From patchwork Fri Jun  8 01:08:02 2012
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Subject: MIPS/GDB: Correct stub handling of CP1 FIR
From: "Maciej W. Rozycki" <macro@codesourcery.com>
X-Patchwork-Id: 163704
Message-Id: <alpine.DEB.1.10.1206080138180.23962@tp.orcam.me.uk>
To: <qemu-devel@nongnu.org>
Cc: "Maciej W. Rozycki" <macro@codesourcery.com>,
 Aurelien Jarno <aurelien@aurel32.net>
Date: Fri, 8 Jun 2012 02:08:02 +0100

The CP1 FIR register is read-only, ignore any write attempts from the GDB 
stub.

Signed-off-by: Maciej W. Rozycki <macro@codesourcery.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>

---
Definitely obvious, please apply.

  Maciej

qemu-mips-fir.diff

Index: qemu-git-trunk/gdbstub.c
===================================================================
--- qemu-git-trunk.orig/gdbstub.c	2012-06-08 01:11:04.000000000 +0100
+++ qemu-git-trunk/gdbstub.c	2012-06-08 01:42:22.865584444 +0100
@@ -1130,7 +1130,9 @@ static int cpu_gdb_write_register(CPUMIP
             /* set rounding mode */
             RESTORE_ROUNDING_MODE;
             break;
-        case 71: env->active_fpu.fcr0 = tmp; break;
+        case 71:
+            /* FIR is read-only.  Ignore writes.  */
+            break;
         }
         return sizeof(target_ulong);
     }