NASM 고수분들께 질문입니다.

현재 제가 만들고 있는 부트로더 일부분입니다..VMWare으로 돌리고 있는데요~

잘 실행되다가

mov eax, cr0
or eax, 0x00000001
mov cr0, eax

이부분에서 VMWare가 Stack fault를 일으킵니다..

왜 이런 오류가 일어 납니까? 단순히 cr0의 마지막 비트를 1로 셋팅하고 싶은데요!

도와주세요!

읽어주셔서 감사합니다.

[org 0]
[bits 16]
%define INITSS 0x1000
%define INITSP 0xffff

%define BOOTSEG 0x07c0 ;boot segment: 0x7c00:0x0000
%define INITSEG 0x9000 ;boot loader itself moves to here
%define SETUPSEG 0x9020 ;setup segment: 0x9020:0x0000
%define SYSSEG 0x1000 ;beginning of kernel image

;here we assume cs: 0000h ip:7c00h
;reload
cld
mov ax, INITSEG
mov es, ax
xor di, di
mov ax, BOOTSEG
mov ds, ax
xor si, si
mov cx, 0x100 ;256 * 2byte(movsw) = 512 byte
repz movsw

jmp INITSEG:main
;=========================================
; main procedure
;=========================================
main:
mov ax, cs ;cs has INITSEG:0x9000
mov ds, ax
mov es, ax
;mov ss, ax ;;cs = ds = es = ss
;mov sp, 0x07c0

;init video
mov ax, 0600h
mov bh, 07h
xor cx, cx
mov dx, 1850h ;row:24 column:80
int 10h ;reset window

mov ah, 02h
xor bh, bh
xor dx, dx
int 10h ;set cursor position onto the top-left

;loading msg
mov si, WORD msg_loading
.msg_loop:
lodsb
or al, al
jz .out
mov ah, 0x0e
mov bl, 0x07
int 10h
jmp .msg_loop
.out:
mov ah, 02h
xor bh, bh
inc dh
mov dl, 00h
int 10h
.read_setup:
;read setup from disk
;setup will be loaded at 0x9020:0000
mov ax, SETUPSEG
mov es, ax
mov bx, 0 ;es:bx 0x9020:0000

mov ax, 0x0201
mov cx, 0x0002
mov dx, 0x0000
int 0x13

jc .read_setup
.load_kernel:
;load kernel image into memory
;kernel is loaded at 0x1000:0x0000
mov ax, SYSSEG
mov es, ax
mov bx, 0

mov ax, 0x0201
mov cx, 0x0003
mov dx, 0x0000
int 0x13

jc .load_kernel

mov dx, 0x3F2 ;turn off disk motor
xor al, al
out dx, al

;jump to setup() code 0x9020:0x0000
jmp SETUPSEG:0x0000
;=========================================
; data used by boot procedure
;=========================================
msg_loading db 'Loading...', 0
;==========================================
; boot signature
;==========================================
times 510-($-$$) db 0
dw 0xaa55

[org 0]
[bits 16]
start:
mov ax, cs ;CS has 0x9020:0000
mov ds, ax
xor ax, ax
mov ss, ax

;mov si, WORD msg_setup
;.msg_loop:
; lodsb
; or al, al
; jz .out
; mov ah, 0x0e
; mov bl, 0x07
; int 10h
; jmp .msg_loop
;.out:
cli
lgdt[gdtr]

mov eax, cr0
or eax, 0x00000001
mov cr0, eax

jmp $+2
nop
nop

jmp dword SysCodeSelector:PM_Start
;=========================================
;***********Protected Mode****************
;=========================================
[bits 32]

PM_Start:
mov bx, SysDataSelector
mov ds, bx
mov es, bx
mov fs, bx
mov gs, bx
mov ss, bx

mov si, WORD msg_starting
.msg_loop:
lodsb
or al, al
jz .out
mov ah, 0x0e
mov bl, 0x07
int 10h
jmp .msg_loop
.out:
jmp $

;=========================================
; **************GDT Table*****************
;=========================================
gdtr:
dw gdt_end-gdt-1 ;limit of GDT
dd gdt+0x90200
;NULL Descriptor
gdt:
dw 0
dw 0
db 0
db 0
db 0
db 0
;Kernel Code Segment Descriptor
SysCodeSelector equ 0x10
dw 0xFFFF ;limit 0xFFFFF
dw 0x9020 ;base 0~15bit
db 0x00 ;base 16~23bit
db 0x9A ;P:1, DPL:0, S:1, Code, Non-Conforming, readable
db 0xCF ;G:1, D:1, limit 16~19 bit:0xF
db 0x00 ;base 24~32bit
;Kernel Data Segment Descriptor
SysDataSelector equ 0x18
dw 0xFFFF ;limit 0xFFFFF
dw 0x0000 ;base 0~15bit
db 0x00 ;base 16~23bit
db 0x92 ;P:1, DPL:0, S:1, Data, expand-up, writable
db 0xCF ;G:1, D:1, limit 16~19 bit:0xF
db 0x00 ;base 24~32bit
;User Code Segment Descriptor
UserCodeSelector equ 0x20
dw 0xFFFF ;limit 0xFFFFF
dw 0x0000 ;base 0~15bit
db 0x00 ;base 16~23bit
db 0xFA ;P:1, DPL:3, S:1, Data, expand-up, writable
db 0xCF ;G:1, D:1, limit 16~19 bit:0xF
db 0x00 ;base 24~32bit
;User Data Segment Descriptor
UserDataSelector equ 0x28
dw 0xFFFF ;limit 0xFFFFF
dw 0x0000 ;base 0~15bit
db 0x00 ;base 16~23bit
db 0x92 ;P:1, DPL:0, Data, expand-up, writable
db 0xCF ;G:1, D:1, limit 16~19 bit:0xF
db 0x00 ;base 24~32bit
gdt_end:
;=========================================
; data used by setup procedure
;=========================================
msg_setup db 'Loaded Setup...', 0
msg_starting db 'PM is Starting...', 0