snRuntime: Mutexes might be uninitialized

[huettern]

crt0 currently doesn't init the .bss section. A mutex placed in .bss (e.g. clint_mutex in interrupt.c) is therefore in an uninitialized state leading to deadlocks. A fix to this should also conform to multi-cluster systems which are not participating in the cluster-wide barrier at the end of crt0.

[paulsc96]

@colluca Does this issue still apply? I don't see start.S initializing .bss; maybe a define-guarded init as for thread and cluster could be done.

[colluca]

@colluca Does this issue still apply? I don't see start.S initializing .bss; maybe a define-guarded init as for thread and cluster could be done.

@paulsc96 This shouldn't apply anymore. BSS section is initialized here:

snitch_cluster/sw/snRuntime/src/start.c

Lines 45 to 56 in b5016fe

	static inline void snrt_init_bss() {
	extern volatile uint32_t __bss_start, __bss_end;
	// Only one core needs to perform the initialization
	if (snrt_cluster_idx() == 0 && snrt_is_dm_core()) {
	volatile uint32_t* p;
	for (p = (uint32_t*)(&__bss_start); p < (uint32_t*)(&__bss_end); p++) {
	*p = 0;
	}
	}
	}