diff --git a/include/luares.h b/include/luares.h
index fcf54ee..15287d3 100644
--- a/include/luares.h
+++ b/include/luares.h
@@ -3,6 +3,7 @@
 extern char lua_boot[];
 extern char lua_component[];
 extern char lua_computer[];
+extern char lua_debug[];
 extern char lua_eeprom[];
 extern char lua_filesystem[];
 extern char lua_init[];
diff --git a/src/c/lnative.c b/src/c/lnative.c
index d31877e..ce428d8 100644
--- a/src/c/lnative.c
+++ b/src/c/lnative.c
@@ -62,10 +62,20 @@ void logm(const char *message) {
     fclose(file);
   }
 }
+
+static int l_log (lua_State *L) {
+  const char* t = lua_tostring(L, 1);
+  logn(t);
+  return 0;
+}
+
 #else
 #define logn(m)
 #define logi(m)
 #define logm(m)
+static int l_log (lua_State *L) {
+  return 0;
+}
 #endif
 
 static int l_sleep (lua_State *L) {
@@ -370,6 +380,7 @@ void luanative_start(lua_State *L) {
   lua_createtable (L, 0, 1);
   
   pushctuple(L, "sleep", l_sleep);
+  pushctuple(L, "log", l_log);
 
   pushctuple(L, "fs_exists", l_fs_exists);
   pushctuple(L, "fs_mkdir", l_fs_mkdir);
@@ -397,5 +408,11 @@ void luanative_start(lua_State *L) {
   pushctuple(L, "freeMemory", l_freeMemory);
   pushctuple(L, "pull", l_pull);
 
+  #ifdef DEBUG
+    lua_pushstring(L, "debug");
+    lua_pushboolean(L, 1);
+    lua_settable(L, -3);
+  #endif
+
   lua_setglobal(L, "native");
 }
diff --git a/src/c/modules.c b/src/c/modules.c
index 92645e0..8b371c4 100644
--- a/src/c/modules.c
+++ b/src/c/modules.c
@@ -13,6 +13,7 @@ void setup_modules(lua_State *L) {
   pushstuple(L, "color", lua_util_color);
   pushstuple(L, "component", lua_component);
   pushstuple(L, "computer", lua_computer);
+  pushstuple(L, "debug", lua_debug);
   pushstuple(L, "eeprom", lua_eeprom);
   pushstuple(L, "filesystem", lua_filesystem);
   pushstuple(L, "internet", lua_internet);
diff --git a/src/lua/core/boot.lua b/src/lua/core/boot.lua
index 46ed552..42b946b 100644
--- a/src/lua/core/boot.lua
+++ b/src/lua/core/boot.lua
@@ -5,20 +5,29 @@ function boot.boot()
   local w, h = gpu.getResolution()
 
   local function bsod(...)
-    gpu.setBackground(0x0000FF)
-    gpu.setForeground(0xFFFFFF)
-    gpu.fill(1, 1, w, h, " ")
-    gpu.set(2, 2, "CRITICAL ERROR OCCURED")
-    gpu.set(2, 3, "Lua BIOS has failed:")
-    for n, v in pairs({...}) do
-      gpu.set(2, 4 + n, tostring(v))
-    end
-    gpu.set(2, h-1, "SYSTEM WILL STOP")
-    gpu.setForeground(0xFFFFFF)
-    gpu.setBackground(0x000000)
+    local arg = {...}
+    pcall(function()    
+      native.log("> LuPI BSOD")
+      for n, v in pairs(arg) do
+        native.log(tostring(v))
+      end
+    end)
+    pcall(function()
+      gpu.setBackground(0x0000FF)
+      gpu.setForeground(0xFFFFFF)
+      gpu.fill(1, 1, w, h, " ")
+      gpu.set(2, 2, "CRITICAL ERROR OCCURED")
+      gpu.set(2, 3, "Lua BIOS has failed:")
+      for n, v in pairs(arg) do
+        gpu.set(2, 4 + n, tostring(v))
+      end
+      gpu.set(2, h-1, "SYSTEM WILL STOP")
+      gpu.setForeground(0xFFFFFF)
+      gpu.setBackground(0x000000)
 
