1029 lines
30 KiB
C
1029 lines
30 KiB
C
/* Target-machine dependent code for the AMD 29000
|
||
Copyright 1990, 1991, 1992, 1993, 1994, 1995
|
||
Free Software Foundation, Inc.
|
||
Contributed by Cygnus Support. Written by Jim Kingdon.
|
||
|
||
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 "gdbcore.h"
|
||
#include "frame.h"
|
||
#include "value.h"
|
||
#include "symtab.h"
|
||
#include "inferior.h"
|
||
#include "gdbcmd.h"
|
||
|
||
/* If all these bits in an instruction word are zero, it is a "tag word"
|
||
which precedes a function entry point and gives stack traceback info.
|
||
This used to be defined as 0xff000000, but that treated 0x00000deb as
|
||
a tag word, while it is really used as a breakpoint. */
|
||
#define TAGWORD_ZERO_MASK 0xff00f800
|
||
|
||
extern CORE_ADDR text_start; /* FIXME, kludge... */
|
||
|
||
/* The user-settable top of the register stack in virtual memory. We
|
||
won't attempt to access any stored registers above this address, if set
|
||
nonzero. */
|
||
|
||
static CORE_ADDR rstack_high_address = UINT_MAX;
|
||
|
||
/* Structure to hold cached info about function prologues. */
|
||
|
||
struct prologue_info
|
||
{
|
||
CORE_ADDR pc; /* First addr after fn prologue */
|
||
unsigned rsize, msize; /* register stack frame size, mem stack ditto */
|
||
unsigned mfp_used : 1; /* memory frame pointer used */
|
||
unsigned rsize_valid : 1; /* Validity bits for the above */
|
||
unsigned msize_valid : 1;
|
||
unsigned mfp_valid : 1;
|
||
};
|
||
|
||
/* Examine the prologue of a function which starts at PC. Return
|
||
the first addess past the prologue. If MSIZE is non-NULL, then
|
||
set *MSIZE to the memory stack frame size. If RSIZE is non-NULL,
|
||
then set *RSIZE to the register stack frame size (not including
|
||
incoming arguments and the return address & frame pointer stored
|
||
with them). If no prologue is found, *RSIZE is set to zero.
|
||
If no prologue is found, or a prologue which doesn't involve
|
||
allocating a memory stack frame, then set *MSIZE to zero.
|
||
|
||
Note that both msize and rsize are in bytes. This is not consistent
|
||
with the _User's Manual_ with respect to rsize, but it is much more
|
||
convenient.
|
||
|
||
If MFP_USED is non-NULL, *MFP_USED is set to nonzero if a memory
|
||
frame pointer is being used. */
|
||
|
||
CORE_ADDR
|
||
examine_prologue (pc, rsize, msize, mfp_used)
|
||
CORE_ADDR pc;
|
||
unsigned *msize;
|
||
unsigned *rsize;
|
||
int *mfp_used;
|
||
{
|
||
long insn;
|
||
CORE_ADDR p = pc;
|
||
struct minimal_symbol *msymbol = lookup_minimal_symbol_by_pc (pc);
|
||
struct prologue_info *mi = 0;
|
||
|
||
if (msymbol != NULL)
|
||
mi = (struct prologue_info *) msymbol -> info;
|
||
|
||
if (mi != 0)
|
||
{
|
||
int valid = 1;
|
||
if (rsize != NULL)
|
||
{
|
||
*rsize = mi->rsize;
|
||
valid &= mi->rsize_valid;
|
||
}
|
||
if (msize != NULL)
|
||
{
|
||
*msize = mi->msize;
|
||
valid &= mi->msize_valid;
|
||
}
|
||
if (mfp_used != NULL)
|
||
{
|
||
*mfp_used = mi->mfp_used;
|
||
valid &= mi->mfp_valid;
|
||
}
|
||
if (valid)
|
||
return mi->pc;
|
||
}
|
||
|
||
if (rsize != NULL)
|
||
*rsize = 0;
|
||
if (msize != NULL)
|
||
*msize = 0;
|
||
if (mfp_used != NULL)
|
||
*mfp_used = 0;
|
||
|
||
/* Prologue must start with subtracting a constant from gr1.
