$2.(15$ pts$)$ Linked List

A student wrote a subroutine to reverse a linked list, where each element consists of a pointer to the next element and a value. The subroutine takes a pointer to the first element $($the head$)$ in RO and returns a pointer to the new head in RO$.$ However, it's not behaving as it should. Find and correct the mistakes. Just like last time, there are $3$ mistakes.

$```$

reverse

ST R$1,$ reverse$\_$r$1$

ST R$2,$ reverse$\_$r$2$

loop

LDR R$2,$ R$0,$ #$0$

STR R$1,$ R$0,$ #$0$

ADD R$1,$ R$0,$ #$0$

ADD R$0,$ R$2,$ #$0$

BRz loop

LD R$1,$ reverse$\_$r$1$

LD R$2,$ reverse$\_$r$2$

RET

reverse$\_$r$1.$BLKW #$1$

reverse$\_$r$2.$BLKW #$1$

$```$