gdb/alpha-nat.c

   1 /* Low level Alpha interface, for GDB when running native.
   2    Copyright 1993, 1995, 1996 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 static void fetch_core_registers PARAMS ((char *, unsigned, int, unsigned));
  34
  35 /* Size of elements in jmpbuf */
  36
  37 #define JB_ELEMENT_SIZE 8
  38
  39 /* The definition for JB_PC in machine/reg.h is wrong.
  40    And we can't get at the correct definition in setjmp.h as it is
  41    not always available (eg. if _POSIX_SOURCE is defined which is the
  42    default). As the defintion is unlikely to change (see comment
  43    in <setjmp.h>, define the correct value here.  */
  44
  45 #undef JB_PC
  46 #define JB_PC 2
  47
  48 /* Figure out where the longjmp will land.
  49    We expect the first arg to be a pointer to the jmp_buf structure from which
  50    we extract the pc (JB_PC) that we will land at.  The pc is copied into PC.
  51    This routine returns true on success. */
  52
  53 int
  54 get_longjmp_target (pc)
  55      CORE_ADDR *pc;
  56 {
  57   CORE_ADDR jb_addr;
  58   char raw_buffer[MAX_REGISTER_RAW_SIZE];
  59
  60   jb_addr = read_register(A0_REGNUM);
  61
  62   if (target_read_memory(jb_addr + JB_PC * JB_ELEMENT_SIZE, raw_buffer,
  63                          sizeof(CORE_ADDR)))
  64     return 0;
  65
  66   *pc = extract_address (raw_buffer, sizeof(CORE_ADDR));
  67   return 1;
  68 }
  69
  70 /* Extract the register values out of the core file and store
  71    them where `read_register' will find them.
  72
  73    CORE_REG_SECT points to the register values themselves, read into memory.
  74    CORE_REG_SIZE is the size of that area.
  75    WHICH says which set of registers we are handling (0 = int, 2 = float
  76          on machines where they are discontiguous).
  77    REG_ADDR is the offset from u.u_ar0 to the register values relative to
  78             core_reg_sect.  This is used with old-fashioned core files to
  79             locate the registers in a large upage-plus-stack ".reg" section.
  80             Original upage address X is at location core_reg_sect+x+reg_addr.
  81  */
  82
  83 static void
  84 fetch_core_registers (core_reg_sect, core_reg_size, which, reg_addr)
  85      char *core_reg_sect;
  86      unsigned core_reg_size;
  87      int which;
  88      unsigned 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] = {0};
 110
 111   for (regno = 0; regno < NUM_REGS; regno++)
 112     {
 113       if (CANNOT_FETCH_REGISTER (regno))
 114         {
 115           supply_register (regno, zerobuf);
 116           continue;
 117         }
 118       addr = 8 * core_reg_mapping[regno];
 119       if (addr < 0 || addr >= core_reg_size)
 120         {
 121           if (bad_reg < 0)
 122             bad_reg = regno;
 123         }
 124       else
 125         {
 126           supply_register (regno, core_reg_sect + addr);
 127         }
 128     }
 129   if (bad_reg >= 0)
 130     {
 131       error ("Register %s not found in core file.", reg_names[bad_reg]);
 132     }
 133 }
 134
 135 /* Map gdb internal register number to a ptrace ``address''.
 136    These ``addresses'' are defined in <sys/ptrace.h> */
 137
 138 #define REGISTER_PTRACE_ADDR(regno) \
 139    (regno < FP0_REGNUM ?        GPR_BASE + (regno) \
 140   : regno == PC_REGNUM ?        PC      \
 141   : regno >= FP0_REGNUM ?       FPR_BASE + ((regno) - FP0_REGNUM) \
 142   : 0)
 143
 144 /* Return the ptrace ``address'' of register REGNO. */
 145
 146 unsigned int
 147 register_addr (regno, blockend)
 148      int regno;
 149      int blockend;
 150 {
 151   return REGISTER_PTRACE_ADDR (regno);
 152 }
 153
 154 int
 155 kernel_u_size ()
 156 {
 157   return (sizeof (struct user));
 158 }
 159
 160 #ifdef USE_PROC_FS
 161 #include <sys/procfs.h>
 162
 163 /*
 164  * See the comment in m68k-tdep.c regarding the utility of these functions.
 165  */
 166
 167 void
 168 supply_gregset (gregsetp)
 169      gregset_t *gregsetp;
 170 {
 171   register int regi;
 172   register long *regp = gregsetp->regs;
 173   static char zerobuf[MAX_REGISTER_RAW_SIZE] = {0};
 174
 175   for (regi = 0; regi < 31; regi++)
 176     supply_register (regi, (char *)(regp + regi));
 177
 178   supply_register (PC_REGNUM, (char *)(regp + 31));
 179
 180   /* Fill inaccessible registers with zero.  */
 181   supply_register (ZERO_REGNUM, zerobuf);
 182   supply_register (FP_REGNUM, zerobuf);
 183 }
 184
 185 void
 186 fill_gregset (gregsetp, regno)
 187      gregset_t *gregsetp;
 188      int regno;
 189 {
 190   int regi;
 191   register long *regp = gregsetp->regs;
 192
 193   for (regi = 0; regi < 31; regi++)
 194     if ((regno == -1) || (regno == regi))
 195       *(regp + regi) = *(long *) &registers[REGISTER_BYTE (regi)];
 196
 197   if ((regno == -1) || (regno == PC_REGNUM))
 198     *(regp + 31) = *(long *) &registers[REGISTER_BYTE (PC_REGNUM)];
 199 }
 200
 201 /*
 202  * Now we do the same thing for floating-point registers.
 203  * Again, see the comments in m68k-tdep.c.
 204  */
 205
 206 void
 207 supply_fpregset (fpregsetp)
 208      fpregset_t *fpregsetp;
 209 {
 210   register int regi;
 211   register long *regp = fpregsetp->regs;
 212
 213   for (regi = 0; regi < 32; regi++)
 214     supply_register (regi + FP0_REGNUM, (char *)(regp + regi));
 215 }
 216
 217 void
 218 fill_fpregset (fpregsetp, regno)
 219      fpregset_t *fpregsetp;
 220      int regno;
 221 {
 222   int regi;
 223   register long *regp = fpregsetp->regs;
 224
 225   for (regi = FP0_REGNUM; regi < FP0_REGNUM + 32; regi++)
 226     {
 227       if ((regno == -1) || (regno == regi))
 228         {
 229           *(regp + regi - FP0_REGNUM) =
 230             *(long *) &registers[REGISTER_BYTE (regi)];
 231         }
 232     }
 233 }
 234 #endif
 235
 236 \f
 237 /* Register that we are able to handle alpha core file formats. */
 238
 239 static struct core_fns alpha_core_fns =
 240 {
 241   bfd_target_aout_flavour,
 242   fetch_core_registers,
 243   NULL
 244 };
 245
 246 void
 247 _initialize_core_alpha ()
 248 {
 249   add_core_fns (&alpha_core_fns);
 250 }