system_call.s

别人的根据linux0.11改的一个小的操作系统

	.file	"system_call.c"
	.section .text
.globl __clrscr
__clrscr:
	pushl	%ebp
	movl	%esp, %ebp
	pushl	%edi
/APP
	pushw	%es;movw	$0x18,%ax;movw	%ax,%es;movl	$1000,%ecx;xorl	%eax,%eax;xorl	%edi,%edi;cld;rep	stosl;popw	%es;
/NO_APP
	movl	$0, __scr_loc
	popl	%edi
	popl	%ebp
	ret
.globl __scr_up
__scr_up:
	pushl	%ebp
	movl	%esp, %ebp
	pushl	%edi
	pushl	%esi
/APP
	pushw	%ds;pushw	%es;movw	$0x18,%ax;movw	%ax,%ds;movw	%ax,%es;movl	$160,%esi;xorl	%edi,%edi;movl	$960,%ecx;cld;rep	movsl;movl	$40,%ecx;xorl	%eax,%eax;rep	stosl;popw	%es;popw	%ds;
/NO_APP
	movl	$3840, __scr_loc
	popl	%esi
	popl	%edi
	popl	%ebp
	ret
.comm _desc,1008
.comm _task,1648
.comm _process_id,16
.comm _p_current,16
.comm _p_previous,16
.comm _p_ready,16
.comm _p_head,16
	.ident	"GCC: (GNU) 4.2.1"