839 lines
26 KiB
C
839 lines
26 KiB
C
/* Target-machine dependent code for the Intel 960
|
||
Copyright 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
|
||
Contributed by Intel Corporation.
|
||
examine_prologue and other parts contributed by Wind River Systems.
|
||
|
||
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 "symtab.h"
|
||
#include "value.h"
|
||
#include "frame.h"
|
||
#include "floatformat.h"
|
||
#include "target.h"
|
||
#include "gdbcore.h"
|
||
|
||
static CORE_ADDR next_insn PARAMS ((CORE_ADDR memaddr,
|
||
unsigned int *pword1,
|
||
unsigned int *pword2));
|
||
|
||
/* Does the specified function use the "struct returning" convention
|
||
or the "value returning" convention? The "value returning" convention
|
||
almost invariably returns the entire value in registers. The
|
||
"struct returning" convention often returns the entire value in
|
||
memory, and passes a pointer (out of or into the function) saying
|
||
where the value (is or should go).
|
||
|
||
Since this sometimes depends on whether it was compiled with GCC,
|
||
this is also an argument. This is used in call_function to build a
|
||
stack, and in value_being_returned to print return values.
|
||
|
||
On i960, a structure is returned in registers g0-g3, if it will fit.
|
||
If it's more than 16 bytes long, g13 pointed to it on entry. */
|
||
|
||
int
|
||
i960_use_struct_convention (gcc_p, type)
|
||
int gcc_p;
|
||
struct type *type;
|
||
{
|
||
return (TYPE_LENGTH (type) > 16);
|
||
}
|
||
|
||
/* gdb960 is always running on a non-960 host. Check its characteristics.
|
||
This routine must be called as part of gdb initialization. */
|
||
|
||
static void
|
||
check_host()
|
||
{
|
||
int i;
|
||
|
||
static struct typestruct {
|
||
int hostsize; /* Size of type on host */
|
||
int i960size; /* Size of type on i960 */
|
||
char *typename; /* Name of type, for error msg */
|
||
} types[] = {
|
||
{ sizeof(short), 2, "short" },
|
||
{ sizeof(int), 4, "int" },
|
||
{ sizeof(long), 4, "long" },
|
||
{ sizeof(float), 4, "float" },
|
||
{ sizeof(double), 8, "double" },
|
||
{ sizeof(char *), 4, "pointer" },
|
||
};
|
||
#define TYPELEN (sizeof(types) / sizeof(struct typestruct))
|
||
|
||
/* Make sure that host type sizes are same as i960
|
||
*/
|
||
for ( i = 0; i < TYPELEN; i++ ){
|
||
if ( types[i].hostsize != types[i].i960size ){
|
||
printf_unfiltered("sizeof(%s) != %d: PROCEED AT YOUR OWN RISK!\n",
|
||
types[i].typename, types[i].i960size );
|
||
}
|
||
|
||
}
|
||
}
|
||
|
||
/* Examine an i960 function prologue, recording the addresses at which
|
||
registers are saved explicitly by the prologue code, and returning
|
||
the address of the first instruction after the prologue (but not
|
||
after the instruction at address LIMIT, as explained below).
|
||
|
||
LIMIT places an upper bound on addresses of the instructions to be
|
||
examined. If the prologue code scan reaches LIMIT, the scan is
|
||
aborted and LIMIT is returned. This is used, when examining the
|
||
prologue for the current frame, to keep examine_prologue () from
|
||
claiming that a given register has been saved when in fact the
|
||
instruction that saves it has not yet been executed. LIMIT is used
|
||
at other times to stop the scan when we hit code after the true
|
||
function prologue (e.g. for the first source line) which might
|
||
otherwise be mistaken for function prologue.
|
||
|
||
The format of the function prologue matched by this routine is
|
||
derived from examination of the source to gcc960 1.21, particularly
|
||
the routine i960_function_prologue (). A "regular expression" for
|
||
the function prologue is given below:
|
||
|
||
(lda LRn, g14
|
||
mov g14, g[0-7]
|
||
(mov 0, g14) | (lda 0, g14))?
|
||
|
||
(mov[qtl]? g[0-15], r[4-15])*
|
||
((addo [1-31], sp, sp) | (lda n(sp), sp))?
|
||
(st[qtl]? g[0-15], n(fp))*
|
||
|
||
(cmpobne 0, g14, LFn
|
||
mov sp, g14
|
||
lda 0x30(sp), sp
|
||
LFn: stq g0, (g14)
|
||
stq g4, 0x10(g14)
|
||
stq g8, 0x20(g14))?
