pvmfw: Integrate buddy_system_allocator

Add support for heap allocation.

Test: atest MicrodroidTestApp
Change-Id: I6b4df790b3cd86fe29db87dd312d5c671548e607
diff --git a/pvmfw/src/entry.rs b/pvmfw/src/entry.rs
index 1ea95bc..dc2087d 100644
--- a/pvmfw/src/entry.rs
+++ b/pvmfw/src/entry.rs
@@ -14,6 +14,7 @@
 
 //! Low-level entry and exit points of pvmfw.
 
+use crate::heap;
 use crate::helpers;
 use crate::mmio_guard;
 use core::arch::asm;
@@ -52,6 +53,10 @@
     // - only access MMIO once (and while) it has been mapped and configured
     // - only perform logging once the logger has been initialized
     // - only access non-pvmfw memory once (and while) it has been mapped
+
+    // SAFETY - This function should and will only be called once, here.
+    unsafe { heap::init() };
+
     logger::init(LevelFilter::Info).map_err(|_| RebootReason::InternalError)?;
 
     const FDT_MAX_SIZE: usize = helpers::SIZE_2MB;