bodyCursor = headerSize + 1
+
+        local state = emu.getState()
+        for i=1,count do
+            local itemSize = server.readUint8(command.body, bodyCursor + 0)
+            local regId = server.readUint8(command.body, bodyCursor + 1)
+            local regVal = server.readUint16(command.body, bodyCursor + 2)
+
+            if itemSize < 3 then
+                server.errorResponse(server.errorType.CMD_INVALID_LENGTH, command.requestId)
+                return
+            end
+
+            if not validateRegister(memspace, regId) then
+                server.errorResponse(server.errorType.OBJECT_MISSING, command.requestId)
+                return
+            end
+
+            for name, meta in pairs(regMeta) do
+                if meta.id == regId then
+                    state.cpu[name] = regVal
+                    break
+                end
+            end
+
+            bodyCursor = bodyCursor + itemSize + 1
+        end
+
+        emu.setState(state)
+
+        responseRegisterInfo(command.requestId, memspace)
+    end
+
+    function me.processCommand(apiVersion, bodyLength, remainingHeader, body)
+        local command = {}
+        command.apiVersion = apiVersion
+        if command.apiVersion < 0x01 or command.apiVersion > 0x02 then
+            server.errorResponse(server.errorType.INVALID_API_VERSION, command.requestId)
+        end
+
+        command.length = bodyLength
+
+        command.requestId = server.readUint32(remainingHeader, 1)
+        command.type = server.readUint8(remainingHeader, 5)
+        command.body = body
+
+        print(string.format("Command start: %02x", command.type))
+
+        local ct = command.type
+
+        if ct == server.commandType.MEM_GET then
+            processMemoryGet(command)
+        elseif ct == server.commandType.MEM_SET then
+            processMemorySet(command)
+
+        elseif ct == server.commandType.CHECKPOINT_GET then
+            processCheckpointGet(command)
+        elseif ct == server.commandType.CHECKPOINT_SET then
+            processCheckpointSet(command)
+        elseif ct == server.commandType.CHECKPOINT_DELETE then
+            processCheckpointDelete(command)
+        elseif ct == server.commandType.CHECKPOINT_LIST then
+            processCheckpointList(command)
+        elseif ct == server.commandType.CHECKPOINT_TOGGLE then
+            processCheckpointToggle(command)
+
+        elseif ct == server.commandType.REGISTERS_GET then
+            processRegistersGet(command)
+        elseif ct == server.commandType.REGISTERS_SET then
+            processRegistersSet(command)
+
+        elseif ct == server.commandType.ADVANCE_INSTRUCTIONS then
+            processAdvanceInstructions(command)
+
+        elseif ct == server.commandType.PING then
+            processPing(command)
+
+        elseif ct == server.commandType.EXIT then
+            processExit(command)
+        elseif ct == server.commandType.RESET then
+            processReset(command)
+        else
+            server.errorResponse(server.errorType.CMD_INVALID_TYPE, command.requestId)
+            print(string.format("unknown command: %d, skipping command length %d", command.type, command.length))
+        end
+
+        print(string.format("Command finished: %02x", command.type))
+    end
+
+    function trapHandle(trap)
+        print("Trap")
+
+        if conn == nil then
+            return
+        end
+
+        if trap.stop then
+            me.monitorOpened()
+        end
+        responseCheckpointInfo(requestId, trap, true)
+        if not trap.stop then
+            return
+        end
+
+        server.running = false
+
+        server.deregisterFrameCallback()
+        emu.breakExecution()
+        server.registerFrameCallback()
+    end
+
+    return me
+end

main.lua

@@ -3,881 +3,11 @@ local function print(data)
   _p(data .. "")
 end
 
-local socket = require("socket.core")
+local baseDir = os.getenv("MESEN_REMOTE_BASEDIR")
 
-local running = true
+local server = dofile(baseDir.."/server.lua")
-
-local regMeta = {
-  a =  { name = "A",  id = 0, size = 1 },
-  x =  { name = "X",  id = 1, size = 1 },
-  y =  { name = "Y",  id = 2, size = 1 },
-  pc = { name = "PC", id = 3, size = 2 },
-  sp =  { name = "SP", id = 4, size = 1 },
-  status =  { name = "FL", id = 5, size = 1 },
-}
 
 local host = os.getenv("MESEN_REMOTE_HOST") or "localhost"
 local port = os.getenv("MESEN_REMOTE_PORT") or 9355
 
-print("Binding to host '" ..host.. "' and port " ..port.. "...")
+server.start(host, port)
-
-local server = assert(socket.tcp())
-assert(server:bind(host, port))
-assert(server:listen(32))
-server:settimeout(0)
-
-local i, p   = server:getsockname()
-assert(i, p)
-
-print("Waiting for connection on " .. i .. ":" .. p .. "...")