|
||
Normally this is sub gr1,gr1,<rsize * 4>. */
|
||
insn = read_memory_integer (p, 4);
|
||
if ((insn & 0xffffff00) != 0x25010100)
|
||
{
|
||
/* If the frame is large, instead of a single instruction it
|
||
might be a pair of instructions:
|
||
const <reg>, <rsize * 4>
|
||
sub gr1,gr1,<reg>
|
||
*/
|
||
int reg;
|
||
/* Possible value for rsize. */
|
||
unsigned int rsize0;
|
||
|
||
if ((insn & 0xff000000) != 0x03000000)
|
||
{
|
||
p = pc;
|
||
goto done;
|
||
}
|
||
reg = (insn >> 8) & 0xff;
|
||
rsize0 = (((insn >> 8) & 0xff00) | (insn & 0xff));
|
||
p += 4;
|
||
insn = read_memory_integer (p, 4);
|
||
if ((insn & 0xffffff00) != 0x24010100
|
||
|| (insn & 0xff) != reg)
|
||
{
|
||
p = pc;
|
||
goto done;
|
||
}
|
||
if (rsize != NULL)
|
||
*rsize = rsize0;
|
||
}
|
||
else
|
||
{
|
||
if (rsize != NULL)
|
||
*rsize = (insn & 0xff);
|
||
}
|
||
p += 4;
|
||
|
||
/* Next instruction ought to be asgeu V_SPILL,gr1,rab.
|
||
* We don't check the vector number to allow for kernel debugging. The
|
||
* kernel will use a different trap number.
|
||
* If this insn is missing, we just keep going; Metaware R2.3u compiler
|
||
* generates prologue that intermixes initializations and puts the asgeu
|
||
* way down.
|
||
*/
|
||
insn = read_memory_integer (p, 4);
|
||
if ((insn & 0xff00ffff) == (0x5e000100|RAB_HW_REGNUM))
|
||
{
|
||
p += 4;
|
||
}
|
||
|
||
/* Next instruction usually sets the frame pointer (lr1) by adding
|
||
<size * 4> from gr1. However, this can (and high C does) be
|
||
deferred until anytime before the first function call. So it is
|
||
OK if we don't see anything which sets lr1.
|
||
To allow for alternate register sets (gcc -mkernel-registers) the msp
|
||
register number is a compile time constant. */
|
||
|
||
/* Normally this is just add lr1,gr1,<size * 4>. */
|
||
insn = read_memory_integer (p, 4);
|
||
if ((insn & 0xffffff00) == 0x15810100)
|
||
p += 4;
|
||
else
|
||
{
|
||
/* However, for large frames it can be
|
||
const <reg>, <size *4>
|
||
add lr1,gr1,<reg>
|
||
*/
|
||
int reg;
|
||
CORE_ADDR q;
|
||
|
||
if ((insn & 0xff000000) == 0x03000000)
|
||
{
|
||
reg = (insn >> 8) & 0xff;
|
||
q = p + 4;
|
||
insn = read_memory_integer (q, 4);
|
||
if ((insn & 0xffffff00) == 0x14810100
|
||
&& (insn & 0xff) == reg)
|
||
p = q;
|
||
}
|
||
}
|
||
|
||
/* Next comes "add lr{<rsize-1>},msp,0", but only if a memory
|
||
frame pointer is in use. We just check for add lr<anything>,msp,0;
|
||
we don't check this rsize against the first instruction, and
|
||
we don't check that the trace-back tag indicates a memory frame pointer
|
||
is in use.
|
||
To allow for alternate register sets (gcc -mkernel-registers) the msp
|
||
register number is a compile time constant.
|
||
|
||
The recommended instruction is actually "sll lr<whatever>,msp,0".
|
||
We check for that, too. Originally Jim Kingdon's code seemed
|
||
to be looking for a "sub" instruction here, but the mask was set
|
||
up to lose all the time. */
|
||
insn = read_memory_integer (p, 4);
|
||
if (((insn & 0xff80ffff) == (0x15800000|(MSP_HW_REGNUM<<8))) /* add */
|
||
|| ((insn & 0xff80ffff) == (0x81800000|(MSP_HW_REGNUM<<8)))) /* sll */
|
||
{
|
||
p += 4;
|
||
if (mfp_used != NULL)
|
||
*mfp_used = 1;
|
||
}
|
||
|
||
/* Next comes a subtraction from msp to allocate a memory frame,
|
||
but only if a memory frame is
|
||
being used. We don't check msize against the trace-back tag.
