.globl    query_bitness
    .type    query_bitness, @function
    .equ MISA, 0x301            #hardware dependent address of MISA register (0x301 for Longan Nano)
--

query_bitness:
    csrr    t2, MISA            #reads MISA register with a system register reading pseudocode command
    beqz    t2, no_avail        #if the register is empty, branch to no_avail
    lui       t3, 0xC0000       #value 11000000... LUI writes to the highest 20-bits
    bgeu    t2, t3, is_128      #if MISA is higher or equal than t3's value, must be 128-bit
    lui       t3, 0x80000       #value 10000000...
    bgeu    t2, t3, is_64       #if MISA is higher than new t3 value, must be 64-bit
    li        a0, 32             #otherwise it's 32-bit, a0 is return value's register
    jr        ra                 #jump to return address
no_avail:
    li        a0, 0                   
    jr        ra                      
is_128:
    li        a0, 128
    jr        ra
is_64:
    li        a0, 64
    jr        ra