feat(nuttx): add defer feature for nuttx image cache (#5967)

src/drivers/nuttx/lv_nuttx_image_cache.c

@@ -34,6 +34,8 @@ typedef struct {
 
     struct mm_heap_s * heap;
     uint32_t heap_size;
+
+    bool initialized;
 } lv_nuttx_ctx_image_cache_t;
 /**********************
  *  STATIC PROTOTYPES
@@ -63,10 +65,29 @@ void lv_nuttx_image_cache_init(void)
     ctx = lv_malloc_zeroed(sizeof(lv_nuttx_ctx_image_cache_t));
     LV_ASSERT_MALLOC(ctx);
 
-    ctx->mem_size = LV_CACHE_DEF_SIZE;
+    ctx->initialized = false;
+}
+
+/**********************
+ *   STATIC FUNCTIONS
+ **********************/
+
+static bool defer_init(void)
+{
+    if(ctx->mem != NULL && ctx->heap != NULL) {
+        return true;
+    }
+
+    ctx->mem_size = img_cache_p->max_size;
     ctx->mem = malloc(ctx->mem_size);
     LV_ASSERT_MALLOC(ctx->mem);
 
+    if(ctx->mem == NULL) {
+        LV_LOG_ERROR("Failed to allocate memory for image cache");
+        ctx->initialized = false;
+        return false;
+    }
+
     ctx->heap = mm_initialize(
                     HEAP_NAME,
                     ctx->mem,
@@ -86,16 +107,19 @@ void lv_nuttx_image_cache_init(void)
     LV_LOG_USER("  mxordblk: %d", info.mxordblk);
     LV_LOG_USER("  uordblks: %d", info.uordblks);
     LV_LOG_USER("  fordblks: %d", info.fordblks);
-}
 
-/**********************
+    ctx->initialized = true;
- *   STATIC FUNCTIONS
+    return true;
- **********************/
+}
 
 static void * malloc_cb(size_t size_bytes, lv_color_format_t color_format)
 {
     LV_UNUSED(color_format);
 
+    if(ctx->initialized == false) {
+        if(defer_init() == false) return NULL;
+    }
+
     /*Allocate larger memory to be sure it can be aligned as needed*/
     size_bytes += LV_DRAW_BUF_ALIGN - 1;
     uint32_t cache_max_size = lv_cache_get_max_size(img_cache_p, NULL);