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, Boston, MA 02111-1307, USA.  */
  19
  20 #include "defs.h"
  21 #include "inferior.h"
  22 #include "gdbcore.h"
  23 #include "target.h"
  24 #include <sys/ptrace.h>
  25 #ifdef __linux__
  26 # include <asm/reg.h>
  27 # include <alpha/ptrace.h>
  28 #else
  29 # include <machine/reg.h>
  30 #endif
  31 #include <sys/user.h>
  32
  33 /* Prototypes for local functions. */
  34
  35 static void fetch_osf_core_registers PARAMS ((char *,
  36                                               unsigned, int, CORE_ADDR));
  37 static void fetch_elf_core_registers PARAMS ((char *,
  38                                               unsigned, int, CORE_ADDR));
  39
  40 /* Size of elements in jmpbuf */
  41
  42 #define JB_ELEMENT_SIZE 8
  43
  44 /* The definition for JB_PC in machine/reg.h is wrong.
  45    And we can't get at the correct definition in setjmp.h as it is
  46    not always available (eg. if _POSIX_SOURCE is defined which is the
  47    default). As the defintion is unlikely to change (see comment
  48    in <setjmp.h>, define the correct value here.  */
  49
  50 #undef JB_PC
  51 #define JB_PC 2
  52
  53 /* Figure out where the longjmp will land.
  54    We expect the first arg to be a pointer to the jmp_buf structure from which
  55    we extract the pc (JB_PC) that we will land at.  The pc is copied into PC.
  56    This routine returns true on success. */
  57
  58 int
  59 get_longjmp_target (pc)
  60      CORE_ADDR *pc;
  61 {
  62   CORE_ADDR jb_addr;
  63   char raw_buffer[MAX_REGISTER_RAW_SIZE];
  64
  65   jb_addr = read_register(A0_REGNUM);
  66
  67   if (target_read_memory(jb_addr + JB_PC * JB_ELEMENT_SIZE, raw_buffer,
  68                          sizeof(CORE_ADDR)))
  69     return 0;
  70
  71   *pc = extract_address (raw_buffer, sizeof(CORE_ADDR));
  72   return 1;
  73 }
  74
  75 /* Extract the register values out of the core file and store
  76    them where `read_register' will find them.
  77
  78    CORE_REG_SECT points to the register values themselves, read into memory.
  79    CORE_REG_SIZE is the size of that area.
  80    WHICH says which set of registers we are handling (0 = int, 2 = float
  81          on machines where they are discontiguous).
  82    REG_ADDR is the offset from u.u_ar0 to the register values relative to
  83             core_reg_sect.  This is used with old-fashioned core files to
  84             locate the registers in a large upage-plus-stack ".reg" section.
  85             Original upage address X is at location core_reg_sect+x+reg_addr.
  86  */
  87
  88 static void
  89 fetch_osf_core_registers (core_reg_sect, core_reg_size, which, reg_addr)
  90      char *core_reg_sect;
  91      unsigned core_reg_size;
  92      int which;
  93      CORE_ADDR reg_addr;
  94 {
  95   register int regno;
  96   register int addr;
  97   int bad_reg = -1;
  98
  99   /* Table to map a gdb regnum to an index in the core register section.
 100      The floating point register values are garbage in OSF/1.2 core files.  */
 101   static int core_reg_mapping[NUM_REGS] =
 102   {
 103 #define EFL (EF_SIZE / 8)
 104         EF_V0,  EF_T0,  EF_T1,  EF_T2,  EF_T3,  EF_T4,  EF_T5,  EF_T6,
 105         EF_T7,  EF_S0,  EF_S1,  EF_S2,  EF_S3,  EF_S4,  EF_S5,  EF_S6,
 106         EF_A0,  EF_A1,  EF_A2,  EF_A3,  EF_A4,  EF_A5,  EF_T8,  EF_T9,
 107         EF_T10, EF_T11, EF_RA,  EF_T12, EF_AT,  EF_GP,  EF_SP,  -1,
 108         EFL+0,  EFL+1,  EFL+2,  EFL+3,  EFL+4,  EFL+5,  EFL+6,  EFL+7,
 109         EFL+8,  EFL+9,  EFL+10, EFL+11, EFL+12, EFL+13, EFL+14, EFL+15,
 110         EFL+16, EFL+17, EFL+18, EFL+19, EFL+20, EFL+21, EFL+22, EFL+23,
 111         EFL+24, EFL+25, EFL+26, EFL+27, EFL+28, EFL+29, EFL+30, EFL+31,
 112         EF_PC,  -1
 113   };
 114   static char zerobuf[MAX_REGISTER_RAW_SIZE] = {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 /*
 201  * See the comment in m68k-tdep.c regarding the utility of these functions.