|
||
|
||
To allow for alternate register sets (gcc -mkernel-registers) the msp
|
||
register number is a compile time constant.
|
||
|
||
Normally this is just
|
||
sub msp,msp,<msize>
|
||
*/
|
||
insn = read_memory_integer (p, 4);
|
||
if ((insn & 0xffffff00) ==
|
||
(0x25000000|(MSP_HW_REGNUM<<16)|(MSP_HW_REGNUM<<8)))
|
||
{
|
||
p += 4;
|
||
if (msize != NULL)
|
||
*msize = insn & 0xff;
|
||
}
|
||
else
|
||
{
|
||
/* For large frames, instead of a single instruction it might
|
||
be
|
||
|
||
const <reg>, <msize>
|
||
consth <reg>, <msize> ; optional
|
||
sub msp,msp,<reg>
|
||
*/
|
||
int reg;
|
||
unsigned msize0;
|
||
CORE_ADDR q = p;
|
||
|
||
if ((insn & 0xff000000) == 0x03000000)
|
||
{
|
||
reg = (insn >> 8) & 0xff;
|
||
msize0 = ((insn >> 8) & 0xff00) | (insn & 0xff);
|
||
q += 4;
|
||
insn = read_memory_integer (q, 4);
|
||
/* Check for consth. */
|
||
if ((insn & 0xff000000) == 0x02000000
|
||
&& (insn & 0x0000ff00) == reg)
|
||
{
|
||
msize0 |= (insn << 8) & 0xff000000;
|
||
msize0 |= (insn << 16) & 0x00ff0000;
|
||
q += 4;
|
||
insn = read_memory_integer (q, 4);
|
||
}
|
||
/* Check for sub msp,msp,<reg>. */
|
||
if ((insn & 0xffffff00) ==
|
||
(0x24000000|(MSP_HW_REGNUM<<16)|(MSP_HW_REGNUM<<8))
|
||
&& (insn & 0xff) == reg)
|
||
{
|
||
p = q + 4;
|
||
if (msize != NULL)
|
||
*msize = msize0;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Next instruction might be asgeu V_SPILL,gr1,rab.
|
||
* We don't check the vector number to allow for kernel debugging. The
|
||
* kernel will use a different trap number.
|
||
* Metaware R2.3u compiler
|
||
* generates prologue that intermixes initializations and puts the asgeu
|
||
* way down after everything else.
|
||
*/
|
||
insn = read_memory_integer (p, 4);
|
||
if ((insn & 0xff00ffff) == (0x5e000100|RAB_HW_REGNUM))
|
||
{
|
||
p += 4;
|
||
}
|
||
|
||
done:
|
||
if (msymbol != NULL)
|
||
{
|
||
if (mi == 0)
|
||
{
|
||
/* Add a new cache entry. */
|
||
mi = (struct prologue_info *)xmalloc (sizeof (struct prologue_info));
|
||
msymbol -> info = (char *)mi;
|
||
mi->rsize_valid = 0;
|
||
mi->msize_valid = 0;
|
||
mi->mfp_valid = 0;
|
||
}
|
||
/* else, cache entry exists, but info is incomplete. */
|
||
mi->pc = p;
|
||
if (rsize != NULL)
|
||
{
|
||
mi->rsize = *rsize;
|
||
mi->rsize_valid = 1;
|
||
}
|
||
if (msize != NULL)
|
||
{
|
||
mi->msize = *msize;
|
||
mi->msize_valid = 1;
|
||
}
|
||
if (mfp_used != NULL)
|
||
{
|
||
mi->mfp_used = *mfp_used;
|
||
mi->mfp_valid = 1;
|
||
}
|
||
}
|
||
return p;
|
||
}
|
||
|
||
/* Advance PC across any function entry prologue instructions
|
||
to reach some "real" code. */
|
||
|
||
CORE_ADDR
|
||
skip_prologue (pc)
|
||
CORE_ADDR pc;
|
||
{
|
||
return examine_prologue (pc, NULL, NULL, NULL);
|
||
}
|
||
|
||
/*
|
||
* Examine the one or two word tag at the beginning of a function.
|
||
* The tag word is expect to be at 'p', if it is not there, we fail
|
||
* by returning 0. The documentation for the tag word was taken from
|
||
* page 7-15 of the 29050 User's Manual. We are assuming that the
|
||
* m bit is in bit 22 of the tag word, which seems to be the agreed upon
|
||
* convention today (1/15/92).
