binutils-gdb/gdb/mips-xdep.c
John Gilmore 2886f8b253 Support for accessing arbitrary MIPS stack frames in memory.
* blockframe.c (get_prev_frame_info):  If INIT_FRAME_PC_FIRST is
set, run it before INIT_EXTRA_FRAME_INFO.
* stack.c (frame_info):  If PRINT_EXTRA_FRAME_INFO defined, call it.

* mips-tdep.c (init_extra_frame_info): Only clobber the `frame'
(FP) value in the frame_info struct if it is zero (as from top of
execution stack).
(setup_arbitrary_frame):  Implement FRAME_SPECIFICATION_DYADIC.

* mips-xdep.c (fetch_inferior_registers):  ZERO_REGNUM always
comes back as zero.  So does FP_REGNUM, as a trigger for
init_extra_frame_info.

* tm-mips.h (INIT_FRAME_PC_FIRST):  Kludge, FIXME, defined to get
the program counter set before INIT_EXTRA_FRAME_INFO is run.
(INIT_FRAME_PC):  Defined to null.
(PRINT_EXTRA_FRAME_INFO): print frame pointer location via symtab.
(FRAME_SPECIFICATION_DYADIC):  Ask for two args in frame command.
Briefly explain MIPS stacks in GDB.
1992-09-18 09:20:15 +00:00

164 lines
4.2 KiB
C

/* Low level MIPS interface to ptrace, for GDB when running under Unix.
Copyright 1988, 1989, 1991, 1992 Free Software Foundation, Inc.
Contributed by Alessandro Forin(af@cs.cmu.edu) at CMU
and by Per Bothner(bothner@cs.wisc.edu) at U.Wisconsin.
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., 675 Mass Ave, Cambridge, MA 02139, USA. */
#include "defs.h"
#include "inferior.h"
#include "gdbcore.h"
/* For now we stub this out; sgi core format is super-hairy (and completely
different in the new release).
For most mips systems, this function is defined in coredep.c. */
#if defined(sgi)
void
fetch_core_registers (core_reg_sect, core_reg_size, which, reg_addr)
char *core_reg_sect;
unsigned core_reg_size;
int which;
unsigned int reg_addr;
{
return;
}
#endif
/* Access to the inferior is only good for native systems, not cross.
I am not sure why this is stubbed out on SGI... --gnu@cygnus.com */
#if defined(sgi) || !defined(GDB_TARGET_IS_MIPS)
/* ARGSUSED */
void
fetch_inferior_registers (regno)
int regno;
{
return;
}
/* ARGSUSED */
void
store_inferior_registers (regno)
int regno;
{
return;
}
#else
/* DECstation native... */
#include <sys/ptrace.h>
/* Map gdb internal register number to ptrace ``address''.
These ``addresses'' are defined in DECstation <sys/ptrace.h> */
#define REGISTER_PTRACE_ADDR(regno) \
(regno < 32 ? GPR_BASE + regno \
: regno == PC_REGNUM ? PC \
: regno == CAUSE_REGNUM ? CAUSE \
: regno == HI_REGNUM ? MMHI \
: regno == LO_REGNUM ? MMLO \
: regno == FCRCS_REGNUM ? FPC_CSR \
: regno == FCRIR_REGNUM ? FPC_EIR \
: regno >= FP0_REGNUM ? FPR_BASE + (regno - FP0_REGNUM) \
: 0)
static const char zerobuf[MAX_REGISTER_RAW_SIZE];
/* Get all registers from the inferior */
void
fetch_inferior_registers (regno)
int regno;
{
register unsigned int regaddr;
char buf[MAX_REGISTER_RAW_SIZE];
register int i;
registers_fetched ();
for (regno = 1; regno < NUM_REGS; regno++)
{
regaddr = REGISTER_PTRACE_ADDR (regno);
for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int))
{
*(int *) &buf[i] = ptrace (PT_READ_U, inferior_pid,
(PTRACE_ARG3_TYPE) regaddr, 0);
regaddr += sizeof (int);
}
supply_register (regno, buf);
}
supply_register (ZERO_REGNUM, zerobuf);
/* Frame ptr reg must appear to be 0; it is faked by stack handling code. */
supply_register (FP_REGNUM, zerobuf);
}
/* Store our register values back into the inferior.
If REGNO is -1, do this for all registers.
Otherwise, REGNO specifies which register (so we can save time). */
void
store_inferior_registers (regno)
int regno;
{
register unsigned int regaddr;
char buf[80];
if (regno == 0)
return;
if (regno > 0)
{
regaddr = REGISTER_PTRACE_ADDR (regno);
errno = 0;
ptrace (PT_WRITE_U, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
read_register (regno));
if (errno != 0)
{
sprintf (buf, "writing register number %d", regno);
perror_with_name (buf);
}
}
else
{
for (regno = 0; regno < NUM_REGS; regno++)
{
if (regno == ZERO_REGNUM || regno == PS_REGNUM
|| regno == BADVADDR_REGNUM || regno == CAUSE_REGNUM
|| regno == FCRIR_REGNUM || regno == FP_REGNUM
|| (regno >= FIRST_EMBED_REGNUM && regno <= LAST_EMBED_REGNUM))
continue;
regaddr = register_addr (regno, 1);
errno = 0;
ptrace (6, inferior_pid, (PTRACE_ARG3_TYPE) regaddr,
read_register (regno));
if (errno != 0)
{
sprintf (buf, "writing all regs, number %d", regno);
perror_with_name (buf);
}
}
}
}
#endif /* sgi */