843 lines
24 KiB
C
843 lines
24 KiB
C
/* Target-machine dependent code for the AMD 29000
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Copyright 1990, 1991, 1992, 1993 Free Software Foundation, Inc.
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Contributed by Cygnus Support. Written by Jim Kingdon.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
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#include "defs.h"
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#include "gdbcore.h"
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#include "frame.h"
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#include "value.h"
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#include "symtab.h"
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#include "inferior.h"
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#include "gdbcmd.h"
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/* If all these bits in an instruction word are zero, it is a "tag word"
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which precedes a function entry point and gives stack traceback info.
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This used to be defined as 0xff000000, but that treated 0x00000deb as
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a tag word, while it is really used as a breakpoint. */
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#define TAGWORD_ZERO_MASK 0xff00f800
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extern CORE_ADDR text_start; /* FIXME, kludge... */
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/* The user-settable top of the register stack in virtual memory. We
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won't attempt to access any stored registers above this address, if set
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nonzero. */
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static CORE_ADDR rstack_high_address = UINT_MAX;
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/* Structure to hold cached info about function prologues. */
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struct prologue_info
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{
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CORE_ADDR pc; /* First addr after fn prologue */
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unsigned rsize, msize; /* register stack frame size, mem stack ditto */
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unsigned mfp_used : 1; /* memory frame pointer used */
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unsigned rsize_valid : 1; /* Validity bits for the above */
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unsigned msize_valid : 1;
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unsigned mfp_valid : 1;
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};
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/* Examine the prologue of a function which starts at PC. Return
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the first addess past the prologue. If MSIZE is non-NULL, then
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set *MSIZE to the memory stack frame size. If RSIZE is non-NULL,
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then set *RSIZE to the register stack frame size (not including
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incoming arguments and the return address & frame pointer stored
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with them). If no prologue is found, *RSIZE is set to zero.
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If no prologue is found, or a prologue which doesn't involve
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allocating a memory stack frame, then set *MSIZE to zero.
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Note that both msize and rsize are in bytes. This is not consistent
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with the _User's Manual_ with respect to rsize, but it is much more
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convenient.
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If MFP_USED is non-NULL, *MFP_USED is set to nonzero if a memory
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frame pointer is being used. */
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CORE_ADDR
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examine_prologue (pc, rsize, msize, mfp_used)
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CORE_ADDR pc;
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unsigned *msize;
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unsigned *rsize;
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int *mfp_used;
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{
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long insn;
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CORE_ADDR p = pc;
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struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (pc);
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struct prologue_info *mi = 0;
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if (msymbol != NULL)
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mi = (struct prologue_info *) msymbol -> info;
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if (mi != 0)
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{
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int valid = 1;
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if (rsize != NULL)
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{
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*rsize = mi->rsize;
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valid &= mi->rsize_valid;
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}
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if (msize != NULL)
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{
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*msize = mi->msize;
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valid &= mi->msize_valid;
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}
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if (mfp_used != NULL)
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{
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*mfp_used = mi->mfp_used;
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valid &= mi->mfp_valid;
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}
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if (valid)
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return mi->pc;
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}
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if (rsize != NULL)
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*rsize = 0;
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if (msize != NULL)
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*msize = 0;
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if (mfp_used != NULL)
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*mfp_used = 0;
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/* Prologue must start with subtracting a constant from gr1.
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Normally this is sub gr1,gr1,<rsize * 4>. */
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insn = read_memory_integer (p, 4);
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if ((insn & 0xffffff00) != 0x25010100)
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{
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/* If the frame is large, instead of a single instruction it
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might be a pair of instructions:
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const <reg>, <rsize * 4>
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sub gr1,gr1,<reg>
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*/
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int reg;
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/* Possible value for rsize. */
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unsigned int rsize0;
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if ((insn & 0xff000000) != 0x03000000)
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{
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p = pc;
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goto done;
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}
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reg = (insn >> 8) & 0xff;
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rsize0 = (((insn >> 8) & 0xff00) | (insn & 0xff));
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p += 4;
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insn = read_memory_integer (p, 4);
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if ((insn & 0xffffff00) != 0x24010100
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|| (insn & 0xff) != reg)
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{
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p = pc;
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goto done;
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}
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if (rsize != NULL)
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*rsize = rsize0;
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}
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else
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{
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if (rsize != NULL)
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*rsize = (insn & 0xff);
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}
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p += 4;
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/* Next instruction must be asgeu V_SPILL,gr1,rab.