 202  */
 203
 204 void
 205 supply_gregset (gregsetp)
 206      gregset_t *gregsetp;
 207 {
 208   register int regi;
 209   register long *regp = ALPHA_REGSET_BASE (gregsetp);
 210   static char zerobuf[MAX_REGISTER_RAW_SIZE] = {0};
 211
 212   for (regi = 0; regi < 31; regi++)
 213     supply_register (regi, (char *)(regp + regi));
 214
 215   supply_register (PC_REGNUM, (char *)(regp + 31));
 216
 217   /* Fill inaccessible registers with zero.  */
 218   supply_register (ZERO_REGNUM, zerobuf);
 219   supply_register (FP_REGNUM, zerobuf);
 220 }
 221
 222 void
 223 fill_gregset (gregsetp, regno)
 224      gregset_t *gregsetp;
 225      int regno;
 226 {
 227   int regi;
 228   register long *regp = ALPHA_REGSET_BASE (gregsetp);
 229
 230   for (regi = 0; regi < 31; regi++)
 231     if ((regno == -1) || (regno == regi))
 232       *(regp + regi) = *(long *) &registers[REGISTER_BYTE (regi)];
 233
 234   if ((regno == -1) || (regno == PC_REGNUM))
 235     *(regp + 31) = *(long *) &registers[REGISTER_BYTE (PC_REGNUM)];
 236 }
 237
 238 /*
 239  * Now we do the same thing for floating-point registers.
 240  * Again, see the comments in m68k-tdep.c.
 241  */
 242
 243 void
 244 supply_fpregset (fpregsetp)
 245      fpregset_t *fpregsetp;
 246 {
 247   register int regi;
 248   register long *regp = ALPHA_REGSET_BASE (fpregsetp);
 249
 250   for (regi = 0; regi < 32; regi++)
 251     supply_register (regi + FP0_REGNUM, (char *)(regp + regi));
 252 }
 253
 254 void
 255 fill_fpregset (fpregsetp, regno)
 256      fpregset_t *fpregsetp;
 257      int regno;
 258 {
 259   int regi;
 260   register long *regp = ALPHA_REGSET_BASE (fpregsetp);
 261
 262   for (regi = FP0_REGNUM; regi < FP0_REGNUM + 32; regi++)
 263     {
 264       if ((regno == -1) || (regno == regi))
 265         {
 266           *(regp + regi - FP0_REGNUM) =
 267             *(long *) &registers[REGISTER_BYTE (regi)];
 268         }
 269     }
 270 }
 271 #endif
 272
 273 \f
 274 /* Register that we are able to handle alpha core file formats. */
 275
 276 static struct core_fns alpha_osf_core_fns =
 277 {
 278   /* This really is bfd_target_unknown_flavour.  */
 279
 280   bfd_target_unknown_flavour,
 281   fetch_osf_core_registers,
 282   NULL
 283 };
 284
 285 static struct core_fns alpha_elf_core_fns =
 286 {
 287   bfd_target_elf_flavour,
 288   fetch_elf_core_registers,
 289   NULL
 290 };
 291
 292 void
 293 _initialize_core_alpha ()
 294 {
 295   add_core_fns (&alpha_osf_core_fns);
 296   add_core_fns (&alpha_elf_core_fns);
 297 }