gdb/mipsv4-nat.c

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