Added multiboot header, ports methods and added new part of libc(string)

kernel/cpu/ports.asm

@@ -0,0 +1,21 @@
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;             iceOS Kernel            ;
+; Developed by Marco 'icebit' Cetica  ;
+;              (c) 2019               ;
+;        Released under GPLv3         ;
+;   https://github.com/ice-bit/iceOS  ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+global outb ; Output from port
+global inb  ; Input to port
+
+outb:
+    mov al, [esp + 3]
+    mov dx, [esp + 4]
+    out dx, al
+    ret
+
+inb:
+    mov dx, [esp]
+    in al, dx
+    ret