|
||
|
||
(st g14, n(fp))?
|
||
(mov g13,r[4-15])?
|
||
*/
|
||
|
||
/* Macros for extracting fields from i960 instructions. */
|
||
|
||
#define BITMASK(pos, width) (((0x1 << (width)) - 1) << (pos))
|
||
#define EXTRACT_FIELD(val, pos, width) ((val) >> (pos) & BITMASK (0, width))
|
||
|
||
#define REG_SRC1(insn) EXTRACT_FIELD (insn, 0, 5)
|
||
#define REG_SRC2(insn) EXTRACT_FIELD (insn, 14, 5)
|
||
#define REG_SRCDST(insn) EXTRACT_FIELD (insn, 19, 5)
|
||
#define MEM_SRCDST(insn) EXTRACT_FIELD (insn, 19, 5)
|
||
#define MEMA_OFFSET(insn) EXTRACT_FIELD (insn, 0, 12)
|
||
|
||
/* Fetch the instruction at ADDR, returning 0 if ADDR is beyond LIM or
|
||
is not the address of a valid instruction, the address of the next
|
||
instruction beyond ADDR otherwise. *PWORD1 receives the first word
|
||
of the instruction, and (for two-word instructions), *PWORD2 receives
|
||
the second. */
|
||
|
||
#define NEXT_PROLOGUE_INSN(addr, lim, pword1, pword2) \
|
||
(((addr) < (lim)) ? next_insn (addr, pword1, pword2) : 0)
|
||
|
||
static CORE_ADDR
|
||
examine_prologue (ip, limit, frame_addr, fsr)
|
||
register CORE_ADDR ip;
|
||
register CORE_ADDR limit;
|
||
CORE_ADDR frame_addr;
|
||
struct frame_saved_regs *fsr;
|
||
{
|
||
register CORE_ADDR next_ip;
|
||
register int src, dst;
|
||
register unsigned int *pcode;
|
||
unsigned int insn1, insn2;
|
||
int size;
|
||
int within_leaf_prologue;
|
||
CORE_ADDR save_addr;
|
||
static unsigned int varargs_prologue_code [] =
|
||
{
|
||
0x3507a00c, /* cmpobne 0x0, g14, LFn */
|
||
0x5cf01601, /* mov sp, g14 */
|
||
0x8c086030, /* lda 0x30(sp), sp */
|
||
0xb2879000, /* LFn: stq g0, (g14) */
|
||
0xb2a7a010, /* stq g4, 0x10(g14) */
|
||
0xb2c7a020 /* stq g8, 0x20(g14) */
|
||
};
|
||
|
||
/* Accept a leaf procedure prologue code fragment if present.
|
||
Note that ip might point to either the leaf or non-leaf
|
||
entry point; we look for the non-leaf entry point first: */
|
||
|
||
within_leaf_prologue = 0;
|
||
if ((next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2))
|
||
&& ((insn1 & 0xfffff000) == 0x8cf00000 /* lda LRx, g14 (MEMA) */
|
||
|| (insn1 & 0xfffffc60) == 0x8cf03000)) /* lda LRx, g14 (MEMB) */
|
||
{
|
||
within_leaf_prologue = 1;
|
||
next_ip = NEXT_PROLOGUE_INSN (next_ip, limit, &insn1, &insn2);
|
||
}
|
||
|
||
/* Now look for the prologue code at a leaf entry point: */
|
||
|
||
if (next_ip
|
||
&& (insn1 & 0xff87ffff) == 0x5c80161e /* mov g14, gx */
|
||
&& REG_SRCDST (insn1) <= G0_REGNUM + 7)
|
||
{
|
||
within_leaf_prologue = 1;
|
||
if ((next_ip = NEXT_PROLOGUE_INSN (next_ip, limit, &insn1, &insn2))
|
||
&& (insn1 == 0x8cf00000 /* lda 0, g14 */
|
||
|| insn1 == 0x5cf01e00)) /* mov 0, g14 */
|
||
{
|
||
ip = next_ip;
|
||
next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2);
|
||
within_leaf_prologue = 0;
|
||
}
|
||
}
|
||
|
||
/* If something that looks like the beginning of a leaf prologue
|
||
has been seen, but the remainder of the prologue is missing, bail.
|
||
We don't know what we've got. */
|
||
|
||
if (within_leaf_prologue)
|
||
return (ip);
|
||
|
||
/* Accept zero or more instances of "mov[qtl]? gx, ry", where y >= 4.
