Universal bootloader

Packages/UniversalBootloader/EEPROM.lua

@@ -0,0 +1,175 @@
+bootloader = {
+    init = nil,
+    port = 8,
+    srv = "/srv",
+    storageMounted = false,
+}
+
+local fs = filesystem
+
+function bootloader:mountStorage(searchFile)
+    if self.storageMounted then
+        return
+    end
+
+    fs.initFileSystem("/dev")
+
+    local devs = fs.children("/dev")
+	for _, dev in pairs(devs) do
+		local drive = filesystem.path("/dev", dev)
+        fs.mount(drive, self.srv)
+        if searchFile == nil or self:programExists(searchFile) then
+            self.storageMounted = true
+            return true
+        end
+        fs.unmount(drive)
+	end
+
+    return false
+end
+
+function bootloader:programExists(name)
+    local path = filesystem.path(self.srv, name)
+    return filesystem.exists(path) and filesystem.isFile(path)
+end
+
+function bootloader:loadFromStorage(name)
+    if not self.storageMounted then
+        self:mountStorage()
+    end
+
+    if not self:programExists(name) then
+        return nil
+    end
+
+	fd = fs.open("/srv/"..name, "r")
+	content = ""
+	while true do
+		chunk = fd:read(1024)
+		if chunk == nil or #chunk == 0 then
+			break
+		end
+		content = content .. chunk
+	end
+	return content
+end
+
+function bootloader:initNetBoot()
+    if self.netBootInitDone then
+        return
+    end
+    self.net = computer.getPCIDevices(classes.NetworkCard)[1]
+    if not self.net then
+        error("Net-Boot: Failed to Start: No Network Card available!")
+    end
+    self.net:open(self.port)
+    event.listen(self.net)
+
+    -- Wrap event.pull() and filter Net-Boot messages
+    local og_event_pull = event.pull
+    function event.pull(timeout)
+        local args = {og_event_pull(timeout)}
+        local e, _, s, p, cmd, programName = table.unpack(args)
+        if e == "NetworkMessage" and p == self.port then
+            if cmd == "reset" and programName == self.init then
+                computer.log(2, "Net-Boot: Received reset command from Server \"" .. s .. "\"")
+                if netBootReset then
+                    pcall(netBootReset)
+                end
+                computer.reset()
+            end
+        end
+        return table.unpack(args)
+    end
+    self.netBootInitDone = true
+end
+
+function bootloader:loadFromNetBoot(name)
+    if not self.netBootInitDone then
+        self:initNetBoot()
+    end
+    self.net:broadcast(self.port, "getEEPROM", name)
+    local program = nil
+    while program == nil do
+        local e, _, s, p, cmd, programName, code = event.pull(30)
+        if e == "NetworkMessage" and p == self.port and cmd == "setEEPROM" and programName == name then
+            print("Net-Boot: Got Code for Program \"" .. name .. "\" from Server \"" .. s .. "\"")
+            return code
+        elseif e == nil then
+            computer.log(3, "Net-Boot: Request Timeout reached! Retry...")
+            break
+        end
+    end
+    return nil
+end
+
+function bootloader:loadCode(name)
+    if not self.storageMounted then
+        computer.log(0, "Mounting storage")
+        self:mountStorage()
+    end
+
+    local content = nil
+    if self.storageMounted then
+        computer.log(0, "Loading " .. name .. " from storage")
+        content = self:loadFromStorage(name)
+    else
+        computer.log(0, "No storage available")
+    end
+
+    if not content then
+        computer.log(0, "Loading " .. name .. " from net boot")
+        content = self:loadFromNetBoot(name)
+    end
+
+    return content
+end
+
+function bootloader:parseModule(name)
+    local content = self:loadCode(name)
+    if content then
+        computer.log(0, "Parsing loaded content")
+        local code, error = load(content)
+        if not code then
+            computer.log(4, "Failed to parse " .. name .. ": " .. tostring(error))
+            event.pull(2)
+            computer.reset()
+        end
+        return code
+    else
+        computer.log(3, "Could not load " .. name .. ": Not found.")
+        return nil
+    end
+end
+
+function bootloader:loadModule(name)
+    computer.log(0, "Loading " .. name .. " through the bootloader")
+    local code = self:parseModule(name)
+    if code then
+        -- We don't really expect this to return
+        computer.log(0, "Starting " .. name)
+        local success, error = pcall(code)
+        if not success then
+            computer.log(3, error)
+            event.pull(2)
+            computer.reset()
+        end
+    else
+        computer.log(4, "Failed to load module "..name)
+    end
+end
+
+function bootloader:main()
+    if not self.init then
+        self.init = computer.getInstance().nick
+    end
+    if not self.init then
+        computer.log(4, "No init program set")
+        computer.stop()
+    end
+    self.init = string.gsub(self.init, "#.*$", "")
+    computer.log(1, "Booting " .. self.init)
+    self:loadModule(self.init)
+end
+
+bootloader:main()

Packages/UniversalBootloader/README.md

@@ -0,0 +1,34 @@
+# Universal Bootloader
+
+This package implements a bootloader that will load scripts using several different
+methods.
+
+## How to specify which script to load
+
+You can specify the script to load in two ways:
+
+* Change the nick of the computer cabinet to the name of the script you want to
+run.  Anything after a `#` character in the nick will be ignored.
+* Edit the bootloader code to set `init = "name-of-script.lua"` at line 2.
+
+## How the bootloader looks for the script
+
+The bootloader will first look for any drives in the cabinet.  If a drive is
+found containing the file specified then it will load the file from that drive.
+
+If no drive is found containing the requested file then the file will be requested
+from the network using the net-boot protocol on port 8.
+
+## Loading multiple modules
+
+If you want to split your scripts up into multiple Lua files then you can use
+the bootloader to load them.  Suppose you your code split into two files,
+`main.lua` and `display.lua`.  Then you can start `main.lua` with:
+
+```lua
+bootloader:loadModule("display.lua")
+```
+
+This will load and execute `display.lua`.  Note that `display.lua` should only
+contain declarations; it should (normally) run and end once all the declarations
+are complete so that the code in `main.lua` can then run.

Packages/UniversalBootloader/metadata.toml

@@ -0,0 +1,5 @@
+name = "UniversalBootloader"
+version = "1.0"
+short_description = "Bootloader that uses both storage and net-boot"
+tags = ["boot", "network"]
+authors = ["tomkcook"]

README.adoc

@@ -8,7 +8,7 @@ It contains templates, full-fledged programs and examples provided by the mod's
 
 Anyone with a GitHub account can publish a package.
 
-Create fork of this git repository and add a folder with an alphanumeric name (`[a-zA-Z0-9_\-]+`) to the link:/Repository[`Repository`] folder.
+Create fork of this git repository and add a folder with an alphanumeric name (`[a-zA-Z0-9_\-]+`) to the link:/Packages[`Packages`] folder.
 
 In this newly created folder create a `README.adoc` or `README.md` containing a description of your package. +
 Add a `EEPROM.lua` file containing your EEPROM Code. +