gdb/bfin-linux-tdep.c

   1 /* Target-dependent code for Analog Devices Blackfin processor, for GDB.
   2
   3    Copyright (C) 2005-2015 Free Software Foundation, Inc.
   4
   5    Contributed by Analog Devices, Inc.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 #include "defs.h"
  23 #include "arch-utils.h"
  24 #include "regcache.h"
  25 #include "tramp-frame.h"
  26 #include "trad-frame.h"
  27 #include "osabi.h"
  28 #include "xml-syscall.h"
  29 #include "linux-tdep.h"
  30 #include "bfin-tdep.h"
  31
  32 /* From <asm/sigcontext.h>.  */
  33
  34 #define SIGCONTEXT_OFFSET       168
  35
  36 static const int bfin_linux_sigcontext_reg_offset[BFIN_NUM_REGS] =
  37 {
  38   0 * 4,        /* %r0 */
  39   1 * 4,        /* %r1 */
  40   2 * 4,        /* %r2 */
  41   3 * 4,        /* %r3 */
  42   4 * 4,        /* %r4 */
  43   5 * 4,        /* %r5 */
  44   6 * 4,        /* %r6 */
  45   7 * 4,        /* %r7 */
  46   8 * 4,        /* %p0 */
  47   9 * 4,        /* %p1 */
  48   10 * 4,       /* %p2 */
  49   11 * 4,       /* %p3 */
  50   12 * 4,       /* %p4 */
  51   13 * 4,       /* %p5 */
  52   14 * 4,       /* %sp */
  53   23 * 4,       /* %fp */
  54   24 * 4,       /* %i0 */
  55   25 * 4,       /* %i1 */
  56   26 * 4,       /* %i2 */
  57   27 * 4,       /* %i3 */
  58   28 * 4,       /* %m0 */
  59   29 * 4,       /* %m1 */
  60   30 * 4,       /* %m2 */
  61   31 * 4,       /* %m3 */
  62   36 * 4,       /* %b0 */
  63   37 * 4,       /* %b1 */
  64   38 * 4,       /* %b2 */
  65   39 * 4,       /* %b3 */
  66   32 * 4,       /* %l0 */
  67   33 * 4,       /* %l1 */
  68   34 * 4,       /* %l2 */
  69   35 * 4,       /* %l3 */
  70   17 * 4,       /* %a0x */
  71   15 * 4,       /* %a0w */
  72   18 * 4,       /* %a1x */
  73   16 * 4,       /* %a1w */
  74   19 * 4,       /* %astat */
  75   20 * 4,       /* %rets */
  76   40 * 4,       /* %lc0 */
  77   42 * 4,       /* %lt0 */
  78   44 * 4,       /* %lb0 */
  79   41 * 4,       /* %lc1 */
  80   43 * 4,       /* %lt1 */
  81   45 * 4,       /* %lb1 */
  82   -1,           /* %cycles */
  83   -1,           /* %cycles2 */
  84   -1,           /* %usp */
  85   46 * 4,       /* %seqstat */
  86   -1,           /* syscfg */
  87   21 * 4,       /* %reti */
  88   22 * 4,       /* %retx */
  89   -1,           /* %retn */
  90   -1,           /* %rete */
  91   21 * 4,       /* %pc */
  92 };
  93
  94 /* Signal trampolines.  */
  95
  96 static void
  97 bfin_linux_sigframe_init (const struct tramp_frame *self,
  98                           struct frame_info *this_frame,
  99                           struct trad_frame_cache *this_cache,
 100                           CORE_ADDR func)
 101 {
 102   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 103   CORE_ADDR sp = get_frame_sp (this_frame);
 104   CORE_ADDR pc = get_frame_pc (this_frame);
 105   CORE_ADDR sigcontext = sp + SIGCONTEXT_OFFSET;
 106   const int *reg_offset = bfin_linux_sigcontext_reg_offset;
 107   int i;
 108
 109   for (i = 0; i < BFIN_NUM_REGS; i++)
 110     if (reg_offset[i] != -1)
 111       trad_frame_set_reg_addr (this_cache, i, sigcontext + reg_offset[i]);
 112
 113   /* This would come after the LINK instruction in the ret_from_signal
 114      function, hence the frame id would be SP + 8.  */
 115   trad_frame_set_id (this_cache, frame_id_build (sp + 8, pc));
 116 }
 117
 118 static const struct tramp_frame bfin_linux_sigframe =
 119 {
 120   SIGTRAMP_FRAME,
 121   4,
 122   {
 123     { 0x00ADE128, 0xffffffff }, /* P0 = __NR_rt_sigreturn; */
 124     { 0x00A0, 0xffff },         /* EXCPT 0; */
 125     { TRAMP_SENTINEL_INSN, -1 },
 126   },
 127   bfin_linux_sigframe_init,
 128 };
 129
 130 static LONGEST
 131 bfin_linux_get_syscall_number (struct gdbarch *gdbarch,
 132                                ptid_t ptid)
 133 {
 134   struct regcache *regcache = get_thread_regcache (ptid);
 135   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 136   /* The content of a register.  */
 137   gdb_byte buf[4];
 138   /* The result.  */
 139   LONGEST ret;
 140
 141   /* Getting the system call number from the register.
 142      When dealing with Blackfin architecture, this information
 143      is stored at %p0 register.  */
 144   regcache_cooked_read (regcache, BFIN_P0_REGNUM, buf);
 145
 146   ret = extract_signed_integer (buf, 4, byte_order);
 147
 148   return ret;
 149 }
 150
 151 static void
 152 bfin_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 153 {
 154   linux_init_abi (info, gdbarch);
 155
 156   /* Set the sigtramp frame sniffer.  */
 157   tramp_frame_prepend_unwinder (gdbarch, &bfin_linux_sigframe);
 158
 159   /* Functions for 'catch syscall'.  */
 160   set_xml_syscall_file_name (gdbarch, "syscalls/bfin-linux.xml");
 161   set_gdbarch_get_syscall_number (gdbarch,
 162                                   bfin_linux_get_syscall_number);
 163 }
 164
 165 /* Provide a prototype to silence -Wmissing-prototypes.  */
 166 extern initialize_file_ftype _initialize_bfin_linux_tdep;
 167
 168 void
 169 _initialize_bfin_linux_tdep (void)
 170 {
 171   gdbarch_register_osabi (bfd_arch_bfin, 0, GDB_OSABI_LINUX,
 172                           bfin_linux_init_abi);
 173 }