|
||
* msize is return in bytes.
|
||
*/
|
||
|
||
static int /* 0/1 - failure/success of finding the tag word */
|
||
examine_tag (p, is_trans, argcount, msize, mfp_used)
|
||
CORE_ADDR p;
|
||
int *is_trans;
|
||
int *argcount;
|
||
unsigned *msize;
|
||
int *mfp_used;
|
||
{
|
||
unsigned int tag1, tag2;
|
||
|
||
tag1 = read_memory_integer (p, 4);
|
||
if ((tag1 & TAGWORD_ZERO_MASK) != 0) /* Not a tag word */
|
||
return 0;
|
||
if (tag1 & (1<<23)) /* A two word tag */
|
||
{
|
||
tag2 = read_memory_integer (p-4, 4);
|
||
if (msize)
|
||
*msize = tag2 * 2;
|
||
}
|
||
else /* A one word tag */
|
||
{
|
||
if (msize)
|
||
*msize = tag1 & 0x7ff;
|
||
}
|
||
if (is_trans)
|
||
*is_trans = ((tag1 & (1<<21)) ? 1 : 0);
|
||
/* Note that this includes the frame pointer and the return address
|
||
register, so the actual number of registers of arguments is two less.
|
||
argcount can be zero, however, sometimes, for strange assembler
|
||
routines. */
|
||
if (argcount)
|
||
*argcount = (tag1 >> 16) & 0x1f;
|
||
if (mfp_used)
|
||
*mfp_used = ((tag1 & (1<<22)) ? 1 : 0);
|
||
return 1;
|
||
}
|
||
|
||
/* Initialize the frame. In addition to setting "extra" frame info,
|
||
we also set ->frame because we use it in a nonstandard way, and ->pc
|
||
because we need to know it to get the other stuff. See the diagram
|
||
of stacks and the frame cache in tm-a29k.h for more detail. */
|
||
|
||
static void
|
||
init_frame_info (innermost_frame, frame)
|
||
int innermost_frame;
|
||
struct frame_info *frame;
|
||
{
|
||
CORE_ADDR p;
|
||
long insn;
|
||
unsigned rsize;
|
||
unsigned msize;
|
||
int mfp_used, trans;
|
||
struct symbol *func;
|
||
|
||
p = frame->pc;
|
||
|
||
if (innermost_frame)
|
||
frame->frame = read_register (GR1_REGNUM);
|
||
else
|
||
frame->frame = frame->next->frame + frame->next->rsize;
|
||
|
||
#if 0 /* CALL_DUMMY_LOCATION == ON_STACK */
|
||
This wont work;
|
||
#else
|
||
if (PC_IN_CALL_DUMMY (p, 0, 0))
|
||
#endif
|
||
{
|
||
frame->rsize = DUMMY_FRAME_RSIZE;
|
||
/* This doesn't matter since we never try to get locals or args
|
||
from a dummy frame. */
|
||
frame->msize = 0;
|
||
/* Dummy frames always use a memory frame pointer. */
|
||
frame->saved_msp =
|
||
read_register_stack_integer (frame->frame + DUMMY_FRAME_RSIZE - 4, 4);
|
||
frame->flags |= (TRANSPARENT|MFP_USED);
|
||
return;
|
||
}
|
||
|
||
func = find_pc_function (p);
|
||
if (func != NULL)
|
||
p = BLOCK_START (SYMBOL_BLOCK_VALUE (func));
|
||
else
|
||
{
|
||
/* Search backward to find the trace-back tag. However,
|
||
do not trace back beyond the start of the text segment
|
||
(just as a sanity check to avoid going into never-never land). */
|
||
#if 1
|
||
while (p >= text_start
|
||
&& ((insn = read_memory_integer (p, 4)) & TAGWORD_ZERO_MASK) != 0)
|
||
p -= 4;
|
||
#else /* 0 */
|
||
char pat[4] = {0, 0, 0, 0};
|
||
char mask[4];
|
||
char insn_raw[4];
|
||
store_unsigned_integer (mask, 4, TAGWORD_ZERO_MASK);
|
||
/* Enable this once target_search is enabled and tested. */
|
||
target_search (4, pat, mask, p, -4, text_start, p+1, &p, &insn_raw);
|
||
insn = extract_unsigned_integer (insn_raw, 4);
|
||
#endif /* 0 */
|
||
|
||
if (p < text_start)
|
||
{
|
||
/* Couldn't find the trace-back tag.
