_start: 
    li  x1, 8      // ITERATION * 4
    li  x2, 5 * 4 // MAX ITERATIONS * 4
    li  x6, 0x100000 // MEM OFFSET

    li  x5, 1
    sw  x5, 4(x6)
fib: 
    add x3, x6, x1
    lw  x4, -4(x3) // get a
    lw  x5, -8(x3) // get b
    add x4, x4, x5 // a = a + b
    sw  x4, (x3)   // store a to c

    // increment or stop
    add x1, x1, 4
    bne x1, x2, fib

    li  x5, 12345678
    sw  x5, (x6)
    li  x5, 0
    lw  x5, (x6)
    mv  x6, x5