Unify all heaps (stdlib + LVGL + FreeRTOS) into a single heap managed by FreeRTOS and heap_4_infinitime.c.

LVGL supports custom implementation of malloc() and free() so using pvPortMalloc() and vPortFree() is just a matter of setting the right variables.

Other libraries (NimBLE, LittleFS) and InfiniTime code (new) call malloc() and free() from stdlib. InfiniTime now provides the file stdlib.c that provides a custom implementation for malloc(), free(), calloc() and realloc(). This ensures that all calls to the standard allocator are redirected to the FreeRTOS memory manager.

Note that realloc() is needed by NimBLE.

src/CMakeLists.txt

@@ -367,6 +367,7 @@ list(APPEND IMAGE_FILES
         displayapp/icons/battery/batteryicon.c
         )
 list(APPEND SOURCE_FILES
+        stdlib.c
         FreeRTOS/heap_4_infinitime.c
         BootloaderVersion.cpp
         logging/NrfLogger.cpp
@@ -496,6 +497,7 @@ list(APPEND SOURCE_FILES
         )
 
 list(APPEND RECOVERY_SOURCE_FILES
+        stdlib.c
         FreeRTOS/heap_4_infinitime.c
 
         BootloaderVersion.cpp
@@ -560,6 +562,7 @@ list(APPEND RECOVERY_SOURCE_FILES
         )
 
 list(APPEND RECOVERYLOADER_SOURCE_FILES
+        stdlib.c
         FreeRTOS/heap_4_infinitime.c
 
         # FreeRTOS
@@ -786,7 +789,7 @@ add_definitions(-DOS_CPUTIME_FREQ)
 add_definitions(-DNRF52 -DNRF52832 -DNRF52832_XXAA -DNRF52_PAN_74 -DNRF52_PAN_64 -DNRF52_PAN_12 -DNRF52_PAN_58 -DNRF52_PAN_54 -DNRF52_PAN_31 -DNRF52_PAN_51 -DNRF52_PAN_36 -DNRF52_PAN_15 -DNRF52_PAN_20 -DNRF52_PAN_55 -DBOARD_PCA10040)
 add_definitions(-DFREERTOS)
 add_definitions(-D__STACK_SIZE=1024)
-add_definitions(-D__HEAP_SIZE=4096)
+add_definitions(-D__HEAP_SIZE=0)
 add_definitions(-DMYNEWT_VAL_BLE_LL_RFMGMT_ENABLE_TIME=1500)
 
 # Note: Only use this for debugging