|
||
This may cause us to mistake the moving of a register
|
||
parameter to a local register for the saving of a callee-saved
|
||
register, but that can't be helped, since with the
|
||
"-fcall-saved" flag, any register can be made callee-saved. */
|
||
|
||
while (next_ip
|
||
&& (insn1 & 0xfc802fb0) == 0x5c000610
|
||
&& (dst = REG_SRCDST (insn1)) >= (R0_REGNUM + 4))
|
||
{
|
||
src = REG_SRC1 (insn1);
|
||
size = EXTRACT_FIELD (insn1, 24, 2) + 1;
|
||
save_addr = frame_addr + ((dst - R0_REGNUM) * 4);
|
||
while (size--)
|
||
{
|
||
fsr->regs[src++] = save_addr;
|
||
save_addr += 4;
|
||
}
|
||
ip = next_ip;
|
||
next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2);
|
||
}
|
||
|
||
/* Accept an optional "addo n, sp, sp" or "lda n(sp), sp". */
|
||
|
||
if (next_ip &&
|
||
((insn1 & 0xffffffe0) == 0x59084800 /* addo n, sp, sp */
|
||
|| (insn1 & 0xfffff000) == 0x8c086000 /* lda n(sp), sp (MEMA) */
|
||
|| (insn1 & 0xfffffc60) == 0x8c087400)) /* lda n(sp), sp (MEMB) */
|
||
{
|
||
ip = next_ip;
|
||
next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2);
|
||
}
|
||
|
||
/* Accept zero or more instances of "st[qtl]? gx, n(fp)".
|
||
This may cause us to mistake the copying of a register
|
||
parameter to the frame for the saving of a callee-saved
|
||
register, but that can't be helped, since with the
|
||
"-fcall-saved" flag, any register can be made callee-saved.
|
||
We can, however, refuse to accept a save of register g14,
|
||
since that is matched explicitly below. */
|
||
|
||
while (next_ip &&
|
||
((insn1 & 0xf787f000) == 0x9287e000 /* stl? gx, n(fp) (MEMA) */
|
||
|| (insn1 & 0xf787fc60) == 0x9287f400 /* stl? gx, n(fp) (MEMB) */
|
||
|| (insn1 & 0xef87f000) == 0xa287e000 /* st[tq] gx, n(fp) (MEMA) */
|
||
|| (insn1 & 0xef87fc60) == 0xa287f400) /* st[tq] gx, n(fp) (MEMB) */
|
||
&& ((src = MEM_SRCDST (insn1)) != G14_REGNUM))
|
||
{
|
||
save_addr = frame_addr + ((insn1 & BITMASK (12, 1))
|
||
? insn2 : MEMA_OFFSET (insn1));
|
||
size = (insn1 & BITMASK (29, 1)) ? ((insn1 & BITMASK (28, 1)) ? 4 : 3)
|
||
: ((insn1 & BITMASK (27, 1)) ? 2 : 1);
|
||
while (size--)
|
||
{
|
||
fsr->regs[src++] = save_addr;
|
||
save_addr += 4;
|
||
}
|
||
ip = next_ip;
|
||
next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2);
|
||
}
|
||
|
||
/* Accept the varargs prologue code if present. */
|
||
|
||
size = sizeof (varargs_prologue_code) / sizeof (int);
|
||
pcode = varargs_prologue_code;
|
||
while (size-- && next_ip && *pcode++ == insn1)
|
||
{
|
||
ip = next_ip;
|
||
next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2);
|
||
}
|
||
|
||
/* Accept an optional "st g14, n(fp)". */
|
||
|
||
if (next_ip &&
|
||
((insn1 & 0xfffff000) == 0x92f7e000 /* st g14, n(fp) (MEMA) */
|
||
|| (insn1 & 0xfffffc60) == 0x92f7f400)) /* st g14, n(fp) (MEMB) */
|
||
{
|
||
fsr->regs[G14_REGNUM] = frame_addr + ((insn1 & BITMASK (12, 1))
|
||
? insn2 : MEMA_OFFSET (insn1));
|
||
ip = next_ip;
|
||
next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2);
|
||
}
|
||
|
||
/* Accept zero or one instance of "mov g13, ry", where y >= 4.
