gdb/tic6x-linux-tdep.c

   1 /* GNU/Linux on  TI C6x target support.
   2    Copyright (C) 2011-2015 Free Software Foundation, Inc.
   3    Contributed by Yao Qi <yao@codesourcery.com>
   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 "solib.h"
  22 #include "osabi.h"
  23 #include "linux-tdep.h"
  24 #include "tic6x-tdep.h"
  25 #include "trad-frame.h"
  26 #include "tramp-frame.h"
  27 #include "elf-bfd.h"
  28 #include "elf/tic6x.h"
  29
  30 #include "features/tic6x-c64xp-linux.c"
  31 #include "features/tic6x-c64x-linux.c"
  32 #include "features/tic6x-c62x-linux.c"
  33
  34 /* The offset from rt_sigframe pointer to SP register.  */
  35 #define TIC6X_SP_RT_SIGFRAME 8
  36 /* Size of struct siginfo info.  */
  37 #define TIC6X_SIGINFO_SIZE 128
  38 /* Size of type stack_t, which contains three fields of type void*, int, and
  39    size_t respectively.  */
  40 #define TIC6X_STACK_T_SIZE (3 * 4)
  41
  42 static const gdb_byte tic6x_bkpt_bnop_be[] = { 0x00, 0x00, 0xa1, 0x22 };
  43 static const gdb_byte tic6x_bkpt_bnop_le[] = { 0x22, 0xa1, 0x00, 0x00 };
  44
  45 /* Return the offset of register REGNUM in struct sigcontext.  Return 0 if no
  46    such register in sigcontext.  */
  47
  48 static unsigned int
  49 tic6x_register_sigcontext_offset (unsigned int regnum, struct gdbarch *gdbarch)
  50 {
  51   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  52
  53   if (regnum == TIC6X_A4_REGNUM || regnum == TIC6X_A4_REGNUM + 2
  54       || regnum == TIC6X_A4_REGNUM + 4)
  55     return 4 * (regnum - TIC6X_A4_REGNUM + 2);  /* A4, A6, A8 */
  56   else if (regnum == TIC6X_A5_REGNUM || regnum == TIC6X_A5_REGNUM + 2
  57            || regnum == TIC6X_A5_REGNUM + 4)
  58     return 4 * (regnum - TIC6X_A5_REGNUM + 12); /* A5, A7, A9 */
  59   else if (regnum == TIC6X_B4_REGNUM || regnum == TIC6X_B4_REGNUM + 2
  60            || regnum == TIC6X_B4_REGNUM + 4)
  61     return 4 * (regnum - TIC6X_B4_REGNUM + 3);  /* B4, B6, B8 */
  62   else if (regnum == TIC6X_B5_REGNUM || regnum == TIC6X_B5_REGNUM + 2
  63            || regnum == TIC6X_B5_REGNUM + 4)
  64     return 4 * (regnum - TIC6X_B5_REGNUM + 19); /* B5, B7, B9 */
  65   else if (regnum < TIC6X_A4_REGNUM)
  66     return 4 * (regnum - 0 + 8);        /* A0 - A3 */
  67   else if (regnum >= TIC6X_B0_REGNUM && regnum < TIC6X_B4_REGNUM)
  68     return 4 * (regnum - TIC6X_B0_REGNUM + 15); /* B0 - B3 */
  69   else if (regnum >= 34 && regnum < 34 + 32)
  70     return 4 * (regnum - 34 + 23);      /* A16 - A31, B16 - B31 */
  71   else if (regnum == TIC6X_PC_REGNUM)
  72     return 4 * (tdep->has_gp ? 55 : 23);
  73   else if (regnum == TIC6X_SP_REGNUM)
  74     return 4;
  75
  76   return 0;
  77 }
  78
  79 /* Support unwinding frame in signal trampoline.  We don't check sigreturn,
  80    since it is not used in kernel.  */
  81
  82 static void
  83 tic6x_linux_rt_sigreturn_init (const struct tramp_frame *self,
  84                                struct frame_info *this_frame,
  85                                struct trad_frame_cache *this_cache,
  86                                CORE_ADDR func)
  87 {
  88   struct gdbarch *gdbarch = get_frame_arch (this_frame);
  89   CORE_ADDR sp = get_frame_register_unsigned (this_frame, TIC6X_SP_REGNUM);
  90   /* The base of struct sigcontext is computed by examining the definition of
  91      struct rt_sigframe in linux kernel source arch/c6x/kernel/signal.c.  */
  92   CORE_ADDR base = (sp + TIC6X_SP_RT_SIGFRAME
  93                     /* Pointer type *pinfo and *puc in struct rt_sigframe.  */
  94                     + 4 + 4
  95                     + TIC6X_SIGINFO_SIZE
  96                     + 4 + 4 /* uc_flags and *uc_link in struct ucontext.  */
  97                     + TIC6X_STACK_T_SIZE);
  98   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  99   unsigned int reg_offset;
 100   unsigned int i;
 101
 102   for (i = 0; i < 10; i++)      /* A0 - A9 */
 103     {
 104       reg_offset = tic6x_register_sigcontext_offset (i, gdbarch);
 105       gdb_assert (reg_offset != 0);
 106
 107       trad_frame_set_reg_addr (this_cache, i, base + reg_offset);
