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