correct ebreak implementation, gdbstub watcher

everything in gdb should work now :)

src/cpu/rv32cpu.c

@@ -512,7 +512,10 @@ static void cpu_execute(rv32_cpu_t* cpu, instruction_t* instruction)
 							fprintf(stderr, "ECALL: a7(sbi ext id) = %d, a6(sbi funct id) = %d\n", cpu->regs.a7, cpu->regs.a6);
 							break;
 						case IMM_EBREAK:
-							fprintf(stderr, "EBREAK\n");
+							// EBREAK : on debug, give back hand to debugger ; without debug, end simulation
+							// In any way, we set back simulation ticks to 0
+							cpu->sim_ticks_left = 1;
+							cpu->pc -= 4;
 							break;
 						default:
 							fprintf(stderr, "FATAL: Unknown IMM for ECALL/EBREAK instruction while executing (IMM=0x%x)\n", instruction->immediate);
@@ -650,6 +653,11 @@ void cpu_loop(rv32_cpu_t* cpu)
 	{
 		// Aquire CPU and memory mutex
 		pthread_mutex_lock(&cpu0_mutex);
+
+		// No simulation ticks left : wakeup people waiting on sim end
+		if(!cpu->sim_ticks_left)
+			pthread_cond_signal(&cpu0->sim_condition);
+		// Then, wait for simulation state to change until we get more ticks to simulate
 		while(!cpu->sim_ticks_left)
 			pthread_cond_wait(&cpu0->sim_condition, &cpu0_mutex);