| /* Target-dependent code for Intel 386 running LynxOS. |
| Copyright 1993 Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| |
| #include "defs.h" |
| #include "inferior.h" |
| #include "target.h" |
| #include "gdbcore.h" |
| |
| /* Return the PC of the caller from the call frame. Assumes the subr prologue |
| has already been executed, and the frame pointer setup. If this is the |
| outermost frame, we check to see if we are in a system call by examining the |
| previous instruction. If so, then the return PC is actually at SP+4 because |
| system calls use a different calling sequence. */ |
| |
| CORE_ADDR |
| i386lynx_saved_pc_after_call (frame) |
| struct frame_info *frame; |
| { |
| char opcode[7]; |
| static const unsigned char call_inst[] = {0x9a, 0, 0, 0, 0, 8, 0}; /* lcall 0x8,0x0 */ |
| |
| read_memory (frame->pc - 7, opcode, 7); |
| if (memcmp (opcode, call_inst, 7) == 0) |
| return read_memory_integer (read_register (SP_REGNUM) + 4, 4); |
| |
| return read_memory_integer (read_register (SP_REGNUM), 4); |
| } |