gdb/alpha-nat.c

   1 /* Low level Alpha interface, for GDB when running native.
   2    Copyright 1993, 1995, 1996, 1998, 1999, 2000, 2001
   3    Free Software Foundation, Inc.
   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 2 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, write to the Free Software
  19    Foundation, Inc., 59 Temple Place - Suite 330,
  20    Boston, MA 02111-1307, USA.  */
  21
  22 #include "defs.h"
  23 #include "inferior.h"
  24 #include "gdbcore.h"
  25 #include "target.h"
  26 #include "regcache.h"
  27 #include <sys/ptrace.h>
  28 #ifdef __linux__
  29 #include <asm/reg.h>
  30 #include <alpha/ptrace.h>
  31 #else
  32 #include <machine/reg.h>
  33 #endif
  34 #include <sys/user.h>
  35
  36 /* Prototypes for local functions. */
  37
  38 static void fetch_osf_core_registers (char *, unsigned, int, CORE_ADDR);
  39 static void fetch_elf_core_registers (char *, 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 (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 (char *core_reg_sect, unsigned core_reg_size,
  90                           int which, CORE_ADDR reg_addr)
  91 {
  92   register int regno;
  93   register int addr;
  94   int bad_reg = -1;
  95
  96   /* Table to map a gdb regnum to an index in the core register section.
  97      The floating point register values are garbage in OSF/1.2 core files.  */
  98   static int core_reg_mapping[NUM_REGS] =
  99   {
 100 #define EFL (EF_SIZE / 8)
 101     EF_V0, EF_T0, EF_T1, EF_T2, EF_T3, EF_T4, EF_T5, EF_T6,
 102     EF_T7, EF_S0, EF_S1, EF_S2, EF_S3, EF_S4, EF_S5, EF_S6,
 103     EF_A0, EF_A1, EF_A2, EF_A3, EF_A4, EF_A5, EF_T8, EF_T9,
 104     EF_T10, EF_T11, EF_RA, EF_T12, EF_AT, EF_GP, EF_SP, -1,
 105     EFL + 0, EFL + 1, EFL + 2, EFL + 3, EFL + 4, EFL + 5, EFL + 6, EFL + 7,
 106     EFL + 8, EFL + 9, EFL + 10, EFL + 11, EFL + 12, EFL + 13, EFL + 14, EFL + 15,
 107     EFL + 16, EFL + 17, EFL + 18, EFL + 19, EFL + 20, EFL + 21, EFL + 22, EFL + 23,
 108     EFL + 24, EFL + 25, EFL + 26, EFL + 27, EFL + 28, EFL + 29, EFL + 30, EFL + 31,
 109     EF_PC, -1
 110   };
 111   static char zerobuf[MAX_REGISTER_RAW_SIZE] =
 112   {0};
 113
 114   for (regno = 0; regno < NUM_REGS; regno++)
 115     {
 116       if (CANNOT_FETCH_REGISTER (regno))
 117         {
 118           supply_register (regno, zerobuf);
 119           continue;
 120         }
 121       addr = 8 * core_reg_mapping[regno];
 122       if (addr < 0 || addr >= core_reg_size)
 123         {
 124           if (bad_reg < 0)
 125             bad_reg = regno;
 126         }
 127       else
 128         {
 129           supply_register (regno, core_reg_sect + addr);
 130         }
 131     }
 132   if (bad_reg >= 0)
 133     {
 134       error ("Register %s not found in core file.", REGISTER_NAME (bad_reg));
 135     }
 136 }
 137
 138 static void
 139 fetch_elf_core_registers (char *core_reg_sect, unsigned core_reg_size,
 140                           int which, CORE_ADDR reg_addr)
 141 {
 142   if (core_reg_size < 32 * 8)
 143     {
 144       error ("Core file register section too small (%u bytes).", core_reg_size);
 145       return;
 146     }
 147
 148   if (which == 2)
 149     {
 150       /* The FPU Registers.  */
 151       memcpy (&registers[REGISTER_BYTE (FP0_REGNUM)], core_reg_sect, 31 * 8);
 152       memset (&registers[REGISTER_BYTE (FP0_REGNUM + 31)], 0, 8);
 153       memset (&register_valid[FP0_REGNUM], 1, 32);
 154     }
 155   else
 156     {
 157       /* The General Registers.  */
 158       memcpy (&registers[REGISTER_BYTE (V0_REGNUM)], core_reg_sect, 31 * 8);
 159       memcpy (&registers[REGISTER_BYTE (PC_REGNUM)], core_reg_sect + 31 * 8, 8);
 160       memset (&registers[REGISTER_BYTE (ZERO_REGNUM)], 0, 8);
 161       memset (&register_valid[V0_REGNUM], 1, 32);
 162       register_valid[PC_REGNUM] = 1;
 163     }
 164 }
 165
 166
 167 /* Map gdb internal register number to a ptrace ``address''.
