diff --git a/kernel/Makefile b/kernel/Makefile
index 73df900..bb1bd93 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -12,7 +12,11 @@ SRCS	= kernel.asm \
 			lock.inc \
 			gdt.inc \
 			isr.inc \
-			pic.inc
+			pic.inc \
+			idt.inc \
+			dev/at/pit.inc \
+			dev/at/cga.inc \
+			dev/at/kbd.inc
 
 .PHONY: all
 all: $(KERNEL)
diff --git a/kernel/dev/at/cga.inc b/kernel/dev/at/cga.inc
new file mode 100644
index 0000000..bbbbdfb
--- /dev/null
+++ b/kernel/dev/at/cga.inc
@@ -0,0 +1,131 @@
+	;; File: cga.inc
+	;;
+	;; Usefull links:
+	;; - <http://www.techhelpmanual.com/901-color_graphics_adapter_i_o_ports.html>
+	;; - <http://www.osdever.net/FreeVGA/vga/crtcreg.htm>
+CGA_MEMORY      = 0xC00B8000
+CGA_COMMAND     = 0x3d4
+CGA_DATA        = 0x3d5
+CGA_CURSOR_HIGH = 0xE
+CGA_CURSOR_LOW  = 0xF
+CGA_COLUMNS = 80
+CGA_LINES = 24
+
+	;; Function: cga_getpos
+	;; 
+	;; Out:
+	;;    AX - cursor position
+cga_getpos:
+	; read cursor position
+	xor ax, ax
+
+	xchg bx, bx
+	
+	; get high
+	mov dx, CGA_COMMAND
+	mov al, CGA_CURSOR_HIGH
+	out dx, al
+	mov dx, CGA_DATA
+	in al, dx
+	xchg al, ah
+
+	; get low
+	mov dx, CGA_COMMAND
+	mov al, CGA_CURSOR_LOW
+	out dx, al
+	mov dx, CGA_DATA
+	in al, dx
+
+	ret
+
+	;; Function: cga_setpos
+	;; 
+	;; In:
+	;;    AX - cursor position
+cga_setpos:
+	xchg bx, bx
+	mov dx, CGA_COMMAND
+	push ax
+	mov al, CGA_CURSOR_HIGH
+	out dx, al
+	pop ax
+	xchg al, ah
+	mov dx, CGA_DATA
+	out dx, al
+
+	mov dx, CGA_COMMAND
+	mov al, CGA_CURSOR_LOW
+	out dx, al
+	xchg al, ah
+	mov dx, CGA_DATA
+	out dx, al
+
+	ret
+
+	;; Function: cga_putc
+	;; 
+	;; In:
+	;;    AL - charactere to print
+cga_putc:
+	push ebp
+	mov ebp, esp
+	sub esp, 0x2
+
+	push eax
+	call cga_getpos
+	mov [ebp-0x2], ax
+	pop eax
+
+	cmp al, LF
+	jne @f
+	mov ax, [ebp-0x2]
+	mov dl, CGA_COLUMNS
+	div dl
+	mov al, CGA_COLUMNS
+	sub al, ah
+	xor ah, ah
+	mov cx, [ebp-0x2]
+	add cx, ax
+	jmp .end
+@@:
+	mov edx, CGA_MEMORY
+	xor ecx, ecx
+	mov cx, [ebp-0x2]
+	shl cx, 1
+	add edx, ecx
+	mov ah, 0x07
+	mov word [edx], ax
+	mov cx, [ebp-0x2]
+	inc cx
+
+	mov ax, cx
+	mov dl, CGA_COLUMNS
+	div dl
+	cmp al, CGA_LINES
+	jbe .end
+
+	mov [ebp-0x2], cx
+
+	; scroll up
+	push esi
+	push edi
+	mov ecx, CGA_COLUMNS*(CGA_LINES-1)
+	mov edi, CGA_MEMORY
+	mov esi, CGA_MEMORY+80*2
+	rep movsw
+
+	mov ecx, CGA_COLUMNS
+	xor ax, ax
+	mov edi, CGA_MEMORY+(CGA_COLUMNS*(CGA_LINES-1)*2)
+	rep stosw
+
+	pop esi
+	pop edi
+
+	mov cx, CGA_COLUMNS*(CGA_LINES-1)
+.end:
+	mov ax, cx
+	call cga_setpos
+
+	leave
+	ret
diff --git a/kernel/dev/at/kbd.inc b/kernel/dev/at/kbd.inc
new file mode 100644
index 0000000..83e07c2
--- /dev/null
+++ b/kernel/dev/at/kbd.inc
@@ -0,0 +1,18 @@
+	;; File: kbd.inc
+
+kbd_getc:
+	ret
+
+kbd_irq:
+	pusha
+
+	mov esi, szMsgKbdIRQ
+	call klog
+
+	mov al, PIC_EOI
+	out PIC1_COMMAND, al
+
+	popa
+	iret
+
+szMsgKbdIRQ db "KBD: IRQ", 0
diff --git a/kernel/dev/at/pit.inc b/kernel/dev/at/pit.inc
new file mode 100644
index 0000000..f41d2af
--- /dev/null
+++ b/kernel/dev/at/pit.inc
@@ -0,0 +1,29 @@
+	;; File: pit.inc
+	;;
+	;; Usefull links:
+	;; - <http://www.osdever.net/bkerndev/Docs/pit.htm>
+
+PIT_CHANNEL0 = 0x40
+PIT_CHANNEL1 = 0x40
+PIT_CHANNEL2 = 0x42
+PIT_COMMAND  = 0x43
+
+	;; Function: pit_init
+pit_init:
+	ret
+
+	;; Function: pit_irq
+pit_irq:
+	pusha
+
+	;mov esi, szMsgPitIRQ
+	;call klog
+
+	mov al, PIC_EOI
+	out PIC1_COMMAND, al
+
+	popa 
+
+	iret
+
+szMsgPitIRQ db "PIT: IRQ", 0
diff --git a/kernel/dev/console.inc b/kernel/dev/console.inc
new file mode 100644
index 0000000..3335d2a
--- /dev/null
+++ b/kernel/dev/console.inc
@@ -0,0 +1,2 @@
+	;; File: console.inc
+
diff --git a/kernel/dev/dev.inc b/kernel/dev/dev.inc
new file mode 100644
index 0000000..3a5836b
--- /dev/null
+++ b/kernel/dev/dev.inc
@@ -0,0 +1,9 @@
+	;; File: dev.inc
+
+
+
+struc Device {
+	.write dd ?
+	.read  dd ?
+}
+
diff --git a/kernel/gdt.inc b/kernel/gdt.inc
index b68ad50..fe20f62 100644
--- a/kernel/gdt.inc
+++ b/kernel/gdt.inc
@@ -1,3 +1,4 @@
+	;; File: gdt.inc
 
