gdb/mips-nat.c

   1 /* Low level DECstation interface to ptrace, for GDB when running native.
   2    Copyright 1988, 1989, 1991, 1992 Free Software Foundation, Inc.
   3    Contributed by Alessandro Forin(af@cs.cmu.edu) at CMU
   4    and by Per Bothner(bothner@cs.wisc.edu) at U.Wisconsin.
   5
   6 This file is part of GDB.
   7
   8 This program is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 2 of the License, or
  11 (at your option) any later version.
  12
  13 This program is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with this program; if not, write to the Free Software
  20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  21
  22 #include "defs.h"
  23 #include "inferior.h"
  24 #include "gdbcore.h"
  25 #include <sys/ptrace.h>
  26 #include <sys/types.h>
  27 #include <sys/param.h>
  28 #include <sys/user.h>
  29 #undef JB_S0
  30 #undef JB_S1
  31 #undef JB_S2
  32 #undef JB_S3
  33 #undef JB_S4
  34 #undef JB_S5
  35 #undef JB_S6
  36 #undef JB_S7
  37 #undef JB_SP
  38 #undef JB_S8
  39 #undef JB_PC
  40 #undef JB_SR
  41 #undef NJBREGS
  42 #include <setjmp.h>             /* For JB_XXX.  */
  43
  44 /* Size of elements in jmpbuf */
  45
  46 #define JB_ELEMENT_SIZE 4
  47
  48 /* Map gdb internal register number to ptrace ``address''.
  49    These ``addresses'' are defined in DECstation <sys/ptrace.h> */
  50
  51 #define REGISTER_PTRACE_ADDR(regno) \
  52    (regno < 32 ?                GPR_BASE + regno \
  53   : regno == PC_REGNUM ?        PC      \
  54   : regno == CAUSE_REGNUM ?     CAUSE   \
  55   : regno == HI_REGNUM ?        MMHI    \
  56   : regno == LO_REGNUM ?        MMLO    \
  57   : regno == FCRCS_REGNUM ?     FPC_CSR \
  58   : regno == FCRIR_REGNUM ?     FPC_EIR \
  59   : regno >= FP0_REGNUM ?       FPR_BASE + (regno - FP0_REGNUM) \
  60   : 0)
  61
  62 static char zerobuf[MAX_REGISTER_RAW_SIZE] = {0};
  63
  64 /* Get all registers from the inferior */
  65
  66 void
  67 fetch_inferior_registers (regno)
  68      int regno;
  69 {
  70   register unsigned int regaddr;
  71   char buf[MAX_REGISTER_RAW_SIZE];
  72   register int i;
  73
  74   registers_fetched ();
  75
  76   for (regno = 1; regno < NUM_REGS; regno++)
  77     {
  78       regaddr = REGISTER_PTRACE_ADDR (regno);
  79       for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int))
  80         {
  81           *(int *) &buf[i] = ptrace (PT_READ_U, inferior_pid,
  82                                      (PTRACE_ARG3_TYPE) regaddr, 0);
  83           regaddr += sizeof (int);
  84         }
  85       supply_register (regno, buf);
  86     }
  87
  88   supply_register (ZERO_REGNUM, zerobuf);
  89   /* Frame ptr reg must appear to be 0; it is faked by stack handling code. */
  90   supply_register (FP_REGNUM, zerobuf);
  91 }
  92
  93 /* Store our register values back into the inferior.
  94    If REGNO is -1, do this for all registers.
  95    Otherwise, REGNO specifies which register (so we can save time).  */
  96
  97 void
  98 store_inferior_registers (regno)
  99      int regno;
 100 {
 101   register unsigned int regaddr;
 102   char buf[80];
 103
 104   if (regno == 0)
 105     return;
 106
 107   if (regno > 0)
 108     {
 109       regaddr = REGISTER_PTRACE_ADDR (regno);
 110       errno = 0;
 111       ptrace (PT_WRITE_U, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
 112               read_register (regno));
 113       if (errno != 0)
 114         {
 115           sprintf (buf, "writing register number %d", regno);
 116           perror_with_name (buf);
 117         }
 118     }
 119   else
 120     {
 121       for (regno = 0; regno < NUM_REGS; regno++)
 122         {
 123           if (regno == ZERO_REGNUM || regno == PS_REGNUM
 124               || regno == BADVADDR_REGNUM || regno == CAUSE_REGNUM
 125               || regno == FCRIR_REGNUM || regno == FP_REGNUM
 126               || (regno >= FIRST_EMBED_REGNUM && regno <= LAST_EMBED_REGNUM))
 127             continue;
 128           regaddr = REGISTER_PTRACE_ADDR (regno);
 129           errno = 0;
 130           ptrace (6, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
 131                   read_register (regno));
 132           if (errno != 0)
 133             {
 134               sprintf (buf, "writing all regs, number %d", regno);
 135               perror_with_name (buf);
 136             }
 137         }
 138     }
 139 }
 140
 141
 142 /* Figure out where the longjmp will land.