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* We don't check the vector number to allow for kernel debugging. The
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* kernel will use a different trap number.
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*/
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insn = read_memory_integer (p, 4);
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if ((insn & 0xff00ffff) != (0x5e000100|RAB_HW_REGNUM))
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{
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p = pc;
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goto done;
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}
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p += 4;
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/* Next instruction usually sets the frame pointer (lr1) by adding
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<size * 4> from gr1. However, this can (and high C does) be
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deferred until anytime before the first function call. So it is
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OK if we don't see anything which sets lr1.
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To allow for alternate register sets (gcc -mkernel-registers) the msp
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register number is a compile time constant. */
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/* Normally this is just add lr1,gr1,<size * 4>. */
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insn = read_memory_integer (p, 4);
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if ((insn & 0xffffff00) == 0x15810100)
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p += 4;
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else
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{
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/* However, for large frames it can be
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const <reg>, <size *4>
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add lr1,gr1,<reg>
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*/
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int reg;
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CORE_ADDR q;
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if ((insn & 0xff000000) == 0x03000000)
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{
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reg = (insn >> 8) & 0xff;
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q = p + 4;
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insn = read_memory_integer (q, 4);
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if ((insn & 0xffffff00) == 0x14810100
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&& (insn & 0xff) == reg)
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p = q;
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}
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}
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/* Next comes "add lr{<rsize-1>},msp,0", but only if a memory
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frame pointer is in use. We just check for add lr<anything>,msp,0;
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we don't check this rsize against the first instruction, and
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we don't check that the trace-back tag indicates a memory frame pointer
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is in use.
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To allow for alternate register sets (gcc -mkernel-registers) the msp
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register number is a compile time constant.
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The recommended instruction is actually "sll lr<whatever>,msp,0".
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We check for that, too. Originally Jim Kingdon's code seemed
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to be looking for a "sub" instruction here, but the mask was set
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up to lose all the time. */
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insn = read_memory_integer (p, 4);
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if (((insn & 0xff80ffff) == (0x15800000|(MSP_HW_REGNUM<<8))) /* add */
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|| ((insn & 0xff80ffff) == (0x81800000|(MSP_HW_REGNUM<<8)))) /* sll */
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{
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p += 4;
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if (mfp_used != NULL)
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*mfp_used = 1;
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}
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/* Next comes a subtraction from msp to allocate a memory frame,
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but only if a memory frame is
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being used. We don't check msize against the trace-back tag.
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To allow for alternate register sets (gcc -mkernel-registers) the msp
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register number is a compile time constant.
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Normally this is just
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sub msp,msp,<msize>
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*/
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insn = read_memory_integer (p, 4);
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if ((insn & 0xffffff00) ==
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(0x25000000|(MSP_HW_REGNUM<<16)|(MSP_HW_REGNUM<<8)))
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{
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p += 4;
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if (msize != NULL)
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*msize = insn & 0xff;
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}
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else
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{
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/* For large frames, instead of a single instruction it might
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be
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const <reg>, <msize>
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consth <reg>, <msize> ; optional
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sub msp,msp,<reg>
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*/
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int reg;
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unsigned msize0;
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CORE_ADDR q = p;
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if ((insn & 0xff000000) == 0x03000000)
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{
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reg = (insn >> 8) & 0xff;
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msize0 = ((insn >> 8) & 0xff00) | (insn & 0xff);
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q += 4;
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insn = read_memory_integer (q, 4);
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/* Check for consth. */
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if ((insn & 0xff000000) == 0x02000000
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&& (insn & 0x0000ff00) == reg)
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{
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msize0 |= (insn << 8) & 0xff000000;
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msize0 |= (insn << 16) & 0x00ff0000;
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q += 4;
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insn = read_memory_integer (q, 4);
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}
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/* Check for sub msp,msp,<reg>. */
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if ((insn & 0xffffff00) ==
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(0x24000000|(MSP_HW_REGNUM<<16)|(MSP_HW_REGNUM<<8))
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&& (insn & 0xff) == reg)
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{
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p = q + 4;
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if (msize != NULL)
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*msize = msize0;
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}
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}
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}
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done:
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if (msymbol != NULL)
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{
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if (mi == 0)
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{
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/* Add a new cache entry. */
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mi = (struct prologue_info *)xmalloc (sizeof (struct prologue_info));
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msymbol -> info = (char *)mi;
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mi->rsize_valid = 0;
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mi->msize_valid = 0;
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mi->mfp_valid = 0;
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}
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/* else, cache entry exists, but info is incomplete. */
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mi->pc = p;
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if (rsize != NULL)
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{
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mi->rsize = *rsize;
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mi->rsize_valid = 1;
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}
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if (msize != NULL)
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{
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mi->msize = *msize;
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mi->msize_valid = 1;
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}
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if (mfp_used != NULL)
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{
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mi->mfp_used = *mfp_used;
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mi->mfp_valid = 1;
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}
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}
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return p;
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}
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/* Advance PC across any function entry prologue instructions
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to reach some "real" code. */
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CORE_ADDR
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skip_prologue (pc)
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CORE_ADDR pc;
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{
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return examine_prologue (pc, (unsigned *)NULL, (unsigned *)NULL,
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(int *)NULL);
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}
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/*
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* Examine the one or two word tag at the beginning of a function.
