The linked list will contain a $sentinel$ node, used $to$ indicate the end $of$ the list. The elements $in$ the list should $be$ allocated $on$ the heap, with memory allocated using the $sbrk$ syscall available $in$ RARS.

Assignment Details

The assignment consists $of$ implementing $6$ procedures $(functions)$ defined $inlinke{d}_l$ist.asm. Each procedure $is$ documented $in$ the comment above the relevant procedure label. You can assume any pre$-$conditions are fulfilled when the procedure $is$ called. $If$ applicable, your solution must adhere $to$ the post$-$conditions specified $in$ the documentation.

The first procedure you should implement $isL{L}_{P}US{H}_F$RONT. The tests for every other procedure requires instantiating the linked list, which involves pushing $an$ element $to$ the front $of$ the list. The other procedures can $be$ implemented $in$ any order. You will receive partial credit for each procedure implemented correctly.

Specification

Your solution must follow the following specification:

$1.$ Use $32-$bit RISC$-V.$

$2.$ Each node $in$ the linked list should store $a4-$byte integer $as$ well $as$ a pointer $to$ the next node.

$3.$ Memory for nodes $in$ the linked list should $be$ allocated $on$ the heap using the $sbrk$ syscall $in$ RARS.

$4.An$ empty linked list consists $of$ one $sentinel$ node, which points $to$ memory location $0x0$ and has the value $0.$

$5.$ The linked list should not allocate more memory than necessary. $If$ implemented correctly, all nodes should $bein$ a contiguous section $of$ memory $on$ the heap $ifL{L}_{P}US{H}_F$RONT $is$ called successively. $If$ allocations $(withsbrk)$ are made $in$ between calls $toL{L}_{P}US{H}_F$RONT, then the nodes will not $bein$ a contiguous section $of$ memory. Your code must $be$ able $to$ handle nodes that aren't stored contiguously $in$ memory.

$6.$ You can assume memory addresses returned from $sbrk$ are $4-$byte aligned.

$7.$ You must save any callee$-$saved registers before use $in$ the procedures. Failure $todoso$ may result $inan$ incorrect test output. Linked List Example

After the following instructions $(note,$ not assembly$)$:The heap should look like the following diagram:$Note$ that the Head $of$ Linked List represents a register containing the address $of$ the integer $3in$ the screenshot.