boot/head.s

   1 ##***************************************************************
   2 ##     What's done here is very simple, assign the segments,    *
   3 ##  move the rest of kernel down to low address again. Then     *
   4 ##  call the kernel initial function init().                    *
   5 ##     Yeah, we put the all the rest job of our kernel on it.   *
   6 ##     Hope it don't let's down. :)                             *
   7 ##                                                              *
   8 ##                  Copyright (C) 2007-2008  Aleaxander         *
   9 ##                      Email: Aleaxander@gmail.com             *
  10 ##***************************************************************
  11                 .text
  12                 .globl  pm_mode
  13                 .include "kernel.inc"
  14                 .org 0
  15 pg_dir:
  16 pm_mode:
  17                 movl    $DATA_SEL,%eax
  18                 movw    %ax,    %ds
  19                 movw    %ax,    %es
  20                 movw    %ax,    %fs
  21                 movw    %ax,    %gs
  22                 movw    %ax,    %ss
  23                 movl    $STACK_BOT,%esp
  24
  25                 cld
  26                 movl    $0x10200,%esi
  27                 movl    $0x200, %edi
  28                 movl    $(KERNEL_SECT-1)<<7,%ecx
  29                 rep
  30                 movsl
  31                 jmp     next
  32
  33
  34 /*
  35  * tmp_floppy_area is used by the floppy-driver when DMA cannot
  36  * reach to a buffer-block. It needs to be aligned, so that it isn't
  37  * on a 64kB border.
  38  */
  39 /*.globl tmp_floppy_area
  40         .org 0x1000
  41 tmp_floppy_area:
  42         .fill 1024,1,0
  43   */
  44 next:
  45                 call    init    # we count on it.
  46