lab4: protected mode with paging

bios.s

.arch pentium4
.code16
.section .text

.org 0x100

_gdt:	.quad	0
	.byte	0xFF, 0xFF,	0,   0, 0xF,	0b10011010, 0b00001111,	0	# код
	.byte	0xFF, 0xFF, 	0,   0, 0xF,	0b10010000, 0b00001111,	0	# данные
	.byte	0x00, 0x80, 	0,0x80, 0xB,	0b10010010, 0b00000000,	0	# видео
	.byte	0xFF, 0xFF, 	0,   0,   9,	0b10010010, 0b00000000,	0	# стек, буфер
	.byte	0x00, 0x10,	0,   0,0x12,	0b10010010, 0b00000000, 0	# каталог страниц
_gdt_size = . - _gdt

GDTR:	.word	_gdt_size - 1
	.long	0x10000

_idt:	.rept	0x20
		.quad	0
	.endr
	.quad	0
	.word	i09_handler, 8, 0b1000011000000000, 0
	.rept	0xF
		.quad 0
	.endr
	.word	i16_handler, 8, 0b1000011000000000, 0
_idt_size = . - _idt

IDTR:	.word	_idt_size - 1
	.long	0x11000

start:
	cli
	lss	%cs:STKPTR, %sp
	sti

	mov	$0x0AA55, %di
	mov	$3, %bh

	mov	BEGSEG, %dx

lo:	
	mov	%dx, %ds

        cld
	xor     %si, %si

	mov	%ds:(%si), %ax
	sub	%di, %ax
	jnz	skipp

	mov     %ds:2, %ah
	mov	%ax, %cx

	add	%bh, %ah
	not	%bh
	and	%bh, %ah
	not	%bh

	shr	$3, %ax
	add	%ax, %dx

	call scanbios

check:	cmp	$0xF000, %dx
	jb	lo

        call	init
	call	pm
	call	pg	
	sti
	mov	$0x18, %bx
	mov	%bx, %es
	xor	%ax, %ax
	xor	%di, %di
	mov	$2000, %cx	# clear video memory of text mode
	rep	stosw
	xor	%di, %di
typing:	
	hlt
	int	$0x31
	jz	typing

#	push	word ptr COUNT
#	push	1
#	push	dx
#	push	1
#	int	60h
#	add	sp, 8

#	mov	$0xE, %ah
#	mov	1, %bx
#	int	$0x10

	mov	$0xF,	%ah
	stosw
	jmp	typing

skipp:	add	$0x80, %dx
	jmp	check
        
STKPTR:	.word      0xFFFE,0x9000
BEGSEG:	.word	0xC000

COUNT:	.word	0x9000
PCO:	.word	0x20
com_l:	.byte	0xAA, 0x64, 0xAB, 0x64, 0xFF, 0x60, 0x11
ans_l:	.byte	0x55, 0x11 ,0, 0x11, 0xFA, 0xAA, 0x11 

pm:
	mov	%cs, %ax
	mov	%ax, %ds
	mov	$_gdt, %si
	mov	$0x1000, %ax
	mov	%ax, %es
	xor	%di, %di
	mov	$_gdt_size/4, %cx
	cld
	rep	movsl

	mov	$_idt, %si
	mov	$0x1100, %ax
	mov	%ax, %es
	xor	%di, %di
	mov	$_idt_size/4, %cx
	rep	movsl

	lgdt	GDTR
	lidt	IDTR

	# we do not assign interrupts at all (IDT is empty) -> so disable interrupts at all
	cli			# disable int#
	inb	$0x70
	or	$0x80, %al	# disable NMI
	outb	$0x70

	# turn on 16bit i80286+ protected mode
	mov	%cr0, %eax
	or	$0x00000001, %eax
	mov	%eax, %cr0
	.byte	0xEA
	.word	next
	.word	8