 108     }
 109
 110   for (i = TIC6X_B0_REGNUM; i < TIC6X_B0_REGNUM + 10; i++)      /* B0 - B9 */
 111     {
 112       reg_offset = tic6x_register_sigcontext_offset (i, gdbarch);
 113       gdb_assert (reg_offset != 0);
 114
 115       trad_frame_set_reg_addr (this_cache, i, base + reg_offset);
 116     }
 117
 118   if (tdep->has_gp)
 119     for (i = 34; i < 34 + 32; i++)      /* A16 - A31, B16 - B31 */
 120       {
 121         reg_offset = tic6x_register_sigcontext_offset (i, gdbarch);
 122         gdb_assert (reg_offset != 0);
 123
 124         trad_frame_set_reg_addr (this_cache, i, base + reg_offset);
 125       }
 126
 127   trad_frame_set_reg_addr (this_cache, TIC6X_PC_REGNUM,
 128                            base + tic6x_register_sigcontext_offset (TIC6X_PC_REGNUM,
 129                                                                     gdbarch));
 130   trad_frame_set_reg_addr (this_cache, TIC6X_SP_REGNUM,
 131                            base + tic6x_register_sigcontext_offset (TIC6X_SP_REGNUM,
 132                                                                     gdbarch));
 133
 134   /* Save a frame ID.  */
 135   trad_frame_set_id (this_cache, frame_id_build (sp, func));
 136 }
 137
 138 static struct tramp_frame tic6x_linux_rt_sigreturn_tramp_frame =
 139 {
 140   SIGTRAMP_FRAME,
 141   4,
 142   {
 143     {0x000045aa, 0x0fffffff},   /* mvk .S2 139,b0 */
 144     {0x10000000, -1},           /* swe */
 145     {TRAMP_SENTINEL_INSN}
 146   },
 147   tic6x_linux_rt_sigreturn_init
 148 };
 149
 150 /* When FRAME is at a syscall instruction, return the PC of the next
 151    instruction to be executed.  */
 152
 153 static CORE_ADDR
 154 tic6x_linux_syscall_next_pc (struct frame_info *frame)
 155 {
 156   ULONGEST syscall_number = get_frame_register_unsigned (frame,
 157                                                          TIC6X_B0_REGNUM);
 158   CORE_ADDR pc = get_frame_pc (frame);
 159
 160   if (syscall_number == 139 /* rt_sigreturn */)
 161     return frame_unwind_caller_pc (frame);
 162
 163   return pc + 4;
 164 }
 165
 166
 167 extern struct target_so_ops dsbt_so_ops;
 168 static void
 169 tic6x_uclinux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 170 {
 171   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 172
 173   linux_init_abi (info, gdbarch);
 174
 175   /* Shared library handling.  */
 176   set_solib_ops (gdbarch, &dsbt_so_ops);
 177
 178   tdep->syscall_next_pc = tic6x_linux_syscall_next_pc;
 179
 180 #ifdef HAVE_ELF
 181   /* In tic6x Linux kernel, breakpoint instructions varies on different archs.
 182      On C64x+ and C67x+, breakpoint instruction is 0x56454314, which is an
 183      illegal opcode.  On other arch, breakpoint instruction is 0x0000a122
 184      (BNOP .S2 0,5).  */
 185   if (info.abfd)
 186     switch (bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_PROC, Tag_ISA))
 187       {
 188       case C6XABI_Tag_ISA_C64XP:
 189       case C6XABI_Tag_ISA_C67XP:
 190         if (info.byte_order == BFD_ENDIAN_BIG)
 191           tdep->breakpoint = tic6x_bkpt_illegal_opcode_be;
 192         else
 193           tdep->breakpoint = tic6x_bkpt_illegal_opcode_le;
 194         break;
 195       default:
 196         {
 197           if (info.byte_order == BFD_ENDIAN_BIG)
 198             tdep->breakpoint = tic6x_bkpt_bnop_be;
 199           else
 200             tdep->breakpoint = tic6x_bkpt_bnop_le;
 201         }
 202       }
 203 #endif
 204
 205   /* Signal trampoline support.  */
 206   tramp_frame_prepend_unwinder (gdbarch,
 207                                 &tic6x_linux_rt_sigreturn_tramp_frame);
 208 }
 209
 210 /* Provide a prototype to silence -Wmissing-prototypes.  */
 211 extern initialize_file_ftype _initialize_tic6x_linux_tdep;
 212
 213 void
 214 _initialize_tic6x_linux_tdep (void)
 215 {
 216   gdbarch_register_osabi (bfd_arch_tic6x, 0, GDB_OSABI_LINUX,
 217                           tic6x_uclinux_init_abi);
 218
 219   initialize_tdesc_tic6x_c64xp_linux ();
 220   initialize_tdesc_tic6x_c64x_linux ();
 221   initialize_tdesc_tic6x_c62x_linux ();
 222 }