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+/* Simulate breakpoints by patching locations in the target system, for GDB.
+ Copyright 1990, 1991 Free Software Foundation, Inc.
+ Contributed by Cygnus Support. Written by John Gilmore.
+
+This file is part of GDB.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include "defs.h"
+
+#ifdef BREAKPOINT
+/* This file is only useful if BREAKPOINT is set. If not, we punt. */
+
+#include "symtab.h"
+#include "breakpoint.h"
+#include "inferior.h"
+#include "target.h"
+
+/* This is the sequence of bytes we insert for a breakpoint. On some
+ machines, breakpoints are handled by the target environment and we
+ don't have to worry about them here. */
+
+static unsigned char break_insn[] = BREAKPOINT;
+
+/* This is only to check that BREAKPOINT fits in BREAKPOINT_MAX bytes. */
+
+static unsigned char check_break_insn_size[BREAKPOINT_MAX] = BREAKPOINT;
+
+/* Insert a breakpoint on targets that don't have any better breakpoint
+ support. We read the contents of the target location and stash it,
+ then overwrite it with a breakpoint instruction. ADDR is the target
+ location in the target machine. CONTENTS_CACHE is a pointer to
+ memory allocated for saving the target contents. It is guaranteed
+ by the caller to be long enough to save sizeof BREAKPOINT bytes (this
+ is accomplished via BREAKPOINT_MAX). */
+
+int
+memory_insert_breakpoint (addr, contents_cache)
+ CORE_ADDR addr;
+ char *contents_cache;
+{
+ int val;
+
+ val = target_read_memory (addr, contents_cache, sizeof break_insn);
+
+ if (val == 0)
+ val = target_write_memory (addr, (char *)break_insn, sizeof break_insn);
+
+ return val;
+}
+
+
+int
+memory_remove_breakpoint (addr, contents_cache)
+ CORE_ADDR addr;
+ char *contents_cache;
+{
+ return target_write_memory (addr, contents_cache, sizeof break_insn);
+}
+
+
+/* FIXME: This is a hack and should depend on the debugging target.
+ See comment in breakpoint.c where this is used. */
+
+int memory_breakpoint_size = sizeof (break_insn);
+
+
+#else /* BREAKPOINT */
+
+char nogo[] = "Breakpoints not implemented for this target.";
+
+int
+memory_insert_breakpoint (addr, contents_cache)
+ CORE_ADDR addr;
+ char *contents_cache;
+{
+ error (nogo);
+ return 0; /* lint */
+}
+
+int
+memory_remove_breakpoint (addr, contents_cache)
+ CORE_ADDR addr;
+ char *contents_cache;
+{
+ error (nogo);
+ return 0; /* lint */
+}
+
+int memory_breakpoint_size = -1;
+
+#endif /* BREAKPOINT */
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