An overview of the assembly code in the early Linux kernels

https://mirrors.edge.kernel.org/pub/linux/kernel/Historic/old-versions/old/diffs



! ! ld86 requires an entry symbol. This may as well be the usual one.
! .globl	_main
! _main:
! #if 0 /* hook for debugger, harmless unless BIOS is fussy (old HP) */
! 	int	3
! #endif
  	mov	ax,#BOOTSEG
  	mov	ds,ax
  	mov	ax,#INITSEG
***************
*** 55,71 ****
  	sub	di,di
  	cld
  	rep
! 	movw
  	jmpi	go,INITSEG
  
  go:	mov	ax,cs		
! 	mov	dx,#0xfef4	! arbitrary value >>512 - disk parm size
  
  	mov	ds,ax
  	mov	es,ax
  	push	ax
  
! 	mov	ss,ax		! put stack at 0x9ff00 - 12.
  	mov	sp,dx
  /*
   *	Many BIOS's default disk parameter tables will not 
--- 56,80 ----
  	sub	di,di
  	cld
  	rep
! 	movsw
  	jmpi	go,INITSEG
  
  go:	mov	ax,cs		
! 	mov	dx,#0x4000-12	! 0x4000 is arbitrary value >= length of
! 				! bootsect + length of setup + room for stack
! 				! 12 is disk parm size