	# load other segment registers 
next:	mov	$0x18, %ax
	mov	%ax, %es
	mov	$0x20, %ax
	mov	%ax, %ds
	mov	%ax, %ss

	inb	$0x70
	and	$0x7F, %al	# allow NMI
	outb	$0x70
	sti			# allow int#

	ret

_pde:	.byte	0b010000111, 0, 0, 0	#PS=1, U/S=1, R/W=1, P=1, base=0
pg:
	mov	$0x28, %ax
	mov	%ax, %es
	mov	%cs:_pde, %eax
	xor	%di, %di
	stosl
	mov	$1023, %cx
	xor	%eax, %eax
	rep	stosl
	mov	$0x120000, %eax
	mov	%eax, %cr3
	mov	$1, %eax
	shl	$4, %eax		# PSE=1 // 4th in cr4
	mov	%cr4, %ebx
	or	%eax, %ebx
	mov	%ebx, %cr4
	shl	$27, %eax		# PG=1 //last in cr0
	mov	%cr0, %ebx
	or	%eax, %ebx
	mov	%ebx, %cr0	

	ret

scanbios:

	xor	%bl, %bl
chcksm: 
	lodsw
	addb	%ah, %al
	addb	%al, %bl
	decw	%cx
	jnz	chcksm

	or	%bl, %bl
	jnz	skip

	pusha
	push	%ds
	push	%es
	push	%fs
	push	%gs

	push	%cs
	pushw	$__ret
	push	%ds
	pushw	$3
	lret
__ret:
	pop	%gs
	pop	%fs
	pop	%es
	pop	%ds
	popa
skip:
	ret	$0


.set	P0, 0x20
.set	P1, 0xA0
init:
	mov	$0x20, %al
	outb	$P0
	outb	$P1
	
	mov	$0b00010000, %al
	outb	$P0		#icw1 pic0

	mov	$0x20, %al
	outb	$P0 + 1		#icw2 pic0

	mov	0b100, %al
	outb	$P0 + 1		#icw3 pic0

#	mov	al, 00010000b
#	out	0A0h, al	;icw1 pic1
#
#	mov	al, 70h
#	out	0A1h, al	;icw2 pic1
#
#	mov	al, 10b
#	out	0A1h, al	;icw3 pic1

	mov	$0b11111101, %al
	outb	$P0 + 1		#ocw1 pic0


	mov	$com_l, %di
	mov	$ans_l, %si

w4:	mov	%cs:(%di), %bl
	inc	%di
	cmp	$0x11, %bl
	jz	kb_out

	mov	$0xFFF0, %cx
w40:	inb	$0x64
	test	$2, %al
	jz	w41
	loop	w40

	jmp	error

w41:	mov	%bl, %al
	xor	%dx, %dx
	mov	%cs:(%di), %ah
	inc	%di
	cmp	$0x64, %ah
	jnz	o60
	outb	$0x64
	jmp	l5
o60:	outb	$0x60
#	out	dx, al

l5:	mov	%cs:(%si), %bl
	inc	%si
	cmp	$0x11, %bl
	jz	w4

	mov	$0x2000, %cx
lo4:	inb	$0x64
	test	$1, %al
	jz	w42

	inb	$0x60
	cmp	%al, %bl
	jz	l5		# ok
	jmp	error
	
w42:	loop	lo4
	
	jmp	error	

kb_out:

	
	xor	%ax, %ax
	mov	%ax, %es
	cli
	movw	$i09_handler, %es:9*4
	movw	%cs, %es:9*4+2
	movw	$i16_handler, %es:0x16*4 
	movw	%cs, %es:0x16*4+2
	sti


	mov	%cs:COUNT, %ds	# keyboard preparing
	mov	$1, %al
	mov	%al, %ds:0
	mov	$2, %al
	mov	%al, %ds:1

	call timer_init

	ret

error:
	call wr
	call stop

i09_handler:	
	push	%ax
	push	%bx
	push	%cx
	push	%dx
	push	%si
	push	%ds
	
	
	mov	$0xAD, %al
	outb	$0x64

	xor	%ax, %ax
	inb	$0x60
	test	$0b10000000, %al
	jnz	rls

	mov	%cs:PCO, %ds
	mov	%ds:0, %dx
	cmp	%dl, %dh
	jz	rls

	dec	%ax
	mov	$alpha, %bx
	add	%ax, %bx
	mov	%cs:(%bx), %al
	
	xor	%cx, %cx
	mov	%al, %cl		# shift randomizing
	inb	$0x42
	test	$1, %al
	jz	sss
	xor	$32, %cl

sss:	
	xor	%ax, %ax
	mov	%dh, %al
	mov	%ax, %si
	mov	%cl, %ds:(%si)
	inc	%al
	and	$0b00011111, %al
	jnz	nz
	mov	$2, %al
nz:	mov	%al, %ds:1
	