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* The tag word is expect to be at 'p', if it is not there, we fail
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* by returning 0. The documentation for the tag word was taken from
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* page 7-15 of the 29050 User's Manual. We are assuming that the
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* m bit is in bit 22 of the tag word, which seems to be the agreed upon
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* convention today (1/15/92).
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* msize is return in bytes.
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*/
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static int /* 0/1 - failure/success of finding the tag word */
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examine_tag(p, is_trans, argcount, msize, mfp_used)
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CORE_ADDR p;
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int *is_trans;
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int *argcount;
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unsigned *msize;
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int *mfp_used;
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{
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unsigned int tag1, tag2;
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tag1 = read_memory_integer (p, 4);
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if ((tag1 & TAGWORD_ZERO_MASK) != 0) /* Not a tag word */
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return 0;
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if (tag1 & (1<<23)) /* A two word tag */
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{
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tag2 = read_memory_integer (p+4, 4);
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if (msize)
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*msize = tag2;
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}
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else /* A one word tag */
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{
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if (msize)
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*msize = tag1 & 0x7ff;
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}
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if (is_trans)
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*is_trans = ((tag1 & (1<<21)) ? 1 : 0);
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if (argcount)
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*argcount = (tag1 >> 16) & 0x1f;
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if (mfp_used)
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*mfp_used = ((tag1 & (1<<22)) ? 1 : 0);
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return(1);
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}
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/* Initialize the frame. In addition to setting "extra" frame info,
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we also set ->frame because we use it in a nonstandard way, and ->pc
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because we need to know it to get the other stuff. See the diagram
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of stacks and the frame cache in tm-a29k.h for more detail. */
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static void
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init_frame_info (innermost_frame, fci)
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int innermost_frame;
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struct frame_info *fci;
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{
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CORE_ADDR p;
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long insn;
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unsigned rsize;
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unsigned msize;
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int mfp_used, trans;
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struct symbol *func;
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p = fci->pc;
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if (innermost_frame)
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fci->frame = read_register (GR1_REGNUM);
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else
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fci->frame = fci->next->frame + fci->next->rsize;
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#if CALL_DUMMY_LOCATION == ON_STACK
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This wont work;
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#else
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if (PC_IN_CALL_DUMMY (p, 0, 0))
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#endif
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{
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fci->rsize = DUMMY_FRAME_RSIZE;
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/* This doesn't matter since we never try to get locals or args
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from a dummy frame. */
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fci->msize = 0;
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/* Dummy frames always use a memory frame pointer. */
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fci->saved_msp =
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read_register_stack_integer (fci->frame + DUMMY_FRAME_RSIZE - 4, 4);
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fci->flags |= (TRANSPARENT|MFP_USED);
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return;
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}
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func = find_pc_function (p);
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if (func != NULL)
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p = BLOCK_START (SYMBOL_BLOCK_VALUE (func));
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else
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{
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/* Search backward to find the trace-back tag. However,
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do not trace back beyond the start of the text segment
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(just as a sanity check to avoid going into never-never land). */
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while (p >= text_start
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&& ((insn = read_memory_integer (p, 4)) & TAGWORD_ZERO_MASK) != 0)
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p -= 4;
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if (p < text_start)
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{
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/* Couldn't find the trace-back tag.