-local conn = nil
-
-local function boolToLittleEndian(b)
-    local value = 0
-    if b then
-        value = 1
-    end
-    return string.char(value & 0xff)
-end
-
-local function uint8ToLittleEndian(value)
-    return string.char(value & 0xff)
-end
-
-local function uint16ToLittleEndian(value)
-    return string.char(value & 0xff, (value >> 8) & 0xff)
-end
-
-local function uint32ToLittleEndian(value)
-    return string.char(value & 0xff, (value >> 8) & 0xff, (value >> 16) & 0xff, (value >> 24) & 0xff)
-end
-
-local function readUint32(data, index)
-    return data:byte(index) + (data:byte(index + 1) << 8) + (data:byte(index + 2) << 16) + (data:byte(index + 3) << 24)
-end
-
-local function readUint16(data, index)
-    return data:byte(index) + (data:byte(index + 1) << 8)
-end
-
-local function readUint8(data, index)
-    return data:byte(index)
-end
-
-local function readBool(data, index)
-    return data:byte(index) > 0
-end
-
-local errorType = {
-    OK = 0x00,
-    OBJECT_MISSING = 0x01,
-    INVALID_MEMSPACE = 0x02,
-    CMD_INVALID_LENGTH = 0x80,
-    INVALID_PARAMETER = 0x81,
-    CMD_INVALID_API_VERSION = 0x82,
-    CMD_INVALID_TYPE = 0x83,
-    CMD_FAILURE = 0x8f,
-};
-
-local commandType = {
-    INVALID = 0x00,
-
-    MEM_GET = 0x01,
-    MEM_SET = 0x02,
-
-    CHECKPOINT_GET = 0x11,
-    CHECKPOINT_SET = 0x12,
-    CHECKPOINT_DELETE = 0x13,
-    CHECKPOINT_LIST = 0x14,
-    CHECKPOINT_TOGGLE = 0x15,
-
-    CONDITION_SET = 0x22,
-
-    REGISTERS_GET = 0x31,
-    REGISTERS_SET = 0x32,
-
-    DUMP = 0x41,
-    UNDUMP = 0x42,
-
-    RESOURCE_GET = 0x51,
-    RESOURCE_SET = 0x52,
-
-    ADVANCE_INSTRUCTIONS = 0x71,
-    KEYBOARD_FEED = 0x72,
-    EXECUTE_UNTIL_RETURN = 0x73,
-
-    PING = 0x81,
-    BANKS_AVAILABLE = 0x82,
-    REGISTERS_AVAILABLE = 0x83,
-    DISPLAY_GET = 0x84,
-    VICE_INFO = 0x85,
-
-    PALETTE_GET = 0x91,
-
-    EXIT = 0xaa,
-    QUIT = 0xbb,
-    RESET = 0xcc,
-    AUTOSTART = 0xdd,
-}
-
-local responseType = {
-    MEM_GET = 0x01,
-    MEM_SET = 0x02,
-
-    CHECKPOINT_INFO = 0x11,
-
-    CHECKPOINT_DELETE = 0x13,
-    CHECKPOINT_LIST = 0x14,
-    CHECKPOINT_TOGGLE = 0x15,
-
-    CONDITION_SET = 0x22,
-
-    REGISTER_INFO = 0x31,
-
-    DUMP = 0x41,
-    UNDUMP = 0x42,
-
-    RESOURCE_GET = 0x51,
-    RESOURCE_SET = 0x52,
-
-    JAM = 0x61,
-    STOPPED = 0x62,
-    RESUMED = 0x63,
-
-    ADVANCE_INSTRUCTIONS = 0x71,
-    KEYBOARD_FEED = 0x72,
-    EXECUTE_UNTIL_RETURN = 0x73,
-
-    PING = 0x81,
-    BANKS_AVAILABLE = 0x82,
-    REGISTERS_AVAILABLE = 0x83,
-    DISPLAY_GET = 0x84,
-    VICE_INFO = 0x85,
-
-    PALETTE_GET = 0x91,
-
-    EXIT = 0xaa,
-    QUIT = 0xbb,
-    RESET = 0xcc,
-    AUTOSTART = 0xdd,
-}
-
-local API_VERSION = 0x02
-
-local EVENT_ID = 0xffffffff
-
-local function response(responseType, errorCode, requestId, body)
-    if conn == nil then
-        return
-    end
-
-    local r = {}
-    r[#r+1] = string.char(0x02)
-    r[#r+1] = uint8ToLittleEndian(API_VERSION)
-    if body ~= nil then
-        r[#r+1] = uint32ToLittleEndian(body:len())
-    else
-        r[#r+1] = uint32ToLittleEndian(0)
-    end
-    r[#r+1] = uint8ToLittleEndian(responseType)
-    r[#r+1] = uint8ToLittleEndian(errorCode)
-    r[#r+1] = uint32ToLittleEndian(requestId)
-    conn:send(table.concat(r))
-
-    if body ~= nil then
-        conn:send(body)
-    end
-end
-
-local function responseCheckpointInfo(requestId, checkpt, hit)
-    local r = {}
-
-    r[#r+1] = uint32ToLittleEndian(checkpt.num)
-    r[#r+1] = boolToLittleEndian(hit)
-
-    r[#r+1] = uint16ToLittleEndian(checkpt.start)
-    r[#r+1] = uint16ToLittleEndian(checkpt.finish)
-    r[#r+1] = boolToLittleEndian(checkpt.stop)
-    r[#r+1] = boolToLittleEndian(checkpt.enabled)
-    r[#r+1] = uint8ToLittleEndian(checkpt.op)
-    r[#r+1] = boolToLittleEndian(checkpt.temp)
-
-    r[#r+1] = uint32ToLittleEndian(checkpt.hitCount)
-    r[#r+1] = uint32ToLittleEndian(checkpt.ignoreCount)
-    r[#r+1] = boolToLittleEndian(checkpt.condition ~= nil)
-    r[#r+1] = uint32ToLittleEndian(checkpt.memspace)
-
