From 07d317eb6e27f180b5bec4179e7f218155be7234 Mon Sep 17 00:00:00 2001
From: Brendan Haines <brendan.haines@gmail.com>
Date: Fri, 2 Jul 2021 03:14:37 -0600
Subject: [PATCH] add trailing NOP instructions so non-initialized memory
 doesn't cause issues

---
 hdl/tb/core_tb.v | 8 ++++----
 test/test.S      | 6 ++++++
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/hdl/tb/core_tb.v b/hdl/tb/core_tb.v
index 7abfc8d..07e0ea2 100644
--- a/hdl/tb/core_tb.v
+++ b/hdl/tb/core_tb.v
@@ -32,10 +32,10 @@ wire [31:0] mem_inst_idx = mem_inst_addr >> 2;
 wire [31:0] mem_inst_data = mem_inst_idx < MEM_LENGTH ? mem[mem_inst_idx] : INST_NOP;
 
 initial begin: mem_init
-    integer i;
-    for (i=0; i<MEM_LENGTH; i=i+1) begin
-        mem[i] = INST_NOP;
-    end
+    // integer i;
+    // for (i=0; i<MEM_LENGTH; i=i+1) begin
+    //     mem[i] = INST_NOP;
+    // end
     $readmemh("text.hex", mem);
 end
 
diff --git a/test/test.S b/test/test.S
index 46e4737..1e8cd9e 100644
--- a/test/test.S
+++ b/test/test.S
@@ -361,6 +361,12 @@ fail:
 test_jalr:
     addi    x2, x0, 0x12        # x2 = 0x12
     jalr    x0, x1, 0           # return
+    nop
+    nop
+    nop
+    nop
+    nop
+    nop
 
 
 .data