Increase heap size to 64mib, add missing fabs function

src/heap.rs

@@ -7,7 +7,7 @@ use core::alloc::{GlobalAlloc, Layout};
 pub static ALLOCATOR: Locked<LinkedListAllocator> = Locked::new(LinkedListAllocator::new());
 
 pub const HEAP_START: usize = 0x_4444_4444_0000;
-pub const HEAP_SIZE: usize = 32 * 1024 * 1024; // 32 MiB
+pub const HEAP_SIZE: usize = 64 * 1024 * 1024; // 64 MiB
 
 pub struct LinkedNode {
     pub size: usize,

src/lib.rs

@@ -119,6 +119,11 @@ pub extern "C" fn abs(n: i32) -> i32 {
     n.abs()
 }
 
+#[unsafe(no_mangle)]
+pub extern "C" fn fabs(n: f32) -> f32 {
+    n.abs()
+}
+
 struct FormatBufWriter {
     buf: *mut u8,
     max: usize,