-    response(responseType.CHECKPOINT_INFO, errorType.OK, requestId, table.concat(r))
-end
-
-local function responseRegisterInfo(requestId)
-    local r = {}
-    local regs = emu.getState().cpu
-
-    local count = 0
-    for name, meta in pairs(regMeta) do
-        count = count + 1
-    end
-
-    r[#r+1] = uint16ToLittleEndian(count)
-
-    local itemSize = 3
-    for name, meta in pairs(regMeta) do
-        r[#r+1] = uint8ToLittleEndian(itemSize)
-        r[#r+1] = uint8ToLittleEndian(meta.id)
-        r[#r+1] = uint16ToLittleEndian(regs[name])
-    end
-
-    response(responseType.REGISTER_INFO, errorType.OK, requestId, table.concat(r))
-end
-
-local function responseStopped()
-    local pc = emu.getState().cpu.pc
-
-    response(responseType.STOPPED, errorType.OK, EVENT_ID, uint16ToLittleEndian(pc))
-end
-
-local function responseResumed()
-    local pc = emu.getState().cpu.pc
-
-    response(responseType.RESUMED, errorType.OK, EVENT_ID, uint16ToLittleEndian(pc))
-end
-
-local function monitorOpened()
-    print("Monitor opened")
-    responseRegisterInfo(EVENT_ID)
-    responseStopped(EVENT_ID)
-end
-
-local function monitorClosed()
-    print("Monitor closed")
-    responseRegisterInfo(EVENT_ID)
-    responseResumed(EVENT_ID)
-end
-
-local function errorResponse(errorCode, requestId)
-    response(0, errorCode, requestId, nil)
-end
-
-local stepping = false
-local function processAdvanceInstructions(command)
-    if command.length < 3 then
-        errorResponse(errorType.CMD_INVALID_LENGTH, command.requestId)
-        return
-    end
-
-    local stepOverSubroutines = readBool(command.body, 1);
-    local count = readUint16(command.body, 2);
-
-    stepping = true
-    if stepOverSubroutines then
-        -- FIXME
-        emu.execute(count, emu.executeCountType.cpuInstructions)
-    else
-        emu.execute(count, emu.executeCountType.cpuInstructions)
-    end
-
-    running = true
-
-    response(responseType.ADVANCE_INSTRUCTIONS, errorType.OK, command.requestId, nil);
-
-    monitorClosed()
-end
-
-local function processPing(command)
-    response(responseType.PING, errorType.OK, command.requestId, nil)
-end
-
-local function processExit(command)
-    running = true
-
-    response(responseType.EXIT, errorType.OK, command.requestId, nil)
-
-    monitorClosed()
-end
-
-local function processReset(command)
-    running = true
-    emu.reset()
-
-    response(responseType.RESET, errorType.OK, command.requestId, nil)
-
-    monitorClosed()
-end
-
-local memspaces = {
-    MAIN = 0,
-    INVALID = -1,
-}
-
-local function getRequestedMemspace(requestedMemspace)
-    if requestedMemspace == 0 then
-        return memspaces.MAIN
-    else
-        return memspaces.INVALID
-    end
-end
-
-local banks = {
-    default = 0,
-    cpu = 1,
-    ppu = 2,
-    palette = 3,
-    oam = 4,
-    secondaryOam = 5
-}
-
-local function validateBanknum(memspace, banknum)
-    return memspace == memspaces.MAIN and banknum >= banks.default and banknum <= banks.secondaryOam
-end
-
-local function processMemorySet(command)
-    local newSidefx = readBool(command.body, 1)
-
-    local startAddress = readUint16(command.body, 2);
-    local endAddress = readUint16(command.body, 4);
-
-    if startAddress > endAddress then
-        errorResponse(errorType.INVALID_PARAMETER, command.requestId)
-        return
-    end
-
-    local length = endAddress - startAddress + 1;
-
-    if command.length < length + 8 then
-        errorResponse(errorType.CMD_INVALID_LENGTH, command.requestId)
-        return
-    end
-
-    local requestedMemspace = readUint8(command.body, 6);
-    local requestedBanknum = readUint16(command.body, 7);
-
-    local memspace = getRequestedMemspace(requestedMemspace);
-
-    if memspace == memspaces.INVALID then
-        errorResponse(errorType.INVALID_MEMSPACE, command.requestId)
-        return
-    end
-
-    if not validateBanknum(memspace, requestedBanknum) then
-        errorResponse(errorType.INVALID_PARAMETER, command.requestId)
-        return
-    end
-
-    local banknum = requestedBanknum;
-
-    if banknum == banks.default then
