binutils-gdb/gdb/am29k-tdep.c

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1991-03-29 00:28:29 +08:00
/* Target-machine dependent code for the AMD 29000
Copyright 1990, 1991 Free Software Foundation, Inc.
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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.
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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. */
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#include "defs.h"
#include "gdbcore.h"
#include <stdio.h>
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#include "frame.h"
#include "value.h"
/*#include <sys/param.h> */
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#include "symtab.h"
#include "inferior.h"
extern CORE_ADDR text_start; /* FIXME, kludge... */
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/* 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);
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struct prologue_info *mi = 0;
if (msymbol != NULL)
mi = (struct prologue_info *) msymbol -> info;
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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 must 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.
*/
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insn = read_memory_integer (p, 4);
if ((insn & 0xff00ffff) != (0x5e000100|RAB_HW_REGNUM))
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{
p = pc;
goto done;
}
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. */
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/* 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.
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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 */
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{
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.
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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)))
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{
p += 4;
if (msize != NULL)
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*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))
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&& (insn & 0xff) == reg)
{
p = q + 4;
if (msize != NULL)
*msize = msize0;
}
}
}
done:
if (msymbol != NULL)
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{
if (mi == 0)
{
/* Add a new cache entry. */
mi = (struct prologue_info *)xmalloc (sizeof (struct prologue_info));
msymbol -> info = (char *)mi;
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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, (unsigned *)NULL, (unsigned *)NULL,
(int *)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 & 0xff000000) != 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;
}
else /* A one word tag */
{
if (msize)
*msize = tag1 & 0x7ff;
}
if (is_trans)
*is_trans = ((tag1 & (1<<21)) ? 1 : 0);
if (argcount)
*argcount = (tag1 >> 16) & 0x1f;
if (mfp_used)
*mfp_used = ((tag1 & (1<<22)) ? 1 : 0);
return(1);
}
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/* 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-29k.h for more detail. */
static void
init_frame_info (innermost_frame, fci)
int innermost_frame;
struct frame_info *fci;
{
CORE_ADDR p;
long insn;
unsigned rsize;
unsigned msize;
int mfp_used, trans;
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struct symbol *func;
p = fci->pc;
if (innermost_frame)
fci->frame = read_register (GR1_REGNUM);
else
fci->frame = fci->next_frame + fci->next->rsize;
#if CALL_DUMMY_LOCATION == ON_STACK
This wont work;
#else
if (PC_IN_CALL_DUMMY (p, 0, 0))
#endif
{
fci->rsize = DUMMY_FRAME_RSIZE;
/* This doesn't matter since we never try to get locals or args
from a dummy frame. */
fci->msize = 0;
/* Dummy frames always use a memory frame pointer. */
fci->saved_msp =
read_register_stack_integer (fci->frame + DUMMY_FRAME_RSIZE - 4, 4);
fci->flags |= (TRANSPARENT|MFP_USED);
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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). */
while (p >= text_start
&& ((insn = read_memory_integer (p, 4)) & 0xff000000) != 0)
p -= 4;
if (p < text_start)
{
/* Couldn't find the trace-back tag.
Something strange is going on. */
fci->saved_msp = 0;
fci->rsize = 0;
fci->msize = 0;
fci->flags = TRANSPARENT;
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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. For now we don't care about the argcount or
* whether or not the routine is transparent.
*/
if (examine_tag(p-4,&trans,NULL,&msize,&mfp_used)) /* Found a good tag */
examine_prologue (p, &rsize, 0, 0);
else /* No tag try prologue */
examine_prologue (p, &rsize, &msize, &mfp_used);
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fci->rsize = rsize;
fci->msize = msize;
fci->flags = 0;
if (mfp_used)
fci->flags |= MFP_USED;
if (trans)
fci->flags |= TRANSPARENT;
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if (innermost_frame)
{
fci->saved_msp = read_register (MSP_REGNUM) + msize;
}
else
{
if (mfp_used)
fci->saved_msp =
read_register_stack_integer (fci->frame + rsize - 4, 4);
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else
fci->saved_msp = fci->next->saved_msp + msize;
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}
}
void
init_extra_frame_info (fci)
struct frame_info *fci;
{
if (fci->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, fci);
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else {
/* We're in get_prev_frame_info.