|
||
This is saving the address where a struct should be returned. */
|
||
|
||
if (next_ip
|
||
&& (insn1 & 0xff802fbf) == 0x5c00061d
|
||
&& (dst = REG_SRCDST (insn1)) >= (R0_REGNUM + 4))
|
||
{
|
||
save_addr = frame_addr + ((dst - R0_REGNUM) * 4);
|
||
fsr->regs[G0_REGNUM+13] = save_addr;
|
||
ip = next_ip;
|
||
#if 0 /* We'll need this once there is a subsequent instruction examined. */
|
||
next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn1, &insn2);
|
||
#endif
|
||
}
|
||
|
||
return (ip);
|
||
}
|
||
|
||
/* Given an ip value corresponding to the start of a function,
|
||
return the ip of the first instruction after the function
|
||
prologue. */
|
||
|
||
CORE_ADDR
|
||
skip_prologue (ip)
|
||
CORE_ADDR (ip);
|
||
{
|
||
struct frame_saved_regs saved_regs_dummy;
|
||
struct symtab_and_line sal;
|
||
CORE_ADDR limit;
|
||
|
||
sal = find_pc_line (ip, 0);
|
||
limit = (sal.end) ? sal.end : 0xffffffff;
|
||
|
||
return (examine_prologue (ip, limit, (CORE_ADDR) 0, &saved_regs_dummy));
|
||
}
|
||
|
||
/* Put here the code to store, into a struct frame_saved_regs,
|
||
the addresses of the saved registers of frame described by FRAME_INFO.
|
||
This includes special registers such as pc and fp saved in special
|
||
ways in the stack frame. sp is even more special:
|
||
the address we return for it IS the sp for the next frame.
|
||
|
||
We cache the result of doing this in the frame_obstack, since it is
|
||
fairly expensive. */
|
||
|
||
void
|
||
frame_find_saved_regs (fi, fsr)
|
||
struct frame_info *fi;
|
||
struct frame_saved_regs *fsr;
|
||
{
|
||
register CORE_ADDR next_addr;
|
||
register CORE_ADDR *saved_regs;
|
||
register int regnum;
|
||
register struct frame_saved_regs *cache_fsr;
|
||
CORE_ADDR ip;
|
||
struct symtab_and_line sal;
|
||
CORE_ADDR limit;
|
||
|
||
if (!fi->fsr)
|
||
{
|
||
cache_fsr = (struct frame_saved_regs *)
|
||
frame_obstack_alloc (sizeof (struct frame_saved_regs));
|
||
memset (cache_fsr, '\0', sizeof (struct frame_saved_regs));
|
||
fi->fsr = cache_fsr;
|
||
|
||
/* Find the start and end of the function prologue. If the PC
|
||
is in the function prologue, we only consider the part that
|
||
has executed already. */
|
||
|
||
ip = get_pc_function_start (fi->pc);
|
||
sal = find_pc_line (ip, 0);
|
||
limit = (sal.end && sal.end < fi->pc) ? sal.end: fi->pc;
|
||
|
||
examine_prologue (ip, limit, fi->frame, cache_fsr);
|
||
|
||
/* Record the addresses at which the local registers are saved.
|
||
Strictly speaking, we should only do this for non-leaf procedures,
|
||
but no one will ever look at these values if it is a leaf procedure,
|
||
since local registers are always caller-saved. */
|
||
|
||
next_addr = (CORE_ADDR) fi->frame;
|
||
saved_regs = cache_fsr->regs;
|
||
for (regnum = R0_REGNUM; regnum <= R15_REGNUM; regnum++)
|
||
{
|
||
*saved_regs++ = next_addr;
|
||
next_addr += 4;
|
||
}
|
||
|
||
cache_fsr->regs[FP_REGNUM] = cache_fsr->regs[PFP_REGNUM];
|
||
}
|
||
|
||
*fsr = *fi->fsr;
|
||
|
||
/* Fetch the value of the sp from memory every time, since it
|
||
is conceivable that it has changed since the cache was flushed.
|
||
This unfortunately undoes much of the savings from caching the
|
||
saved register values. I suggest adding an argument to
|
||
get_frame_saved_regs () specifying the register number we're
|
||
interested in (or -1 for all registers). This would be passed
|
||
through to FRAME_FIND_SAVED_REGS (), permitting more efficient
|
||
computation of saved register addresses (e.g., on the i960,
|
||
we don't have to examine the prologue to find local registers).