|
||
Something strange is going on. */
|
||
frame->saved_msp = 0;
|
||
frame->rsize = 0;
|
||
frame->msize = 0;
|
||
frame->flags = TRANSPARENT;
|
||
return;
|
||
}
|
||
else
|
||
/* Advance to the first word of the function, i.e. the word
|
||
after the trace-back tag. */
|
||
p += 4;
|
||
}
|
||
|
||
/* We've found the start of the function.
|
||
Try looking for a tag word that indicates whether there is a
|
||
memory frame pointer and what the memory stack allocation is.
|
||
If one doesn't exist, try using a more exhaustive search of
|
||
the prologue. */
|
||
|
||
if (examine_tag(p-4,&trans,(int *)NULL,&msize,&mfp_used)) /* Found good tag */
|
||
examine_prologue (p, &rsize, 0, 0);
|
||
else /* No tag try prologue */
|
||
examine_prologue (p, &rsize, &msize, &mfp_used);
|
||
|
||
frame->rsize = rsize;
|
||
frame->msize = msize;
|
||
frame->flags = 0;
|
||
if (mfp_used)
|
||
frame->flags |= MFP_USED;
|
||
if (trans)
|
||
frame->flags |= TRANSPARENT;
|
||
if (innermost_frame)
|
||
{
|
||
frame->saved_msp = read_register (MSP_REGNUM) + msize;
|
||
}
|
||
else
|
||
{
|
||
if (mfp_used)
|
||
frame->saved_msp =
|
||
read_register_stack_integer (frame->frame + rsize - 4, 4);
|
||
else
|
||
frame->saved_msp = frame->next->saved_msp + msize;
|
||
}
|
||
}
|
||
|
||
void
|
||
init_extra_frame_info (frame)
|
||
struct frame_info *frame;
|
||
{
|
||
if (frame->next == 0)
|
||
/* Assume innermost frame. May produce strange results for "info frame"
|
||
but there isn't any way to tell the difference. */
|
||
init_frame_info (1, frame);
|
||
else {
|
||
/* We're in get_prev_frame_info.
|
||
Take care of everything in init_frame_pc. */
|
||
;
|
||
}
|
||
}
|
||
|
||
void
|
||
init_frame_pc (fromleaf, frame)
|
||
int fromleaf;
|
||
struct frame_info *frame;
|
||
{
|
||
frame->pc = (fromleaf ? SAVED_PC_AFTER_CALL (frame->next) :
|
||
frame->next ? FRAME_SAVED_PC (frame->next) : read_pc ());
|
||
init_frame_info (fromleaf, frame);
|
||
}
|
||
|
||
/* Local variables (i.e. LOC_LOCAL) are on the memory stack, with their
|
||
offsets being relative to the memory stack pointer (high C) or
|
||
saved_msp (gcc). */
|
||
|
||
CORE_ADDR
|
||
frame_locals_address (fi)
|
||
struct frame_info *fi;
|
||
{
|
||
if (fi->flags & MFP_USED)
|
||
return fi->saved_msp;
|
||
else
|
||
return fi->saved_msp - fi->msize;
|
||
}
|
||
|
||
/* Routines for reading the register stack. The caller gets to treat
|
||
the register stack as a uniform stack in memory, from address $gr1
|
||
straight through $rfb and beyond. */
|
||
|
||
/* Analogous to read_memory except the length is understood to be 4.
