Use memory addresses instead of creating static arrays in Rust template

Static arrays will increase the size of the cartridge, because at runtime they will be initialized with the values used in the source (which is then ignored by the allocator).

Author: claudiomattera

cli/assets/templates/rust/src/alloc.rs

@@ -5,12 +5,12 @@ const FAST_HEAP_SIZE: usize = 4 * 1024; // 4 KB
 const HEAP_SIZE: usize = 16 * 1024; // 16 KB
 const LEAF_SIZE: usize = 16;
 
-static mut FAST_HEAP: [u8; FAST_HEAP_SIZE] = [0u8; FAST_HEAP_SIZE];
-static mut HEAP: [u8; HEAP_SIZE] = [0u8; HEAP_SIZE];
+static mut FAST_HEAP: *mut [u8; FAST_HEAP_SIZE] = (0x10000 - HEAP_SIZE - FAST_HEAP_SIZE) as *mut [u8; FAST_HEAP_SIZE];
+static mut HEAP: *mut [u8; HEAP_SIZE] = (0x10000 - HEAP_SIZE) as *mut [u8; HEAP_SIZE];
 
 #[global_allocator]
 static ALLOC: NonThreadsafeAlloc = unsafe {
-    let fast_param = FastAllocParam::new(FAST_HEAP.as_ptr(), FAST_HEAP_SIZE);
-    let buddy_param = BuddyAllocParam::new(HEAP.as_ptr(), HEAP_SIZE, LEAF_SIZE);
+    let fast_param = FastAllocParam::new(FAST_HEAP as *mut u8, FAST_HEAP_SIZE);
+    let buddy_param = BuddyAllocParam::new(HEAP as *mut u8, HEAP_SIZE, LEAF_SIZE);
     NonThreadsafeAlloc::new(fast_param, buddy_param)
 };