GitFOSS

def say_hello
  puts "Hello from Crystal!"
end


# def outb(port : UInt16, value : UInt8)
#   asm (%(outb %al, %dx) : : "a"(value), "Nd"(port))
# end

# def set_cursor_position(row : Int32, col : Int32)
#   position = (80 * row + col).to_u16

#   # # Write the high byte
#   # outb(0x3D4_u16, 0x0E_u8);
#   # outb(0x3D5_u16, ((position >> 8) & 0xFF).to_u8);

#   # # Write the low byte
#   # outb(0x3D4_u16, 0x0F_u8);
#   # outb(0x3D5_u16, (position & 0xFF).to_u8);
# end

# def clear_screen
#   video_memory = Pointer(UInt8).new(0xB8000_u64)
#   screen_size = 80 * 25
#   i = 0
#   while i < screen_size
#     (video_memory + (i * 2)).value = " ".to_unsafe.value
#     (video_memory + (i * 2) + 1).value = 0x07_u8
#     i += 1
#   end
# end

# message = "[CrystalOS Kernel] Hello from Crystal"
  
# clear_screen
# set_cursor_position(0, 0)

# _str : Pointer(UInt8) = message.to_unsafe
# video_memory = Pointer(UInt8).new(0xB8000_u64)
# i = 0
# ch = _str.value
# while ch > 0
#   ch = (_str + i).value
#   break if ch == 0
#   (video_memory + (i * 2)).value = ch
#   (video_memory + (i * 2) + 1).value = 0xB0_u8
#   i += 1
# end