|
||
Also, myaddr can be NULL (meaning don't bother to read), and
|
||
if actual_mem_addr is non-NULL, store there the address that it
|
||
was fetched from (or if from a register the offset within
|
||
registers). Set *LVAL to lval_memory or lval_register, depending
|
||
on where it came from. The contents written into MYADDR are in
|
||
target format. */
|
||
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;
|
||
struct frame_info *frame;
|
||
int regnum;
|
||
enum lval_type *lvalp;
|
||
{
|
||
struct frame_info *fi;
|
||
CORE_ADDR addr;
|
||
enum lval_type lval;
|
||
|
||
if (!target_has_registers)
|
||
error ("No registers.");
|
||
|
||
/* Probably now redundant with the target_has_registers check. */
|
||
if (frame == 0)
|
||
return;
|
||
|
||
/* 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_SIZE (regnum), frame->frame);
|
||
}
|
||
if (lvalp != NULL)
|
||
*lvalp = not_lval;
|
||
return;
|
||
}
|
||
else if (regnum == PC_REGNUM)
|
||
{
|
||
if (raw_buffer != NULL)
|
||
{
|
||
store_address (raw_buffer, REGISTER_RAW_SIZE (regnum), frame->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 (frame->next != NULL)
|
||
{
|
||
store_address (raw_buffer, REGISTER_RAW_SIZE (regnum),
|
||
frame->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 = frame->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 ()
|
||
{
|
||
struct frame_info *frame = get_current_frame ();
|
||
CORE_ADDR rfb = read_register (RFB_REGNUM);
|
||
CORE_ADDR gr1 = frame->frame + frame->rsize;
|
||
CORE_ADDR lr1;
|
||
CORE_ADDR original_lr0;
|
||
int must_fix_lr0 = 0;
|
||
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 (frame)))
|
||
{
|
||
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 and prepare to restore LR0. */
|
||
write_register(PC_REGNUM, read_register (lrnum++));
|
||
write_register(NPC_REGNUM, read_register (lrnum++));
|
||
write_register(PC2_REGNUM, read_register (lrnum++));
|
||
original_lr0 = read_register (lrnum++);
|
||
must_fix_lr0 = 1;
|
||
}
|
||
|
||
/* Restore the memory stack pointer. */
|
||
write_register (MSP_REGNUM, frame->saved_msp);
|
||
/* Restore the register stack pointer. */
|
||
write_register (GR1_REGNUM, gr1);
|
||
|
||
/* If we popped a dummy frame, restore lr0 now that gr1 has been restored. */
|
||
if (must_fix_lr0)
|
||
write_register (LR0_REGNUM, original_lr0);
|
||
|
||
/* 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 ();
|
||
}
|
||
|
||
/* 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;
|
||
CORE_ADDR original_lr0;
|
||
|
||
/* Read original lr0 before changing gr1. This order isn't really needed
|
||
since GDB happens to have a snapshot of all the regs and doesn't toss
|
||
it when gr1 is changed. But it's The Right Thing To Do. */
|
||
original_lr0 = read_register (LR0_REGNUM);
|
||
|
||
/* Allocate the new frame. */
|
||
gr1 = read_register (GR1_REGNUM) - DUMMY_FRAME_RSIZE;
|
||
write_register (GR1_REGNUM, gr1);
|
||
|
||
#ifdef VXWORKS_TARGET
|
||
/* We force re-reading all registers to get the new local registers set
|
||
after gr1 has been modified. This fix is due to the lack of single
|
||
register read/write operation in the RPC interface between VxGDB and
|
||
VxWorks. This really must be changed ! */
|
||
|
||
vx_read_register (-1);
|
||
|
||
#endif /* VXWORK_TARGET */
|
||
|
||
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 and LR0. */
|
||
write_register (lrnum++, read_register (PC_REGNUM));
|
||
write_register (lrnum++, read_register (NPC_REGNUM));
|
||
write_register (lrnum++, read_register (PC2_REGNUM));
|
||
|
||
/* Why are we saving LR0? What would clobber it? (the dummy frame should
|
||
be below it on the register stack, no?). */
|
||
write_register (lrnum++, original_lr0);
|
||
}
|
||
|
||
|
||
|
||
/*
|
||
This routine takes three arguments and makes the cached frames look
|
||
