gdb/alpha-nat.c

   1 /* Low level Alpha interface, for GDB when running native.
   2    Copyright 1993 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., 675 Mass Ave, Cambridge, MA 02139, 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
  27 /* Size of elements in jmpbuf */
  28
  29 #define JB_ELEMENT_SIZE 8
  30
  31 /* The definition for JB_PC in machine/reg.h is wrong.
  32    And we can't get at the correct definition in setjmp.h as it is
  33    not always available (eg. if _POSIX_SOURCE is defined which is the
  34    default). As the defintion is unlikely to change (see comment
  35    in <setjmp.h>, define the correct value here.  */
  36
  37 #undef JB_PC
  38 #define JB_PC 2
  39
  40 /* Figure out where the longjmp will land.
  41    We expect the first arg to be a pointer to the jmp_buf structure from which
  42    we extract the pc (JB_PC) that we will land at.  The pc is copied into PC.
  43    This routine returns true on success. */
  44
  45 int
  46 get_longjmp_target (pc)
  47      CORE_ADDR *pc;
  48 {
  49   CORE_ADDR jb_addr;
  50   char raw_buffer[MAX_REGISTER_RAW_SIZE];
  51
  52   jb_addr = read_register(A0_REGNUM);
  53
  54   if (target_read_memory(jb_addr + JB_PC * JB_ELEMENT_SIZE, raw_buffer,
  55                          sizeof(CORE_ADDR)))
  56     return 0;
  57
  58   *pc = extract_address (raw_buffer, sizeof(CORE_ADDR));
  59   return 1;
  60 }
  61
  62 /* Extract the register values out of the core file and store
  63    them where `read_register' will find them.
  64
  65    CORE_REG_SECT points to the register values themselves, read into memory.
  66    CORE_REG_SIZE is the size of that area.
  67    WHICH says which set of registers we are handling (0 = int, 2 = float
  68          on machines where they are discontiguous).
  69    REG_ADDR is the offset from u.u_ar0 to the register values relative to
  70             core_reg_sect.  This is used with old-fashioned core files to
  71             locate the registers in a large upage-plus-stack ".reg" section.
  72             Original upage address X is at location core_reg_sect+x+reg_addr.
  73  */
  74
  75 void
  76 fetch_core_registers (core_reg_sect, core_reg_size, which, reg_addr)
  77      char *core_reg_sect;
  78      unsigned core_reg_size;
  79      int which;
  80      unsigned reg_addr;
  81 {
  82   register int regno;
  83   register int addr;
  84   int bad_reg = -1;
  85
  86   /* Table to map a gdb regnum to an index in the core register section.
  87      The floating point register values are garbage in OSF/1.2 core files.  */
  88   static int core_reg_mapping[NUM_REGS] =
  89   {
  90 #define EFL (EF_SIZE / 8)
  91         EF_V0,  EF_T0,  EF_T1,  EF_T2,  EF_T3,  EF_T4,  EF_T5,  EF_T6,
  92         EF_T7,  EF_S0,  EF_S1,  EF_S2,  EF_S3,  EF_S4,  EF_S5,  EF_S6,
  93         EF_A0,  EF_A1,  EF_A2,  EF_A3,  EF_A4,  EF_A5,  EF_T8,  EF_T9,
  94         EF_T10, EF_T11, EF_RA,  EF_T12, EF_AT,  EF_GP,  EF_SP,  -1,
  95         EFL+0,  EFL+1,  EFL+2,  EFL+3,  EFL+4,  EFL+5,  EFL+6,  EFL+7,
  96         EFL+8,  EFL+9,  EFL+10, EFL+11, EFL+12, EFL+13, EFL+14, EFL+15,
  97         EFL+16, EFL+17, EFL+18, EFL+19, EFL+20, EFL+21, EFL+22, EFL+23,
  98         EFL+24, EFL+25, EFL+26, EFL+27, EFL+28, EFL+29, EFL+30, EFL+31,
  99         EF_PC,  -1
 100   };
 101   static char zerobuf[MAX_REGISTER_RAW_SIZE] = {0};
 102
 103   for (regno = 0; regno < NUM_REGS; regno++)
 104     {
 105       if (CANNOT_FETCH_REGISTER (regno))
 106         {
 107           supply_register (regno, zerobuf);
 108           continue;
 109         }
 110       addr = 8 * core_reg_mapping[regno];
 111       if (addr < 0 || addr >= core_reg_size)
 112         {
 113           if (bad_reg < 0)
 114             bad_reg = regno;
 115         }
 116       else
 117         {
 118           supply_register (regno, core_reg_sect + addr);
 119         }
 120     }
 121   if (bad_reg >= 0)
 122     {
 123       error ("Register %s not found in core file.", reg_names[bad_reg]);
 124     }
 125 }
 126
 127 /* Map gdb internal register number to a ptrace ``address''.
 128    These ``addresses'' are defined in <sys/ptrace.h> */
 129
 130 #define REGISTER_PTRACE_ADDR(regno) \
 131    (regno < FP0_REGNUM ?        GPR_BASE + (regno) \
 132   : regno == PC_REGNUM ?        PC      \
 133   : regno >= FP0_REGNUM ?       FPR_BASE + ((regno) - FP0_REGNUM) \
 134   : 0)
 135
 136 /* Return the ptrace ``address'' of register REGNO. */
 137
 138 unsigned int
 139 register_addr (regno, blockend)
 140      int regno;
 141      int blockend;
 142 {
 143   return REGISTER_PTRACE_ADDR (regno);
 144 }