Only init crosscore when FreeRTOS runs in multicore mode, add warning…

…s that cross_int calls are private.

components/esp32/cpu_start.c

@@ -147,7 +147,9 @@ void start_cpu0_default(void)
     uart_div_modify(0, (APB_CLK_FREQ << 4) / 115200);
     ets_setup_syscalls();
     do_global_ctors();
+#if !CONFIG_FREERTOS_UNICORE
     esp_crosscore_int_init();
+#endif
     esp_ipc_init();
     spi_flash_init();
     xTaskCreatePinnedToCore(&main_task, "main",

components/esp32/crosscore_int.c

@@ -49,8 +49,8 @@ static void esp_crosscore_isr(void *arg) {
     //A pointer to the correct reason array item is passed to this ISR.
     volatile uint32_t *myReason=arg;
 #else
-    //Does not work yet, the interrupt code needs work to understand two separate interrupt and argument
-    //tables...
+    //The previous line does not work yet, the interrupt code needs work to understand two separate interrupt and argument
+    //tables... this is a valid but slightly less optimal replacement.
     volatile uint32_t *myReason=&reason[xPortGetCoreID()];
 #endif
     //Clear the interrupt first.

components/esp32/include/esp_crosscore_int.h

@@ -19,6 +19,10 @@
  * Initialize the crosscore interrupt system for this CPU.
  * This needs to be called once on every CPU that is used
  * by FreeRTOS.
+ *
+ * If multicore FreeRTOS support is enabled, this will be
+ * called automatically by the startup code and should not
+ * be called manually.
  */
 void esp_crosscore_int_init();
 
@@ -28,6 +32,9 @@ void esp_crosscore_int_init();
  * currently running task in favour of a higher-priority task
  * that presumably just woke up.
  *
+ * This is used internally by FreeRTOS in multicore mode
+ * and should not be called by the user.
+ *
  * @param coreID Core that should do the yielding
  */
 void esp_crosscore_int_send_yield(int coreId);