|
||
-- markf@wrs.com
|
||
FIXME, we don't need to refetch this, since the cache is cleared
|
||
every time the child process is restarted. If GDB itself
|
||
modifies SP, it has to clear the cache by hand (does it?). -gnu */
|
||
|
||
fsr->regs[SP_REGNUM] = read_memory_integer (fsr->regs[SP_REGNUM], 4);
|
||
}
|
||
|
||
/* Return the address of the argument block for the frame
|
||
described by FI. Returns 0 if the address is unknown. */
|
||
|
||
CORE_ADDR
|
||
frame_args_address (fi, must_be_correct)
|
||
struct frame_info *fi;
|
||
{
|
||
struct frame_saved_regs fsr;
|
||
CORE_ADDR ap;
|
||
|
||
/* If g14 was saved in the frame by the function prologue code, return
|
||
the saved value. If the frame is current and we are being sloppy,
|
||
return the value of g14. Otherwise, return zero. */
|
||
|
||
get_frame_saved_regs (fi, &fsr);
|
||
if (fsr.regs[G14_REGNUM])
|
||
ap = read_memory_integer (fsr.regs[G14_REGNUM],4);
|
||
else
|
||
{
|
||
if (must_be_correct)
|
||
return 0; /* Don't cache this result */
|
||
if (get_next_frame (fi))
|
||
ap = 0;
|
||
else
|
||
ap = read_register (G14_REGNUM);
|
||
if (ap == 0)
|
||
ap = fi->frame;
|
||
}
|
||
fi->arg_pointer = ap; /* Cache it for next time */
|
||
return ap;
|
||
}
|
||
|
||
/* Return the address of the return struct for the frame
|
||
described by FI. Returns 0 if the address is unknown. */
|
||
|
||
CORE_ADDR
|
||
frame_struct_result_address (fi)
|
||
struct frame_info *fi;
|
||
{
|
||
struct frame_saved_regs fsr;
|
||
CORE_ADDR ap;
|
||
|
||
/* If the frame is non-current, check to see if g14 was saved in the
|
||
frame by the function prologue code; return the saved value if so,
|
||
zero otherwise. If the frame is current, return the value of g14.
|
||
|
||
FIXME, shouldn't this use the saved value as long as we are past
|
||
the function prologue, and only use the current value if we have
|
||
no saved value and are at TOS? -- gnu@cygnus.com */
|
||
|
||
if (get_next_frame (fi))
|
||
{
|
||
get_frame_saved_regs (fi, &fsr);
|
||
if (fsr.regs[G13_REGNUM])
|
||
ap = read_memory_integer (fsr.regs[G13_REGNUM],4);
|
||
else
|
||
ap = 0;
|
||
}
|
||
else
|
||
ap = read_register (G13_REGNUM);
|
||
|
||
return ap;
|
||
}
|
||
|
||
/* Return address to which the currently executing leafproc will return,
|
||
or 0 if ip is not in a leafproc (or if we can't tell if it is).
|
||
|
||
Do this by finding the starting address of the routine in which ip lies.
|
||
If the instruction there is "mov g14, gx" (where x is in [0,7]), this
|
||
is a leafproc and the return address is in register gx. Well, this is
|
||
true unless the return address points at a RET instruction in the current
|
||
procedure, which indicates that we have a 'dual entry' routine that
|
||
has been entered through the CALL entry point. */
|
||
|
||
CORE_ADDR
|
||
leafproc_return (ip)
|
||
CORE_ADDR ip; /* ip from currently executing function */
|
||
{
|
||
register struct minimal_symbol *msymbol;
|
||
char *p;
|
||
int dst;
|
||
unsigned int insn1, insn2;
|
||
CORE_ADDR return_addr;
|
||
|
||
if ((msymbol = lookup_minimal_symbol_by_pc (ip)) != NULL)
|
||
{
|
||
if ((p = strchr(SYMBOL_NAME (msymbol), '.')) && STREQ (p, ".lf"))
|
||
{
|
||
if (next_insn (SYMBOL_VALUE_ADDRESS (msymbol), &insn1, &insn2)
|
||
&& (insn1 & 0xff87ffff) == 0x5c80161e /* mov g14, gx */
|
||
&& (dst = REG_SRCDST (insn1)) <= G0_REGNUM + 7)
|
||
{
|
||
/* Get the return address. If the "mov g14, gx"
|
||
instruction hasn't been executed yet, read
|
||
the return address from g14; otherwise, read it
|
||
from the register into which g14 was moved. */
|
||
|
||
return_addr =
|
||
read_register ((ip == SYMBOL_VALUE_ADDRESS (msymbol))
|
||
? G14_REGNUM : dst);
|
||
|
||
/* We know we are in a leaf procedure, but we don't know
|
||
whether the caller actually did a "bal" to the ".lf"
|
||
entry point, or a normal "call" to the non-leaf entry
|
||
point one instruction before. In the latter case, the
|
||
return address will be the address of a "ret"
|
||
instruction within the procedure itself. We test for
|
||
this below. */
|
||
|
||
if (!next_insn (return_addr, &insn1, &insn2)
|
||
|| (insn1 & 0xff000000) != 0xa000000 /* ret */
|
||
|| lookup_minimal_symbol_by_pc (return_addr) != msymbol)
|
||
return (return_addr);
|
||
}
|
||
}
|
||
}
|
||
|
||
return (0);
|
||
}
|
||
|
||
/* Immediately after a function call, return the saved pc.