Take care of everything in init_frame_pc. */
;
}
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}
void
init_frame_pc (fromleaf, fci)
int fromleaf;
struct frame_info *fci;
{
fci->pc = (fromleaf ? SAVED_PC_AFTER_CALL (fci->next) :
fci->next ? FRAME_SAVED_PC (fci->next) : read_pc ());
init_frame_info (fromleaf, fci);
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}
/* 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)
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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. */
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);
#ifdef RSTACK_HIGH_ADDR /* Highest allowed address in register stack */
/* If we don't do this 'info register' stops in the middle. */
if (memaddr >= RSTACK_HIGH_ADDR)
{
int val=-1; /* a bogus value */
/* It's in a local register, but off the end of the stack. */
int regnum = (memaddr - rsp) / 4 + LR0_REGNUM;
if (myaddr != NULL)
*(int*)myaddr = val; /* Provide bogusness */
supply_register(regnum,&val); /* More bogusness */
if (lval != NULL)
*lval = lval_register;
if (actual_mem_addr != NULL)
*actual_mem_addr = REGISTER_BYTE (regnum);
}
else
#endif /* RSTACK_HIGH_ADDR */
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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)
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);
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if (lval != NULL)
*lval = lval_memory;
if (actual_mem_addr != NULL)
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*actual_mem_addr = memaddr;
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}
}
/* 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;
{
long buf;
read_register_stack (memaddr, &buf, NULL, NULL);
SWAP_TARGET_AND_HOST (&buf, 4);
return buf;
}
/* 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);
#ifdef RSTACK_HIGH_ADDR /* Highest allowed address in register stack */
/* If we don't do this 'info register' stops in the middle. */
if (memaddr >= RSTACK_HIGH_ADDR)
{
/* It's in a register, but off the end of the stack. */
if (actual_mem_addr != NULL)
*actual_mem_addr = NULL;
}
else
#endif /* RSTACK_HIGH_ADDR */
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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 = NULL;
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}
else
{
/* It's in the memory portion of the register stack. */
if (myaddr != NULL)
write_memory (memaddr, myaddr, 4);
if (actual_mem_addr != NULL)
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*actual_mem_addr = memaddr;
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}
}
/* 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;
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CORE_ADDR addr;
enum lval_type lval;
if (frame == 0)
return;
fi = get_frame_info (frame);
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/* 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)
*(CORE_ADDR *)raw_buffer = fi->frame;
if (lvalp != NULL)
*lvalp = not_lval;
return;
}
else if (regnum == PC_REGNUM)
{
if (raw_buffer != NULL)
*(CORE_ADDR *)raw_buffer = 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)
*(CORE_ADDR *)raw_buffer = fi->next->saved_msp;
else
*(CORE_ADDR *)raw_buffer = read_register (MSP_REGNUM);
}
/* 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)
*(CORE_ADDR *)raw_buffer = read_register (regnum);
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;
}
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/* 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;
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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));
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}
/* 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;
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/* Allocate the new frame. */
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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. */
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read_register_gen (LR0_REGNUM + i / 4, &word);
write_memory (rfb - num_bytes + i, &word, 4);
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}
}
/* 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;
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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));
}
reginv_com (args, fromtty)
char *args;
int fromtty;
{
registers_changed();
if (fromtty)
printf_filtered("Gdb's register cache invalidated.\n");
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}
/* We use this mostly for debugging gdb */
void
_initialize_29k()
{
add_com ("reginv ", class_obscure, reginv_com,
"Invalidate gdb's internal register cache.");
}