commit 0dd5ce38fbeb2fb97b01cc8c1c97292211e48ee6
author Martijn van den Broek <martijn.vdbrk@gmail.com> Tue Aug 06 20:45:39 2013 +0200
committer Anthony Liguori <aliguori@us.ibm.com> Wed Aug 07 12:46:40 2013 -0500
tree b0e7cc97bf0b06eaa674a281dd27f04cde79530e
parent 6c0f48f5b6c4cf3e1ec8ec6fa7bfe1b97dc92a9c

Bugfix for loading multiboot kernels

This patch fixes a bug in rom_copy introduced by
commit d60fa42e8bae39440f997ebfe8fe328269a57d16.

rom_copy failed to load roms with a "datasize" of 0.
As a result, multiboot kernels were not loaded correctly
when they contain a segment with a "file size" of 0.

https://bugs.launchpad.net/qemu/+bug/1208944

Signed-off-by: Martijn van den Broek <martijn.vdbrk@gmail.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: CAG1x_oET1u3TMPu3r_zzd3ZXsTWQLiaM0zAc+RkHFCwvJjGOvg@mail.gmail.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

hw/core/loader.c

diff --git a/hw/core/loader.c b/hw/core/loader.c
index c3c28cf..6875b7e 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -814,9 +814,6 @@
         if (rom->addr > end) {
             break;
         }
-        if (!rom->data) {
-            continue;
-        }
 
         d = dest + (rom->addr - addr);
         s = rom->data;
@@ -826,7 +823,9 @@
             l = dest - d;
         }
 
-        memcpy(d, s, l);
+        if (l > 0) {
+            memcpy(d, s, l);
+        }
 
         if (rom->romsize > rom->datasize) {
             /* If datasize is less than romsize, it means that we didn't