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