-        banknum = banks.cpu
-    end
-
-    if not newSidefx and ( banknum == banks.cpu or banknum == banks.ppu ) then
-        banknum = banknum + 0x100
-    end
-
-    banknum = banknum - 1
-
-    for i = 0,length - 1,1 do
-        local val = command.body:byte(8 + i + 1)
-        print(val)
-        emu.write(startAddress + i, val, banknum)
-    end
-
-    response(responseType.MEM_SET, errorType.OK, command.requestId, nil);
-end
-
-local function processMemoryGet(command)
-    if command.length < 8 then
-        errorResponse(errorType.CMD_INVALID_LENGTH, command.requestId)
-        return
-    end
-
-    local newSidefx = readBool(command.body, 1)
-
-    local startAddress = readUint16(command.body, 2);
-    local endAddress = readUint16(command.body, 4);
-
-    if startAddress > endAddress then
-        errorResponse(errorType.INVALID_PARAMETER, command.requestId)
-        return
-    end
-
-    local requestedMemspace = readUint8(command.body, 6);
-    local memspace = getRequestedMemspace(requestedMemspace);
-
-    if memspace == memspaces.INVALID then
-        errorResponse(errorType.INVALID_MEMSPACE, command.requestId)
-        return
-    end
-
-    local length = endAddress - startAddress + 1;
-
-    local requestedBanknum = readUint16(command.body, 7);
-
-    if not validateBanknum(memspace, requestedBanknum) then
-        errorResponse(errorType.INVALID_PARAMETER, command.requestId)
-        return
-    end
-
-    local banknum = requestedBanknum;
-
-    local r = {}
-
-    r[#r+1] = uint16ToLittleEndian(length);
-
-    if banknum == banks.default then
-        banknum = banks.cpu
-    end
-
-    if not newSidefx and ( banknum == banks.cpu or banknum == banks.ppu ) then
-        banknum = banknum + 0x100
-    end
-
-    banknum = banknum - 1
-
-    local remainingByte = length % 2 ~= 0
-    for addr=startAddress,endAddress-1,2 do
-        r[#r+1] = uint16ToLittleEndian(emu.readWord(addr, banknum))
-    end
-    if remainingByte then
-        r[#r+1] = uint8ToLittleEndian(emu.read(addr, banknum))
-    end
-
-    response(responseType.MEM_GET, errorType.OK, command.requestId, table.concat(r))
-end
-
-nextTrap = 1
-traps = {}
-local operation = {
-    READ  = 0x01,
-    WRITE = 0x02,
-    EXEC  = 0x04,
-}
-
-local trapHandle
-
-local function addCheckpoint(start, finish, stop, enabled, op, temp)
-    local num = nextTrap
-    nextTrap = nextTrap+1
-    local trap = {
-        start = start,
-        finish = finish,
-        stop = stop,
-        enabled = enabled,
-        op = op,
-        temp = temp,
-        hitCount = 0,
-        ignoreCount = 0,
-        condition = nil,
-        memspace = 0,
-        num = num,
-    }
-    traps[#traps+1] = trap
-
-    if trap.op & operation.EXEC ~= 0 then
-        trap.execRegistration = emu.addMemoryCallback(function()
-            if trap.enabled then
-                trapHandle(trap)
-            end
-        end, emu.memCallbackType.cpuExec, trap.start, trap.finish)
-    end
-    if trap.op & operation.READ ~= 0 then
-        trap.readRegistration = emu.addMemoryCallback(function()
-            if trap.enabled then
-                trapHandle(trap)
-            end
-        end, emu.memCallbackType.cpuRead, trap.start, trap.finish)
-    end
-    if trap.op & operation.WRITE ~= 0 then
-        trap.writeRegistration = emu.addMemoryCallback(function()
-            if trap.enabled then
-                trapHandle(trap)
-            end
-        end, emu.memCallbackType.cpuRead, trap.start, trap.finish)
-    end
-    return trap
-end
-
-local function removeCheckpoint(num)
-    local trap
-    for i=#traps,1,-1 do
-        trap = traps[i]
-        if trap.num == num then
-            table.remove(traps, i)
-            break
-        end
-        trap = nil
-    end
-
-    if trap == nil then
-        return false
-    end
-
-    if trap.execRegistration ~= nil then
-        emu.removeMemoryCallback(trap.execRegistration, emu.memCallbackType.cpuExec, trap.start, trap.finish)
-    end
-    if trap.readRegistration ~= nil then