 168    These ``addresses'' are defined in <sys/ptrace.h> */
 169
 170 #define REGISTER_PTRACE_ADDR(regno) \
 171    (regno < FP0_REGNUM ?        GPR_BASE + (regno) \
 172   : regno == PC_REGNUM ?        PC      \
 173   : regno >= FP0_REGNUM ?       FPR_BASE + ((regno) - FP0_REGNUM) \
 174   : 0)
 175
 176 /* Return the ptrace ``address'' of register REGNO. */
 177
 178 CORE_ADDR
 179 register_addr (int regno, CORE_ADDR blockend)
 180 {
 181   return REGISTER_PTRACE_ADDR (regno);
 182 }
 183
 184 int
 185 kernel_u_size (void)
 186 {
 187   return (sizeof (struct user));
 188 }
 189
 190 #if defined(USE_PROC_FS) || defined(HAVE_GREGSET_T)
 191 #include <sys/procfs.h>
 192
 193 /* Prototypes for supply_gregset etc. */
 194 #include "gregset.h"
 195
 196 /*
 197  * See the comment in m68k-tdep.c regarding the utility of these functions.
 198  */
 199
 200 void
 201 supply_gregset (gdb_gregset_t *gregsetp)
 202 {
 203   register int regi;
 204   register long *regp = ALPHA_REGSET_BASE (gregsetp);
 205   static char zerobuf[MAX_REGISTER_RAW_SIZE] =
 206   {0};
 207
 208   for (regi = 0; regi < 31; regi++)
 209     supply_register (regi, (char *) (regp + regi));
 210
 211   supply_register (PC_REGNUM, (char *) (regp + 31));
 212
 213   /* Fill inaccessible registers with zero.  */
 214   supply_register (ZERO_REGNUM, zerobuf);
 215   supply_register (FP_REGNUM, zerobuf);
 216 }
 217
 218 void
 219 fill_gregset (gdb_gregset_t *gregsetp, int regno)
 220 {
 221   int regi;
 222   register long *regp = ALPHA_REGSET_BASE (gregsetp);
 223
 224   for (regi = 0; regi < 31; regi++)
 225     if ((regno == -1) || (regno == regi))
 226       *(regp + regi) = *(long *) &registers[REGISTER_BYTE (regi)];
 227
 228   if ((regno == -1) || (regno == PC_REGNUM))
 229     *(regp + 31) = *(long *) &registers[REGISTER_BYTE (PC_REGNUM)];
 230 }
 231
 232 /*
 233  * Now we do the same thing for floating-point registers.
 234  * Again, see the comments in m68k-tdep.c.
 235  */
 236
 237 void
 238 supply_fpregset (gdb_fpregset_t *fpregsetp)
 239 {
 240   register int regi;
 241   register long *regp = ALPHA_REGSET_BASE (fpregsetp);
 242
 243   for (regi = 0; regi < 32; regi++)
 244     supply_register (regi + FP0_REGNUM, (char *) (regp + regi));
 245 }
 246
 247 void
 248 fill_fpregset (gdb_fpregset_t *fpregsetp, int regno)
 249 {
 250   int regi;
 251   register long *regp = ALPHA_REGSET_BASE (fpregsetp);
 252
 253   for (regi = FP0_REGNUM; regi < FP0_REGNUM + 32; regi++)
 254     {
 255       if ((regno == -1) || (regno == regi))
 256         {
 257           *(regp + regi - FP0_REGNUM) =
 258             *(long *) &registers[REGISTER_BYTE (regi)];
 259         }
 260     }
 261 }
 262 #endif
 263 \f
 264
 265 /* Register that we are able to handle alpha core file formats. */
 266
 267 static struct core_fns alpha_osf_core_fns =
 268 {
 269   /* This really is bfd_target_unknown_flavour.  */
 270
 271   bfd_target_unknown_flavour,           /* core_flavour */
 272   default_check_format,                 /* check_format */
 273   default_core_sniffer,                 /* core_sniffer */
 274   fetch_osf_core_registers,             /* core_read_registers */
 275   NULL                                  /* next */
 276 };
 277
 278 static struct core_fns alpha_elf_core_fns =
 279 {
 280   bfd_target_elf_flavour,               /* core_flavour */
 281   default_check_format,                 /* check_format */
 282   default_core_sniffer,                 /* core_sniffer */
 283   fetch_elf_core_registers,             /* core_read_registers */
 284   NULL                                  /* next */
 285 };
 286
 287 void
 288 _initialize_core_alpha (void)
 289 {
 290   add_core_fns (&alpha_osf_core_fns);
 291   add_core_fns (&alpha_elf_core_fns);
 292 }