RP2040 fixes (#424)

* RP2040: malloc needs to be thread safe for FreeRTOS whether both cores are used or not

* RP2040: CMake file had broken left over test code

* RP2040: portIS_FREE_RTOS_CORE() returned an incorrect value prior to scheduler init when the application was compiled without multicore support

* RP2040: Bad initialization code was causing IRQs to get disabled before main() was called when using non static allocation

portable/ThirdParty/GCC/RP2040/FreeRTOS_Kernel_import.cmake

@@ -33,8 +33,7 @@ endif ()
 if (NOT FREERTOS_KERNEL_PATH)
     foreach(POSSIBLE_SUFFIX Source FreeRTOS-Kernel FreeRTOS/Source)
         # check if FreeRTOS-Kernel exists under directory that included us
-        set(SEARCH_ROOT ${CMAKE_CURRENT_SOURCE_DIR}})
+        set(SEARCH_ROOT ${CMAKE_CURRENT_SOURCE_DIR})
-        set(SEARCH_ROOT ../../../..)
         get_filename_component(_POSSIBLE_PATH ${SEARCH_ROOT}/${POSSIBLE_SUFFIX} REALPATH)
         if (EXISTS ${_POSSIBLE_PATH}/${FREERTOS_KERNEL_RP2040_RELATIVE_PATH}/CMakeLists.txt)
             get_filename_component(FREERTOS_KERNEL_PATH ${_POSSIBLE_PATH} REALPATH)

portable/ThirdParty/GCC/RP2040/include/freertos_sdk_config.h

@@ -32,7 +32,10 @@
 #ifndef __ASSEMBLER__
     #include "FreeRTOSConfig.h"
     #include "rp2040_config.h"
-
+    #ifndef PICO_USE_MALLOC_MUTEX
+        // malloc needs to be made thread safe
+        #define PICO_USE_MALLOC_MUTEX 1
+    #endif /* PICO_USE_MALLOC_MUTEX */
     #if ( configSUPPORT_PICO_SYNC_INTEROP == 1 )
         // increase the amount of time it may reasonably take to wake us up
         #ifndef PICO_TIME_SLEEP_OVERHEAD_ADJUST_US

portable/ThirdParty/GCC/RP2040/port.c

@@ -110,8 +110,9 @@ static void prvTaskExitError( void );
 /*-----------------------------------------------------------*/
 
 /* Each task maintains its own interrupt status in the critical nesting
- * variable. */
+ * variable. This is initialized to 0 to allow vPortEnter/ExitCritical
-static UBaseType_t uxCriticalNesting = {0xaaaaaaaa};
+ * to be called before the scheduler is started */
+static UBaseType_t uxCriticalNesting;
 
 /*-----------------------------------------------------------*/
 
@@ -158,13 +159,9 @@ static UBaseType_t uxCriticalNesting = {0xaaaaaaaa};
 
 /*-----------------------------------------------------------*/
 
-#if ( LIB_PICO_MULTICORE == 1 )
 #define INVALID_LAUNCH_CORE_NUM 0xffu
 static uint8_t ucLaunchCoreNum = INVALID_LAUNCH_CORE_NUM;
 #define portIS_FREE_RTOS_CORE() ( ucLaunchCoreNum == get_core_num() )
-#else
-    #define portIS_FREE_RTOS_CORE() pdTRUE
-#endif /* LIB_PICO_MULTICORE */
 
 /*
  * See header file for description.
@@ -266,8 +263,8 @@ BaseType_t xPortStartScheduler( void )
     /* Initialise the critical nesting count ready for the first task. */
     uxCriticalNesting = 0;
 
-    #if (LIB_PICO_MULTICORE == 1)
     ucLaunchCoreNum = get_core_num();
+    #if (LIB_PICO_MULTICORE == 1)
         #if ( configSUPPORT_PICO_SYNC_INTEROP == 1)
             multicore_fifo_clear_irq();
             multicore_fifo_drain();
@@ -728,7 +725,6 @@ __attribute__( ( weak ) ) void vPortSetupTimerInterrupt( void )
     void vPortLockInternalSpinUnlockWithWait( struct lock_core * pxLock, uint32_t ulSave )
     {
         configASSERT( !portCHECK_IF_IN_ISR() );
-        // note no need to check LIB_PICO_MULTICORE, as this is always returns true if that is not defined
         if( !portIS_FREE_RTOS_CORE() )
         {
             spin_unlock(pxLock->spin_lock, ulSave );
@@ -806,7 +802,6 @@ __attribute__( ( weak ) ) void vPortSetupTimerInterrupt( void )
         }
         else
         {
-            configASSERT( portIS_FREE_RTOS_CORE() );
             configASSERT( pxYieldSpinLock == NULL );
 
             TickType_t uxTicksToWait = prvGetTicksToWaitBefore( uxUntil );
@@ -858,6 +853,10 @@ __attribute__( ( weak ) ) void vPortSetupTimerInterrupt( void )
             #if ( configSUPPORT_STATIC_ALLOCATION == 1 )
                 xEventGroup = xEventGroupCreateStatic(&xStaticEventGroup);
             #else
+                /* Note that it is slightly dubious calling this here before the scheduler is initialized,
+                 * however the only thing it touches is the allocator which then calls vPortEnterCritical
+                 * and vPortExitCritical, and allocating here saves us checking the one time initialized variable in
+                 * some rather critical code paths */
                 xEventGroup = xEventGroupCreate();
             #endif /* configSUPPORT_STATIC_ALLOCATION */
         }