| 1 | /* Simulate breakpoints by patching locations in the target system, for GDB. |
| 2 | |
| 3 | Copyright (C) 1990, 1991, 1992, 1993, 1995, 1997, 1998, 1999, 2000, 2002, |
| 4 | 2007 Free Software Foundation, Inc. |
| 5 | |
| 6 | Contributed by Cygnus Support. Written by John Gilmore. |
| 7 | |
| 8 | This file is part of GDB. |
| 9 | |
| 10 | This program is free software; you can redistribute it and/or modify |
| 11 | it under the terms of the GNU General Public License as published by |
| 12 | the Free Software Foundation; either version 3 of the License, or |
| 13 | (at your option) any later version. |
| 14 | |
| 15 | This program is distributed in the hope that it will be useful, |
| 16 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 18 | GNU General Public License for more details. |
| 19 | |
| 20 | You should have received a copy of the GNU General Public License |
| 21 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 22 | |
| 23 | #include "defs.h" |
| 24 | |
| 25 | /* This file is only useful if BREAKPOINT_FROM_PC is set. If not, we |
| 26 | punt. */ |
| 27 | |
| 28 | #include "symtab.h" |
| 29 | #include "breakpoint.h" |
| 30 | #include "inferior.h" |
| 31 | #include "target.h" |
| 32 | |
| 33 | |
| 34 | /* Insert a breakpoint on targets that don't have any better |
| 35 | breakpoint support. We read the contents of the target location |
| 36 | and stash it, then overwrite it with a breakpoint instruction. |
| 37 | BP_TGT->placed_address is the target location in the target |
| 38 | machine. BP_TGT->shadow_contents is some memory allocated for |
| 39 | saving the target contents. It is guaranteed by the caller to be |
| 40 | long enough to save BREAKPOINT_LEN bytes (this is accomplished via |
| 41 | BREAKPOINT_MAX). */ |
| 42 | |
| 43 | int |
| 44 | default_memory_insert_breakpoint (struct bp_target_info *bp_tgt) |
| 45 | { |
| 46 | int val; |
| 47 | const unsigned char *bp; |
| 48 | int bplen; |
| 49 | |
| 50 | /* Determine appropriate breakpoint contents and size for this address. */ |
| 51 | bp = gdbarch_breakpoint_from_pc |
| 52 | (current_gdbarch, &bp_tgt->placed_address, &bp_tgt->placed_size); |
| 53 | if (bp == NULL) |
| 54 | error (_("Software breakpoints not implemented for this target.")); |
| 55 | |
| 56 | /* Save the memory contents. */ |
| 57 | bp_tgt->shadow_len = bp_tgt->placed_size; |
| 58 | val = target_read_memory (bp_tgt->placed_address, bp_tgt->shadow_contents, |
| 59 | bp_tgt->placed_size); |
| 60 | |
| 61 | /* Write the breakpoint. */ |
| 62 | if (val == 0) |
| 63 | val = target_write_memory (bp_tgt->placed_address, bp, |
| 64 | bp_tgt->placed_size); |
| 65 | |
| 66 | return val; |
| 67 | } |
| 68 | |
| 69 | |
| 70 | int |
| 71 | default_memory_remove_breakpoint (struct bp_target_info *bp_tgt) |
| 72 | { |
| 73 | return target_write_memory (bp_tgt->placed_address, bp_tgt->shadow_contents, |
| 74 | bp_tgt->placed_size); |
| 75 | } |
| 76 | |
| 77 | |
| 78 | int |
| 79 | memory_insert_breakpoint (struct bp_target_info *bp_tgt) |
| 80 | { |
| 81 | return gdbarch_memory_insert_breakpoint (current_gdbarch, bp_tgt); |
| 82 | } |
| 83 | |
| 84 | int |
| 85 | memory_remove_breakpoint (struct bp_target_info *bp_tgt) |
| 86 | { |
| 87 | return gdbarch_memory_remove_breakpoint (current_gdbarch, bp_tgt); |
| 88 | } |