-        emu.removeMemoryCallback(trap.readRegistration, emu.memCallbackType.cpuRead, trap.start, trap.finish)
-    end
-    if trap.writeRegistration ~= nil then
-        emu.removeMemoryCallback(trap.writeRegistration, emu.memCallbackType.cpuWrite, trap.start, trap.finish)
-    end
-
-    return true
-end
-
-local function toggleCheckpoint(enable, num)
-    for i=#traps,1,-1 do
-        trap = traps[i]
-        if trap.num == num then
-            break
-        end
-        trap = nil
-    end
-
-    if trap == nil then
-        return false
-    end
-
-    trap.enabled = enable
-
-    return true
-end
-
-local function processCheckpointGet(command)
-    if command.length < 4 then
-        errorResponse(errorType.CMD_INVALID_LENGTH, command.requestId)
-        return
-    end
-
-    local num = readUint32(command.body, 1);
-
-    for i=#traps,1,-1 do
-        trap = traps[i]
-        if trap.num == num then
-            break
-        end
-        trap = nil
-    end
-
-    if not trap then
-        errorResponse(errorType.OBJECT_MISSING, command.requestId)
-        return
-    end
-
-    responseCheckpointInfo(command.requestId, trap, false);
-end
-
-local function processCheckpointSet(command)
-    if command.length < 8 then
-        errorResponse(errorType.CMD_INVALID_LENGTH, command.requestId)
-        return
-    end
-
-    -- Ignore the memspace - byte 9
-    local checkpt = addCheckpoint(
-        readUint16(command.body, 1),
-        readUint16(command.body, 3),
-        readBool(command.body, 5),
-        readBool(command.body, 6),
-        readUint8(command.body, 7),
-        readBool(command.body, 8)
-    )
-
-    responseCheckpointInfo(command.requestId, checkpt, 0)
-end
-
-local function processCheckpointDelete(command)
-    if command.length < 4 then
-        errorResponse(errorType.CMD_INVALID_LENGTH, command.requestId)
-        return
-    end
-    
-    local brkNum = readUint32(command.body, 1)
-    local success = removeCheckpoint(brkNum)
-
-    if not success then
-        errorResponse(errorType.OBJECT_MISSING, command.requestId)
-        return
-    end
-
-    response(responseType.CHECKPOINT_DELETE, errorType.OK, command.requestId, nil)
-end
-
-local function processCheckpointList(command)
-    for i = 1,#traps,1 do
-        responseCheckpointInfo(command.requestId, traps[i], false);
-    end
-
-    local r = uint32ToLittleEndian(#traps)
-
-    response(responseType.CHECKPOINT_LIST, errorType.OK, command.requestId, r);
-end
-
-local function processCheckpointToggle(command)
-    if command.length < 5 then
-        errorResponse(errorType.CMD_INVALID_LENGTH, command.requestId)
-        return
-    end
-
-    local num = readUint32(command.body, 1);
-    local enable = readBool(command.body, 5);
-    
-    if not toggleCheckpoint(enable, num) then
-        errorResponse(errorType.OBJECT_MISSING, command.requestId)
-        return
-    end
-
-    response(responseType.CHECKPOINT_TOGGLE, errorType.OK, command.requestId, nil);
-end
-
-local function validateRegister(memspace, regId)
-    return memspace == memspaces.MAIN and regId >= regMeta.a.id and regId <= regMeta.status.id
-end
-
-local function processRegistersGet(command)
-    if command.length < 1 then
-        errorResponse(errorType.CMD_INVALID_LENGTH, command.requestId)
-        return
-    end
-
-    local requestedMemspace = readUint8(command.body, 1);
-    local memspace = getRequestedMemspace(requestedMemspace);
-
-    if memspace == memspaces.INVALID then
-        errorResponse(errorType.INVALID_MEMSPACE, command.requestId)
-        return
-    end
-
-    responseRegisterInfo(command.requestId, memspace);
-end
-
-local function processRegistersSet(command)
-    local headerSize = 3
-    local count = readUint16(command.body, 2);
-
-    if command.length < headerSize + count * (3 + 1) then
-        errorResponse(errorType.CMD_INVALID_LENGTH, command.requestId)
-        return
-    end
-
-    local requestedMemspace = readUint8(command.body, 1);
-    local memspace = getRequestedMemspace(requestedMemspace);
-
-    if memspace == memspaces.INVALID then