-    native.sleep(4000000)
-    os.exit(1)
+      native.sleep(4000000)
+      os.exit(1)
+    end)
   end
 
   gpu.fill(1, 1, w, h, " ")
@@ -31,6 +40,7 @@ function boot.boot()
   if not f then
     bsod(reason)
   else
+    local crash = false
     xpcall(f, function(e)
       local trace = {}
 
@@ -38,9 +48,11 @@ function boot.boot()
         trace[#trace + 1] = s
       end
       bsod("System crashed", "Stack traceback:", table.unpack(trace))
-      os.exit(4) --TODO: Run exit hooks
+      crash = true
     end)
-    bsod("System quit")
+    if not crash then
+      bsod("System quit")
+    end
   end
 end
 
diff --git a/src/lua/core/component.lua b/src/lua/core/component.lua
index cb6e90e..e429f7a 100644
--- a/src/lua/core/component.lua
+++ b/src/lua/core/component.lua
@@ -10,6 +10,29 @@ local componentCallback = {
   __tostring = function(self) return (components[self.address] ~= nil and components[self.address].doc[self.name] ~= nil) and components[self.address].doc[self.name] or "function" end
 }
 
+if native.debug then
+  local start = native.uptime()
+  local last = native.uptime()
+  componentCallback.__call = function(self, ...)
+    local t = {}
+    for k,v in pairs({...}) do
+      if type(v) == "string" then
+        v = "\"" .. v .. "\""
+      end
+      t[k] = tostring(v)
+    end
+
+    local caller = debug.getinfo(2)
+    local msg = tostring((native.uptime() - start) / 1000) .. " [+" .. native.uptime() - last .. "] " .. caller.short_src .. ":".. caller.currentline .. " > invoke(" .. self.address .. "): "
+      .. components[self.address].type ..  "." .. self.name
+      .. "(" .. table.concat(t, ", ") .. ")"
+
+    native.log(msg)
+    last = native.uptime()
+    return components[self.address].rawproxy[self.name](...)
+  end
+end
+
 function component.prepare()
   print("Assembling initial component tree")
 end
diff --git a/src/lua/core/computer.lua b/src/lua/core/computer.lua
index aa62295..92f3025 100644
--- a/src/lua/core/computer.lua
+++ b/src/lua/core/computer.lua
@@ -118,12 +118,17 @@ function api.pushSignal(s, ...)
 end
 
 function api.pullSignal(timeout)
-  if signalQueue[1] then return table.unpack(table.remove(signalQueue, 1)) end
+  --native.log("pullSignal for " .. (timeout or " infinite") .. " s")
+  if signalQueue[1] then
+    native.log("pullSignal direct: " .. signalQueue[1][1])
+    return table.unpack(table.remove(signalQueue, 1))
+  end
   local timeoutuptime = math.huge
 
   if not timeout then
     timeout = -1
   else
+    if timeout < 0 then timeout = 0 end
     timeout = timeout * 1000
     timeoutuptime = native.uptime() + timeout
   end
@@ -131,7 +136,11 @@ function api.pullSignal(timeout)
   repeat
     nevts = native.pull(timeout)
   until nevts > 0 or native.uptime() > timeoutuptime
-  if signalQueue[1] then return table.unpack(table.remove(signalQueue, 1)) end
+  if signalQueue[1] then
+    native.log("pullSignal native: " .. signalQueue[1][1])
+    return table.unpack(table.remove(signalQueue, 1))
+  end
+  --native.log("pullSignal timeout")
 end
 
 function api.uptime()
@@ -158,6 +167,17 @@ function api.totalMemory()
 end
 
 function api.shutdown()
+  --TODO: Longjmp to init somehow?
+  print("Running shutdown hooks")
+  for k, hook in ipairs(deadhooks) do
+    local state, cause = pcall(hook)
+    if not state then
+      print("Shutdown hook with following error:")
+      print(cause)
+    end
+  end
+  print("Hooks executed: " .. #deadhooks)
+
   os.exit(0)
 end
 