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Something strange is going on. */
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fci->saved_msp = 0;
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fci->rsize = 0;
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fci->msize = 0;
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fci->flags = TRANSPARENT;
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return;
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}
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else
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/* Advance to the first word of the function, i.e. the word
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after the trace-back tag. */
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p += 4;
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}
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/* We've found the start of the function.
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* Try looking for a tag word that indicates whether there is a
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* memory frame pointer and what the memory stack allocation is.
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* If one doesn't exist, try using a more exhaustive search of
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* the prologue. For now we don't care about the argcount or
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* whether or not the routine is transparent.
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*/
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if (examine_tag(p-4,&trans,NULL,&msize,&mfp_used)) /* Found a good tag */
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examine_prologue (p, &rsize, 0, 0);
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else /* No tag try prologue */
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examine_prologue (p, &rsize, &msize, &mfp_used);
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fci->rsize = rsize;
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fci->msize = msize;
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fci->flags = 0;
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if (mfp_used)
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fci->flags |= MFP_USED;
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if (trans)
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fci->flags |= TRANSPARENT;
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if (innermost_frame)
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{
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fci->saved_msp = read_register (MSP_REGNUM) + msize;
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}
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else
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{
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if (mfp_used)
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fci->saved_msp =
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read_register_stack_integer (fci->frame + rsize - 4, 4);
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else
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fci->saved_msp = fci->next->saved_msp + msize;
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}
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}
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void
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init_extra_frame_info (fci)
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struct frame_info *fci;
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{
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if (fci->next == 0)
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/* Assume innermost frame. May produce strange results for "info frame"
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but there isn't any way to tell the difference. */
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init_frame_info (1, fci);
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else {
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/* We're in get_prev_frame_info.
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Take care of everything in init_frame_pc. */
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;
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}
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}
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void
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init_frame_pc (fromleaf, fci)
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int fromleaf;
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struct frame_info *fci;
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{
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fci->pc = (fromleaf ? SAVED_PC_AFTER_CALL (fci->next) :
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fci->next ? FRAME_SAVED_PC (fci->next) : read_pc ());
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init_frame_info (fromleaf, fci);
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}
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/* Local variables (i.e. LOC_LOCAL) are on the memory stack, with their
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offsets being relative to the memory stack pointer (high C) or
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saved_msp (gcc). */