-        errorResponse(errorType.INVALID_MEMSPACE, command.requestId)
-        return
-    end
-
-    local bodyCursor = headerSize + 1;
-
-    local state = emu.getState()
-    for i=1,count do
-        local itemSize = readUint8(command.body, bodyCursor + 0)
-        local regId = readUint8(command.body, bodyCursor + 1)
-        local regVal = readUint16(command.body, bodyCursor + 2)
-
-        if itemSize < 3 then
-            errorResponse(errorType.CMD_INVALID_LENGTH, command.requestId)
-            return
-        end
-
-        if not validateRegister(memspace, regId) then
-            errorResponse(errorType.OBJECT_MISSING, command.requestId)
-            return
-        end
-
-        for name, meta in pairs(regMeta) do
-            if meta.id == regId then
-                state.cpu[name] = regVal
-                break
-            end
-        end
-
-        bodyCursor = bodyCursor + itemSize + 1;
-    end
-
-    emu.setState(state)
-
-    responseRegisterInfo(command.requestId, memspace);
-end
-
-local function processCommand(apiVersion, bodyLength, remainingHeader, body)
-    local command = {}
-    command.apiVersion = apiVersion
-    if command.apiVersion < 0x01 or command.apiVersion > 0x02 then
-        errorResponse(errorType.INVALID_API_VERSION, command.requestId)
-    end
-
-    command.length = bodyLength
-
-    command.requestId = readUint32(remainingHeader, 1)
-    command.type = readUint8(remainingHeader, 5)
-    command.body = body
-
-    print(string.format("Command start: %02x", command.type))
-
-    local ct = command.type
-
-    if ct == commandType.MEM_GET then
-        processMemoryGet(command)
-    elseif ct == commandType.MEM_SET then
-        processMemorySet(command)
-
-    elseif ct == commandType.CHECKPOINT_GET then
-        processCheckpointGet(command)
-    elseif ct == commandType.CHECKPOINT_SET then
-        processCheckpointSet(command)
-    elseif ct == commandType.CHECKPOINT_DELETE then
-        processCheckpointDelete(command)
-    elseif ct == commandType.CHECKPOINT_LIST then
-        processCheckpointList(command)
-    elseif ct == commandType.CHECKPOINT_TOGGLE then
-        processCheckpointToggle(command)
-
-    elseif ct == commandType.REGISTERS_GET then
-        processRegistersGet(command)
-    elseif ct == commandType.REGISTERS_SET then
-        processRegistersSet(command)
-
-    elseif ct == commandType.ADVANCE_INSTRUCTIONS then
-        processAdvanceInstructions(command)
-
-    elseif ct == commandType.PING then
-        processPing(command)
-
-    elseif ct == commandType.EXIT then
-        processExit(command)
-    elseif ct == commandType.RESET then
-        processReset(command)
-    else
-        errorResponse(errorType.CMD_INVALID_TYPE, command.requestId)
-        print(string.format("unknown command: %d, skipping command length %d", command.type, command.length))
-    end
-
-    print(string.format("Command finished: %02x", command.type))
-end
-
-local function prepareCommand()
-    if conn == nil then
-        running = true
-        return
-    end
-
-    if running then
-        conn:settimeout(0)
-    else
-        conn:settimeout(-1)
-    end
-
-    local data, status, partial = conn:receive(1)
-    if status == "timeout" then
-        return
-    elseif status == "closed" then
-        conn = nil
-        running = true
-        return
-    end
-
-    if data:byte(1) ~= 0x02 then
-        return
-    end
-
-    if running then
-        running = false
-        monitorOpened()
-    end
-    conn:settimeout(-1)
-
-    data, status = conn:receive(1 + 4)
-
-    local apiVersion = readUint8(data, 1)
-
-    local bodyLength = readUint32(data, 2)
-
-    local remainingHeaderSize = 5
-
-    local remainingHeader, status = conn:receive(remainingHeaderSize)
-
-    local body
-    if bodyLength > 0 then
-        body, status = conn:receive(bodyLength)
-    end
-
-    processCommand(apiVersion, bodyLength, remainingHeader, body)
-end
-
-local function initConnection()
-    if conn == nil then
-        conn, err = server:accept()
