Use statically allocated stack for the main task

Enable FreeRTOS static allocation of tasks and stacks, use it for the main task.
FreeRTOS also requires that idle and timer tasks be statically allocated in that case.

On STM32L4 where data is placed in a separate memory segment this frees up approx 20K of heap.
On other platforms this is neutral in terms of usage but will reduce heap fragmentation a bit.

Does not apply to CC3200 because its FreeRTOS is too old.

CL: Use statically allocated stack for the main task

PUBLISHED_FROM=551879996ca98fbbc0502f1a0462ebbbab597095

mos.yml

@@ -23,4 +23,21 @@ tags:
   - core
   - docs:core:Core meta-library
 
+conds:
+  # FreeRTOS option to enable statically allocated task stacks.
+  - when: mos.platform == "stm32"
+    apply:
+      cdefs:
+        configSUPPORT_STATIC_ALLOCATION: 1
+  - when: mos.platform == "cc3220"
+    apply:
+      cdefs:
+        configSUPPORT_STATIC_ALLOCATION: 1
+  - when: mos.platform == "esp32"
+    apply:
+      build_vars:
+        ESP_IDF_SDKCONFIG_OPTS: >
+          ${build_vars.ESP_IDF_SDKCONFIG_OPTS}
+          CONFIG_SUPPORT_STATIC_ALLOCATION=1
+
 manifest_version: 2018-06-12