add basic kernel

raven.lua

@@ -0,0 +1,115 @@
+_G._KERNEL_VERSION = "0.1.0"
+_G._KERNEL_NAME = "Raven"
+_G.raven = {}
+_G._OS_INFO = "Raven kernel operating system"
+_G._OS_VERSION = 0
+
+colors = {}
+colors.white = 1
+colors.orange = 2
+colors.magenta = 4
+colors.lightBlue = 8
+colors.yellow = 16
+colors.lime = 32
+colors.pink = 64
+colors.gray = 128
+colors.lightGray = 256
+colors.cyan = 512
+colors.purple = 1024
+colors.blue = 2048
+colors.brown = 4096
+colors.green = 8192
+colors.red = 16384
+colors.black = 32768
+
+colours = {}
+setmetatable(colours, {__index = colors})
+colours.grey = colors.gray
+colours.lightGrey = colors.lightGray
+
+term.clear()
+term.setCursorPos(1, 1)
+print("Raven kernel " .. _G._KERNEL_VERSION .. " booting.")
+
+if _G._FEATHER_VERSION or _G._PELICAN_VERSION then
+    print("Removing S1 and S2 version numbers from the env.")
+    _G._FEATHER_VERSION = nil
+    _G._PELICAN_VERSION = nil
+end
+
+print("Initalising error handler.")
+function raven.writeColour(colour, text)
+    local precolour = term.getTextColour()
+    term.setTextColour(colour)
+    write(text)
+    term.setTextColour(precolour)
+    return
+end
+
+function raven.writeColor(color, text)
+    raven.writeColour(color, text)
+    return
+end
+
+function error(e)
+    raven.writeColour(0x4000, "An error has occured: ")
+    term.setTextColour(0x1)
+    if e then
+        write(e .. "\n")
+    else
+        write("Undefined error." .. "\n")
+    end
+    return
+end
+
+print("Initialising benign API functions.")
+function raven.fullTermClear()
+    term.clear()
+    term.setCursorPos(1, 1)
+end
+
+print("Initialising execution functions.")
+function raven.run(path, env, ...)
+    local _ARGS = {...}
+    env._ARGS = _ARGS
+    local file, e = loadfile(path, env)
+    if file then
+        file()
+        return true
+    else
+        error(e)
+        return false
+    end
+end
+
+function raven.exec(path, ...)
+    local sandbox = {}
+    setmetatable(sandbox, {__index = _G})
+    if raven.run(path, sandbox, ...) then
+        return true
+    else
+        return false
+    end
+end
+
+print("Loading kernel configuration.")
+dofile(fs.combine(_G._KERNEL_ROOT, "/boot/raven.conf.lua"))
+
+if _G._SHELL then
+    print("Executing shell.")
+    dofile(fs.combine(_G._KERNEL_ROOT, _G._SHELL))    
+else
+    print("Shell not defined in configuration file.")
+    print("Entering basic kernel-level shell.")
+    print("Programs can be executed with the direct path.")
+    print("Programs will most likely exist within /bin/.")
+    while true do
+        write("> ")
+        local exec = read()
+        if fs.exists(fs.combine(_G._KERNEL_ROOT, exec)) and not fs.isDir(fs.combine(_G._KERNEL_ROOT, exec)) then
+            raven.exec(fs.combine(_G._KERNEL_ROOT, exec))
+        else
+            error("Program not found.")
+        end
+    end
+end