gdb/irix4-nat.c

   1 /* Native support for the SGI Iris running IRIX version 4, for GDB.
   2    Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1995, 1996, 1999, 2000,
   3    2001 Free Software Foundation, Inc.
   4    Contributed by Alessandro Forin(af@cs.cmu.edu) at CMU
   5    and by Per Bothner(bothner@cs.wisc.edu) at U.Wisconsin.
   6    Implemented for Irix 4.x by Garrett A. Wollman.
   7
   8    This file is part of GDB.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 2 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program; if not, write to the Free Software
  22    Foundation, Inc., 59 Temple Place - Suite 330,
  23    Boston, MA 02111-1307, USA.  */
  24
  25 #include "defs.h"
  26 #include "inferior.h"
  27 #include "gdbcore.h"
  28 #include "regcache.h"
  29
  30 #include <sys/time.h>
  31 #include <sys/procfs.h>
  32 #include <setjmp.h>             /* For JB_XXX.  */
  33
  34 /* Prototypes for supply_gregset etc. */
  35 #include "gregset.h"
  36
  37 /* Size of elements in jmpbuf */
  38
  39 #define JB_ELEMENT_SIZE 4
  40
  41 typedef unsigned int greg_t;    /* why isn't this defined? */
  42
  43 static void fetch_core_registers (char *, unsigned int, int, CORE_ADDR);
  44
  45 /*
  46  * See the comment in m68k-tdep.c regarding the utility of these functions.
  47  */
  48
  49 void
  50 supply_gregset (gregset_t *gregsetp)
  51 {
  52   register int regi;
  53   register greg_t *regp = (greg_t *) (gregsetp->gp_regs);
  54   char zerobuf[MAX_REGISTER_SIZE];
  55   memset (zerobuf, 0, MAX_REGISTER_SIZE);
  56
  57   /* FIXME: somewhere, there should be a #define for the meaning
  58      of this magic number 32; we should use that. */
  59   for (regi = 0; regi < 32; regi++)
  60     supply_register (regi, (char *) (regp + regi));
  61
  62   supply_register (PC_REGNUM, (char *) &(gregsetp->gp_pc));
  63   supply_register (HI_REGNUM, (char *) &(gregsetp->gp_mdhi));
  64   supply_register (LO_REGNUM, (char *) &(gregsetp->gp_mdlo));
  65   supply_register (CAUSE_REGNUM, (char *) &(gregsetp->gp_cause));
  66
  67   /* Fill inaccessible registers with zero.  */
  68   supply_register (BADVADDR_REGNUM, zerobuf);
  69 }
  70
  71 void
  72 fill_gregset (gregset_t *gregsetp, int regno)
  73 {
  74   int regi;
  75   register greg_t *regp = (greg_t *) (gregsetp->gp_regs);
  76
  77   /* same FIXME as above wrt 32 */
  78   for (regi = 0; regi < 32; regi++)
  79     if ((regno == -1) || (regno == regi))
  80       *(regp + regi) = *(greg_t *) & deprecated_registers[REGISTER_BYTE (regi)];
  81
  82   if ((regno == -1) || (regno == PC_REGNUM))
  83     gregsetp->gp_pc = *(greg_t *) & deprecated_registers[REGISTER_BYTE (PC_REGNUM)];
  84
  85   if ((regno == -1) || (regno == CAUSE_REGNUM))
  86     gregsetp->gp_cause = *(greg_t *) & deprecated_registers[REGISTER_BYTE (CAUSE_REGNUM)];
  87
  88   if ((regno == -1) || (regno == HI_REGNUM))
  89     gregsetp->gp_mdhi = *(greg_t *) & deprecated_registers[REGISTER_BYTE (HI_REGNUM)];
  90
  91   if ((regno == -1) || (regno == LO_REGNUM))
  92     gregsetp->gp_mdlo = *(greg_t *) & deprecated_registers[REGISTER_BYTE (LO_REGNUM)];
  93 }
  94
  95 /*
  96  * Now we do the same thing for floating-point registers.
  97  * We don't bother to condition on FP0_REGNUM since any
  98  * reasonable MIPS configuration has an R3010 in it.
