Write basic bootloader

index.json

@@ -2,6 +2,11 @@
   {
     "src": "src/startup.lua",
     "dest": "/startup.lua",
-    "hash": "07219cd9561b41ce1f39209958076c471b17855679c968b42767b0122423c782"
+    "hash": "7c9e7a50d1fda475f1b3cc1d0b06fc1606cbdf9220a60f0a7707c9871e5c07e5"
+  },
+  {
+    "src": "src/kernel/entry.lua",
+    "dest": "/kernel/entry.lua",
+    "hash": "5d17a09860a3d14346105e363c0b3333bf720c75c4670add778fd20a736dafb7"
   }
 ]

src/kernel/entry.lua

@@ -0,0 +1,5 @@
+-- kernel entrypoint
+-- this is responsible for initializing core kernel services
+-- required to advance to the next step of the OS
+
+os.run({}, "/rom/programs/advanced/multishell.lua") -- placeholder

src/startup.lua

@@ -1 +1,38 @@
-print("Hello, World!")
+-- Bootloader
+-- This script is only responsible for killing rednet and jumping to the kernel
+
+-- based on some code rph wrote and gave me
+local function main()
+  if not _G["rednet"] then
+    os.run({}, "/kernel/entry.lua")
+    return
+  end
+
+  local o = os.pullEventRaw
+
+  os.pullEventRaw = function()
+    local a = table.pack(o())
+    if a[1] == "modem_message" then
+      if string.match(debug.traceback(), "/rom/apis/rednet.lua") then
+        print("[D] Rednet called os.pullEventRaw, crashing")
+        error("nya")
+      end
+    end
+    return table.unpack(a)
+  end
+
+  local p = _G.printError
+
+  _G.printError = function()
+    print("[D] Got printError call, cleaning and jumping to kernel")
+    _G.printError = p
+    _G.os.pullEventRaw = o
+    _G["rednet"] = nil
+    os.run({}, "/kernel/entry.lua")
+  end
+
+  print("[D] Queueing bogus modem message")
+  os.queueEvent("modem_message")
+end
+
+main()