 gdt:
 	; null descriptor
@@ -30,3 +31,7 @@ gdt:
 pGDT:
 	dw gdt.end - gdt - 1
 	dd gdt
+
+gdt_set_tss:
+	
+	ret
diff --git a/kernel/idt.inc b/kernel/idt.inc
index a344cca..88c4fd5 100644
--- a/kernel/idt.inc
+++ b/kernel/idt.inc
@@ -1,10 +1,51 @@
+	;; File: idt.inc
 
-idt_set_table:
+idt_set_gate:
+	mov [aInterruptGate + (ecx * 8)], ax
+	mov [aInterruptGate + (ecx * 8) + 2], word 0x08
+
+	mov [aInterruptGate + (ecx * 8) + 5], word 0x8E
+	shr eax, 16
+	mov [aInterruptGate + (ecx * 8) + 6], ax
 	ret
 
 idt_setup:
+	xor ecx, ecx
+@@:
+	mov eax, [aISRTable + (ecx * 4)]
+	call idt_set_gate
+	inc ecx
+	cmp ecx, 32
+	jb @b
+
+	mov eax, pit_irq
+	call idt_set_gate
+	inc ecx
+
+	mov eax, kbd_irq
+	call idt_set_gate
+	inc ecx
+
+@@:
+	mov eax, irq_dummy
+	call idt_set_gate
+	inc ecx
+	cmp ecx, 0x30
+	jb @b
+
+	mov ecx, 0x42
+	mov eax, isr_syscall
+	call idt_set_gate
+
+	lidt [pIDT]
+	sti
 	ret
 
-pIdt:
-	dw ?
-	dd ?
+pIDT:
+	dw aInterruptGate.end-aInterruptGate-1
+	dd aInterruptGate
+
+; variable: idt_entries
+aInterruptGate:
+	dd 256*2 dup(0)
+.end:
diff --git a/kernel/irq.inc b/kernel/irq.inc
index e69de29..cbbd5b5 100644
--- a/kernel/irq.inc
+++ b/kernel/irq.inc
@@ -0,0 +1,2 @@
+irq_dummy:
+	iret
diff --git a/kernel/isr.inc b/kernel/isr.inc
index 1f1c785..1936ed3 100644
--- a/kernel/isr.inc
+++ b/kernel/isr.inc
@@ -18,54 +18,6 @@ forward
 				 
 }
 
-idt_setup:
-	xor ecx, ecx
-@@:
-	mov eax, [aISRTable + (ecx * 4)]
-	mov [aInterruptGate + (ecx * 8)], ax
-	mov [aInterruptGate + (ecx * 8) + 2], word 0x08
-
-	mov [aInterruptGate + (ecx * 8) + 5], word 0x8E
-	shr eax, 16
-	mov [aInterruptGate + (ecx * 8) + 6], ax
-	inc ecx
-	cmp ecx, 32
-	jb @b
-@@:
-	mov eax, irq_dummy
-	mov [aInterruptGate + (ecx * 8)], ax
-	mov [aInterruptGate + (ecx * 8) + 2], word 0x08
-
-	mov [aInterruptGate + (ecx * 8) + 5], word 0x8E
-	shr eax, 16
-	mov [aInterruptGate + (ecx * 8) + 6], ax
-	inc ecx
-	cmp ecx, 0x30
-	jb @b
-
-	mov ecx, 0x42
-	mov eax, isr_syscall
-	mov [aInterruptGate + (ecx * 8)], ax
-	mov [aInterruptGate + (ecx * 8) + 2], word 0x08
-
-	mov [aInterruptGate + (ecx * 8) + 5], word 0x8E
-	shr eax, 16
-	mov [aInterruptGate + (ecx * 8) + 6], ax
-
-	lidt [pIDT]
-	sti
-	ret
-
-pIDT:
-	dw aInterruptGate.end-aInterruptGate-1
-	dd aInterruptGate
-
-; variable: idt_entries
-aInterruptGate:
-	dd 256*2 dup(0)
-.end:
-
-
 irq_dummy:
 	iret
 
diff --git a/kernel/kernel.asm b/kernel/kernel.asm
index c487854..1c1f2fa 100644
--- a/kernel/kernel.asm
+++ b/kernel/kernel.asm
@@ -60,10 +60,15 @@ kmain:
 	lgdt [pGDT]
 	; I don't think i need to reload segment cuz their value are already correct
 
-
 	call idt_setup
 
-	;int 0x42
+	call pit_init
+
+	mov eax, SYSCALL_EXIT
+	int 0x42
+
+	mov al, 'X'
+	call cga_putc
 
 .halt:
 	hlt
@@ -81,7 +86,11 @@ kmain:
 	include 'gdt.inc'
 	include 'syscall.inc'
 	include 'isr.inc'
+	include 'idt.inc'
 	include 'pic.inc'
+	include 'dev/at/pit.inc'
+	include 'dev/at/kbd.inc'
+	include 'dev/at/cga.inc'
 
 
 szMsgKernelAlive db "Kernel (", VERSION_FULL , ") is alive", 0
diff --git a/kernel/klog.inc b/kernel/klog.inc
index ff16731..0231086 100644
--- a/kernel/klog.inc
+++ b/kernel/klog.inc
@@ -34,7 +34,7 @@ klog_print:
 	or al, al
 	jz @f
 	out dx, al
-	;call klog_kputc
+	;call klog_kput
 	jmp @b
 @@:
 	ret
diff --git a/kernel/sys/coff.inc b/kernel/sys/coff.inc
index d9988ec..8c2ffb9 100644
--- a/kernel/sys/coff.inc
+++ b/kernel/sys/coff.inc
@@ -1,3 +1,6 @@
+	;; File: coff.inc
+
+	;; Struc: COFFFileHdr
 struc COFFFileHdr {
 	.f_magic  dw ?
 	.f_nscns  dw ?
diff --git a/lib/crypto/rc4/rc4.asm b/lib/crypto/rc4/rc4.asm
index 842fd8b..c71c0b5 100644
--- a/lib/crypto/rc4/rc4.asm
+++ b/lib/crypto/rc4/rc4.asm
@@ -16,10 +16,21 @@ rc4_init:
 	mov ebp, esp
 
 	mov eax, [ebp+8]
-	xor ecx, ecx
+	xor cx, cx
 
-.loop:
+@@:
+	mov byte [eax], byte cx
+	inc cx
+	inc eax
+	cmp cx, 255
+	jne @b
+
+	xor cx, cx
+	mov eax, [ebp+8]
+@@:
 	
+
+
 .end:
 	leave
 	ret
diff --git a/lib/crypto/sha2/sha256.asm b/lib/crypto/sha2/sha256.asm
index cd3670b..bf2b540 100644
--- a/lib/crypto/sha2/sha256.asm
+++ b/lib/crypto/sha2/sha256.asm
@@ -1,131 +1,131 @@
-	;; File: sha256.asm
-	;; SHA-256 cryptographic hash
-
-	; Implementation is based on <Wikipedia's pseudocode at https://en.wikipedia.org/wiki/SHA-2#Pseudocode>
-	format COFF
-	use32
-
-	section '.data' data
-	; Constant: K
-	; SHA-256 round constants 
-K:
-	dd 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5
-	dd 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174
-	dd 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da
-	dd 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967
-	dd 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85
-	dd 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070
-	dd 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3
-	dd 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
-
-section '.text' code
-
-	;; Function: sha256_compute_block
-sha256_compute_block:
-	push ebp
-	mov ebp, esp
-
-	leave
-	ret
-
-	;; Function: sha256_internal
-	;; 
-	;; Parameters:
-	;;
-	;;     [esp+8]  - state
-	;;     [esp+12] - input buffer
-	;;     [esp+16] - size of the input buffer
-	;;
-sha256_internal:
-	push ebp
-	push edi
-	mov ebp, esp
-	sub esp, 64+8
-
-	mov eax, dword [ebp+16]
-	xor edx, edx
-
-	; set padlen to (len << 3)
-	shld edx, eax, 3 ;  64-bit left shit
-	sal eax, 3
-	mov dword [ebp-(64+8)], eax
-	mov dword [ebp-(64+4)], edx
-
-.for_block:
-	cmp dword [ebp+16], 64
-	jb .done
-	push dword [ebp+12] ; push in
-	push dword [ebp+8]  ; push state
-	call sha256_compute_block
-	add esp, 8
-	sub dword [ebp+16], 64 ; len -= 64
-	add dword [ebp+12], 64 ; in += 64
-	jmp .for_block
-.done:
-
-	; ensure padding buffer is full of zero
-	lea edi, [ebp-64]
-	mov ecx, 16
-	xor eax, eax
-	rep stosd
-
-	
-
-	pop edi
-	leave
-	ret
-
-	;; Function: sha256
-	;; 
-	;; Parameters:
-	;;
-	;;     [esp+8]  - output buffer
-	;;     [esp+12] - input buffer
-	;;     [esp+16] - size of the input buffer
-	;;
-	public sha256
-sha256:
-	push ebp
-	mov ebp, esp
-	sub esp, 8*4 ; uint32_t state[8]
-
-	; setup initial state
-	mov dword [ebp-8*4], 0x6a09e667
-	mov dword [ebp-7*4], 0xbb67ae85
-	mov dword [ebp-6*4], 0x3c6ef372
-	mov dword [ebp-5*4], 0xa54ff53a
-	mov dword [ebp-4*4], 0x510e527f
-	mov dword [ebp-3*4], 0x9b05688c
-	mov dword [ebp-2*4], 0x1f83d9ab
-	mov dword [ebp-1*4], 0x5be0cd19
-
-	; 
-
-	; copy state to uint8_t *out
-	mov edx, dword [ebp+8]
-	mov eax, dword [ebp-8*4]
-	bswap eax
-	mov dword [edx], eax      ; out[0] = bswap(state[0])
-	mov eax, dword [ebp-7*4] 
-	bswap eax
-	mov dword [edx+4], eax    ; out[1] = bswap(state[1])
-	mov eax, dword [ebp-6*4]
-	bswap eax
-	mov dword [edx+8], eax    ; out[2] = bswap(state[2])
-	mov eax, dword [ebp-5*4]
-	bswap eax
-	mov dword [edx+12], eax   ; out[3] = bswap(state[3])
-	mov eax, dword [ebp-4*4]
-	bswap eax
-	mov dword [edx+16], eax   ; out[4] = bswap(state[4])
-	mov eax, dword [ebp-3*4]
-	bswap eax
-	mov dword [edx+20], eax   ; out[5] = bswap(state[5])
-	mov eax, dword [ebp-2*4]
-	bswap eax
-	mov dword [edx+24], eax   ; out[6] = bswap(state[6])
-	mov eax, dword [ebp-1*4]
-	bswap eax
-	mov dword [edx+28], eax   ; out[7] = bswap(state[7])
-	leave
-	ret
+	;; File: sha256.asm
+	;; SHA-256 cryptographic hash
+
+	; Implementation is based on <Wikipedia's pseudocode at https://en.wikipedia.org/wiki/SHA-2#Pseudocode>
+	format COFF
+	use32
+
+	section '.data' data
+	; Constant: K
+	; SHA-256 round constants 
+K:
+	dd 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5
+	dd 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174
+	dd 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da
+	dd 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967
+	dd 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85
+	dd 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070
+	dd 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3
+	dd 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
+
+section '.text' code
+
+	;; Function: sha256_compute_block
+sha256_compute_block:
+	push ebp
+	mov ebp, esp
+
+	leave
+	ret
+
+	;; Function: sha256_internal
+	;; 
+	;; Parameters:
+	;;
+	;;     [esp+8]  - state
+	;;     [esp+12] - input buffer
+	;;     [esp+16] - size of the input buffer
+	;;
+sha256_internal:
+	push ebp
+	push edi
+	mov ebp, esp
+	sub esp, 64+8
+
+	mov eax, dword [ebp+16]
+	xor edx, edx
+
+	; set padlen to (len << 3)
+	shld edx, eax, 3 ;  64-bit left shit
+	sal eax, 3
+	mov dword [ebp-(64+8)], eax
+	mov dword [ebp-(64+4)], edx
+
+.for_block:
+	cmp dword [ebp+16], 64
+	jb .done
+	push dword [ebp+12] ; push in
+	push dword [ebp+8]  ; push state
+	call sha256_compute_block
+	add esp, 8
+	sub dword [ebp+16], 64 ; len -= 64
+	add dword [ebp+12], 64 ; in += 64
+	jmp .for_block
+.done:
+
+	; ensure padding buffer is full of zero
+	lea edi, [ebp-64]
+	mov ecx, 16
+	xor eax, eax
+	rep stosd
+
+	
+
+	pop edi
+	leave
+	ret
+
+	;; Function: sha256
+	;; 
+	;; Parameters:
+	;;
+	;;     [esp+8]  - output buffer
+	;;     [esp+12] - input buffer
+	;;     [esp+16] - size of the input buffer
+	;;
+	public sha256
+sha256:
+	push ebp
+	mov ebp, esp
+	sub esp, 8*4 ; uint32_t state[8]
+
+	; setup initial state
+	mov dword [ebp-8*4], 0x6a09e667
+	mov dword [ebp-7*4], 0xbb67ae85
+	mov dword [ebp-6*4], 0x3c6ef372
+	mov dword [ebp-5*4], 0xa54ff53a
+	mov dword [ebp-4*4], 0x510e527f
+	mov dword [ebp-3*4], 0x9b05688c
+	mov dword [ebp-2*4], 0x1f83d9ab
+	mov dword [ebp-1*4], 0x5be0cd19
+
+	; 
+
+	; copy state to uint8_t *out
+	mov edx, dword [ebp+8]
+	mov eax, dword [ebp-8*4]
+	bswap eax
+	mov dword [edx], eax      ; out[0] = bswap(state[0])
+	mov eax, dword [ebp-7*4] 
+	bswap eax
+	mov dword [edx+4], eax    ; out[1] = bswap(state[1])
+	mov eax, dword [ebp-6*4]
+	bswap eax
+	mov dword [edx+8], eax    ; out[2] = bswap(state[2])
+	mov eax, dword [ebp-5*4]
+	bswap eax
+	mov dword [edx+12], eax   ; out[3] = bswap(state[3])
+	mov eax, dword [ebp-4*4]
+	bswap eax
+	mov dword [edx+16], eax   ; out[4] = bswap(state[4])
+	mov eax, dword [ebp-3*4]
+	bswap eax
+	mov dword [edx+20], eax   ; out[5] = bswap(state[5])
+	mov eax, dword [ebp-2*4]
+	bswap eax
+	mov dword [edx+24], eax   ; out[6] = bswap(state[6])
+	mov eax, dword [ebp-1*4]
+	bswap eax
+	mov dword [edx+28], eax   ; out[7] = bswap(state[7])
+	leave
+	ret