2002-10-04 Michael Snyder <msnyder@redhat.com>

        * m32r/m32r-lib.c (exceptionHandler): Fix computation of
        exception vector address, as suggested by Mitsubishi.
        (getExceptionVector): Ditto.

diff --git a/libgloss/ChangeLog b/libgloss/ChangeLog
index 9aeb478..43f542c 100644 (file)
--- a/libgloss/ChangeLog
+++ b/libgloss/ChangeLog
@@ -7,6 +7,12 @@
        * mips/ddb.ld: KEEP .init and .fini.
        * mips/ddb-kseg0.ld: Likewise.
 
+2002-10-04  Michael Snyder  <msnyder@redhat.com>
+
+        * m32r/m32r-lib.c (exceptionHandler): Fix computation of
+        exception vector address, as suggested by Mitsubishi.
+        (getExceptionVector): Ditto.
+
 2002-08-01  Chris Demetriou  <cgd@broadcom.com>
 
        * mips/cfe.ld (STARTUP): New definition.

diff --git a/libgloss/m32r/m32r-lib.c b/libgloss/m32r/m32r-lib.c
index cad55f5..1d2d291 100644 (file)
--- a/libgloss/m32r/m32r-lib.c
+++ b/libgloss/m32r/m32r-lib.c
@@ -109,15 +109,22 @@ void phex(long x)
   mesg(buf);
 }
 
-/* Setup trap TT to go to ROUTINE. */
+/*
+ * These routines set and get exception handlers.  They look a little
+ * funny because the M32R uses branch instructions in its exception
+ * vectors, not just the addresses.  The instruction format used is
+ * BRA pcdisp24.
+ */
 
-void
+#define TRAP_VECTOR_BASE_ADDR   0x00000040
+
+/* Setup trap TT to go to ROUTINE. */
+void 
 exceptionHandler (int tt, unsigned long routine)
 {
 #ifndef REVC
-  unsigned long *tb = (unsigned long *) 0x40;  /* Trap vector base address */
-
-  tb[tt] = ((routine >> 2) | 0xff000000) - tt - (0x40 >> 2);
+  unsigned long *tb = (unsigned long *) TRAP_VECTOR_BASE_ADDR;
+  tb[tt] = (0xff000000 | ((routine - (unsigned long) (&tb[tt])) >> 2));
 #else
   unsigned long *tb = 0;       /* Trap vector base address */
 
@@ -126,14 +133,12 @@ exceptionHandler (int tt, unsigned long routine)
 }
 
 /* Return the address of trap TT handler */
-
 unsigned long
 getExceptionHandler (int tt)
 {
 #ifndef REVC
-  unsigned long *tb = (unsigned long *) 0x40;  /* Trap vector base address */
-
-  return ((tb[tt] + tt + (0x40 >> 2)) | 0xff000000) << 2;
+  unsigned long *tb = (unsigned long *) TRAP_VECTOR_BASE_ADDR;
+  return ((tb[tt] & ~0xff000000) << 2) + (unsigned long) (&tb[tt]);
 #else
   unsigned long *tb = 0;       /* Trap vector base address */