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

kernel/cpu/kernel_load.asm

@@ -0,0 +1,25 @@
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;             iceOS Kernel            ;
+; Developed by Marco 'icebit' Cetica  ;
+;              (c) 2019               ;
+;        Released under GPLv3         ;
+;   https://github.com/ice-bit/iceOS  ;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+global kernel_loader
+extern main
+
+section .text
+kernel_loader:
+    mov esp, kernel_stack + KERNEL_STACK_SZ ; Stack pointer
+    push ebx
+    call main ; jump to kernel's main function
+.loop:
+    jmp .loop ; endless loop
+
+KERNEL_STACK_SZ equ 4096 ; 4 KB for the stack
+
+section .bss
+align 4
+kernel_stack:
+    resb KERNEL_STACK_SZ ; Reserver 4 KB