-        if conn == nil or err ~= nil then
-            return
-        end
-    end
-end
-
-local deregisterFrameCallback
-local registerFrameCallback
-local function frameHandle()
-    initConnection()
-
-    if conn == nil then
-        return
-    end
-
-    prepareCommand()
-    if not running then
-        deregisterFrameCallback()
-        emu.breakExecution()
-        registerFrameCallback()
-    end
-end
-
-local frameCallback = nil
-function registerFrameCallback()
-    frameCallback = emu.addEventCallback(frameHandle, emu.eventType.inputPolled)
-end
-
-function deregisterFrameCallback() 
-    emu.removeEventCallback(frameCallback, emu.eventType.inputPolled)
-end
-
-function trapHandle(trap)
-    print("Trap")
-
-    if conn == nil then
-        return
-    end
-
-    if trap.stop then
-        monitorOpened()
-    end
-    responseCheckpointInfo(requestId, trap, true)
-    if not trap.stop then
-        return
-    end
-
-    running = false
-
-    deregisterFrameCallback()
-    emu.breakExecution()
-    registerFrameCallback()
-end
-
-local function breakHandle()
-    print("Break")
-
-    if stepping then
-        stepping = false
-        monitorOpened()
-    end
-
-    repeat
-        prepareCommand()
-    until running
-
-    emu.resume()
-end
-
-registerFrameCallback()
-
-emu.addEventCallback(breakHandle, emu.eventType.codeBreak)

server.lua

@@ -0,0 +1,312 @@
+local _p = emu.log
+local function print(data)
+  _p(data .. "")
+end
+
+local baseDir = os.getenv("MESEN_REMOTE_BASEDIR")
+
+local socket = require("socket.core")
+local me = {}
+local commands = dofile(baseDir.."/commands.lua")(me)
+
+me.running = false
+me.stepping = false
+me.conn = nil
+me.server = nil
+
+function me.boolToLittleEndian(b)
+    local value = 0
+    if b then
+        value = 1
+    end
+    return string.char(value & 0xff)
+end
+
+function me.uint8ToLittleEndian(value)
+    if value == nil then
+        error("value is nil", 2)
+    end
+    return string.char(value & 0xff)
+end
+
+function me.uint16ToLittleEndian(value)
+    if value == nil then
+        error("value is nil", 2)
+    end
+    return string.char(value & 0xff, (value >> 8) & 0xff)
+end
+
+function me.uint32ToLittleEndian(value)
+    if value == nil then
+        error("value is nil", 2)
+    end
+    return string.char(value & 0xff, (value >> 8) & 0xff, (value >> 16) & 0xff, (value >> 24) & 0xff)
+end
+
+function me.readUint32(data, index)
+    return data:byte(index) + (data:byte(index + 1) << 8) + (data:byte(index + 2) << 16) + (data:byte(index + 3) << 24)
+end
+
+function me.readUint16(data, index)
+    return data:byte(index) + (data:byte(index + 1) << 8)
+end
+
+function me.readUint8(data, index)
+    return data:byte(index)
+end
+
+function me.readBool(data, index)
+    return data:byte(index) > 0
+end
+
+me.errorType = {
+    OK = 0x00,
+    OBJECT_MISSING = 0x01,
+    INVALID_MEMSPACE = 0x02,
+    CMD_INVALID_LENGTH = 0x80,
+    INVALID_PARAMETER = 0x81,
+    CMD_INVALID_API_VERSION = 0x82,
+    CMD_INVALID_TYPE = 0x83,
+    CMD_FAILURE = 0x8f,
+};
+
+me.commandType = {
+    INVALID = 0x00,
+
+    MEM_GET = 0x01,
+    MEM_SET = 0x02,
+
+    CHECKPOINT_GET = 0x11,
+    CHECKPOINT_SET = 0x12,
+    CHECKPOINT_DELETE = 0x13,
+    CHECKPOINT_LIST = 0x14,
+    CHECKPOINT_TOGGLE = 0x15,
+
+    CONDITION_SET = 0x22,
+
+    REGISTERS_GET = 0x31,
+    REGISTERS_SET = 0x32,
+
+    DUMP = 0x41,
+    UNDUMP = 0x42,
+
+    RESOURCE_GET = 0x51,
+    RESOURCE_SET = 0x52,
+
+    ADVANCE_INSTRUCTIONS = 0x71,
+    KEYBOARD_FEED = 0x72,
+    EXECUTE_UNTIL_RETURN = 0x73,
+
+    PING = 0x81,
+    BANKS_AVAILABLE = 0x82,
+    REGISTERS_AVAILABLE = 0x83,
+    DISPLAY_GET = 0x84,
+    VICE_INFO = 0x85,
+
+    PALETTE_GET = 0x91,
+
+    EXIT = 0xaa,
+    QUIT = 0xbb,
+    RESET = 0xcc,
+    AUTOSTART = 0xdd,
+}
+
+me.responseType = {
+    MEM_GET = 0x01,
+    MEM_SET = 0x02,
+
+    CHECKPOINT_INFO = 0x11,
+
+    CHECKPOINT_DELETE = 0x13,
+    CHECKPOINT_LIST = 0x14,
+    CHECKPOINT_TOGGLE = 0x15,
+
+    CONDITION_SET = 0x22,
+
+    REGISTER_INFO = 0x31,
+
+    DUMP = 0x41,
