gdb/alpha-nat.c

   1 /* Low level Alpha interface, for GDB when running native.
   2    Copyright 1993, 1995, 1996, 1998 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21 #include "defs.h"
  22 #include "inferior.h"
  23 #include "gdbcore.h"
  24 #include "target.h"
  25 #include <sys/ptrace.h>
  26 #ifdef __linux__
  27 #include <asm/reg.h>
  28 #include <alpha/ptrace.h>
  29 #else
  30 #include <machine/reg.h>
  31 #endif
  32 #include <sys/user.h>
  33
  34 /* Prototypes for local functions. */
  35
  36 static void fetch_osf_core_registers (char *, unsigned, int, CORE_ADDR);
  37 static void fetch_elf_core_registers (char *, unsigned, int, CORE_ADDR);
  38
  39 /* Size of elements in jmpbuf */
  40
  41 #define JB_ELEMENT_SIZE 8
  42
  43 /* The definition for JB_PC in machine/reg.h is wrong.
  44    And we can't get at the correct definition in setjmp.h as it is
  45    not always available (eg. if _POSIX_SOURCE is defined which is the
  46    default). As the defintion is unlikely to change (see comment
  47    in <setjmp.h>, define the correct value here.  */
  48
  49 #undef JB_PC
  50 #define JB_PC 2
  51
  52 /* Figure out where the longjmp will land.
  53    We expect the first arg to be a pointer to the jmp_buf structure from which
  54    we extract the pc (JB_PC) that we will land at.  The pc is copied into PC.
  55    This routine returns true on success. */
  56
  57 int
  58 get_longjmp_target (pc)
  59      CORE_ADDR *pc;
  60 {
  61   CORE_ADDR jb_addr;
  62   char raw_buffer[MAX_REGISTER_RAW_SIZE];
  63
  64   jb_addr = read_register (A0_REGNUM);
  65
  66   if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, raw_buffer,
  67                           sizeof (CORE_ADDR)))
  68     return 0;
  69
  70   *pc = extract_address (raw_buffer, sizeof (CORE_ADDR));
  71   return 1;
  72 }
  73
  74 /* Extract the register values out of the core file and store
  75    them where `read_register' will find them.
  76
  77    CORE_REG_SECT points to the register values themselves, read into memory.
  78    CORE_REG_SIZE is the size of that area.
  79    WHICH says which set of registers we are handling (0 = int, 2 = float
  80    on machines where they are discontiguous).
  81    REG_ADDR is the offset from u.u_ar0 to the register values relative to
  82    core_reg_sect.  This is used with old-fashioned core files to
  83    locate the registers in a large upage-plus-stack ".reg" section.
  84    Original upage address X is at location core_reg_sect+x+reg_addr.
  85  */
  86
  87 static void
  88 fetch_osf_core_registers (core_reg_sect, core_reg_size, which, reg_addr)
  89      char *core_reg_sect;
  90      unsigned core_reg_size;
  91      int which;
  92      CORE_ADDR reg_addr;
  93 {
  94   register int regno;
  95   register int addr;
  96   int bad_reg = -1;
  97
  98   /* Table to map a gdb regnum to an index in the core register section.
