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 PARAMS ((char *,
  37                                               unsigned, int, CORE_ADDR));
  38 static void fetch_elf_core_registers PARAMS ((char *,
  39                                               unsigned, int, CORE_ADDR));
  40
  41 /* Size of elements in jmpbuf */
  42
  43 #define JB_ELEMENT_SIZE 8
  44
  45 /* The definition for JB_PC in machine/reg.h is wrong.
  46    And we can't get at the correct definition in setjmp.h as it is
  47    not always available (eg. if _POSIX_SOURCE is defined which is the
  48    default). As the defintion is unlikely to change (see comment
  49    in <setjmp.h>, define the correct value here.  */
  50
  51 #undef JB_PC
  52 #define JB_PC 2
  53
  54 /* Figure out where the longjmp will land.
  55    We expect the first arg to be a pointer to the jmp_buf structure from which
  56    we extract the pc (JB_PC) that we will land at.  The pc is copied into PC.
  57    This routine returns true on success. */
  58
  59 int
  60 get_longjmp_target (pc)
  61      CORE_ADDR *pc;
  62 {
  63   CORE_ADDR jb_addr;
  64   char raw_buffer[MAX_REGISTER_RAW_SIZE];
  65
  66   jb_addr = read_register (A0_REGNUM);
  67
  68   if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, raw_buffer,
  69                           sizeof (CORE_ADDR)))
  70     return 0;
  71
  72   *pc = extract_address (raw_buffer, sizeof (CORE_ADDR));
  73   return 1;
  74 }
  75
  76 /* Extract the register values out of the core file and store
  77    them where `read_register' will find them.
  78
  79    CORE_REG_SECT points to the register values themselves, read into memory.
  80    CORE_REG_SIZE is the size of that area.
  81    WHICH says which set of registers we are handling (0 = int, 2 = float
  82    on machines where they are discontiguous).
  83    REG_ADDR is the offset from u.u_ar0 to the register values relative to
  84    core_reg_sect.  This is used with old-fashioned core files to
  85    locate the registers in a large upage-plus-stack ".reg" section.
  86    Original upage address X is at location core_reg_sect+x+reg_addr.
  87  */
  88
  89 static void
  90 fetch_osf_core_registers (core_reg_sect, core_reg_size, which, reg_addr)
  91      char *core_reg_sect;
  92      unsigned core_reg_size;
  93      int which;
  94      CORE_ADDR reg_addr;
  95 {
  96   register int regno;
  97   register int addr;
  98   int bad_reg = -1;
  99
 100   /* Table to map a gdb regnum to an index in the core register section.
 101      The floating point register values are garbage in OSF/1.2 core files.  */
 102   static int core_reg_mapping[NUM_REGS] =
 103   {
 104 #define EFL (EF_SIZE / 8)
 105     EF_V0, EF_T0, EF_T1, EF_T2, EF_T3, EF_T4, EF_T5, EF_T6,
 106     EF_T7, EF_S0, EF_S1, EF_S2, EF_S3, EF_S4, EF_S5, EF_S6,
 107     EF_A0, EF_A1, EF_A2, EF_A3, EF_A4, EF_A5, EF_T8, EF_T9,
 108     EF_T10, EF_T11, EF_RA, EF_T12, EF_AT, EF_GP, EF_SP, -1,
 109     EFL + 0, EFL + 1, EFL + 2, EFL + 3, EFL + 4, EFL + 5, EFL + 6, EFL + 7,
 110     EFL + 8, EFL + 9, EFL + 10, EFL + 11, EFL + 12, EFL + 13, EFL + 14, EFL + 15,
 111     EFL + 16, EFL + 17, EFL + 18, EFL + 19, EFL + 20, EFL + 21, EFL + 22, EFL + 23,
 112     EFL + 24, EFL + 25, EFL + 26, EFL + 27, EFL + 28, EFL + 29, EFL + 30, EFL + 31,
 113     EF_PC, -1
 114   };
 115   static char zerobuf[MAX_REGISTER_RAW_SIZE] =
 116   {0};
 117
 118   for (regno = 0; regno < NUM_REGS; regno++)
 119     {
 120       if (CANNOT_FETCH_REGISTER (regno))
 121         {
 122           supply_register (regno, zerobuf);
 123           continue;
 124         }
 125       addr = 8 * core_reg_mapping[regno];
 126       if (addr < 0 || addr >= core_reg_size)
 127         {
 128           if (bad_reg < 0)
 129             bad_reg = regno;
 130         }
 131       else
 132         {
 133           supply_register (regno, core_reg_sect + addr);
 134         }
 135     }
 136   if (bad_reg >= 0)
 137     {
 138       error ("Register %s not found in core file.", REGISTER_NAME (bad_reg));
 139     }
 140 }
 141
 142 static void
 143 fetch_elf_core_registers (core_reg_sect, core_reg_size, which, reg_addr)
 144      char *core_reg_sect;
 145      unsigned core_reg_size;
 146      int which;
 147      CORE_ADDR reg_addr;
 148 {
 149   if (core_reg_size < 32 * 8)
 150     {
 151       error ("Core file register section too small (%u bytes).", core_reg_size);
 152       return;
 153     }
 154
 155   if (which == 2)
 156     {
 157       /* The FPU Registers.  */
 158       memcpy (&registers[REGISTER_BYTE (FP0_REGNUM)], core_reg_sect, 31 * 8);
 159       memset (&registers[REGISTER_BYTE (FP0_REGNUM + 31)], 0, 8);
 160       memset (&register_valid[FP0_REGNUM], 1, 32);
 161     }
 162   else
 163     {
 164       /* The General Registers.  */
 165       memcpy (&registers[REGISTER_BYTE (V0_REGNUM)], core_reg_sect, 31 * 8);
 166       memcpy (&registers[REGISTER_BYTE (PC_REGNUM)], core_reg_sect + 31 * 8, 8);
 167       memset (&registers[REGISTER_BYTE (ZERO_REGNUM)], 0, 8);
 168       memset (&register_valid[V0_REGNUM], 1, 32);
 169       register_valid[PC_REGNUM] = 1;
 170     }
 171 }
 172
 173
 174 /* Map gdb internal register number to a ptrace ``address''.
