Possible issues with reset flow

[DL8]

While implementing a basic piece of software, I found that I should call the global setup handler only once per core and not once per thread. Therefore, I thought of the following approach:

1. Global setup handler: called once per core (used for global initialization)
2. Local setup handler: called once per thread (used for thread-local initialization)
3. Thread code: called in a loop in each thread (actual code)

To implement this, I need a way to run the global setup in one thread and prevent others from running. Unfortunately, since there is no guarantee about memory contents, I couldn't find a way to make one thread execute the global handler and other threads to wait for it (there is no guarantee about timing between threads, so I can't initialize some flag in memory and be sure that it will happen before other threads reach it).

To make it work, I have the following hardware change in mind:

1. On reset, only thread 0 starts running (others are waiting)
2. Software initializes whatever is needed to synchronize execution with thread 0
3. Software wakes up other threads
4. Software runs global initialization only on thread 0 and other threads wait for it to continue
5. Software lets other threads run

I haven't thought the details of how synchronization is going to happen, but here are some options:

1. Use some word in memory (thread 0 initializes to zero, other threads wait until it's non-zero. Thread 0 writes 1 when done)
2. Wake up others only after global init is done

The disadvantage of this approach is that resetting one thread may become a problem (because it may no longer be possible to initialize the core properly)