  99      The floating point register values are garbage in OSF/1.2 core files.  */
 100   static int core_reg_mapping[NUM_REGS] =
 101   {
 102 #define EFL (EF_SIZE / 8)
 103     EF_V0, EF_T0, EF_T1, EF_T2, EF_T3, EF_T4, EF_T5, EF_T6,
 104     EF_T7, EF_S0, EF_S1, EF_S2, EF_S3, EF_S4, EF_S5, EF_S6,
 105     EF_A0, EF_A1, EF_A2, EF_A3, EF_A4, EF_A5, EF_T8, EF_T9,
 106     EF_T10, EF_T11, EF_RA, EF_T12, EF_AT, EF_GP, EF_SP, -1,
 107     EFL + 0, EFL + 1, EFL + 2, EFL + 3, EFL + 4, EFL + 5, EFL + 6, EFL + 7,
 108     EFL + 8, EFL + 9, EFL + 10, EFL + 11, EFL + 12, EFL + 13, EFL + 14, EFL + 15,
 109     EFL + 16, EFL + 17, EFL + 18, EFL + 19, EFL + 20, EFL + 21, EFL + 22, EFL + 23,
 110     EFL + 24, EFL + 25, EFL + 26, EFL + 27, EFL + 28, EFL + 29, EFL + 30, EFL + 31,
 111     EF_PC, -1
 112   };
 113   static char zerobuf[MAX_REGISTER_RAW_SIZE] =
 114   {0};
 115
 116   for (regno = 0; regno < NUM_REGS; regno++)
 117     {
 118       if (CANNOT_FETCH_REGISTER (regno))
 119         {
 120           supply_register (regno, zerobuf);
 121           continue;
 122         }
 123       addr = 8 * core_reg_mapping[regno];
 124       if (addr < 0 || addr >= core_reg_size)
 125         {
 126           if (bad_reg < 0)
 127             bad_reg = regno;
 128         }
 129       else
 130         {
 131           supply_register (regno, core_reg_sect + addr);
 132         }
 133     }
 134   if (bad_reg >= 0)
 135     {
 136       error ("Register %s not found in core file.", REGISTER_NAME (bad_reg));
 137     }
 138 }
 139
 140 static void
 141 fetch_elf_core_registers (core_reg_sect, core_reg_size, which, reg_addr)
 142      char *core_reg_sect;
 143      unsigned core_reg_size;
 144      int which;
 145      CORE_ADDR reg_addr;
 146 {
 147   if (core_reg_size < 32 * 8)
 148     {
 149       error ("Core file register section too small (%u bytes).", core_reg_size);
 150       return;
 151     }
 152
 153   if (which == 2)
 154     {
 155       /* The FPU Registers.  */
 156       memcpy (&registers[REGISTER_BYTE (FP0_REGNUM)], core_reg_sect, 31 * 8);
 157       memset (&registers[REGISTER_BYTE (FP0_REGNUM + 31)], 0, 8);
 158       memset (&register_valid[FP0_REGNUM], 1, 32);
 159     }
 160   else
 161     {
 162       /* The General Registers.  */
 163       memcpy (&registers[REGISTER_BYTE (V0_REGNUM)], core_reg_sect, 31 * 8);
 164       memcpy (&registers[REGISTER_BYTE (PC_REGNUM)], core_reg_sect + 31 * 8, 8);
 165       memset (&registers[REGISTER_BYTE (ZERO_REGNUM)], 0, 8);
 166       memset (&register_valid[V0_REGNUM], 1, 32);
 167       register_valid[PC_REGNUM] = 1;
 168     }
 169 }
 170
 171
 172 /* Map gdb internal register number to a ptrace ``address''.
 173    These ``addresses'' are defined in <sys/ptrace.h> */
 174
 175 #define REGISTER_PTRACE_ADDR(regno) \
 176    (regno < FP0_REGNUM ?        GPR_BASE + (regno) \
 177   : regno == PC_REGNUM ?        PC      \
 178   : regno >= FP0_REGNUM ?       FPR_BASE + ((regno) - FP0_REGNUM) \
 179   : 0)
 180
 181 /* Return the ptrace ``address'' of register REGNO. */
 182
 183 CORE_ADDR
 184 register_addr (regno, blockend)
 185      int regno;
 186      CORE_ADDR blockend;
 187 {
 188   return REGISTER_PTRACE_ADDR (regno);
 189 }
 190
 191 int
 192 kernel_u_size ()
 193 {
 194   return (sizeof (struct user));
 195 }
 196
 197 #if defined(USE_PROC_FS) || defined(HAVE_GREGSET_T)
 198 #include <sys/procfs.h>
 199
 200 /* Prototypes for supply_gregset etc. */
 201 #include "gregset.h"
 202
 203 /*
 204  * See the comment in m68k-tdep.c regarding the utility of these functions.