 175    These ``addresses'' are defined in <sys/ptrace.h> */
 176
 177 #define REGISTER_PTRACE_ADDR(regno) \
 178    (regno < FP0_REGNUM ?        GPR_BASE + (regno) \
 179   : regno == PC_REGNUM ?        PC      \
 180   : regno >= FP0_REGNUM ?       FPR_BASE + ((regno) - FP0_REGNUM) \
 181   : 0)
 182
 183 /* Return the ptrace ``address'' of register REGNO. */
 184
 185 CORE_ADDR
 186 register_addr (regno, blockend)
 187      int regno;
 188      CORE_ADDR blockend;
 189 {
 190   return REGISTER_PTRACE_ADDR (regno);
 191 }
 192
 193 int
 194 kernel_u_size ()
 195 {
 196   return (sizeof (struct user));
 197 }
 198
 199 #if defined(USE_PROC_FS) || defined(HAVE_GREGSET_T)
 200 #include <sys/procfs.h>
 201
 202 /*
 203  * See the comment in m68k-tdep.c regarding the utility of these functions.
 204  */
 205
 206 void
 207 supply_gregset (gregsetp)
 208      gregset_t *gregsetp;
 209 {
 210   register int regi;
 211   register long *regp = ALPHA_REGSET_BASE (gregsetp);
 212   static char zerobuf[MAX_REGISTER_RAW_SIZE] =
 213   {0};
 214
 215   for (regi = 0; regi < 31; regi++)
 216     supply_register (regi, (char *) (regp + regi));
 217
 218   supply_register (PC_REGNUM, (char *) (regp + 31));
 219
 220   /* Fill inaccessible registers with zero.  */
 221   supply_register (ZERO_REGNUM, zerobuf);
 222   supply_register (FP_REGNUM, zerobuf);
 223 }
 224
 225 void
 226 fill_gregset (gregsetp, regno)
 227      gregset_t *gregsetp;
 228      int regno;
 229 {
 230   int regi;
 231   register long *regp = ALPHA_REGSET_BASE (gregsetp);
 232
 233   for (regi = 0; regi < 31; regi++)
 234     if ((regno == -1) || (regno == regi))
 235       *(regp + regi) = *(long *) &registers[REGISTER_BYTE (regi)];
 236
 237   if ((regno == -1) || (regno == PC_REGNUM))
 238     *(regp + 31) = *(long *) &registers[REGISTER_BYTE (PC_REGNUM)];
 239 }
 240
 241 /*
 242  * Now we do the same thing for floating-point registers.
 243  * Again, see the comments in m68k-tdep.c.
 244  */
 245
 246 void
 247 supply_fpregset (fpregsetp)
 248      fpregset_t *fpregsetp;
 249 {
 250   register int regi;
 251   register long *regp = ALPHA_REGSET_BASE (fpregsetp);
 252
 253   for (regi = 0; regi < 32; regi++)
 254     supply_register (regi + FP0_REGNUM, (char *) (regp + regi));
 255 }
 256
 257 void
 258 fill_fpregset (fpregsetp, regno)
 259      fpregset_t *fpregsetp;
 260      int regno;
 261 {
 262   int regi;
 263   register long *regp = ALPHA_REGSET_BASE (fpregsetp);
 264
 265   for (regi = FP0_REGNUM; regi < FP0_REGNUM + 32; regi++)
 266     {
 267       if ((regno == -1) || (regno == regi))
 268         {
 269           *(regp + regi - FP0_REGNUM) =
 270             *(long *) &registers[REGISTER_BYTE (regi)];
 271         }
 272     }
 273 }
 274 #endif
 275 \f
 276
 277 /* Register that we are able to handle alpha core file formats. */
 278
 279 static struct core_fns alpha_osf_core_fns =
 280 {
 281   /* This really is bfd_target_unknown_flavour.  */
 282
 283   bfd_target_unknown_flavour,
 284   fetch_osf_core_registers,
 285   NULL
 286 };
 287
 288 static struct core_fns alpha_elf_core_fns =
 289 {
 290   bfd_target_elf_flavour,
 291   fetch_elf_core_registers,
 292   NULL
 293 };
 294
 295 void
 296 _initialize_core_alpha ()
 297 {
 298   add_core_fns (&alpha_osf_core_fns);
 299   add_core_fns (&alpha_elf_core_fns);
 300 }