|
||
Can't go through the frames for this because on some machines
|
||
the new frame is not set up until the new function executes
|
||
some instructions.
|
||
On the i960, the frame *is* set up immediately after the call,
|
||
unless the function is a leaf procedure. */
|
||
|
||
CORE_ADDR
|
||
saved_pc_after_call (frame)
|
||
struct frame_info *frame;
|
||
{
|
||
CORE_ADDR saved_pc;
|
||
|
||
saved_pc = leafproc_return (get_frame_pc (frame));
|
||
if (!saved_pc)
|
||
saved_pc = FRAME_SAVED_PC (frame);
|
||
|
||
return saved_pc;
|
||
}
|
||
|
||
/* Discard from the stack the innermost frame,
|
||
restoring all saved registers. */
|
||
|
||
void
|
||
pop_frame ()
|
||
{
|
||
register struct frame_info *current_fi, *prev_fi;
|
||
register int i;
|
||
CORE_ADDR save_addr;
|
||
CORE_ADDR leaf_return_addr;
|
||
struct frame_saved_regs fsr;
|
||
char local_regs_buf[16 * 4];
|
||
|
||
current_fi = get_current_frame ();
|
||
|
||
/* First, undo what the hardware does when we return.
|
||
If this is a non-leaf procedure, restore local registers from
|
||
the save area in the calling frame. Otherwise, load the return
|
||
address obtained from leafproc_return () into the rip. */
|
||
|
||
leaf_return_addr = leafproc_return (current_fi->pc);
|
||
if (!leaf_return_addr)
|
||
{
|
||
/* Non-leaf procedure. Restore local registers, incl IP. */
|
||
prev_fi = get_prev_frame (current_fi);
|
||
read_memory (prev_fi->frame, local_regs_buf, sizeof (local_regs_buf));
|
||
write_register_bytes (REGISTER_BYTE (R0_REGNUM), local_regs_buf,
|
||
sizeof (local_regs_buf));
|
||
|
||
/* Restore frame pointer. */
|
||
write_register (FP_REGNUM, prev_fi->frame);
|
||
}
|
||
else
|
||
{
|
||
/* Leaf procedure. Just restore the return address into the IP. */
|
||
write_register (RIP_REGNUM, leaf_return_addr);
|
||
}
|
||
|
||
/* Now restore any global regs that the current function had saved. */
|
||
get_frame_saved_regs (current_fi, &fsr);
|
||
for (i = G0_REGNUM; i < G14_REGNUM; i++)
|
||
{
|
||
if (save_addr = fsr.regs[i])
|
||
write_register (i, read_memory_integer (save_addr, 4));
|
||
}
|
||
|
||
/* Flush the frame cache, create a frame for the new innermost frame,
|
||
and make it the current frame. */
|
||
|
||
flush_cached_frames ();
|
||
}
|
||
|
||
/* Given a 960 stop code (fault or trace), return the signal which
|
||
corresponds. */
|
||
|
||
enum target_signal
|
||
i960_fault_to_signal (fault)
|
||
int fault;
|
||
{
|
||
switch (fault)
|
||
{
|
||
case 0: return TARGET_SIGNAL_BUS; /* parallel fault */
|
||
case 1: return TARGET_SIGNAL_UNKNOWN;
|
||
case 2: return TARGET_SIGNAL_ILL; /* operation fault */
|
||
case 3: return TARGET_SIGNAL_FPE; /* arithmetic fault */
|
||
case 4: return TARGET_SIGNAL_FPE; /* floating point fault */
|
||
|
||
/* constraint fault. This appears not to distinguish between
|
||
a range constraint fault (which should be SIGFPE) and a privileged
|
||
fault (which should be SIGILL). */
|
||
case 5: return TARGET_SIGNAL_ILL;
|
||
|
||
case 6: return TARGET_SIGNAL_SEGV; /* virtual memory fault */
|
||
|
||
/* protection fault. This is for an out-of-range argument to
|
||
"calls". I guess it also could be SIGILL. */
|
||
case 7: return TARGET_SIGNAL_SEGV;
|
||
|
||
case 8: return TARGET_SIGNAL_BUS; /* machine fault */
|
||
case 9: return TARGET_SIGNAL_BUS; /* structural fault */
|
||
case 0xa: return TARGET_SIGNAL_ILL; /* type fault */
|
||
case 0xb: return TARGET_SIGNAL_UNKNOWN; /* reserved fault */
|
||
case 0xc: return TARGET_SIGNAL_BUS; /* process fault */
|
||
case 0xd: return TARGET_SIGNAL_SEGV; /* descriptor fault */
|
||
case 0xe: return TARGET_SIGNAL_BUS; /* event fault */
