kernel/16bit/gdt.asm

   1 ;----------------------------------------------------------;
   2 ; BOS kernel                Christoffer Bubach, 2004-2005. ;
   3 ;----------------------------------------------------------;
   4 ;                                                          ;
   5 ;     Global Descriptor Table (GDT).                       ;
   6 ;                                                          ;
   7 ;----------------------------------------------------------;
   8
   9 ;-------------------;
  10 ;  pointer to GDT   ;
  11 ;-------------------;
  12 gdtr:
  13      .size           dw   gdt_end - gdt - 1
  14      .address        dd   0x7400                      ; this is where we move
  15                                                       ; the gdt
  16 ;-----------------------------------;
  17 ;  Global Descriptor Table (GDT).   ;
  18 ;-----------------------------------;
  19 gdt:
  20      .null           dw   0x0000,0x0000,0x0000,0x0000 ; null desc.
  21      .BOS_code:      dw   0xFFFF,0x0000,0x9A00,0x00CF ; 0x08 , was 9800 before.
  22      .BOS_data:      dw   0xFFFF,0x0000,0x9200,0x00CF ; 0x10
  23      .BOS_16code:    dw   0xFFFF,0x0000,0x9A00,0x0000 ; 0x18
  24      .BOS_16data:    dw   0xFFFF,0x0000,0x9200,0x0000 ; 0x20
  25
  26 gdt_end: