feat: log has now printf like formating

kernel/drivers/serial.s

@@ -44,5 +44,5 @@ serial_write:
 	mov ebp, esp
 	mov ecx, [ebp + 8]
 	COM_OUT COM1, THR, cl 
-	pop ebp
+	leave
 	ret

lib/base/log.s

@@ -9,9 +9,11 @@ section .text
 putstr:
 	push ebp
 	mov ebp, esp
-	mov ebx, [ebp + 8]
+	push edi
+	mov edi, [ebp + 8]
+
 .loop:
-	mov eax, [ebx]
+	mov eax, [edi]
 	cmp al, 0
 	je .end
 	push eax
@@ -20,30 +22,56 @@ putstr:
 %else
 %endif
 	add esp, 4
-	inc ebx
+	inc edi
 	jmp .loop
 .end:
-	pop ebp
+	pop edi
+	leave
 	ret
 
-putuint:
+puthex:
+	xchg bx, bx
 	push ebp
 	mov ebp, esp
+	push edi
+	push esi
+	mov edi, [ebp + 8] ; number
 	
-	mov ebx, [ebp + 8]
+	mov eax, hexprefix
-	mov edx, [ebp + 12]
+	push hexprefix
+	call putstr
+	add esp, 4
+
+	mov edx, 0xF
+	mov ecx, 0x8
+	mov esi, buffer
+.loop:
+	rol edi, 4
+	mov eax, edi
+	and eax, edx
+	mov al, [digits + eax]
+	mov [esi], al
+	inc esi
+	dec ecx
+	jnz .loop
 
 	mov eax, buffer
 	push eax
 	call putstr
+	add esp, 4
 
-	pop ebp
+	pop esi
+	pop edi
+	leave
 	ret
 
 global log_impl
 log_impl:
 	push ebp
 	mov ebp, esp
+	push edi
+	push esi
+	push ebx
 	mov eax, [ebp + 8]
 
 	push eax
@@ -51,19 +79,62 @@ log_impl:
 	add esp, 4
 
 %ifdef __KERNEL__
-	push ':'
+	mov eax, ':'
+	push eax
 	call serial_write
 	add esp, 4
 %else
 %endif
 
+	mov edi, [ebp + 12]
+	mov esi, 12
 .loop:
-	mov eax, [ebp + 12]
+	mov eax, [edi]
+	cmp al, 0
+	je .end
+	cmp al, '%'
+	jne .putchar
+	inc edi
+	mov eax, [edi]
+	cmp al, '%'
+	je .next
+	cmp al, 'x'
+	jne .check_s
+	add esi, 4
+	mov ebx, ebp
+	add ebx, esi
+	mov eax, [ebx]
+	push eax
+	call puthex
+	add esp, 4
+	jmp .next
+.check_s:
+	cmp al, 's'
+	jne .unknown_format
+	add esi, 4
+	mov ebx, ebp
+	add ebx, esi
+	mov eax, [ebx]
 	push eax
 	call putstr
 	add esp, 4
+	jmp .next
+.unknown_format:
+	mov al, '?'
+.putchar:
+	push eax
+%ifdef __KERNEL__
+	call serial_write
+%else
+	;; TODO
+%endif
+	add esp, 4
+.next:
+	inc edi
+	jmp .loop
 .end:
 
+	;;  print new line
 %ifdef __KERNEL__
 	mov al, 0xA
 	push eax
@@ -71,8 +142,12 @@ log_impl:
 	add esp, 4
 %else
 %endif
-	pop ebp
+	pop ebx
+	pop esi
+	pop edi
+	leave
 	ret
 
 digits db '0123456789ABCDEF'
-buffer db '0000000000', 0
+hexprefix db '0x', 0
+buffer db '00000000', 0