gdb/gdbserver/linux-ppc-low.c

   1 /* GNU/Linux/PowerPC specific low level interface, for the remote server for
   2    GDB.
   3    Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2005, 2007
   4    Free Software Foundation, Inc.
   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 3 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, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "server.h"
  22 #include "linux-low.h"
  23
  24 #include <asm/ptrace.h>
  25
  26 #define ppc_num_regs 71
  27
  28 /* Currently, don't check/send MQ.  */
  29 static int ppc_regmap[] =
  30  {PT_R0 * 4,     PT_R1 * 4,     PT_R2 * 4,     PT_R3 * 4,
  31   PT_R4 * 4,     PT_R5 * 4,     PT_R6 * 4,     PT_R7 * 4,
  32   PT_R8 * 4,     PT_R9 * 4,     PT_R10 * 4,    PT_R11 * 4,
  33   PT_R12 * 4,    PT_R13 * 4,    PT_R14 * 4,    PT_R15 * 4,
  34   PT_R16 * 4,    PT_R17 * 4,    PT_R18 * 4,    PT_R19 * 4,
  35   PT_R20 * 4,    PT_R21 * 4,    PT_R22 * 4,    PT_R23 * 4,
  36   PT_R24 * 4,    PT_R25 * 4,    PT_R26 * 4,    PT_R27 * 4,
  37   PT_R28 * 4,    PT_R29 * 4,    PT_R30 * 4,    PT_R31 * 4,
  38   PT_FPR0*4,     PT_FPR0*4 + 8, PT_FPR0*4+16,  PT_FPR0*4+24,
  39   PT_FPR0*4+32,  PT_FPR0*4+40,  PT_FPR0*4+48,  PT_FPR0*4+56,
  40   PT_FPR0*4+64,  PT_FPR0*4+72,  PT_FPR0*4+80,  PT_FPR0*4+88,
  41   PT_FPR0*4+96,  PT_FPR0*4+104,  PT_FPR0*4+112,  PT_FPR0*4+120,
  42   PT_FPR0*4+128, PT_FPR0*4+136,  PT_FPR0*4+144,  PT_FPR0*4+152,
  43   PT_FPR0*4+160,  PT_FPR0*4+168,  PT_FPR0*4+176,  PT_FPR0*4+184,
  44   PT_FPR0*4+192,  PT_FPR0*4+200,  PT_FPR0*4+208,  PT_FPR0*4+216,
  45   PT_FPR0*4+224,  PT_FPR0*4+232,  PT_FPR0*4+240,  PT_FPR0*4+248,
  46   PT_NIP * 4,    PT_MSR * 4,    PT_CCR * 4,    PT_LNK * 4,
  47   PT_CTR * 4,    PT_XER * 4,    PT_FPSCR * 4, };
  48
  49 static int
  50 ppc_cannot_store_register (int regno)
  51 {
  52   /* Some kernels do not allow us to store fpscr.  */
  53   if (regno == find_regno ("fpscr"))
  54     return 2;
  55
  56   return 0;
  57 }
  58
  59 static int
  60 ppc_cannot_fetch_register (int regno)
  61 {
  62   return 0;
  63 }
  64
  65 static CORE_ADDR
  66 ppc_get_pc (void)
  67 {
  68   unsigned long pc;
  69
  70   collect_register_by_name ("pc", &pc);
  71   return (CORE_ADDR) pc;
  72 }
  73
  74 static void
  75 ppc_set_pc (CORE_ADDR pc)
  76 {
  77   unsigned long newpc = pc;
  78
  79   supply_register_by_name ("pc", &newpc);
  80 }
  81
  82 /* Correct in either endianness.  Note that this file is
  83    for PowerPC only, not PowerPC64.
  84    This instruction is "twge r2, r2", which GDB uses as a software
  85    breakpoint.  */
  86 static const unsigned long ppc_breakpoint = 0x7d821008;
  87 #define ppc_breakpoint_len 4
  88
  89 static int
  90 ppc_breakpoint_at (CORE_ADDR where)
  91 {
  92   unsigned long insn;
  93
  94   (*the_target->read_memory) (where, (unsigned char *) &insn, 4);
  95   if (insn == ppc_breakpoint)
  96     return 1;
  97   /* If necessary, recognize more trap instructions here.  GDB only uses the
  98      one.  */
  99   return 0;
 100 }
 101
 102 /* Provide only a fill function for the general register set.  ps_lgetregs
 103    will use this for NPTL support.  */
 104
 105 static void ppc_fill_gregset (void *buf)
 106 {
 107   int i;
 108
 109   for (i = 0; i < 32; i++)
 110     collect_register (i, (char *) buf + ppc_regmap[i]);
 111
 112   for (i = 64; i < 70; i++)
 113     collect_register (i, (char *) buf + ppc_regmap[i]);
 114 }
 115
 116 struct regset_info target_regsets[] = {
 117   { 0, 0, 0, GENERAL_REGS, ppc_fill_gregset, NULL },
 118   { 0, 0, -1, -1, NULL, NULL }
 119 };
 120
 121 struct linux_target_ops the_low_target = {
 122   ppc_num_regs,
 123   ppc_regmap,
 124   ppc_cannot_fetch_register,
 125   ppc_cannot_store_register,
 126   ppc_get_pc,
 127   ppc_set_pc,
 128   (const unsigned char *) &ppc_breakpoint,
 129   ppc_breakpoint_len,
 130   NULL,
 131   0,
 132   ppc_breakpoint_at,
 133 };