gdb/microblaze-linux-tdep.c

   1 /* Target-dependent code for Xilinx MicroBlaze.
   2
   3    Copyright (C) 2009-2020 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
  53   val = target_read_memory (addr, old_contents, bplen);
  54
  55   /* If our breakpoint is no longer at the address, this means that the
  56      program modified the code on us, so it is wrong to put back the
  57      old value.  */
  58   if (val == 0 && memcmp (bp, old_contents, bplen) == 0)
  59     val = target_write_raw_memory (addr, bp_tgt->shadow_contents, bplen);
  60
  61   return val;
  62 }
  63
  64 static void
  65 microblaze_linux_sigtramp_cache (struct frame_info *next_frame,
  66                                  struct trad_frame_cache *this_cache,
  67                                  CORE_ADDR func, LONGEST offset,
  68                                  int bias)
  69 {
  70   CORE_ADDR base;
  71   CORE_ADDR gpregs;
  72   int regnum;
  73
  74   base = frame_unwind_register_unsigned (next_frame, MICROBLAZE_SP_REGNUM);
  75   if (bias > 0 && get_frame_address_in_block (next_frame) != func)
  76     /* See below, some signal trampolines increment the stack as their
  77        first instruction, need to compensate for that.  */
  78     base -= bias;
  79
  80   /* Find the address of the register buffer.  */
  81   gpregs = base + offset;
  82
  83   /* Registers saved on stack.  */
  84   for (regnum = 0; regnum < MICROBLAZE_BTR_REGNUM; regnum++)
  85     trad_frame_set_reg_addr (this_cache, regnum,
  86                              gpregs + regnum * MICROBLAZE_REGISTER_SIZE);
  87   trad_frame_set_id (this_cache, frame_id_build (base, func));
  88 }
  89
  90
  91 static void
  92 microblaze_linux_sighandler_cache_init (const struct tramp_frame *self,
  93                                         struct frame_info *next_frame,
  94                                         struct trad_frame_cache *this_cache,
  95                                         CORE_ADDR func)
  96 {
  97   microblaze_linux_sigtramp_cache (next_frame, this_cache, func,
  98                                    0 /* Offset to ucontext_t.  */
  99                                    + 24 /* Offset to .reg.  */,
 100                                    0);
 101 }
 102
 103 static struct tramp_frame microblaze_linux_sighandler_tramp_frame =
 104 {
 105   SIGTRAMP_FRAME,
 106   4,
 107   {
 108     { 0x31800077, ULONGEST_MAX }, /* addik R12,R0,119.  */
 109     { 0xb9cc0008, ULONGEST_MAX }, /* brki R14,8.  */
 110     { TRAMP_SENTINEL_INSN },
 111   },
 112   microblaze_linux_sighandler_cache_init
 113 };
 114
 115
 116 static void
 117 microblaze_linux_init_abi (struct gdbarch_info info,
 118                            struct gdbarch *gdbarch)
 119 {
 120   linux_init_abi (info, gdbarch);
 121
 122   set_gdbarch_memory_remove_breakpoint (gdbarch,
 123                                         microblaze_linux_memory_remove_breakpoint);
 124
 125   /* Shared library handling.  */
 126   set_solib_svr4_fetch_link_map_offsets (gdbarch,
 127                                          svr4_ilp32_fetch_link_map_offsets);
 128
 129   /* Trampolines.  */
 130   tramp_frame_prepend_unwinder (gdbarch,
 131                                 &microblaze_linux_sighandler_tramp_frame);
 132 }
 133
 134 void
 135 _initialize_microblaze_linux_tdep (void)
 136 {
 137   gdbarch_register_osabi (bfd_arch_microblaze, 0, GDB_OSABI_LINUX,
 138                           microblaze_linux_init_abi);
 139 }