1/* Target-dependent code for Xilinx MicroBlaze.
2
3   Copyright 2009, 2010, 2011 Free Software Foundation, Inc.
4
5   This file is part of GDB.
6
7   This program is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 3 of the License, or
10   (at your option) any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
19
20#include "defs.h"
21#include "frame.h"
22#include "inferior.h"
23#include "symtab.h"
24#include "target.h"
25#include "gdbcore.h"
26#include "gdbcmd.h"
27#include "symfile.h"
28#include "objfiles.h"
29#include "regcache.h"
30#include "value.h"
31#include "osabi.h"
32#include "regset.h"
33#include "solib-svr4.h"
34#include "microblaze-tdep.h"
35#include "trad-frame.h"
36#include "frame-unwind.h"
37#include "tramp-frame.h"
38#include "linux-tdep.h"
39
40static int
41microblaze_linux_memory_remove_breakpoint (struct gdbarch *gdbarch,
42					   struct bp_target_info *bp_tgt)
43{
44  CORE_ADDR addr = bp_tgt->placed_address;
45  const gdb_byte *bp;
46  int val;
47  int bplen;
48  gdb_byte old_contents[BREAKPOINT_MAX];
49
50  /* Determine appropriate breakpoint contents and size for this address.  */
51  bp = gdbarch_breakpoint_from_pc (gdbarch, &addr, &bplen);
52  if (bp == NULL)
53    error (_("Software breakpoints not implemented for this target."));
54
55  val = target_read_memory (addr, old_contents, bplen);
56
57  /* If our breakpoint is no longer at the address, this means that the
58     program modified the code on us, so it is wrong to put back the
59     old value.  */
60  if (val == 0 && memcmp (bp, old_contents, bplen) == 0)
61    val = target_write_memory (addr, bp_tgt->shadow_contents, bplen);
62
63  return val;
64}
65
66static void
67microblaze_linux_sigtramp_cache (struct frame_info *next_frame,
68				 struct trad_frame_cache *this_cache,
69				 CORE_ADDR func, LONGEST offset,
70				 int bias)
71{
72  CORE_ADDR base;
73  CORE_ADDR gpregs;
74  int regnum;
75  struct gdbarch *gdbarch = get_frame_arch (next_frame);
76  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
77
78  base = frame_unwind_register_unsigned (next_frame, MICROBLAZE_SP_REGNUM);
79  if (bias > 0 && get_frame_address_in_block (next_frame) != func)
80    /* See below, some signal trampolines increment the stack as their
81       first instruction, need to compensate for that.  */
82    base -= bias;
83
84  /* Find the address of the register buffer.  */
85  gpregs = base + offset;
86
87  /* Registers saved on stack.  */
88  for (regnum = 0; regnum < MICROBLAZE_BTR_REGNUM; regnum++)
89    trad_frame_set_reg_addr (this_cache, regnum,
90			     gpregs + regnum * MICROBLAZE_REGISTER_SIZE);
91  trad_frame_set_id (this_cache, frame_id_build (base, func));
92}
93
94
95static void
96microblaze_linux_sighandler_cache_init (const struct tramp_frame *self,
97					struct frame_info *next_frame,
98					struct trad_frame_cache *this_cache,
99					CORE_ADDR func)
100{
101  microblaze_linux_sigtramp_cache (next_frame, this_cache, func,
102				   0 /* Offset to ucontext_t.  */
103				   + 24 /* Offset to .reg.  */,
104				   0);
105}
106
107static struct tramp_frame microblaze_linux_sighandler_tramp_frame =
108{
109  SIGTRAMP_FRAME,
110  4,
111  {
112    { 0x31800077, -1 }, /* addik R12,R0,119.  */
113    { 0xb9cc0008, -1 }, /* brki R14,8.  */
114    { TRAMP_SENTINEL_INSN },
115  },
116  microblaze_linux_sighandler_cache_init
117};
118
119
120static void
121microblaze_linux_init_abi (struct gdbarch_info info,
122			   struct gdbarch *gdbarch)
123{
124  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
125
126  linux_init_abi (info, gdbarch);
127
128  set_gdbarch_memory_remove_breakpoint (gdbarch,
129					microblaze_linux_memory_remove_breakpoint);
130
131  /* Shared library handling.  */
132  set_solib_svr4_fetch_link_map_offsets (gdbarch,
133					 svr4_ilp32_fetch_link_map_offsets);
134
135  /* Trampolines.  */
136  tramp_frame_prepend_unwinder (gdbarch,
137				&microblaze_linux_sighandler_tramp_frame);
138}
139
140void
141_initialize_microblaze_linux_tdep (void)
142{
143  gdbarch_register_osabi (bfd_arch_microblaze, 0, GDB_OSABI_LINUX,
144			  microblaze_linux_init_abi);
145}
146