Defer remote commands outside receive stack

src/Nrf52LoopStack.cpp

@@ -0,0 +1,39 @@
+#if defined(NRF52_PLATFORM)
+
+#include <Arduino.h>
+#include <FreeRTOS.h>
+#include <task.h>
+#include <string.h>
+
+#ifndef MESH_NRF52_LOOP_STACK_WORDS
+  #define MESH_NRF52_LOOP_STACK_WORDS 2048
+#endif
+
+static_assert(MESH_NRF52_LOOP_STACK_WORDS >= 1024,
+              "The nRF52 loop task stack must not be smaller than the framework default");
+
+extern "C" BaseType_t __real_xTaskCreate(
+    TaskFunction_t task_code, const char* const task_name,
+    const configSTACK_DEPTH_TYPE stack_depth, void* const parameters,
+    UBaseType_t priority, TaskHandle_t* const created_task);
+
+// The Adafruit nRF52 core hard-codes the Arduino loop task to 1024 32-bit
+// words (4 KiB). Mesh packet verification and authenticated remote commands
+// can legitimately enter Ed25519 routines whose stack peaks do not fit there.
+// Wrap task creation so only the framework's "loop" task receives 8 KiB; all
+// BLE, timer, callback, and application-created tasks retain their requested
+// sizes.
+extern "C" BaseType_t __wrap_xTaskCreate(
+    TaskFunction_t task_code, const char* const task_name,
+    const configSTACK_DEPTH_TYPE stack_depth, void* const parameters,
+    UBaseType_t priority, TaskHandle_t* const created_task) {
+  configSTACK_DEPTH_TYPE adjusted_depth = stack_depth;
+  if (task_name != NULL && strcmp(task_name, "loop") == 0
+      && stack_depth == 1024) {
+    adjusted_depth = MESH_NRF52_LOOP_STACK_WORDS;
+  }
+  return __real_xTaskCreate(task_code, task_name, adjusted_depth, parameters,
+                            priority, created_task);
+}
+
+#endif