gdb/arm-linux-tdep.c

   1 /* GNU/Linux on ARM target support.
   2    Copyright 1999, 2000 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 "target.h"
  23 #include "value.h"
  24 #include "gdbtypes.h"
  25
  26 #ifdef GET_LONGJMP_TARGET
  27
  28 /* Figure out where the longjmp will land.  We expect that we have
  29    just entered longjmp and haven't yet altered r0, r1, so the
  30    arguments are still in the registers.  (A1_REGNUM) points at the
  31    jmp_buf structure from which we extract the pc (JB_PC) that we will
  32    land at.  The pc is copied into ADDR.  This routine returns true on
  33    success. */
  34
  35 #define LONGJMP_TARGET_SIZE     sizeof(int)
  36 #define JB_ELEMENT_SIZE         sizeof(int)
  37 #define JB_SL                   18
  38 #define JB_FP                   19
  39 #define JB_SP                   20
  40 #define JB_PC                   21
  41
  42 int
  43 arm_get_longjmp_target (CORE_ADDR * pc)
  44 {
  45   CORE_ADDR jb_addr;
  46   char buf[LONGJMP_TARGET_SIZE];
  47
  48   jb_addr = read_register (A1_REGNUM);
  49
  50   if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf,
  51                           LONGJMP_TARGET_SIZE))
  52     return 0;
  53
  54   *pc = extract_address (buf, LONGJMP_TARGET_SIZE);
  55   return 1;
  56 }
  57
  58 #endif /* GET_LONGJMP_TARGET */
  59
  60 /* Extract from an array REGBUF containing the (raw) register state
  61    a function return value of type TYPE, and copy that, in virtual format,
  62    into VALBUF.  */
  63
  64 void
  65 arm_linux_extract_return_value (struct type *type,
  66                                 char regbuf[REGISTER_BYTES],
  67                                 char *valbuf)
  68 {
  69   /* ScottB: This needs to be looked at to handle the different
  70      floating point emulators on ARM Linux.  Right now the code
  71      assumes that fetch inferior registers does the right thing for
  72      GDB.  I suspect this won't handle NWFPE registers correctly, nor
  73      will the default ARM version (arm_extract_return_value()).  */
  74
  75   int regnum = (TYPE_CODE_FLT == TYPE_CODE (type)) ? F0_REGNUM : A1_REGNUM;
  76   memcpy (valbuf, &regbuf[REGISTER_BYTE (regnum)], TYPE_LENGTH (type));
  77 }
  78
  79 void
  80 _initialize_arm_linux_tdep (void)
  81 {
  82 }