Reduce the memory footprint of this app

These changes will make the port to an ARMv7-M target easier.

Author: AlessandroA

source/led1.cpp

@@ -31,7 +31,7 @@ static void led1_main(const void *)
     SecureAllocator alloc = secure_allocator_create_with_pages(4 * kB, 1 * kB);
 
     while (1) {
-        static const size_t size = 500;
+        static const size_t size = 50;
         uint16_t seed = (size << 8) | (uvisor_ctx->heartbeat & 0xFF);
 
         led1 = !led1;

source/led2.cpp

@@ -18,7 +18,7 @@ static void led2_main(const void *);
  * We do not need large stacks in either the main nor the interrupt thread, as
  * we do not do anything special in them. */
 UVISOR_BOX_NAMESPACE(NULL);
-UVISOR_BOX_HEAPSIZE(8 * 1024);
+UVISOR_BOX_HEAPSIZE(3 * 1024);
 UVISOR_BOX_MAIN(led2_main, osPriorityNormal, 512);
 UVISOR_BOX_CONFIG(box_led2, acl, 512, box_context);
 
@@ -47,7 +47,7 @@ static void led2_main(const void *)
     secure_allocator_destroy(alloc2);
 
     while (1) {
-        static const size_t size = 300;
+        static const size_t size = 30;
         uint16_t seed = (size << 8) | (uvisor_ctx->heartbeat & 0xFF);
 
         led2 = !led2;

source/led3.cpp

@@ -18,7 +18,7 @@ static void led3_main(const void *);
  * We need at least 1kB in the main thread as we use printf in it. The interrupt
  * stack size can be smaller as we do not do anything special in them. */
 UVISOR_BOX_NAMESPACE(NULL);
-UVISOR_BOX_HEAPSIZE(8 * 1024);
+UVISOR_BOX_HEAPSIZE(3 * 1024);
 UVISOR_BOX_MAIN(led3_main, osPriorityNormal, 1024);
 UVISOR_BOX_CONFIG(box_led3, acl, 512, box_context);
 
@@ -59,7 +59,7 @@ static void led3_main(const void *)
     SecureAllocator alloc = secure_allocator_create_with_pages(4 * kB, 1 * kB);
     /* Prepare the thread definition structure. */
     osThreadDef_t thread_def;
-    thread_def.stacksize = DEFAULT_STACK_SIZE;
+    thread_def.stacksize = 512;
     /* Allocate the stack inside the page allocator! */
     thread_def.stack_pointer = (uint32_t *) secure_malloc(alloc, DEFAULT_STACK_SIZE);
     thread_def.tpriority = osPriorityNormal;

source/main.cpp

@@ -34,7 +34,7 @@ static void main_alloc(void)
     SecureAllocator alloc = secure_allocator_create_with_pages(4 * kB, 1 * kB);
 
     while (1) {
-        alloc_fill_wait_verify_free(500, seed, 577);
+        alloc_fill_wait_verify_free(50, seed, 577);
         specific_alloc_fill_wait_verify_free(alloc, 5 * kB, seed, 97);
         seed++;
     }