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CORE_ADDR
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frame_locals_address (fi)
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struct frame_info *fi;
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{
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if (fi->flags & MFP_USED)
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return fi->saved_msp;
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else
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return fi->saved_msp - fi->msize;
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}
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/* Routines for reading the register stack. The caller gets to treat
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the register stack as a uniform stack in memory, from address $gr1
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straight through $rfb and beyond. */
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/* Analogous to read_memory except the length is understood to be 4.
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Also, myaddr can be NULL (meaning don't bother to read), and
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if actual_mem_addr is non-NULL, store there the address that it
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was fetched from (or if from a register the offset within
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registers). Set *LVAL to lval_memory or lval_register, depending
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on where it came from. The contents written into MYADDR are in
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target format. */
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void
|
||
read_register_stack (memaddr, myaddr, actual_mem_addr, lval)
|
||
CORE_ADDR memaddr;
|
||
char *myaddr;
|
||
CORE_ADDR *actual_mem_addr;
|
||
enum lval_type *lval;
|
||
{
|
||
long rfb = read_register (RFB_REGNUM);
|
||
long rsp = read_register (RSP_REGNUM);
|
||
|
||
/* If we don't do this 'info register' stops in the middle. */
|
||
if (memaddr >= rstack_high_address)
|
||
{
|
||
/* a bogus value */
|
||
static char val[] = {~0, ~0, ~0, ~0};
|
||
/* It's in a local register, but off the end of the stack. */
|
||
int regnum = (memaddr - rsp) / 4 + LR0_REGNUM;
|
||
if (myaddr != NULL)
|
||
{
|
||
/* Provide bogusness */
|
||
memcpy (myaddr, val, 4);
|
||
}
|
||
supply_register(regnum, val); /* More bogusness */
|
||
if (lval != NULL)
|
||
*lval = lval_register;
|
||
if (actual_mem_addr != NULL)
|
||
*actual_mem_addr = REGISTER_BYTE (regnum);
|
||
}
|
||
/* If it's in the part of the register stack that's in real registers,
|
||
get the value from the registers. If it's anywhere else in memory
|
||
(e.g. in another thread's saved stack), skip this part and get
|
||
it from real live memory. */
|
||
else if (memaddr < rfb && memaddr >= rsp)
|
||
{
|
||
/* It's in a register. */
|
||
int regnum = (memaddr - rsp) / 4 + LR0_REGNUM;
|
||
if (regnum > LR0_REGNUM + 127)
|
||
error ("Attempt to read register stack out of range.");
|
||
if (myaddr != NULL)
|
||
read_register_gen (regnum, myaddr);
|
||
if (lval != NULL)
|
||
*lval = lval_register;
|
||
if (actual_mem_addr != NULL)
|
||
*actual_mem_addr = REGISTER_BYTE (regnum);
|
||
}
|
||
else
|
||
{
|
||
/* It's in the memory portion of the register stack. */
|
||
if (myaddr != NULL)
|
||
read_memory (memaddr, myaddr, 4);
|
||
if (lval != NULL)
|
||
*lval = lval_memory;
|
||
if (actual_mem_addr != NULL)
|
||
*actual_mem_addr = memaddr;
|
||
}
|
||
}
|
||
|
||
/* Analogous to read_memory_integer
|
||
except the length is understood to be 4. */
|
||
long
|
||
read_register_stack_integer (memaddr, len)
|
||
CORE_ADDR memaddr;
|
||
int len;
|
||
{
|
||
char buf[4];
|
||
read_register_stack (memaddr, buf, NULL, NULL);
|
||
return extract_signed_integer (buf, 4);
|
||
}
|
||
|
||
/* Copy 4 bytes from GDB memory at MYADDR into inferior memory
|
||
at MEMADDR and put the actual address written into in
|
||
*ACTUAL_MEM_ADDR. */
|
||
static void
|
||
write_register_stack (memaddr, myaddr, actual_mem_addr)
|
||
CORE_ADDR memaddr;
|
||
char *myaddr;
|
||
CORE_ADDR *actual_mem_addr;
|
||
{
|
||
long rfb = read_register (RFB_REGNUM);
|
||
long rsp = read_register (RSP_REGNUM);
|
||
/* If we don't do this 'info register' stops in the middle. */
|
||
if (memaddr >= rstack_high_address)
|
||
{
|
||
/* It's in a register, but off the end of the stack. */
|
||
if (actual_mem_addr != NULL)
|
||
*actual_mem_addr = 0;
|
||
}
|
||
else if (memaddr < rfb)
|
||
{
|
||
/* It's in a register. */
|
||
int regnum = (memaddr - rsp) / 4 + LR0_REGNUM;
|
||
if (regnum < LR0_REGNUM || regnum > LR0_REGNUM + 127)
|
||
error ("Attempt to read register stack out of range.");
|
||
if (myaddr != NULL)
|
||
write_register (regnum, *(long *)myaddr);
|
||
if (actual_mem_addr != NULL)
|
||
*actual_mem_addr = 0;
|
||
}
|
||
else
|
||
{
|
||
/* It's in the memory portion of the register stack. */
|
||
if (myaddr != NULL)
|
||
write_memory (memaddr, myaddr, 4);
|
||
if (actual_mem_addr != NULL)
|
||
*actual_mem_addr = memaddr;
|
||
}
|
||
}
|
||
|
||
/* Find register number REGNUM relative to FRAME and put its
|
||
(raw) contents in *RAW_BUFFER. Set *OPTIMIZED if the variable
|
||
was optimized out (and thus can't be fetched). If the variable
|
||
was fetched from memory, set *ADDRP to where it was fetched from,
|
||
otherwise it was fetched from a register.
