cuda.c: return error for unknown commands

This avoids MacsBug hanging at startup in the absence of ADB mouse
input, by replying with an error (which is also what MOL does) when
it sends an unknown command (0x1c).

Signed-off-by: Alyssa Milburn <fuzzie@fuzzie.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 5 insertions, 0 deletions

diff --git a/hw/misc/macio/cuda.c b/hw/misc/macio/cuda.c
index 0bd90e8456..316c1ac8da 100644
--- a/hw/misc/macio/cuda.c
+++ b/hw/misc/macio/cuda.c
@@ -606,6 +606,11 @@ static void cuda_receive_packet(CUDAState *s,
         }
         break;
     default:
+        obuf[0] = ERROR_PACKET;
+        obuf[1] = 0x2;
+        obuf[2] = CUDA_PACKET;
+        obuf[3] = data[0];
+        cuda_send_packet_to_host(s, obuf, 4);
         break;
     }
 }