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Here is my code. All I want it to do is enter PMode, then hang. But the computer (well, Bochs) does not like the jmp (I'm using NASMP). Help plz!

[SEGMENT .text]
[BITS 16]
[ORG 7c00h]

;struc interrupt_descriptor
;  offset0_15        resw 1  ; low word of handler offset
;  selector0_15      resw 1  ; segment selector
;  zeroByte          resb 1  ; unused in this descriptor format
;  iFlags            resb 1  ; flag-byte
;  offset16_31       resw 1  ; high word of handler offset
;endstruc

start:
    mov ax, 0xb800
    mov gs, ax

    xor eax, eax
    mov ax, cs
    shl eax, 4
    mov [code32Dscr+2], ax
    mov [data32Dscr+2], ax
    shr eax, 16
    mov [code32Dscr+4], al
    mov [data32Dscr+4], al
    mov [code32Dscr+7], ah
    mov [data32Dscr+7], ah
    mov [gs:0], byte '1'

    lgdt [gdtPtr]
    mov eax, cr0
    or al, 1
    mov cr0, eax
    mov [gs:2], byte '2'

    jmp dword CODE_SEL:main32

    mov [gs:4], byte 'X'
    jmp $

[BITS 32]

main32:
    mov [gs:4], byte '3'
    jmp $

[SEGMENT .data]

;struc segmentDesc
;  segLen0_15        resw 1  ; low word of the segment length
;  baseAddr0_15      resw 1  ; low word of base address
;  baseAddr16_23     resb 1  ; low byte of high word of base addr.
;  sFlags            resb 1  ; segment type and misc. flags
;  access            resb 1  ; highest nibble of segment length
;                            ; and access flags
;  baseAddr24_31     resb 1  ; highest byte of base address
;endstruc

gdt         dd  0, 0
CODE_SEL    equ $-gdt
code32Dscr  dw  0xffff, 0
            db  0, 0x9a, 0xcf, 0
DATA_SEL    equ $-gdt
data32Dscr  dw  0xffff, 0
            db  0, 0x92, 0xcf, 0

gdtSize     equ $-gdt
gdtPtr      dw  gdtSize
            dd  gdt