+    UNDUMP = 0x42,
+
+    RESOURCE_GET = 0x51,
+    RESOURCE_SET = 0x52,
+
+    JAM = 0x61,
+    STOPPED = 0x62,
+    RESUMED = 0x63,
+
+    ADVANCE_INSTRUCTIONS = 0x71,
+    KEYBOARD_FEED = 0x72,
+    EXECUTE_UNTIL_RETURN = 0x73,
+
+    PING = 0x81,
+    BANKS_AVAILABLE = 0x82,
+    REGISTERS_AVAILABLE = 0x83,
+    DISPLAY_GET = 0x84,
+    VICE_INFO = 0x85,
+
+    PALETTE_GET = 0x91,
+
+    EXIT = 0xaa,
+    QUIT = 0xbb,
+    RESET = 0xcc,
+    AUTOSTART = 0xdd,
+}
+
+me.API_VERSION = 0x02
+
+me.EVENT_ID = 0xffffffff
+
+function me.response(responseType, errorCode, requestId, body)
+    if responseType == nil or errorCode == nil or requestId == nil then
+        error("A required response value was nil", 2)
+    end
+
+    if me.conn == nil then
+        return
+    end
+
+    local r = {}
+    r[#r+1] = string.char(0x02)
+    r[#r+1] = me.uint8ToLittleEndian(me.API_VERSION)
+    if body ~= nil then
+        r[#r+1] = me.uint32ToLittleEndian(body:len())
+    else
+        r[#r+1] = me.uint32ToLittleEndian(0)
+    end
+    r[#r+1] = me.uint8ToLittleEndian(responseType)
+    r[#r+1] = me.uint8ToLittleEndian(errorCode)
+    r[#r+1] = me.uint32ToLittleEndian(requestId)
+    me.conn:send(table.concat(r))
+
+    if body ~= nil then
+        me.conn:send(body)
+    end
+end
+
+function me.errorResponse(errorCode, requestId)
+    me.response(0, errorCode, requestId, nil)
+end
+
+local function initConnection()
+    if me.conn == nil then
+        me.conn, err = me.server:accept()
+        if me.conn == nil or err ~= nil then
+            return
+        end
+        print("Connected")
+    end
+end
+
+local function prepareCommand()
+    if me.conn == nil then
+        me.running = true
+        return
+    end
+
+    if me.running then
+        me.conn:settimeout(0)
+    else
+        me.conn:settimeout(-1)
+    end
+
+    local data, status, partial = me.conn:receive(1)
+    if status == "timeout" then
+        return
+    elseif status == "closed" then
+        me.conn = nil
+        me.running = true
+        return
+    end
+
+    if data:byte(1) ~= 0x02 then
+        return
+    end
+
+    if me.running then
+        me.running = false
+        commands.monitorOpened()
+    end
+    me.conn:settimeout(-1)
+
+    data, status = me.conn:receive(1 + 4)
+
+    local apiVersion = me.readUint8(data, 1)
+
+    local bodyLength = me.readUint32(data, 2)
+
+    local remainingHeaderSize = 5
+
+    local remainingHeader, status = me.conn:receive(remainingHeaderSize)
+
+    local body
+    if bodyLength > 0 then
+        body, status = me.conn:receive(bodyLength)
+    end
+
+    commands.processCommand(apiVersion, bodyLength, remainingHeader, body)
+end
+
+me.deregisterFrameCallback = nil
+me.registerFrameCallback = nil
+local function frameHandle()
+    initConnection()
+
+    if me.conn == nil then
+        return
+    end
+
+    prepareCommand()
+    if not me.running then
+        me.deregisterFrameCallback()
+        emu.breakExecution()
+        me.registerFrameCallback()
+    end
+end
+
+local frameCallback = nil
+function me.registerFrameCallback()
+    frameCallback = emu.addEventCallback(frameHandle, emu.eventType.inputPolled)
+end
+
+function me.deregisterFrameCallback() 
+    emu.removeEventCallback(frameCallback, emu.eventType.inputPolled)
+end
+
+local function breakHandle()
+    print("Break")
+
+    if me.stepping then
+        me.stepping = false
+        commands.monitorOpened()
+    end
+
+    repeat
+        prepareCommand()
+    until me.running
+
+    emu.resume()
+end
+
+function me.start(host, port)
+    me.stepping = false
+    me.running = true
+
+    print("Binding to host '" ..host.. "' and port " ..port.. "...")
+
+    me.server = assert(socket.tcp())
+    assert(me.server:bind(host, port))
+    assert(me.server:listen(32))
+    me.server:settimeout(0)
+
+    local i, p   = me.server:getsockname()
+    assert(i, p)
+
+    print("Waiting for connection on " .. i .. ":" .. p .. "...")
+
+    me.registerFrameCallback()
+
+    emu.addEventCallback(breakHandle, emu.eventType.codeBreak)
+end
+
+return me