global _start
_start:
%macro disp 2
mov rax,1
mov rdi,1
mov rsi,%1
mov rdx,%2
syscall
%endm

%macro exit 0
mov rax,60
mov rdi,0
syscall
%endm

smsw eax
mov [cr0_data],eax
bt eax,00
jc protected_mode
disp msg,len
exit

protected_mode:
disp msg1,len1
mov ax,[cr0_data+2]
call display
mov ax,[cr0_data]
call display
disp msg6,len6
disp msg2,len2
str [tr_data]
mov ax,[tr_data]
call display
disp msg6,len6
disp msg3,len3
sldt [ldt_data]
mov ax,[ldt_data]
call display
disp msg6,len6
disp msg4,len4
sgdt [gdt_data]
mov ax,[gdt_data+4]
call display
mov ax,[gdt_data+2]
call display
mov ax,[gdt_data]
call display
disp msg6,len6
disp msg5,len5
sidt [idt_data]
mov ax,[idt_data+4]
call display
mov ax,[idt_data+2]
call display
mov ax,[idt_data]
call display
exit




display:
mov rsi,disparr+3;
mov rcx,4;
a2:
mov rdx,0;
mov rbx,10h;
div rbx;
cmp dl,09h;
jbe a1;
add dl,07h;
a1:
add dl,30h;
mov [rsi],dl;
dec rsi
dec rcx;
jnz a2

mov rax,1;
mov rdi,1;
mov rsi,disparr;
mov rdx,4
syscall
ret
section .data
msg db "In real Mode"
len equ $-msg
msg1 db "Content of Cr0:"
len1 equ $-msg1
msg2 db "Content of TR:"
len2 equ $-msg2
msg3 db "Content of ldt:"
len3 equ $-msg3
msg4 db "Content of gdt:"
len4 equ $-msg4
msg5 db "Content of Idt:"
len5 equ $-msg5
msg6 db "",0ah
len6 equ $-msg6
section .bss
disparr resb 32
cr0_data resb 32
tr_data resb 32
ldt_data resb 32
gdt_data resb 32
idt_data resb 32