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
  28 #include "alpha-tdep.h"
  29
  30 #include <sys/ptrace.h>
  31 #ifdef __linux__
  32 #include <asm/reg.h>
  33 #include <alpha/ptrace.h>
  34 #else
  35 #include <alpha/coreregs.h>
  36 #endif
  37 #include <sys/user.h>
  38
  39 /* Prototypes for local functions. */
  40
  41 static void fetch_osf_core_registers (char *, unsigned, int, CORE_ADDR);
  42 static void fetch_elf_core_registers (char *, unsigned, int, CORE_ADDR);
  43
  44 /* Size of elements in jmpbuf */
  45
  46 #define JB_ELEMENT_SIZE 8
  47
  48 /* The definition for JB_PC in machine/reg.h is wrong.
  49    And we can't get at the correct definition in setjmp.h as it is
  50    not always available (eg. if _POSIX_SOURCE is defined which is the
  51    default). As the defintion is unlikely to change (see comment
  52    in <setjmp.h>, define the correct value here.  */
  53
  54 #undef JB_PC
  55 #define JB_PC 2
  56
  57 /* Figure out where the longjmp will land.
  58    We expect the first arg to be a pointer to the jmp_buf structure from which
  59    we extract the pc (JB_PC) that we will land at.  The pc is copied into PC.
  60    This routine returns true on success. */
  61
  62 int
  63 get_longjmp_target (CORE_ADDR *pc)
  64 {
  65   CORE_ADDR jb_addr;
  66   char raw_buffer[ALPHA_MAX_REGISTER_RAW_SIZE];
  67
  68   jb_addr = read_register (ALPHA_A0_REGNUM);
  69
  70   if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, raw_buffer,
  71                           sizeof (CORE_ADDR)))
  72     return 0;
  73
  74   *pc = extract_address (raw_buffer, sizeof (CORE_ADDR));
  75   return 1;
  76 }
  77
  78 /* Extract the register values out of the core file and store
  79    them where `read_register' will find them.
  80
  81    CORE_REG_SECT points to the register values themselves, read into memory.
  82    CORE_REG_SIZE is the size of that area.
  83    WHICH says which set of registers we are handling (0 = int, 2 = float
  84    on machines where they are discontiguous).
  85    REG_ADDR is the offset from u.u_ar0 to the register values relative to
  86    core_reg_sect.  This is used with old-fashioned core files to
  87    locate the registers in a large upage-plus-stack ".reg" section.
  88    Original upage address X is at location core_reg_sect+x+reg_addr.
  89  */
  90
  91 static void
  92 fetch_osf_core_registers (char *core_reg_sect, unsigned core_reg_size,
  93                           int which, 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
 100      section.  The floating point register values are garbage in
 101      OSF/1.2 core files.  OSF5 uses different names for the register
 102      enum list, need to handle two cases.  The actual values are the
 103      same.  */
 104   static int core_reg_mapping[ALPHA_NUM_REGS] =
 105   {
 106 #ifdef NCF_REGS
 107 #define EFL NCF_REGS
 108     CF_V0, CF_T0, CF_T1, CF_T2, CF_T3, CF_T4, CF_T5, CF_T6,
 109     CF_T7, CF_S0, CF_S1, CF_S2, CF_S3, CF_S4, CF_S5, CF_S6,