rls:
	mov	$0x20, %al		#eoi
	outb	$P0

	mov	$0xAE, %al		#scan allow
	outb	$0x64

	pop	%ds
	pop	%si
	pop	%dx
	pop	%cx
	pop	%bx
	pop	%ax
	iret


i16_handler:
	lahf
	
	push	%dx
	push	%bx
	push	%si	
	push	%ds
	
	mov	%ax, %bx

	mov	%cs:PCO, %ds
	mov	%ds:0, %dx

	inc	%dl
	and	$0b00011111, %dl
	jnz	norm
	mov	$2, %dl

norm:	cmp	%dl, %dh
	jz	sk4

	xor	%ax, %ax
	mov	%dl, %al
	mov	%dl, %ds:0
	mov	%ax, %si
	mov	%ds:(%si), %al

	and	$0b10111111, %bh
	jmp	sk5

sk4:	or	$0b1000000, %bh

sk5:	mov	%bh, %ss:12(%esp)
	pop	%ds
	pop	%si
	pop	%bx
	pop	%dx

	iret


timer_init:
	push	%ax

	inb	$0x61
	and	$0b11111101, %al
	or	$0b00000001, %al
	outb	$0x61

	mov	$0b10110100, %al
	outb	$0x43
	xor	%al, %al
	outb	$0x42
	mov	$5, %al
	outb	$0x42

	pop	%ax
	ret


wr:
	push	%cs
	push	$msg1
	push	$0
	int	$0x60
	add	$6, %sp
	ret
msg1:	.asciz	"Error!!1"


stop:
	cli
	hlt
	jmp	stop

alpha:	.ascii	" 1234567890-+  "
	.ascii	"qwertyuiop[]  "
	.ascii	"asdfghjkl;\"` "
	.ascii	"\\zxcvbnm,./  "
	.ascii	"                        "
	.byte	0

# real startup entry begins at F000:FFF0
.org	0xFFF0
	.byte	0xEA
	.word	start
	.word	0xF000



.org	0xFFFE
	.word	0x99FC

.end

lab4 segmenting, paging

.arch pentium4
.code16
.section .text

.org 0x100

_gdt:	.quad	0
	.byte	0xFF, 0xFF,	0,   0, 0xF,	0b10011010, 0b00001111,	0	# код
	.byte	0xFF, 0xFF, 	0,   0, 0xF,	0b10010000, 0b00001111,	0	# данные
	.byte	0x00, 0x80, 	0,0x80, 0xB,	0b10010010, 0b00000000,	0	# видео
	.byte	0xFF, 0xFF, 	0,   0,   9,	0b10010010, 0b00000000,	0	# стек, буфер
	.byte	0x00, 0x10,	0,   0,0x12,	0b10010010, 0b00000000, 0	# каталог страниц
_gdt_size = . - _gdt

GDTR:	.word	_gdt_size - 1
	.long	0x10000

_idt:	.rept	0x20
		.quad	0
	.endr
	.quad	0
	.word	i09_handler, 8, 0b1000011000000000, 0
	.rept	0xF
		.quad 0
	.endr
	.word	i16_handler, 8, 0b1000011000000000, 0
_idt_size = . - _idt

IDTR:	.word	_idt_size - 1
	.long	0x11000

start:
	cli
	lss	%cs:STKPTR, %sp
	sti

	mov	$0x0AA55, %di
	mov	$3, %bh

	mov	BEGSEG, %dx

lo:	
	mov	%dx, %ds

        cld
	xor     %si, %si

	mov	%ds:(%si), %ax
	sub	%di, %ax
	jnz	skipp

	mov     %ds:2, %ah
	mov	%ax, %cx

	add	%bh, %ah
	not	%bh
	and	%bh, %ah
	not	%bh

	shr	$3, %ax
	add	%ax, %dx

	call scanbios

check:	cmp	$0xF000, %dx
	jb	lo

        call	init
	call	pm
	call	pg	
	sti
	mov	$0x18, %ax
	mov	%ax, %es
	xor	%bx, %bx
	mov	$0x7FFF, %ax
nan:	mov	%ax, %di
	mov	%bx, %es:(%di)
	dec	%ax
	jnz	nan

