core: let valid PIDs start with 1

core/include/kernel_types.h

@@ -15,7 +15,7 @@
 /**
  * Canonical identifier for an invalid PID.
  */
-#define KERNEL_PID_UNDEF -1
+#define KERNEL_PID_UNDEF 0
 
 /**
  * The first valid PID (inclusive).

core/include/sched.h

@@ -133,7 +133,7 @@ extern volatile unsigned int sched_context_switch_request;
 /**
  *  Thread table
  */
-extern volatile tcb_t *sched_threads[MAXTHREADS];
+extern volatile tcb_t *sched_threads[KERNEL_PID_LAST + 1];
 
 /**
  *  Currently active thread
@@ -169,7 +169,7 @@ typedef struct {
 /**
  *  Thread statistics table
  */
-extern schedstat sched_pidlist[MAXTHREADS];
+extern schedstat sched_pidlist[KERNEL_PID_LAST + 1];
 
 /**
  *  @brief  Register a callback that will be called on every scheduler run

core/sched.c

@@ -40,7 +40,7 @@ volatile int sched_num_threads = 0;
 
 volatile unsigned int sched_context_switch_request;
 
-volatile tcb_t *sched_threads[MAXTHREADS];
+volatile tcb_t *sched_threads[KERNEL_PID_LAST + 1];
 volatile tcb_t *sched_active_thread;
 
 volatile kernel_pid_t sched_active_pid = KERNEL_PID_UNDEF;
@@ -50,7 +50,7 @@ static uint32_t runqueue_bitcache = 0;
 
 #if SCHEDSTATISTICS
 static void (*sched_cb) (uint32_t timestamp, uint32_t value) = NULL;
-schedstat sched_pidlist[MAXTHREADS];
+schedstat sched_pidlist[KERNEL_PID_LAST + 1];
 #endif
 
 void sched_run(void)

cpu/x86/x86_hwtimer.c

@@ -91,7 +91,7 @@ static void flip_periodic_interrupt_called(uint8_t reg_c)
 static void measure_nop_nop_nops_per_tick(void)
 {
     x86_rtc_set_periodic_callback(flip_periodic_interrupt_called);
-    x86_rtc_set_periodic(TICK_HZ_REG_A, 0, 0, true);
+    x86_rtc_set_periodic(TICK_HZ_REG_A, 0, KERNEL_PID_FIRST, true);
     for (unsigned i = 0; i < NNN_TICK_ITERATIONS; ++i) {
         periodic_interrupt_called = false;
 
@@ -132,7 +132,7 @@ static void update_cb(uint8_t reg_c)
 static void init_bases(void)
 {
     x86_rtc_set_periodic_callback(update_cb);
-    x86_rtc_set_periodic(RTC_REG_A_HZ_2, 0, 0, true);
+    x86_rtc_set_periodic(RTC_REG_A_HZ_2, 0, KERNEL_PID_FIRST, true);
 
     eINT();
     periodic_interrupt_called = false;