|
||
|
||
The argument RAW_BUFFER must point to aligned memory. */
|
||
void
|
||
get_saved_register (raw_buffer, optimized, addrp, frame, regnum, lvalp)
|
||
char *raw_buffer;
|
||
int *optimized;
|
||
CORE_ADDR *addrp;
|
||
FRAME frame;
|
||
int regnum;
|
||
enum lval_type *lvalp;
|
||
{
|
||
struct frame_info *fi;
|
||
CORE_ADDR addr;
|
||
enum lval_type lval;
|
||
|
||
if (frame == 0)
|
||
return;
|
||
|
||
fi = get_frame_info (frame);
|
||
|
||
/* Once something has a register number, it doesn't get optimized out. */
|
||
if (optimized != NULL)
|
||
*optimized = 0;
|
||
if (regnum == RSP_REGNUM)
|
||
{
|
||
if (raw_buffer != NULL)
|
||
{
|
||
store_address (raw_buffer, REGISTER_RAW_BYTES (regnum), fi->frame);
|
||
}
|
||
if (lvalp != NULL)
|
||
*lvalp = not_lval;
|
||
return;
|
||
}
|
||
else if (regnum == PC_REGNUM)
|
||
{
|
||
if (raw_buffer != NULL)
|
||
{
|
||
store_address (raw_buffer, REGISTER_RAW_BYTES (regnum), fi->pc);
|
||
}
|
||
|
||
/* Not sure we have to do this. */
|
||
if (lvalp != NULL)
|
||
*lvalp = not_lval;
|
||
|
||
return;
|
||
}
|
||
else if (regnum == MSP_REGNUM)
|
||
{
|
||
if (raw_buffer != NULL)
|
||
{
|
||
if (fi->next != NULL)
|
||
{
|
||
store_address (raw_buffer, REGISTER_RAW_BYTES (regnum),
|
||
fi->next->saved_msp);
|
||
}
|
||
else
|
||
read_register_gen (MSP_REGNUM, raw_buffer);
|
||
}
|
||
/* The value may have been computed, not fetched. */
|
||
if (lvalp != NULL)
|
||
*lvalp = not_lval;
|
||
return;
|
||
}
|
||
else if (regnum < LR0_REGNUM || regnum >= LR0_REGNUM + 128)
|
||
{
|
||
/* These registers are not saved over procedure calls,
|
||
so just print out the current values. */
|
||
if (raw_buffer != NULL)
|
||
read_register_gen (regnum, raw_buffer);
|
||
if (lvalp != NULL)
|
||
*lvalp = lval_register;
|
||
if (addrp != NULL)
|
||
*addrp = REGISTER_BYTE (regnum);
|
||
return;
|
||
}
|
||
|
||
addr = fi->frame + (regnum - LR0_REGNUM) * 4;
|
||
if (raw_buffer != NULL)
|
||
read_register_stack (addr, raw_buffer, &addr, &lval);
|
||
if (lvalp != NULL)
|
||
*lvalp = lval;
|
||
if (addrp != NULL)
|
||
*addrp = addr;
|
||
}
|
||
|
||
|
||
/* Discard from the stack the innermost frame,
|
||
restoring all saved registers. */
|
||
|
||
void
|
||
pop_frame ()
|
||
{
|
||
FRAME frame = get_current_frame ();
|
||
struct frame_info *fi = get_frame_info (frame);
|
||
CORE_ADDR rfb = read_register (RFB_REGNUM);
|
||
CORE_ADDR gr1 = fi->frame + fi->rsize;
|
||
CORE_ADDR lr1;
|
||
int i;
|
||
|
||
/* If popping a dummy frame, need to restore registers. */
|
||
if (PC_IN_CALL_DUMMY (read_register (PC_REGNUM),
|
||
read_register (SP_REGNUM),
|
||
FRAME_FP (fi)))
|
||
{
|
||
int lrnum = LR0_REGNUM + DUMMY_ARG/4;
|
||
for (i = 0; i < DUMMY_SAVE_SR128; ++i)
|
||
write_register (SR_REGNUM (i + 128),read_register (lrnum++));
|
||
for (i = 0; i < DUMMY_SAVE_SR160; ++i)
|
||
write_register (SR_REGNUM(i+160), read_register (lrnum++));
|
||
for (i = 0; i < DUMMY_SAVE_GREGS; ++i)
|
||
write_register (RETURN_REGNUM + i, read_register (lrnum++));
|
||
/* Restore the PCs. */
|
||
write_register(PC_REGNUM, read_register (lrnum++));
|
||
write_register(NPC_REGNUM, read_register (lrnum));
|
||
}
|
||
|
||
/* Restore the memory stack pointer. */
|
||
write_register (MSP_REGNUM, fi->saved_msp);
|
||
/* Restore the register stack pointer. */
|
||
write_register (GR1_REGNUM, gr1);
|
||