|
||
case 0xf: return TARGET_SIGNAL_UNKNOWN; /* reserved fault */
|
||
case 0x10: return TARGET_SIGNAL_TRAP; /* single-step trace */
|
||
case 0x11: return TARGET_SIGNAL_TRAP; /* branch trace */
|
||
case 0x12: return TARGET_SIGNAL_TRAP; /* call trace */
|
||
case 0x13: return TARGET_SIGNAL_TRAP; /* return trace */
|
||
case 0x14: return TARGET_SIGNAL_TRAP; /* pre-return trace */
|
||
case 0x15: return TARGET_SIGNAL_TRAP; /* supervisor call trace */
|
||
case 0x16: return TARGET_SIGNAL_TRAP; /* breakpoint trace */
|
||
default: return TARGET_SIGNAL_UNKNOWN;
|
||
}
|
||
}
|
||
|
||
/****************************************/
|
||
/* MEM format */
|
||
/****************************************/
|
||
|
||
struct tabent {
|
||
char *name;
|
||
char numops;
|
||
};
|
||
|
||
static int /* returns instruction length: 4 or 8 */
|
||
mem( memaddr, word1, word2, noprint )
|
||
unsigned long memaddr;
|
||
unsigned long word1, word2;
|
||
int noprint; /* If TRUE, return instruction length, but
|
||
don't output any text. */
|
||
{
|
||
int i, j;
|
||
int len;
|
||
int mode;
|
||
int offset;
|
||
const char *reg1, *reg2, *reg3;
|
||
|
||
/* This lookup table is too sparse to make it worth typing in, but not
|
||
* so large as to make a sparse array necessary. We allocate the
|
||
* table at runtime, initialize all entries to empty, and copy the
|
||
* real ones in from an initialization table.
|
||
*
|
||
* NOTE: In this table, the meaning of 'numops' is:
|
||
* 1: single operand
|
||
* 2: 2 operands, load instruction
|
||
* -2: 2 operands, store instruction
|
||
*/
|
||
static struct tabent *mem_tab = NULL;
|
||
/* Opcodes of 0x8X, 9X, aX, bX, and cX must be in the table. */
|
||
#define MEM_MIN 0x80
|
||
#define MEM_MAX 0xcf
|
||
#define MEM_SIZ ((MEM_MAX-MEM_MIN+1) * sizeof(struct tabent))
|
||
|
||
static struct { int opcode; char *name; char numops; } mem_init[] = {
|
||
0x80, "ldob", 2,
|
||
0x82, "stob", -2,
|
||
0x84, "bx", 1,
|
||
0x85, "balx", 2,
|
||
0x86, "callx", 1,
|
||
0x88, "ldos", 2,
|
||
0x8a, "stos", -2,
|
||
0x8c, "lda", 2,
|
||
0x90, "ld", 2,
|
||
0x92, "st", -2,
|
||
0x98, "ldl", 2,
|
||
0x9a, "stl", -2,
|
||
0xa0, "ldt", 2,
|
||
0xa2, "stt", -2,
|
||
0xb0, "ldq", 2,
|
||
0xb2, "stq", -2,
|
||
0xc0, "ldib", 2,
|
||
0xc2, "stib", -2,
|
||
0xc8, "ldis", 2,
|
||
0xca, "stis", -2,
|
||
0, NULL, 0
|
||
};
|
||
|
||
if ( mem_tab == NULL ){
|
||
mem_tab = (struct tabent *) xmalloc( MEM_SIZ );
|
||
memset( mem_tab, '\0', MEM_SIZ );
|
||
for ( i = 0; mem_init[i].opcode != 0; i++ ){
|
||
j = mem_init[i].opcode - MEM_MIN;
|
||
mem_tab[j].name = mem_init[i].name;
|
||
mem_tab[j].numops = mem_init[i].numops;
|
||
}
|
||
}
|
||
|
||
i = ((word1 >> 24) & 0xff) - MEM_MIN;
|
||
mode = (word1 >> 10) & 0xf;
|
||
|
||
if ( (mem_tab[i].name != NULL) /* Valid instruction */
|
||
&& ((mode == 5) || (mode >=12)) ){ /* With 32-bit displacement */
|
||
len = 8;
|
||
} else {
|
||
len = 4;
|
||
}
|
||
|
||
if ( noprint ){
|
||
return len;
|
||
}
|
||
abort ();
|
||
}
|
||
|
||
/* Read the i960 instruction at 'memaddr' and return the address of
|
||
the next instruction after that, or 0 if 'memaddr' is not the
|
||
address of a valid instruction. The first word of the instruction
|
||
is stored at 'pword1', and the second word, if any, is stored at
|
||
'pword2'. */
|
||
|
||
static CORE_ADDR
|
||
next_insn (memaddr, pword1, pword2)
|
||
unsigned int *pword1, *pword2;
|
||
CORE_ADDR memaddr;
|
||
{
|
||
int len;
|
||
char buf[8];
|
||
|
||
/* Read the two (potential) words of the instruction at once,
|
||
to eliminate the overhead of two calls to read_memory ().
