gdb/microblaze-linux-tdep.c

   1 /* Target-dependent code for Xilinx MicroBlaze.
   2
   3    Copyright (C) 2009-2015 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
  40 static int
  41 microblaze_linux_memory_remove_breakpoint (struct gdbarch *gdbarch,
  42                                            struct bp_target_info *bp_tgt)
  43 {
  44   CORE_ADDR addr = bp_tgt->reqstd_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_raw_memory (addr, bp_tgt->shadow_contents, bplen);
  62
  63   return val;
  64 }
  65
  66 static void
  67 microblaze_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
  95 static void
  96 microblaze_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
 107 static 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
 120 static void
 121 microblaze_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
 140 /* -Wmissing-prototypes */
 141 extern initialize_file_ftype _initialize_microblaze_linux_tdep;
 142
 143 void
 144 _initialize_microblaze_linux_tdep (void)
 145 {
 146   gdbarch_register_osabi (bfd_arch_microblaze, 0, GDB_OSABI_LINUX,
 147                           microblaze_linux_init_abi);
 148 }