use16
org 0x5000
start:
  mov ax,3
  int 0x10
  mov ah,1
  mov ch,0x20
  int 0x10
  
  mov ax,0x500
  mov es,ax
  mov ax,cs
  mov ds,ax
  
  mov si,pm_start
  mov di,0
  
  mov cx,100h
  cld
  rep movsb
pm_start:
    cli
    lgdt fword[gdtr]
    mov eax,cr0
    or  al,1
    mov cr0,eax   
    jmp 0x10:0x5000 ;0x10:0x8000

gdt:        dw    0x0000, 0x0000, 0x0000, 0x0000
sys_data:   dw    0xFFFF, 0x0000, 0x9200, 0x00CF
sys_code:   dw    0xFFFF, 0x0000, 0x9800, 0x00CF
gdt_end:
gdtr:       dw gdt_end - gdt - 1
            dd gdt
use32
pm_code:
  mov ax,cs
  mov ds,ax
  mov ss,ax
  mov byte[0xB8000],1
  jmp $