Merge pull request #25 from sifive/ecc_scrub

Limit zeroed memory to 64k.

memory_map.py

@@ -191,8 +191,12 @@ def consolidate_address_ranges(regions):
     for region in sorted_list:
         memories.update({region["name"] : region})
 
-    return memories
+    for _, memory in memories.items():
+        if 'memory' in memory["name"] and memory["length"] > 0x10000:
+            # Only 64KB of memory is zeroed due to limitation in RTL sim run
+            memory["length"] = 0x10000
 
+    return memories
 
 def compute_address_range(region):
     """Extract the address range from the reg of the Node"""

templates/base.lds

@@ -88,6 +88,10 @@ SECTIONS
 
     /* The RAM memories map for ECC scrubbing */
 {% for memory in ram_memories %}
+    {% if 'memory' in memory["name"]: %}
+    /* Default memory to zero-scrub for at most 64KB, for limiting RTL simulation run time. */
+     * User is recommended to enable the full size for manual RTL simulation run! */
+    {% endif %}
     PROVIDE( metal_{{ memory.name }}_memory_start = {{ memory.base_hex }} );
     PROVIDE( metal_{{ memory.name }}_memory_end = {{ memory.base_hex }} + {{ memory.length_hex }} );
 {% endfor %}