diff --git a/src/lua/core/debug.lua b/src/lua/core/debug.lua
new file mode 100644
index 0000000..4cec7de
--- /dev/null
+++ b/src/lua/core/debug.lua
@@ -0,0 +1,26 @@
+local d = {}
+
+local function getCallerInfo()
+  local caller = debug.getinfo(3)
+  return caller.short_src .. ":".. caller.currentline
+end
+
+function d.hook()
+  local sb = modules.sandbox
+
+  local otb = sb.debug.traceback
+  function sb.debug.traceback(m, l, ...)
+    local s = otb(m, l and (type(l) == "number" and (l + 1) or l) or 2, ...)
+    native.log("Native traceback requested for:")
+    native.log(s)
+    return s --TODO: check if there actually is only one return value
+  end
+
+  local oload = sb.load
+  function sb.load(ld, source, mode, env)
+    native.log("load from " .. getCallerInfo() .. ", loading \"" .. (source or type(ld)) .. "\"")
+    return oload(ld, source, mode, env)
+  end
+end
+
+return d
\ No newline at end of file
diff --git a/src/lua/core/init.lua b/src/lua/core/init.lua
index 631e14a..9d9bc83 100644
--- a/src/lua/core/init.lua
+++ b/src/lua/core/init.lua
@@ -17,12 +17,17 @@ end
 -------------------------------------------------------------------------------
 math.randomseed(native.uptime())--TODO: Make it better?
 
-print("LuPI L1 INIT")
+lprint = function (...)
+  print(...)
+  native.log(table.concat({...}, " "))
+end
+
+lprint("LuPI L1 INIT")
 modules = {}
 deadhooks = {}
 
 local function loadModule(name)
-  print("LuPI L1 INIT > Load module > " .. name)
+  lprint("LuPI L1 INIT > Load module > " .. name)
   io.flush()
   --TODO: PRERELEASE: Module sandboxing, preferably secure-ish
   --TODO: ASAP: Handle load errors
@@ -31,7 +36,7 @@ local function loadModule(name)
   end
   local code, reason = load(moduleCode[name], "=Module "..name)
   if not code then
-    print("Failed loading module " .. name .. ": " .. reason)
+    lprint("Failed loading module " .. name .. ": " .. reason)
     io.flush()
   else
     modules[name] = code()
@@ -41,6 +46,9 @@ end
 function main()
   --Load modules
   --Utils
+  if native.debug then
+    loadModule("debug")
+  end
   loadModule("random")
   loadModule("color")
   loadModule("buffer")
@@ -73,20 +81,30 @@ function main()
   modules.computer.tmp = modules.filesystem.register("/tmp/lupi-" .. modules.random.uuid())
   modules.textgpu.start()
 
+  if native.debug then
+    modules.debug.hook()
+  end
+
   modules.boot.boot()
 end
 
-local state, cause = pcall(main)
-if not state then
-  print("LuPI finished with following error:")
-  print(cause)
-end
+local tb = ""
 
-print("Running shutdown hooks")
+local state, cause = xpcall(main, function(e)
+  tb = debug.traceback(e, 2)
+end)
+
+lprint("Running shutdown hooks")
 for k, hook in ipairs(deadhooks) do
   local state, cause = pcall(hook)
   if not state then
-    print("Shutdown hook with following error:")
-    print(cause)
+    lprint("Shutdown hook with following error:")
+    lprint(cause)
   end
 end
+lprint("Hooks executed: " .. #deadhooks)
+
+if not state then
+  lprint("LuPI finished with following error:")
+  lprint(tb)
+end
\ No newline at end of file
diff --git a/src/lua/core/sandbox.lua b/src/lua/core/sandbox.lua
index f15dd60..c971151 100644
--- a/src/lua/core/sandbox.lua
+++ b/src/lua/core/sandbox.lua
@@ -241,7 +241,6 @@ sandbox = {
     end,
   },
   checkArg = checkArg,
-  og = _G
 }
 
 sandbox._G = sandbox