From: Ian Jackson <iwj@mariner.uk.xensource.com>
Date: Wed, 14 May 2008 15:55:37 +0000 (+0100)
Subject: Do not kill ioemu if undefined LSI-SCI registers are read.
X-Git-Tag: xen-3.3.0-rc1~188
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=2c6d1c609b053c9dc0871b941d043d28fbac71fd;p=qemu-xen-4.5-testing.git

Do not kill ioemu if undefined LSI-SCI registers are read.

Imported changeset from xen-unstable:

    changeset:   14902:a7bd11fd5b1b6f4a82135db09dfe654e8966fabe
    user:        kfraser@localhost.localdomain
    date:        Tue Apr 24 12:12:48 2007 +0100
    files:       tools/ioemu/hw/lsi53c895a.c
    description:
    qemu: Do not kill ioemu if undefined LSI-SCI registers are read. Just
    return zeroes. This path is triggered by ASPI8DOS.SYS in DRDOS.
    Signed-off-by: Keir Fraser <keir@xensource.com>

However, this behaviour change was inexplicably made conditional on
CONFIG_DM.  I have removed the conditionality.
---

diff --git a/hw/lsi53c895a.c b/hw/lsi53c895a.c
index a08cfd9e3..24a43b11a 100644
--- a/hw/lsi53c895a.c
+++ b/hw/lsi53c895a.c
@@ -1369,8 +1369,8 @@ static uint8_t lsi_reg_readb(LSIState *s, int offset)
         shift = (offset & 3) * 8;
         return (s->scratch[n] >> shift) & 0xff;
     }
-    BADF("readb 0x%x\n", offset);
-    exit(1);
+    /* XEN: This path can be triggered (e.g. ASPI8DOS.SYS reads 0x8). */
+    return 0;
 #undef CASE_GET_REG32
 }