 110     CF_A0, CF_A1, CF_A2, CF_A3, CF_A4, CF_A5, CF_T8, CF_T9,
 111     CF_T10, CF_T11, CF_RA, CF_T12, CF_AT, CF_GP, CF_SP, -1,
 112     EFL + 0, EFL + 1, EFL + 2, EFL + 3, EFL + 4, EFL + 5, EFL + 6, EFL + 7,
 113     EFL + 8, EFL + 9, EFL + 10, EFL + 11, EFL + 12, EFL + 13, EFL + 14, EFL + 15,
 114     EFL + 16, EFL + 17, EFL + 18, EFL + 19, EFL + 20, EFL + 21, EFL + 22, EFL + 23,
 115     EFL + 24, EFL + 25, EFL + 26, EFL + 27, EFL + 28, EFL + 29, EFL + 30, EFL + 31,
 116     CF_PC, -1
 117 #else
 118 #define EFL (EF_SIZE / 8)
 119     EF_V0, EF_T0, EF_T1, EF_T2, EF_T3, EF_T4, EF_T5, EF_T6,
 120     EF_T7, EF_S0, EF_S1, EF_S2, EF_S3, EF_S4, EF_S5, EF_S6,
 121     EF_A0, EF_A1, EF_A2, EF_A3, EF_A4, EF_A5, EF_T8, EF_T9,
 122     EF_T10, EF_T11, EF_RA, EF_T12, EF_AT, EF_GP, EF_SP, -1,
 123     EFL + 0, EFL + 1, EFL + 2, EFL + 3, EFL + 4, EFL + 5, EFL + 6, EFL + 7,
 124     EFL + 8, EFL + 9, EFL + 10, EFL + 11, EFL + 12, EFL + 13, EFL + 14, EFL + 15,
 125     EFL + 16, EFL + 17, EFL + 18, EFL + 19, EFL + 20, EFL + 21, EFL + 22, EFL + 23,
 126     EFL + 24, EFL + 25, EFL + 26, EFL + 27, EFL + 28, EFL + 29, EFL + 30, EFL + 31,
 127     EF_PC, -1
 128 #endif
 129   };
 130   static char zerobuf[ALPHA_MAX_REGISTER_RAW_SIZE] =
 131   {0};
 132
 133   for (regno = 0; regno < NUM_REGS; regno++)
 134     {
 135       if (CANNOT_FETCH_REGISTER (regno))
 136         {
 137           supply_register (regno, zerobuf);
 138           continue;
 139         }
 140       addr = 8 * core_reg_mapping[regno];
 141       if (addr < 0 || addr >= core_reg_size)
 142         {
 143           if (bad_reg < 0)
 144             bad_reg = regno;
 145         }
 146       else
 147         {
 148           supply_register (regno, core_reg_sect + addr);
 149         }
 150     }
 151   if (bad_reg >= 0)
 152     {
 153       error ("Register %s not found in core file.", REGISTER_NAME (bad_reg));
 154     }
 155 }
 156
 157 static void
 158 fetch_elf_core_registers (char *core_reg_sect, unsigned core_reg_size,
 159                           int which, CORE_ADDR reg_addr)
 160 {
 161   if (core_reg_size < 32 * 8)
 162     {
 163       error ("Core file register section too small (%u bytes).", core_reg_size);
 164       return;
 165     }
 166
 167   if (which == 2)
 168     {
 169       /* The FPU Registers.  */
 170       memcpy (&registers[REGISTER_BYTE (FP0_REGNUM)], core_reg_sect, 31 * 8);
 171       memset (&registers[REGISTER_BYTE (FP0_REGNUM + 31)], 0, 8);
 172       memset (&register_valid[FP0_REGNUM], 1, 32);
 173     }
 174   else
 175     {
 176       /* The General Registers.  */
 177       memcpy (&registers[REGISTER_BYTE (ALPHA_V0_REGNUM)], core_reg_sect,
 178               31 * 8);
 179       memcpy (&registers[REGISTER_BYTE (PC_REGNUM)], core_reg_sect + 31 * 8, 8);
 180       memset (&registers[REGISTER_BYTE (ALPHA_ZERO_REGNUM)], 0, 8);
 181       memset (&register_valid[ALPHA_V0_REGNUM], 1, 32);
 182       register_valid[PC_REGNUM] = 1;
 183     }
 184 }
 185
 186
 187 /* Map gdb internal register number to a ptrace ``address''.
