gdb/config/m68k/tm-sun3.h

   1 /* Parameters for execution on a Sun, for GDB, the GNU debugger.
   2    Copyright (C) 1986, 1987, 1989, 1992 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, Boston, MA 02111-1307, USA.  */
  19
  20 #ifndef TM_SUN3_H
  21 #define TM_SUN3_H
  22
  23 /* Sun3 status includes fpflags, which shows whether the FPU has been used
  24    by the process, and whether the FPU was done with an instruction or
  25    was interrupted in the middle of a long instruction.  See
  26    <machine/reg.h>.  */
  27 /*                      a&d, pc,sr, fp, fpstat, fpflags   */
  28
  29 #define REGISTER_BYTES (16*4 + 8 + 8*12 + 3*4 + 4)
  30
  31 #define NUM_REGS 31
  32
  33 #define REGISTER_BYTES_OK(b) \
  34      ((b) == REGISTER_BYTES \
  35       || (b) == REGISTER_BYTES_FP \
  36       || (b) == REGISTER_BYTES_NOFP)
  37
  38 /* If PC contains this instruction, then we know what we are in a system
  39    call stub, and the return PC is is at SP+4, instead of SP. */
  40
  41 #define SYSCALL_TRAP 0x4e40     /* trap #0 */
  42 #define SYSCALL_TRAP_OFFSET 0   /* PC points at trap instruction */
  43
  44 #include "m68k/tm-m68k.h"
  45
  46 /* Disable alternate breakpoint mechanism needed by 68k stub. */
  47 #undef REMOTE_BREAKPOINT
  48
  49 /* Offsets (in target ints) into jmp_buf.  Not defined by Sun, but at least
  50    documented in a comment in <machine/setjmp.h>! */
  51
  52 #define JB_ELEMENT_SIZE 4
  53
  54 #define JB_ONSSTACK 0
  55 #define JB_SIGMASK 1
  56 #define JB_SP 2
  57 #define JB_PC 3
  58 #define JB_PSL 4
  59 #define JB_D2 5
  60 #define JB_D3 6
  61 #define JB_D4 7
  62 #define JB_D5 8
  63 #define JB_D6 9
  64 #define JB_D7 10
  65 #define JB_A2 11
  66 #define JB_A3 12
  67 #define JB_A4 13
  68 #define JB_A5 14
  69 #define JB_A6 15
  70
  71 /* Figure out where the longjmp will land.  Slurp the args out of the stack.
  72    We expect the first arg to be a pointer to the jmp_buf structure from which
  73    we extract the pc (JB_PC) that we will land at.  The pc is copied into ADDR.
  74    This routine returns true on success */
  75
  76 #define GET_LONGJMP_TARGET(ADDR) get_longjmp_target(ADDR)
  77 extern int get_longjmp_target PARAMS ((CORE_ADDR *));
  78
  79 /* If sun3 pcc says that a parameter is a short, it's a short.  */
  80 #define BELIEVE_PCC_PROMOTION_TYPE
  81
  82 /* Can't define BELIEVE_PCC_PROMOTION for SunOS /bin/cc of SunOS 4.1.1.
  83    Apparently Sun fixed this for the sparc but not the sun3.  */
  84
  85 /* The code which tries to deal with this bug is never harmful on a sun3.  */
  86 #define SUN_FIXED_LBRAC_BUG (0)
  87
  88 /* On the sun3 the kernel pushes a sigcontext on the user stack and then
  89    `calls' _sigtramp in user code. _sigtramp saves the floating point status
  90    on the stack and calls the signal handler function. The stack does not
  91    contain enough information to allow a normal backtrace, but sigcontext
  92    contains the saved user pc/sp. FRAME_CHAIN and friends in tm-m68k.h and
  93    m68k_find_saved_regs deal with this situation by manufacturing a fake frame
  94    for _sigtramp.
  95    SIG_PC_FP_OFFSET is the offset from the signal handler frame to the
  96    saved pc in sigcontext.
  97    SIG_SP_FP_OFFSET is the offset from the signal handler frame to the end
  98    of sigcontext which is identical to the saved sp at SIG_PC_FP_OFFSET - 4.
  99
 100    Please note that it is impossible to correctly backtrace from a breakpoint
 101    in _sigtramp as _sigtramp modifies the stack pointer a few times.  */
 102
 103 #undef SIG_PC_FP_OFFSET
 104 #define SIG_PC_FP_OFFSET 324
 105 #define SIG_SP_FP_OFFSET 332
 106
 107 #endif /* TM_SUN3_H */