typing:	
	hlt
	int	$0x31
	jz	typing

#	push	word ptr COUNT
#	push	1
#	push	dx
#	push	1
#	int	60h
#	add	sp, 8

#	mov	$0xE, %ah
#	mov	1, %bx
#	int	$0x10

	mov	$0xF,	%ah
	mov	%bx,	%di
	mov	%ax,	%es:(%di)
	add	$2,	%bx
	jmp	typing

skipp:	add	$0x80, %dx
	jmp	check
        
STKPTR:	.word      0xFFFE,0x9000
BEGSEG:	.word	0xC000

COUNT:	.word	0x9000
PCO:	.word	0x20
com_l:	.byte	0xAA, 0x64, 0xAB, 0x64, 0xFF, 0x60, 0x11
ans_l:	.byte	0x55, 0x11 ,0, 0x11, 0xFA, 0xAA, 0x11 

pm:
	mov	%cs, %ax
	mov	%ax, %ds
	mov	$_gdt, %si
	mov	$0x1000, %ax
	mov	%ax, %es
	xor	%di, %di
	mov	$_gdt_size/4, %cx
	cld
	rep	movsl

	mov	$_idt, %si
	mov	$0x1100, %ax
	mov	%ax, %es
	xor	%di, %di
	mov	$_idt_size/4, %cx
	rep	movsl

	lgdt	GDTR
	lidt	IDTR

	# we do not assign interrupts at all (IDT is empty) -> so disable interrupts at all
	cli			# disable int#
	inb	$0x70
	or	$0x80, %al	# disable NMI
	outb	$0x70

	# turn on 16bit i80286+ protected mode
	mov	%cr0, %eax
	or	$0x00000001, %eax
	mov	%eax, %cr0
	.byte	0xEA
	.word	next
	.word	8

	# load other segment registers 
next:	mov	$0x18, %ax
	mov	%ax, %es
	mov	$0x20, %ax
	mov	%ax, %ds
	mov	%ax, %ss

	inb	$0x70
	and	$0x7F, %al	# allow NMI
	outb	$0x70
	sti			# allow int#

	ret

_pde:	.byte	0b010000111, 0, 0, 0	#PS=1, U/S=1, R/W=1, P=1, base=0
pg:
	mov	$0x28, %ax
	mov	%ax, %es
	mov	%cs:_pde, %eax
	xor	%di, %di
	stosl
	mov	$1023, %cx
	xor	%eax, %eax
	rep	stosl
	mov	$0x120000, %eax
	mov	%eax, %cr3
	mov	$1, %eax
	shl	$4, %eax		# PSE=1 // 4th in cr4
	mov	%cr4, %ebx
	or	%eax, %ebx
	mov	%ebx, %cr4
	shl	$27, %eax		# PG=1 //last in cr0
	mov	%cr0, %ebx
	or	%eax, %ebx
	mov	%ebx, %cr0	

	ret

scanbios:

	xor	%bl, %bl
chcksm: 
	lodsw
	addb	%ah, %al
	addb	%al, %bl
	decw	%cx
	jnz	chcksm

	or	%bl, %bl
	jnz	skip

	pusha
	push	%ds
	push	%es
	push	%fs
	push	%gs

	push	%cs
	pushw	$__ret
	push	%ds
	pushw	$3
	lret
__ret:
	pop	%gs
	pop	%fs
	pop	%es
	pop	%ds
	popa
skip:
	ret	$0


.set	P0, 0x20
.set	P1, 0xA0
init:
	mov	$0x20, %al
	outb	$P0
	outb	$P1
	
	mov	$0b00010000, %al
	outb	$P0		#icw1 pic0

	mov	$0x20, %al
	outb	$P0 + 1		#icw2 pic0

	mov	0b100, %al
	outb	$P0 + 1		#icw3 pic0

#	mov	al, 00010000b
#	out	0A0h, al	;icw1 pic1
#
#	mov	al, 70h
#	out	0A1h, al	;icw2 pic1
#
#	mov	al, 10b
#	out	0A1h, al	;icw3 pic1