 143    We expect the first arg to be a pointer to the jmp_buf structure from which
 144    we extract the pc (JB_PC) that we will land at.  The pc is copied into PC.
 145    This routine returns true on success. */
 146
 147 int
 148 get_longjmp_target(pc)
 149      CORE_ADDR *pc;
 150 {
 151   CORE_ADDR jb_addr;
 152   char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT];
 153
 154   jb_addr = read_register (A0_REGNUM);
 155
 156   if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf,
 157                           TARGET_PTR_BIT / TARGET_CHAR_BIT))
 158     return 0;
 159
 160   *pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);
 161
 162   return 1;
 163 }
 164
 165 /* Extract the register values out of the core file and store
 166    them where `read_register' will find them.
 167
 168    CORE_REG_SECT points to the register values themselves, read into memory.
 169    CORE_REG_SIZE is the size of that area.
 170    WHICH says which set of registers we are handling (0 = int, 2 = float
 171          on machines where they are discontiguous).
 172    REG_ADDR is the offset from u.u_ar0 to the register values relative to
 173             core_reg_sect.  This is used with old-fashioned core files to
 174             locate the registers in a large upage-plus-stack ".reg" section.
 175             Original upage address X is at location core_reg_sect+x+reg_addr.
 176  */
 177
 178 void
 179 fetch_core_registers (core_reg_sect, core_reg_size, which, reg_addr)
 180      char *core_reg_sect;
 181      unsigned core_reg_size;
 182      int which;
 183      unsigned reg_addr;
 184 {
 185   register int regno;
 186   register unsigned int addr;
 187   int bad_reg = -1;
 188   register reg_ptr = -reg_addr;         /* Original u.u_ar0 is -reg_addr. */
 189
 190   /* If u.u_ar0 was an absolute address in the core file, relativize it now,
 191      so we can use it as an offset into core_reg_sect.  When we're done,
 192      "register 0" will be at core_reg_sect+reg_ptr, and we can use
 193      register_addr to offset to the other registers.  If this is a modern
 194      core file without a upage, reg_ptr will be zero and this is all a big
 195      NOP.  */
 196   if (reg_ptr > core_reg_size)
 197 #ifdef KERNEL_U_ADDR
 198     reg_ptr -= KERNEL_U_ADDR;
 199 #else
 200     error ("Old mips core file can't be processed on this machine.");
 201 #endif
 202
 203   for (regno = 0; regno < NUM_REGS; regno++)
 204     {
 205       addr = register_addr (regno, reg_ptr);
 206       if (addr >= core_reg_size) {
 207         if (bad_reg < 0)
 208           bad_reg = regno;
 209       } else {
 210         supply_register (regno, core_reg_sect + addr);
 211       }
 212     }
 213   if (bad_reg >= 0)
 214     {
 215       error ("Register %s not found in core file.", reg_names[bad_reg]);
 216     }
 217   supply_register (ZERO_REGNUM, zerobuf);
 218   /* Frame ptr reg must appear to be 0; it is faked by stack handling code. */
 219   supply_register (FP_REGNUM, zerobuf);
 220 }
 221
 222 /* Return the address in the core dump or inferior of register REGNO.
 223    BLOCKEND is the address of the end of the user structure.  */
 224
 225 unsigned int
 226 register_addr (regno, blockend)
 227      int regno;
 228      int blockend;
 229 {
 230   int addr;
 231
 232   if (regno < 0 || regno >= NUM_REGS)
 233     error ("Invalid register number %d.", regno);
 234
 235   REGISTER_U_ADDR (addr, blockend, regno);
 236
 237   return addr;
 238 }