One instruction less by using another register

console.asm

@@ -6,41 +6,39 @@
 pub read_line:
 	
 	mov r4, 0 ; Storing the last key here, so we don't repeat the same key
-	mov r2, r1 ; Saving the buffer pointer for return
 	mov r3, r1 ; The pointer to after the last character
 	
 	read_line_keyloop:
-		keyboard r1
+		keyboard r2
 		
-		cmp r1, r4
+		cmp r2, r4
 		je read_line_keyloop ; If the current key is same as previous, we loop
-		mov r4, r1 ; Storing current key as previous
+		mov r4, r2 ; Storing current key as previous
 		
-		cmp r1, 0x100 ; Is the key down or up?
+		cmp r2, 0x100 ; Is the key down or up?
 		jbe read_line_keyloop ; If the key was up, we loop
-		xor r1, r1, 0x100 ; We remove the "down" bit
+		xor r2, r2, 0x100 ; We remove the "down" bit
 		
-		cmp r1, 10 ; Was the key Enter?
+		cmp r2, 10 ; Was the key Enter?
 		je read_line_finished ; If so, we're finished
 
-		cmp r1, 32 ; Was the key under Space? i.e. non-renderable
+		cmp r2, 32 ; Was the key under Space? i.e. non-renderable
 		jb read_line_keyloop ; If so, we loop
 
-		cmp r1, 127 ; Was the key Backspace?
+		cmp r2, 127 ; Was the key Backspace?
 		je read_line_backspace ; If yes we need to move one character back
 
 		read_line_store:
-			store_8 [r3], r1 ; Else, we store the key in the buffer
+			store_8 [r3], r2 ; Else, we store the key in the buffer
 			add r3, r3, 1 ; We advance forward
 			jmp read_line_keyloop
 
 		read_line_backspace:
-			cmp r3, r2
+			cmp r3, r1 ; Compare the current pointer to start of buffer
 			je read_line_keyloop ; If we are at the start, we loop
 			sub r3, r3, 1 ; We move back one character
 			jmp read_line_keyloop
 
 	read_line_finished:
 		store_8 [r3], zr ; We store null at the end so the string is finished
-		mov r1, r2 ; Recovering the buffer pointer
 		jmp r13