 205  */
 206
 207 void
 208 supply_gregset (gregsetp)
 209      gregset_t *gregsetp;
 210 {
 211   register int regi;
 212   register long *regp = ALPHA_REGSET_BASE (gregsetp);
 213   static char zerobuf[MAX_REGISTER_RAW_SIZE] =
 214   {0};
 215
 216   for (regi = 0; regi < 31; regi++)
 217     supply_register (regi, (char *) (regp + regi));
 218
 219   supply_register (PC_REGNUM, (char *) (regp + 31));
 220
 221   /* Fill inaccessible registers with zero.  */
 222   supply_register (ZERO_REGNUM, zerobuf);
 223   supply_register (FP_REGNUM, zerobuf);
 224 }
 225
 226 void
 227 fill_gregset (gregsetp, regno)
 228      gregset_t *gregsetp;
 229      int regno;
 230 {
 231   int regi;
 232   register long *regp = ALPHA_REGSET_BASE (gregsetp);
 233
 234   for (regi = 0; regi < 31; regi++)
 235     if ((regno == -1) || (regno == regi))
 236       *(regp + regi) = *(long *) &registers[REGISTER_BYTE (regi)];
 237
 238   if ((regno == -1) || (regno == PC_REGNUM))
 239     *(regp + 31) = *(long *) &registers[REGISTER_BYTE (PC_REGNUM)];
 240 }
 241
 242 /*
 243  * Now we do the same thing for floating-point registers.
 244  * Again, see the comments in m68k-tdep.c.
 245  */
 246
 247 void
 248 supply_fpregset (fpregsetp)
 249      fpregset_t *fpregsetp;
 250 {
 251   register int regi;
 252   register long *regp = ALPHA_REGSET_BASE (fpregsetp);
 253
 254   for (regi = 0; regi < 32; regi++)
 255     supply_register (regi + FP0_REGNUM, (char *) (regp + regi));
 256 }
 257
 258 void
 259 fill_fpregset (fpregsetp, regno)
 260      fpregset_t *fpregsetp;
 261      int regno;
 262 {
 263   int regi;
 264   register long *regp = ALPHA_REGSET_BASE (fpregsetp);
 265
 266   for (regi = FP0_REGNUM; regi < FP0_REGNUM + 32; regi++)
 267     {
 268       if ((regno == -1) || (regno == regi))
 269         {
 270           *(regp + regi - FP0_REGNUM) =
 271             *(long *) &registers[REGISTER_BYTE (regi)];
 272         }
 273     }
 274 }
 275 #endif
 276 \f
 277
 278 /* Register that we are able to handle alpha core file formats. */
 279
 280 static struct core_fns alpha_osf_core_fns =
 281 {
 282   /* This really is bfd_target_unknown_flavour.  */
 283
 284   bfd_target_unknown_flavour,           /* core_flavour */
 285   default_check_format,                 /* check_format */
 286   default_core_sniffer,                 /* core_sniffer */
 287   fetch_osf_core_registers,             /* core_read_registers */
 288   NULL                                  /* next */
 289 };
 290
 291 static struct core_fns alpha_elf_core_fns =
 292 {
 293   bfd_target_elf_flavour,               /* core_flavour */
 294   default_check_format,                 /* check_format */
 295   default_core_sniffer,                 /* core_sniffer */
 296   fetch_elf_core_registers,             /* core_read_registers */
 297   NULL                                  /* next */
 298 };
 299
 300 void
 301 _initialize_core_alpha ()
 302 {
 303   add_core_fns (&alpha_osf_core_fns);
 304   add_core_fns (&alpha_elf_core_fns);
 305 }