|
||
FIXME: Loses if the first one is readable but the second is not
|
||
(e.g. last word of the segment). */
|
||
|
||
read_memory (memaddr, buf, 8);
|
||
*pword1 = extract_unsigned_integer (buf, 4);
|
||
*pword2 = extract_unsigned_integer (buf + 4, 4);
|
||
|
||
/* Divide instruction set into classes based on high 4 bits of opcode*/
|
||
|
||
switch ((*pword1 >> 28) & 0xf)
|
||
{
|
||
case 0x0:
|
||
case 0x1: /* ctrl */
|
||
|
||
case 0x2:
|
||
case 0x3: /* cobr */
|
||
|
||
case 0x5:
|
||
case 0x6:
|
||
case 0x7: /* reg */
|
||
len = 4;
|
||
break;
|
||
|
||
case 0x8:
|
||
case 0x9:
|
||
case 0xa:
|
||
case 0xb:
|
||
case 0xc:
|
||
len = mem (memaddr, *pword1, *pword2, 1);
|
||
break;
|
||
|
||
default: /* invalid instruction */
|
||
len = 0;
|
||
break;
|
||
}
|
||
|
||
if (len)
|
||
return memaddr + len;
|
||
else
|
||
return 0;
|
||
}
|
||
|
||
/* 'start_frame' is a variable in the MON960 runtime startup routine
|
||
that contains the frame pointer of the 'start' routine (the routine
|
||
that calls 'main'). By reading its contents out of remote memory,
|
||
we can tell where the frame chain ends: backtraces should halt before
|
||
they display this frame. */
|
||
|
||
int
|
||
mon960_frame_chain_valid (chain, curframe)
|
||
CORE_ADDR chain;
|
||
struct frame_info *curframe;
|
||
{
|
||
struct symbol *sym;
|
||
struct minimal_symbol *msymbol;
|
||
|
||
/* crtmon960.o is an assembler module that is assumed to be linked
|
||
* first in an i80960 executable. It contains the true entry point;
|
||
* it performs startup up initialization and then calls 'main'.
|
||
*
|
||
* 'sf' is the name of a variable in crtmon960.o that is set
|
||
* during startup to the address of the first frame.
|
||
*
|
||
* 'a' is the address of that variable in 80960 memory.
|
||
*/
|
||
static char sf[] = "start_frame";
|
||
CORE_ADDR a;
|
||
|
||
|
||
chain &= ~0x3f; /* Zero low 6 bits because previous frame pointers
|
||
contain return status info in them. */
|
||
if ( chain == 0 ){
|
||
return 0;
|
||
}
|
||
|
||
sym = lookup_symbol(sf, 0, VAR_NAMESPACE, (int *)NULL,
|
||
(struct symtab **)NULL);
|
||
if ( sym != 0 ){
|
||
a = SYMBOL_VALUE (sym);
|
||
} else {
|
||
msymbol = lookup_minimal_symbol (sf, NULL, NULL);
|
||
if (msymbol == NULL)
|
||
return 0;
|
||
a = SYMBOL_VALUE_ADDRESS (msymbol);
|
||
}
|
||
|
||
return ( chain != read_memory_integer(a,4) );
|
||
}
|
||
|
||
void
|
||
_initialize_i960_tdep ()
|
||
{
|
||
check_host ();
|
||
|
||
tm_print_insn = print_insn_i960;
|
||
}
|