gdb/mipsv4-nat.c

   1 /* Native support for MIPS running SVR4, for GDB.
   2    Copyright 1994, 1995, 2000, 2001 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 "regcache.h"
  26
  27 #include <sys/time.h>
  28 #include <sys/procfs.h>
  29 #include <setjmp.h>             /* For JB_XXX.  */
  30
  31 /* Prototypes for supply_gregset etc. */
  32 #include "gregset.h"
  33
  34 /* Size of elements in jmpbuf */
  35
  36 #define JB_ELEMENT_SIZE 4
  37
  38 /*
  39  * See the comment in m68k-tdep.c regarding the utility of these functions.
  40  *
  41  * These definitions are from the MIPS SVR4 ABI, so they may work for
  42  * any MIPS SVR4 target.
  43  */
  44
  45 void
  46 supply_gregset (gregset_t *gregsetp)
  47 {
  48   register int regi;
  49   register greg_t *regp = &(*gregsetp)[0];
  50   static char zerobuf[MAX_REGISTER_RAW_SIZE] =
  51   {0};
  52
  53   for (regi = 0; regi <= CXT_RA; regi++)
  54     supply_register (regi, (char *) (regp + regi));
  55
  56   supply_register (PC_REGNUM, (char *) (regp + CXT_EPC));
  57   supply_register (HI_REGNUM, (char *) (regp + CXT_MDHI));
  58   supply_register (LO_REGNUM, (char *) (regp + CXT_MDLO));
  59   supply_register (CAUSE_REGNUM, (char *) (regp + CXT_CAUSE));
  60
  61   /* Fill inaccessible registers with zero.  */
  62   supply_register (PS_REGNUM, zerobuf);
  63   supply_register (BADVADDR_REGNUM, zerobuf);
  64   supply_register (FP_REGNUM, zerobuf);
  65   supply_register (UNUSED_REGNUM, zerobuf);
  66   for (regi = FIRST_EMBED_REGNUM; regi <= LAST_EMBED_REGNUM; regi++)
  67     supply_register (regi, zerobuf);
  68 }
  69
  70 void
  71 fill_gregset (gregset_t *gregsetp, int regno)
  72 {
  73   int regi;
  74   register greg_t *regp = &(*gregsetp)[0];
  75
  76   for (regi = 0; regi <= 32; regi++)
  77     if ((regno == -1) || (regno == regi))
  78       *(regp + regi) = *(greg_t *) & registers[REGISTER_BYTE (regi)];
  79
  80   if ((regno == -1) || (regno == PC_REGNUM))
  81     *(regp + CXT_EPC) = *(greg_t *) & registers[REGISTER_BYTE (PC_REGNUM)];
  82
  83   if ((regno == -1) || (regno == CAUSE_REGNUM))
  84     *(regp + CXT_CAUSE) = *(greg_t *) & registers[REGISTER_BYTE (CAUSE_REGNUM)];
  85
  86   if ((regno == -1) || (regno == HI_REGNUM))
  87     *(regp + CXT_MDHI) = *(greg_t *) & registers[REGISTER_BYTE (HI_REGNUM)];
  88
  89   if ((regno == -1) || (regno == LO_REGNUM))
  90     *(regp + CXT_MDLO) = *(greg_t *) & registers[REGISTER_BYTE (LO_REGNUM)];
  91 }
  92
  93 /*
  94  * Now we do the same thing for floating-point registers.
  95  * We don't bother to condition on FP0_REGNUM since any
  96  * reasonable MIPS configuration has an R3010 in it.
  97  *
  98  * Again, see the comments in m68k-tdep.c.
  99  */
 100
 101 void
 102 supply_fpregset (fpregset_t *fpregsetp)
 103 {
 104   register int regi;
 105   static char zerobuf[MAX_REGISTER_RAW_SIZE] =
 106   {0};
 107
 108   for (regi = 0; regi < 32; regi++)
 109     supply_register (FP0_REGNUM + regi,
 110                      (char *) &fpregsetp->fp_r.fp_regs[regi]);
 111
 112   supply_register (FCRCS_REGNUM, (char *) &fpregsetp->fp_csr);
 113
 114   /* FIXME: how can we supply FCRIR_REGNUM?  The ABI doesn't tell us. */
 115   supply_register (FCRIR_REGNUM, zerobuf);
 116 }
 117
 118 void
 119 fill_fpregset (fpregset_t *fpregsetp, int regno)
 120 {
 121   int regi;
 122   char *from, *to;
 123
 124   for (regi = FP0_REGNUM; regi < FP0_REGNUM + 32; regi++)
 125     {
 126       if ((regno == -1) || (regno == regi))
 127         {
 128           from = (char *) &registers[REGISTER_BYTE (regi)];
 129           to = (char *) &(fpregsetp->fp_r.fp_regs[regi - FP0_REGNUM]);
 130           memcpy (to, from, REGISTER_RAW_SIZE (regi));
 131         }
 132     }
 133
 134   if ((regno == -1) || (regno == FCRCS_REGNUM))
 135     fpregsetp->fp_csr = *(unsigned *) &registers[REGISTER_BYTE (FCRCS_REGNUM)];
 136 }
 137
 138
 139 /* Figure out where the longjmp will land.
 140    We expect the first arg to be a pointer to the jmp_buf structure from which
 141    we extract the pc (_JB_PC) that we will land at.  The pc is copied into PC.
 142    This routine returns true on success. */
 143
 144 int
 145 get_longjmp_target (CORE_ADDR *pc)
 146 {
 147   char *buf;
 148   CORE_ADDR jb_addr;
 149
 150   buf = alloca (TARGET_PTR_BIT / TARGET_CHAR_BIT);
 151   jb_addr = read_register (A0_REGNUM);
 152
 153   if (target_read_memory (jb_addr + _JB_PC * JB_ELEMENT_SIZE, buf,
 154                           TARGET_PTR_BIT / TARGET_CHAR_BIT))
 155     return 0;
 156
 157   *pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
 158
 159   return 1;
 160 }