  99  *
 100  * Again, see the comments in m68k-tdep.c.
 101  */
 102
 103 void
 104 supply_fpregset (fpregset_t *fpregsetp)
 105 {
 106   register int regi;
 107   char zerobuf[MAX_REGISTER_SIZE];
 108   memset (zerobuf, 0, MAX_REGISTER_SIZE);
 109
 110   for (regi = 0; regi < 32; regi++)
 111     supply_register (FP0_REGNUM + regi,
 112                      (char *) &fpregsetp->fp_r.fp_regs[regi]);
 113
 114   supply_register (FCRCS_REGNUM, (char *) &fpregsetp->fp_csr);
 115
 116   /* FIXME: how can we supply FCRIR_REGNUM?  SGI doesn't tell us. */
 117   supply_register (FCRIR_REGNUM, zerobuf);
 118 }
 119
 120 void
 121 fill_fpregset (fpregset_t *fpregsetp, int regno)
 122 {
 123   int regi;
 124   char *from, *to;
 125
 126   for (regi = FP0_REGNUM; regi < FP0_REGNUM + 32; regi++)
 127     {
 128       if ((regno == -1) || (regno == regi))
 129         {
 130           from = (char *) &deprecated_registers[REGISTER_BYTE (regi)];
 131           to = (char *) &(fpregsetp->fp_r.fp_regs[regi - FP0_REGNUM]);
 132           memcpy (to, from, REGISTER_RAW_SIZE (regi));
 133         }
 134     }
 135
 136   if ((regno == -1) || (regno == FCRCS_REGNUM))
 137     fpregsetp->fp_csr = *(unsigned *) &deprecated_registers[REGISTER_BYTE (FCRCS_REGNUM)];
 138 }
 139
 140
 141 /* Figure out where the longjmp will land.
 142    We expect the first arg to be a pointer to the jmp_buf structure from which
 143    we extract the pc (JB_PC) that we will land at.  The pc is copied into PC.
 144    This routine returns true on success. */
 145
 146 int
 147 get_longjmp_target (CORE_ADDR *pc)
 148 {
 149   char *buf;
 150   CORE_ADDR jb_addr;
 151
 152   buf = alloca (TARGET_PTR_BIT / TARGET_CHAR_BIT);
 153   jb_addr = read_register (A0_REGNUM);
 154
 155   if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf,
 156                           TARGET_PTR_BIT / TARGET_CHAR_BIT))
 157     return 0;
 158
 159   *pc = extract_unsigned_integer (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
 160
 161   return 1;
 162 }
 163
 164 /* Provide registers to GDB from a core file.
 165
 166    CORE_REG_SECT points to an array of bytes, which were obtained from
 167    a core file which BFD thinks might contain register contents.
 168    CORE_REG_SIZE is its size.
 169
 170    Normally, WHICH says which register set corelow suspects this is:
 171      0 --- the general-purpose register set
 172      2 --- the floating-point register set
 173    However, for Irix 4, WHICH isn't used.
 174
 175    REG_ADDR is also unused.  */
 176
 177 static void
 178 fetch_core_registers (char *core_reg_sect, unsigned core_reg_size,
 179                       int which, CORE_ADDR reg_addr)
 180 {
 181   if (core_reg_size != DEPRECATED_REGISTER_BYTES)
 182     {
 183       warning ("wrong size gregset struct in core file");
 184       return;
 185     }
 186
 187   memcpy ((char *) deprecated_registers, core_reg_sect, core_reg_size);
 188 }
 189 \f
 190
 191 /* Register that we are able to handle irix4 core file formats.
 192    FIXME: is this really bfd_target_unknown_flavour? */
 193
 194 static struct core_fns irix4_core_fns =
 195 {
 196   bfd_target_unknown_flavour,           /* core_flavour */
 197   default_check_format,                 /* check_format */
 198   default_core_sniffer,                 /* core_sniffer */
 199   fetch_core_registers,                 /* core_read_registers */
 200   NULL                                  /* next */
 201 };
 202
 203 void
 204 _initialize_core_irix4 (void)
 205 {
 206   add_core_fns (&irix4_core_fns);
 207 }