	mov	$0b11111101, %al
	outb	$P0 + 1		#ocw1 pic0


	mov	$com_l, %di
	mov	$ans_l, %si

w4:	mov	%cs:(%di), %bl
	inc	%di
	cmp	$0x11, %bl
	jz	kb_out

	mov	$0xFFF0, %cx
w40:	inb	$0x64
	test	$2, %al
	jz	w41
	loop	w40

	jmp	error

w41:	mov	%bl, %al
	xor	%dx, %dx
	mov	%cs:(%di), %ah
	inc	%di
	cmp	$0x64, %ah
	jnz	o60
	outb	$0x64
	jmp	l5
o60:	outb	$0x60
#	out	dx, al

l5:	mov	%cs:(%si), %bl
	inc	%si
	cmp	$0x11, %bl
	jz	w4

	mov	$0x2000, %cx
lo4:	inb	$0x64
	test	$1, %al
	jz	w42

	inb	$0x60
	cmp	%al, %bl
	jz	l5		# ok
	jmp	error
	
w42:	loop	lo4
	
	jmp	error	

kb_out:

	
	xor	%ax, %ax
	mov	%ax, %es
	cli
	movw	$i09_handler, %es:9*4
	movw	%cs, %es:9*4+2
	movw	$i16_handler, %es:0x16*4 
	movw	%cs, %es:0x16*4+2
	sti


	mov	%cs:COUNT, %ds	# keyboard preparing
	mov	$1, %al
	mov	%al, %ds:0
	mov	$2, %al
	mov	%al, %ds:1

	call timer_init

	ret

error:
	call wr
	call stop

i09_handler:	
	push	%ax
	push	%bx
	push	%cx
	push	%dx
	push	%si
	push	%ds
	
	
	mov	$0xAD, %al
	outb	$0x64

	xor	%ax, %ax
	inb	$0x60
	test	$0b10000000, %al
	jnz	rls

	mov	%cs:PCO, %ds
	mov	%ds:0, %dx
	cmp	%dl, %dh
	jz	rls

	dec	%ax
	mov	$alpha, %bx
	add	%ax, %bx
	mov	%cs:(%bx), %al
	
	xor	%cx, %cx
	mov	%al, %cl		# shift randomizing
	inb	$0x42
	test	$1, %al
	jz	sss
	xor	$32, %cl

sss:	
	xor	%ax, %ax
	mov	%dh, %al
	mov	%ax, %si
	mov	%cl, %ds:(%si)
	inc	%al
	and	$0b00011111, %al
	jnz	nz
	mov	$2, %al
nz:	mov	%al, %ds:1
	

rls:
	mov	$0x20, %al		#eoi
	outb	$P0

	mov	$0xAE, %al		#scan allow
	outb	$0x64

	pop	%ds
	pop	%si
	pop	%dx
	pop	%cx
	pop	%bx
	pop	%ax
	iret


i16_handler:
	lahf
	
	push	%dx
	push	%bx
	push	%si	
	push	%ds
	
	mov	%ax, %bx

	mov	%cs:PCO, %ds
	mov	%ds:0, %dx

	inc	%dl
	and	$0b00011111, %dl
	jnz	norm
	mov	$2, %dl

norm:	cmp	%dl, %dh
	jz	sk4

	xor	%ax, %ax
	mov	%dl, %al
	mov	%dl, %ds:0
	mov	%ax, %si
	mov	%ds:(%si), %al

	and	$0b10111111, %bh
	jmp	sk5

sk4:	or	$0b1000000, %bh

sk5:	mov	%bh, %ss:12(%esp)
	pop	%ds
	pop	%si
	pop	%bx
	pop	%dx

	iret


timer_init:
	push	%ax

	inb	$0x61
	and	$0b11111101, %al
	or	$0b00000001, %al
	outb	$0x61

	mov	$0b10110100, %al
	outb	$0x43
	xor	%al, %al
	outb	$0x42
	mov	$5, %al
	outb	$0x42

	pop	%ax
	ret


wr:
	push	%cs
	push	$msg1
	push	$0
	int	$0x60
	add	$6, %sp
	ret
msg1:	.asciz	"Error!!1"


stop:
	cli
	hlt
	jmp	stop

alpha:	.ascii	" 1234567890-+  "
	.ascii	"qwertyuiop[]  "
	.ascii	"asdfghjkl;\"` "
	.ascii	"\\zxcvbnm,./  "
	.ascii	"                        "
	.byte	0

# real startup entry begins at F000:FFF0
.org	0xFFF0
	.byte	0xEA
	.word	start
	.word	0xF000



.org	0xFFFE
	.word	0x99FC

.end