www.pudn.com > LFYOS.zip > task.s

 
.global setup_task 
 
setup_task:		/*this function setup tss, and put it into GDT*/ 
	movl 0x04(%esp),%eax; 
	movl $(0xc0000800),%eax 
	movl %eax,tss_esp0 
	movl $(0x00000018),tss_ss0 
	movl $(0x00),tss_ss1 
	movl $(0x00),tss_ss2 
	movl $(page_dir),tss_cr3 
	andl $(0x3fffffff),tss_cr3 
 
	lea gdt_table,%edi 
	lea tss,%eax 
	shll $(0x10),%eax 
	addl $(tss_end-tss),%eax 
	lea tss,%edx 
	movl %edx,%ecx 
	shrl $(0x10),%ecx 
	movb %cl,%dl 
	andl $(0xff0000ff),%edx 
	orl  $(0x00008900),%edx 
	movl %eax,1*8(%edi) 
	movl %edx,4+1*8(%edi) 
	 
	lgdt gdt_descr 
	movw $(0x08),%ax 
	ltr %ax 
 
	ret 
 
.align 16 
tss: 
	.long 0 				/*00:	(0,LINK)*/ 
tss_esp0: 
	.long 0xc0000800			/*04:	ESP0  	*/ 
tss_ss0: 
	.long 0x18 				/*08:	(0,SS0)	*/ 
tss_esp1: 
	.long 0 				/*0C:	ESP1	*/ 
tss_ss1: 
	.long 0 				/*10:	(0,SS1)	*/ 
tss_esp2: 
	.long 0 				/*14:	ESP2	*/ 
tss_ss2: 
	.long 0 				/*18:	(0,SS2)	*/ 
tss_cr3: 
	.long 0 				/*1C:	CR3	*/ 
tss_reg: 
	.long 0 				/*20:	EIP	*/ 
	.long 0 				/*24:	EEFLAG	*/ 
	.long 0 				/*28:	EAX	*/ 
	.long 0 				/*2C:	ECX	*/ 
	.long 0 				/*30:	EDX	*/ 
	.long 0 				/*34:	EBX	*/ 
	.long 0					/*38:	ESP	*/ 
	.long 0 				/*3C:	EBP	*/ 
	.long 0 				/*40:	ESI	*/ 
	.long 0 				/*44:	EDI	*/ 
	.long 0x2b				/*48:	(0,ES)	*/ 
	.long 0x23 				/*4C:	(0,CS)	*/ 
	.long 0x2b 				/*50:	(0,SS)	*/ 
	.long 0x2b				/*54:	(0,DS)	*/ 
	.long 0x2b 				/*58:	(0,FS)	*/ 
	.long 0x2b 				/*5C:	(0,GS)	*/ 
	.long 0 				/*60:	(0,LDT)	*/ 
	.long 0 				/*64:	(IObitmap, 0T*/ 
	.org tss+0x70 
tss_end: