Add memory probe support.

c/src/lib/libcpu/m68k/ChangeLog

@@ -1,3 +1,7 @@
+2005-02-03	Eric Norum <norume@aps.anl.gov>
+
+	* shared/misc/memProbe.c: Memory probe support
+
 2005-02-01	Joel Sherrill <joel@OARcorp.com>
 
 	* mcf5282/.cvsignore: New file.

c/src/lib/libcpu/m68k/shared/Makefile.am

@@ -30,7 +30,7 @@ M68K_CPPFLAGS = -Dmcf5272
 endif
 
 noinst_PROGRAMS += misc.rel
-misc_rel_SOURCES = misc/memcpy.c misc/m68kidle.c
+misc_rel_SOURCES = misc/memcpy.c misc/m68kidle.c misc/memProbe.c
 misc_rel_CPPFLAGS = $(AM_CPPFLAGS) $(M68K_CPPFLAGS)
 misc_rel_LDFLAGS = $(RTEMS_RELLDFLAGS)
 endif

c/src/lib/libcpu/m68k/shared/misc/memProbe.c

@@ -0,0 +1,103 @@
+/* 
+ * Address Probing for M68k/ColdFire
+ */
+
+#include <bsp.h>
+#include <string.h>
+
+#if (M68K_COLDFIRE_ARCH == 1)
+# define EXCEPTION_FRAME_PC_OFFSET "4"
+#else
+# define EXCEPTION_FRAME_PC_OFFSET "2"
+#endif
+
+typedef int (*MemProber)(void *from, void *to);
+int memProbeByte(void *from, void *to);
+int memProbeShort(void *from, void *to);
+int memProbeLong(void *from, void *to);
+int memProbeCatcher(void);
+
+__asm__(
+    ".text\n"
+    "memProbeByte:        \n"
+    "   move.l %sp@(4),%a0\n"
+    "   move.b %a0@,%d0   \n"
+    "   move.l %sp@(8),%a0\n"
+    "   move.b %d0,%a0@   \n"
+    "   bra.b 1f          \n"
+    "memProbeShort:       \n"
+    "   move.l %sp@(4),%a0\n"
+    "   move.w %a0@,%d0   \n"
+    "   move.l %sp@(8),%a0\n"
+    "   move.w %d0,%a0@   \n"
+    "   bra.b 1f          \n"
+    "memProbeLong:        \n"
+    "   move.l %sp@(4),%a0\n"
+    "   move.l %a0@,%d0   \n"
+    "   move.l %sp@(8),%a0\n"
+    "   move.l %d0,%a0@   \n"
+    "1: nop               \n"
+    "   moveq.l #1,%d0    \n"
+    "   rts               \n"
+    "memProbeCatcher:     \n"
+    "   move.l #1f,%d0    \n"
+    "   move.l %d0,%sp@(" EXCEPTION_FRAME_PC_OFFSET ")\n"
+    "   rte               \n"
+    "1: clr.l  %d0        \n"
+    "   rts               \n"
+);
+
+rtems_status_code
+bspExtMemProbe(void *addr, int write, int size, void *pval)
+{
+    rtems_status_code rval=RTEMS_SUCCESSFUL;
+    rtems_interrupt_level level;
+    unsigned long buf;
+    MemProber probe;
+    void *saveVector;
+    void **exceptionPointer;
+    void *vbr;
+
+    /*
+     * Sanity check
+     */
+    switch (size) {
+        case sizeof(char):  probe=memProbeByte; break;
+        case sizeof(short): probe=memProbeShort; break;
+        case sizeof(long):  probe=memProbeLong; break;
+        default: return RTEMS_INVALID_SIZE;
+    }
+
+    /*
+     * use a buffer to make sure we don't end up probing 'pval'.
+     */
+    if (write && pval)
+        memcpy(&buf, pval, size);
+
+    /*
+     * Get location of access fault exception
+     */
+    m68k_get_vbr(vbr);
+    exceptionPointer = (void **)((char *)vbr + (2 * 4));
+
+    /*
+     * Probe!
+     */
+    rtems_interrupt_disable(level);
+    saveVector = *exceptionPointer;
+    *exceptionPointer = memProbeCatcher;
+    if (write) {
+        if (probe(&buf, addr) == 0)
+            rval = RTEMS_INVALID_ADDRESS;
+    }
+    else {
+        if (probe(addr, &buf) == 0)
+            rval = RTEMS_INVALID_ADDRESS;
+    }
+    *exceptionPointer = saveVector;
+    rtems_interrupt_enable(level);
+
+    if (!write && pval && (rval == RTEMS_SUCCESSFUL))
+        memcpy(pval, &buf, size);
+    return rval;
+}