From 3cebac2006571a93ea0cbf992faa5eec3454d570 Mon Sep 17 00:00:00 2001
From: Ben Pfaff <blp@cs.stanford.edu>
Date: Tue, 22 Feb 2005 20:54:06 +0000
Subject: [PATCH] Only consider a disk to exist if it has nonzero size.

---
 src/utils/pintos | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/utils/pintos b/src/utils/pintos
index ea4bdcc..40a240c 100755
--- a/src/utils/pintos
+++ b/src/utils/pintos
@@ -214,8 +214,9 @@ sub run_vm {
     our (@disks);
 
     die "$disks[0]: can't find OS disk\n" if ! -e $disks[0];
+    die "$disks[0]: OS disk cannot have zero size\n" if ! -s $disks[0];
     for my $i (1...3) {
-	undef $disks[$i] if ! -e $disks[$i];
+	undef $disks[$i] if ! -s $disks[$i];
     }
 
     if (my ($project) = `pwd` =~ /\b(threads|userprog|vm|filesys)\b/) {
-- 
2.30.2