rectangles work

source/features/screen.asm

@@ -1,15 +1,4 @@
-; ==================================================================
-; MikeOS -- The Mike Operating System kernel
-; Copyright (C) 2006 - 2021 MikeOS Developers -- see doc/LICENSE.TXT
-;
-; SCREEN HANDLING SYSTEM CALLS
-; ==================================================================
-
-; ------------------------------------------------------------------
-; os_print_string -- Displays text
-; IN: SI = message location (zero-terminated string)
-; OUT: Nothing (registers preserved)
-
+; SI = pointer to start of string to be printed
 os_print_string:
 	pusha
 
@@ -29,7 +18,8 @@ os_print_string:
 
 ; Exact same as the above procedure, but this adds a newline 
 ; after priting, similar to the difference between Rust's print! and println!
-os_print_string_nl:				pusha
+os_print_string_nl:				
+	pusha
 
 	mov ah, 0Eh			; int 10h teletype function, we're telling the BIOS we will print something
 
@@ -50,35 +40,33 @@ os_print_string_nl:				pusha
 
 os_print_newline:
 	pusha
+	
+	mov ah, 0Eh
+	mov al, 13
+	int 10h
+	mov al, 10
+	int 10h
 
-	mov ah, 03h
-	int 10h
-	
-	mov ah, 02h
-	add dh, 1
-	mov dl, 0
-	int 10h
-	
 	popa
 	ret
-		
 
 ; -------------------------------------------
 
-os_clear_screen:
-        pusha
-
+os_set_text_mode:
+	pusha
+	; Set mode = 80x25 (text mode)
 	mov ah, 00h
-	mov al, 03h 		; Set video mode to textmode (80x25). 16 colors, 8 pages
+	mov al, 03h
 	int 10h
 
+	; Move cursor to the top left
 	mov ah, 02h
 	mov dh, 0
 	mov dl, 0
 	int 10h
 
-        popa
-        ret
+	popa
+	ret
 
 ; -------------------------------------------
 
@@ -98,15 +86,17 @@ os_read_input:
 
 ; -------------------------------------------
 
-os_display_input:
+os_display_input:	
 	pusha
-	
+	mov cx, [prompt_length] 
+
+.loop:
 	call .check_key_pressed
 
-        jmp os_display_input
+	jmp .loop
 
 .check_key_pressed:	
-        call os_read_input
+	call os_read_input
 
 	cmp al, 08h
 	je .backspace
@@ -117,8 +107,12 @@ os_display_input:
 	cmp al, 1Bh
 	je .esc_key
 
+	cmp cx, 0
+	jb .check_key_pressed
+
 	call .print_current_input
-	ret
+	dec cx
+	jmp .check_key_pressed
 
 .esc_key:
 	call os_reboot
@@ -126,11 +120,14 @@ os_display_input:
 .enter_key:
 	mov al, 0
 	stosb
-	mov di, user_input
-	
+	popa
 	call os_read_cli
 
 .backspace:
+	call .move_cursor_back			; then .move_cursor_back
+	call .loop				; Else .loop
+
+.move_cursor_back:
 	mov ah, 0Eh
 
 	mov al, 08h