Solve problem with mutex debug in early_init()

Development
1

STDIO is initialized in the early_init() function. If vfs is used, the vfs_bind_stdio() function is called, but the OS is not yet running. If the processor is not ready to work with NULL pointers, calling mutex_lock_internal from vfs_bind causes a panic because thread_get_active() returns NULL..

Next changes in mutex_lock_internal resolve this problem:

bool mutex_lock_internal(mutex_t \*mutex, bool block)
{
    uinttxtptr_t pc = 0;
#if IS_USED(MODULE_CORE_MUTEX_DEBUG)
    pc = cpu_get_caller_pc();
#endif
    unsigned irq_state = irq_disable();

    DEBUG("PID\[%" PRIkernel_pid "\] mutex_lock_internal(block=%u).\\n",
          thread_getpid(), (unsigned)block);

    if (mutex->queue.next == NULL) {
        /\* mutex is unlocked. \*/
        mutex->queue.next = MUTEX_LOCKED;
#if IS_USED(MODULE_CORE_MUTEX_PRIORITY_INHERITANCE) \\
        || IS_USED(MODULE_CORE_MUTEX_DEBUG)
        thread_t \*me = thread_get_active();
        if (me != NULL) {
            mutex->owner = me->pid;
        } 
        else {
            mutex->owner = KERNEL_PID_UNDEF;
        }
#endif
#if IS_USED(MODULE_CORE_MUTEX_DEBUG)
        mutex->owner_calling_pc = pc;
#endif
#if IS_USED(MODULE_CORE_MUTEX_PRIORITY_INHERITANCE)
        if (me != NULL) {
            mutex->owner_original_priority = me->priority;
        } 
        else {
            mutex->owner_original_priority = 0;
        }
#endif
        DEBUG("PID\[%" PRIkernel_pid "\] mutex_lock(): early out.\\n",
              thread_getpid());
        irq_restore(irq_state);
    }
    else {
        if (!block) {
            irq_restore(irq_state);
            return false;
        }
        \_block(mutex, irq_state, pc);
    }

    return true;
}
2

Can’t we just move vfs_bind_stdio() to the later init?

diff --git i/core/lib/init.c w/core/lib/init.c
index f7ccce8e91..43d5e14416 100644
--- i/core/lib/init.c
+++ w/core/lib/init.c
@@ -49,6 +49,10 @@ static void *main_trampoline(void *arg)
 {
     (void)arg;
 
+#if MODULE_VFS
+    vfs_bind_stdio();
+#endif
+
     if (IS_USED(MODULE_AUTO_INIT)) {
         auto_init();
     }
@@ -133,8 +137,4 @@ void early_init(void)
     }
 
     stdio_init();
-
-#if MODULE_VFS
-    vfs_bind_stdio();
-#endif
 }
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