 188    These ``addresses'' are defined in <sys/ptrace.h> */
 189
 190 #define REGISTER_PTRACE_ADDR(regno) \
 191    (regno < FP0_REGNUM ?        GPR_BASE + (regno) \
 192   : regno == PC_REGNUM ?        PC      \
 193   : regno >= FP0_REGNUM ?       FPR_BASE + ((regno) - FP0_REGNUM) \
 194   : 0)
 195
 196 /* Return the ptrace ``address'' of register REGNO. */
 197
 198 CORE_ADDR
 199 register_addr (int regno, CORE_ADDR blockend)
 200 {
 201   return REGISTER_PTRACE_ADDR (regno);
 202 }
 203
 204 int
 205 kernel_u_size (void)
 206 {
 207   return (sizeof (struct user));
 208 }
 209
 210 #if defined(USE_PROC_FS) || defined(HAVE_GREGSET_T)
 211 #include <sys/procfs.h>
 212
 213 /* Prototypes for supply_gregset etc. */
 214 #include "gregset.h"
 215
 216 /*
 217  * See the comment in m68k-tdep.c regarding the utility of these functions.
 218  */
 219
 220 void
 221 supply_gregset (gdb_gregset_t *gregsetp)
 222 {
 223   register int regi;
 224   register long *regp = ALPHA_REGSET_BASE (gregsetp);
 225   static char zerobuf[ALPHA_MAX_REGISTER_RAW_SIZE] =
 226   {0};
 227
 228   for (regi = 0; regi < 31; regi++)
 229     supply_register (regi, (char *) (regp + regi));
 230
 231   supply_register (PC_REGNUM, (char *) (regp + 31));
 232
 233   /* Fill inaccessible registers with zero.  */
 234   supply_register (ALPHA_ZERO_REGNUM, zerobuf);
 235   supply_register (FP_REGNUM, zerobuf);
 236 }
 237
 238 void
 239 fill_gregset (gdb_gregset_t *gregsetp, int regno)
 240 {
 241   int regi;
 242   register long *regp = ALPHA_REGSET_BASE (gregsetp);
 243
 244   for (regi = 0; regi < 31; regi++)
 245     if ((regno == -1) || (regno == regi))
 246       *(regp + regi) = *(long *) &registers[REGISTER_BYTE (regi)];
 247
 248   if ((regno == -1) || (regno == PC_REGNUM))
 249     *(regp + 31) = *(long *) &registers[REGISTER_BYTE (PC_REGNUM)];
 250 }
 251
 252 /*
 253  * Now we do the same thing for floating-point registers.
 254  * Again, see the comments in m68k-tdep.c.
 255  */
 256
 257 void
 258 supply_fpregset (gdb_fpregset_t *fpregsetp)
 259 {
 260   register int regi;
 261   register long *regp = ALPHA_REGSET_BASE (fpregsetp);
 262
 263   for (regi = 0; regi < 32; regi++)
 264     supply_register (regi + FP0_REGNUM, (char *) (regp + regi));
 265 }
 266
 267 void
 268 fill_fpregset (gdb_fpregset_t *fpregsetp, int regno)
 269 {
 270   int regi;
 271   register long *regp = ALPHA_REGSET_BASE (fpregsetp);
 272
 273   for (regi = FP0_REGNUM; regi < FP0_REGNUM + 32; regi++)
 274     {
 275       if ((regno == -1) || (regno == regi))
 276         {
 277           *(regp + regi - FP0_REGNUM) =
 278             *(long *) &registers[REGISTER_BYTE (regi)];
 279         }
 280     }
 281 }
 282 #endif
 283 \f
 284
 285 /* Register that we are able to handle alpha core file formats. */
 286
 287 static struct core_fns alpha_osf_core_fns =
 288 {
 289   /* This really is bfd_target_unknown_flavour.  */
 290
 291   bfd_target_unknown_flavour,           /* core_flavour */
 292   default_check_format,                 /* check_format */
 293   default_core_sniffer,                 /* core_sniffer */
 294   fetch_osf_core_registers,             /* core_read_registers */
 295   NULL                                  /* next */
 296 };
 297
 298 static struct core_fns alpha_elf_core_fns =
 299 {
 300   bfd_target_elf_flavour,               /* core_flavour */
 301   default_check_format,                 /* check_format */
 302   default_core_sniffer,                 /* core_sniffer */
 303   fetch_elf_core_registers,             /* core_read_registers */
 304   NULL                                  /* next */
 305 };
 306
 307 void
 308 _initialize_core_alpha (void)
 309 {
 310   add_core_fns (&alpha_osf_core_fns);
 311   add_core_fns (&alpha_elf_core_fns);
 312 }