Microcraft Bootloader

local function s(...) return sleep(...) end
local function w(...) return write(...) end
local function p(...) return print(...) end
local function tw(...) return term.write(...) end
local function scp(...) return term.setCursorPos(...) end
local function sbc(...) return term.setBackgroundColor(...) end
local function stc(...) return term.setTextColor(...) end
local function tc(...) return term.clear(...) end
local function tcl(...) return term.clearLine(...) end
local function r(...) return shell.run(...) end
local function sp(...) return textutils.slowPrint(...) end
local function sw(...) return textutils.slowWrite(...) end
local function fse(...) return fs.exists(...) end
local function pul(...) return paintutils.loadImage(...) end
local function pud(...) return paintutils.drawImage(...) end
local function pfb(...) return paintutils.drawFilledBox(...) end
local function su(...) return os.shutdown(...) end
local function re(...) return os.reboot(...) end
local function pdp(...) return paintutils.drawPixel(...) end
local w, h = term.getSize()
function boot()
tc()
sbc(colors.black)
tc()
sbc(colors.black)
stc(colors.white)
scp(1,2)
p("MineCore Bootloader")
p("(c) 2020 Microcraft")
scp(1,3)
p("Bootloader version: 1.0")
p("Free HDD space: ", fs.getFreeSpace("/"))
scp(1,5)
textutils.slowPrint("Searching for bootable media...")
s(1)
os()
end

function timer()
scp(1,h)
sbc(colors.gray)
stc(colors.white)
write("NextUI will be booted in 10 seconds.")
s(1)
scp(1,h)
sbc(colors.gray)
stc(colors.white)
write("NextUI will be booted in 9 seconds. ")
s(1)
scp(1,h)
sbc(colors.gray)
stc(colors.white)
write("NextUI will be booted in 8 seconds. ")
s(1)
scp(1,h)
sbc(colors.gray)
stc(colors.white)
write("NextUI will be booted in 7 seconds. ")
s(1)
scp(1,h)
sbc(colors.gray)
stc(colors.white)
write("NextUI will be booted in 6 seconds. ")
s(1)
scp(1,h)
sbc(colors.gray)
stc(colors.white)
write("NextUI will be booted in 5 seconds. ")
s(1)
scp(1,h)
sbc(colors.gray)
stc(colors.white)
write("NextUI will be booted in 4 seconds. ")
s(1)
scp(1,h)
sbc(colors.gray)
stc(colors.white)
write("NextUI will be booted in 3 seconds. ")
s(1)
scp(1,h)
sbc(colors.gray)
stc(colors.white)
p("NextUI will be booted in 2 seconds. ")
s(1)
scp(1,h)
sbc(colors.gray)
stc(colors.white)
p("NextUI will be booted in 1 second . ")
s(1)
scp(1,h)
sbc(colors.gray)
stc(colors.white)
p("NextUI will now boot.               ")
s(1)
r("/os/.next")
end

function os()
tc()
pfb(1,1,w,1,colors.gray)
pfb(1,h,w,h,colors.gray)
ac = w/2
scp(ac-10,1)
stc(colors.white)
p("MICROCRAFT BOOTLOADER")
parallel.waitForAny(timer, wybor)
end

pfb(3, 4, 13, 6, colors.orange)
scp(3,5)
stc(colors.white)
p("NextUI")
pfb(27, 4, 37, 6, colors.cyan)
scp(27,5)
stc(colors.white)
p("MineCore")
pfb(15, 4, 25, 6, colors.green)
scp(15,5)
stc(colors.white)
p("BIOS")
pfb(39, 4, 49, 6, colors.red)
scp(39,5)
stc(colors.white)
p("Minedows")
sbc(colors.black)
local event, click, x, y = os.pullEvent("mouse_click")
if x>2 and x<14 and y>3 and y<7 then r("/os/.next") end