/* Check whether we need to fill registers. */
|
||
lr1 = read_register (LR0_REGNUM + 1);
|
||
if (lr1 > rfb)
|
||
{
|
||
/* Fill. */
|
||
int num_bytes = lr1 - rfb;
|
||
int i;
|
||
long word;
|
||
write_register (RAB_REGNUM, read_register (RAB_REGNUM) + num_bytes);
|
||
write_register (RFB_REGNUM, lr1);
|
||
for (i = 0; i < num_bytes; i += 4)
|
||
{
|
||
/* Note: word is in host byte order. */
|
||
word = read_memory_integer (rfb + i, 4);
|
||
write_register (LR0_REGNUM + ((rfb - gr1) % 0x80) + i / 4, word);
|
||
}
|
||
}
|
||
flush_cached_frames ();
|
||
set_current_frame (create_new_frame (0, read_pc()));
|
||
}
|
||
|
||
/* Push an empty stack frame, to record the current PC, etc. */
|
||
|
||
void
|
||
push_dummy_frame ()
|
||
{
|
||
long w;
|
||
CORE_ADDR rab, gr1;
|
||
CORE_ADDR msp = read_register (MSP_REGNUM);
|
||
int lrnum, i, saved_lr0;
|
||
|
||
|
||
/* Allocate the new frame. */
|
||
gr1 = read_register (GR1_REGNUM) - DUMMY_FRAME_RSIZE;
|
||
write_register (GR1_REGNUM, gr1);
|
||
|
||
rab = read_register (RAB_REGNUM);
|
||
if (gr1 < rab)
|
||
{
|
||
/* We need to spill registers. */
|
||
int num_bytes = rab - gr1;
|
||
CORE_ADDR rfb = read_register (RFB_REGNUM);
|
||
int i;
|
||
long word;
|
||
|
||
write_register (RFB_REGNUM, rfb - num_bytes);
|
||
write_register (RAB_REGNUM, gr1);
|
||
for (i = 0; i < num_bytes; i += 4)
|
||
{
|
||
/* Note: word is in target byte order. */
|
||
read_register_gen (LR0_REGNUM + i / 4, (char *) &word);
|
||
write_memory (rfb - num_bytes + i, (char *) &word, 4);
|
||
}
|
||
}
|
||
|
||
/* There are no arguments in to the dummy frame, so we don't need
|
||
more than rsize plus the return address and lr1. */
|
||
write_register (LR0_REGNUM + 1, gr1 + DUMMY_FRAME_RSIZE + 2 * 4);
|
||
|
||
/* Set the memory frame pointer. */
|
||
write_register (LR0_REGNUM + DUMMY_FRAME_RSIZE / 4 - 1, msp);
|
||
|
||
/* Allocate arg_slop. */
|
||
write_register (MSP_REGNUM, msp - 16 * 4);
|
||
|
||
/* Save registers. */
|
||
lrnum = LR0_REGNUM + DUMMY_ARG/4;
|
||
for (i = 0; i < DUMMY_SAVE_SR128; ++i)
|
||
write_register (lrnum++, read_register (SR_REGNUM (i + 128)));
|
||
for (i = 0; i < DUMMY_SAVE_SR160; ++i)
|
||
write_register (lrnum++, read_register (SR_REGNUM (i + 160)));
|
||
for (i = 0; i < DUMMY_SAVE_GREGS; ++i)
|
||
write_register (lrnum++, read_register (RETURN_REGNUM + i));
|
||
/* Save the PCs. */
|
||
write_register (lrnum++, read_register (PC_REGNUM));
|
||
write_register (lrnum, read_register (NPC_REGNUM));
|
||
}
|
||
|
||
|
||
void
|
||
_initialize_29k()
|
||
{
|
||
extern CORE_ADDR text_end;
|
||
|
||
/* FIXME, there should be a way to make a CORE_ADDR variable settable. */
|
||
add_show_from_set
|
||
(add_set_cmd ("rstack_high_address", class_support, var_uinteger,
|
||
(char *)&rstack_high_address,
|
||
"Set top address in memory of the register stack.\n\
|
||
Attempts to access registers saved above this address will be ignored\n\
|
||
or will produce the value -1.", &setlist),
|
||
&showlist);
|
||
|
||
/* FIXME, there should be a way to make a CORE_ADDR variable settable. */
|
||
add_show_from_set
|
||
(add_set_cmd ("call_scratch_address", class_support, var_uinteger,
|
||
(char *)&text_end,
|
||
"Set address in memory where small amounts of RAM can be used\n\
|
||
when making function calls into the inferior.", &setlist),
|
||
&showlist);
|
||
}
|