Mips breakpoint detection using memory scanning

/*
#############################
# MIPS breakpoint detection #
#############################

.text
.abicalls
.global scan

# bool scan(void* code, unsigned int size);
scan:
        li $t0, 0x5000D                 # breakpoint constant
loop:
        lw $t3, ($a0)                   # load bytecode
        beq $t3, $t0, fuck              # if this is a breakpoint fucked
        beq $t3, 0, safe                # if the counter is 0 we are safe
        subu $a1, 1                     # decrement counter
        addu $a0, 1                     # increment our pointer
        j loop                          # if we are looping loop

safe:
        li $v0, 0x0     # return false
        li $v1, 0x0
        jr $ra

fuck:
        li $v0, 0x1     # return true
        li $v1, 0x0
        jr $ra

*/


bool scan(void (*fun), unsigned int depth)  /// scans a function for break points
{
    int i;
    long unsigned int inst;
    for(i=0;i<=depth;i+=sizeof(inst))   /// count from offset start to depth
    {
        inst = (*(volatile unsigned int *)((unsigned int)fun + i));
        if (inst == 0x5000D)    /// if this is a break point
            return true;    /// return true
    }
    return false;
}