as if these arguments defined a frame on the cache. This allows the
|
||
rest of `info frame' to extract the important arguments without much
|
||
difficulty. Since an individual frame on the 29K is determined by
|
||
three values (FP, PC, and MSP), we really need all three to do a
|
||
good job. */
|
||
|
||
struct frame_info *
|
||
setup_arbitrary_frame (argc, argv)
|
||
int argc;
|
||
CORE_ADDR *argv;
|
||
{
|
||
struct frame_info *frame;
|
||
|
||
if (argc != 3)
|
||
error ("AMD 29k frame specifications require three arguments: rsp pc msp");
|
||
|
||
frame = create_new_frame (argv[0], argv[1]);
|
||
|
||
if (!frame)
|
||
fatal ("internal: create_new_frame returned invalid frame id");
|
||
|
||
/* Creating a new frame munges the `frame' value from the current
|
||
GR1, so we restore it again here. FIXME, untangle all this
|
||
29K frame stuff... */
|
||
frame->frame = argv[0];
|
||
|
||
/* Our MSP is in argv[2]. It'd be intelligent if we could just
|
||
save this value in the FRAME. But the way it's set up (FIXME),
|
||
we must save our caller's MSP. We compute that by adding our
|
||
memory stack frame size to our MSP. */
|
||
frame->saved_msp = argv[2] + frame->msize;
|
||
|
||
return frame;
|
||
}
|
||
|
||
int
|
||
gdb_print_insn_a29k (memaddr, info)
|
||
bfd_vma memaddr;
|
||
disassemble_info *info;
|
||
{
|
||
if (TARGET_BYTE_ORDER == BIG_ENDIAN)
|
||
return print_insn_big_a29k (memaddr, info);
|
||
else
|
||
return print_insn_little_a29k (memaddr, info);
|
||
}
|
||
|
||
enum a29k_processor_types processor_type = a29k_unknown;
|
||
|
||
void
|
||
a29k_get_processor_type ()
|
||
{
|
||
unsigned int cfg_reg = (unsigned int) read_register (CFG_REGNUM);
|
||
|
||
/* Most of these don't have freeze mode. */
|
||
processor_type = a29k_no_freeze_mode;
|
||
|
||
switch ((cfg_reg >> 28) & 0xf)
|
||
{
|
||
case 0:
|
||
fprintf_filtered (gdb_stderr, "Remote debugging an Am29000");
|
||
break;
|
||
case 1:
|
||
fprintf_filtered (gdb_stderr, "Remote debugging an Am29005");
|
||
break;
|
||
case 2:
|
||
fprintf_filtered (gdb_stderr, "Remote debugging an Am29050");
|
||
processor_type = a29k_freeze_mode;
|
||
break;
|
||
case 3:
|
||
fprintf_filtered (gdb_stderr, "Remote debugging an Am29035");
|
||
break;
|
||
case 4:
|
||
fprintf_filtered (gdb_stderr, "Remote debugging an Am29030");
|
||
break;
|
||
case 5:
|
||
fprintf_filtered (gdb_stderr, "Remote debugging an Am2920*");
|
||
break;
|
||
case 6:
|
||
fprintf_filtered (gdb_stderr, "Remote debugging an Am2924*");
|
||
break;
|
||
case 7:
|
||
fprintf_filtered (gdb_stderr, "Remote debugging an Am29040");
|
||
break;
|
||
default:
|
||
fprintf_filtered (gdb_stderr, "Remote debugging an unknown Am29k\n");
|
||
/* Don't bother to print the revision. */
|
||
return;
|
||
}
|
||
fprintf_filtered (gdb_stderr, " revision %c\n", 'A' + ((cfg_reg >> 24) & 0x0f));
|
||
}
|
||
|
||
#ifdef GET_LONGJMP_TARGET
|
||
/* Figure out where the longjmp will land. We expect that we have just entered
|
||
longjmp and haven't yet setup the stack frame, so the args are still in the
|
||
output regs. lr2 (LR2_REGNUM) points at the jmp_buf structure from which we
|
||
extract the pc (JB_PC) that we will land at. The pc is copied into ADDR.
|
||
This routine returns true on success */
|
||
|
||
int
|
||
get_longjmp_target(pc)
|
||
CORE_ADDR *pc;
|
||
{
|
||
CORE_ADDR jb_addr;
|
||
char buf[sizeof(CORE_ADDR)];
|
||
|
||
jb_addr = read_register(LR2_REGNUM);
|
||
|
||
if (target_read_memory(jb_addr + JB_PC * JB_ELEMENT_SIZE, (char *) buf,
|
||
sizeof(CORE_ADDR)))
|
||
return 0;
|
||
|
||
*pc = extract_address ((PTR) buf, sizeof(CORE_ADDR));
|
||
return 1;
|
||
}
|
||
#endif /* GET_LONGJMP_TARGET */
|
||
|
||
void
|
||
_initialize_a29k_tdep ()
|
||
{
|
||
extern CORE_ADDR text_end;
|
||
|
||
tm_print_insn = gdb_print_insn_a29k;
|
||
|
||
/* 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);
|
||
}
|