Add HULK header; map virtual memory for HULK bss section

src/hulk/hulk.ld

@@ -1,21 +1,19 @@
-ENTRY(hulk_start)
-
 SECTIONS
 {
     . = 0x0000400000000000;
     _hulk_mem_start = .;
 
-    .text BLOCK(4K) : ALIGN(4K)
-    {
-        *(.hulk_start)
-        *(.text)
-    }
-
     .rodata BLOCK(4K) : ALIGN(4K)
     {
+        *(.hulk_header)
         *(.rodata)
     }
 
+    .text BLOCK(4K) : ALIGN(4K)
+    {
+        *(.text)
+    }
+
     .data BLOCK(4K) : ALIGN(4K)
     {
         *(.data)
@@ -30,4 +28,5 @@ SECTIONS
     . = ALIGN(4K);
 
     _hulk_mem_end = .;
+    _hulk_total_size = _hulk_mem_end - _hulk_mem_start;
 }