0fb34c3a10
* alpha-tdep.c: Fix typo in comment.
* dbxread.c: Fix typo in comment.
* fr30-tdep.c: Fix typo: newline missing after comment.
* mcore-tdep.c: Fix typo in comment.
992 lines
31 KiB
C
992 lines
31 KiB
C
/* Target-machine dependent code for Motorola MCore for GDB, the GNU debugger
|
||
Copyright (C) 1999 Free Software Foundation, Inc.
|
||
|
||
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 "frame.h"
|
||
#include "symtab.h"
|
||
#include "value.h"
|
||
#include "gdbcmd.h"
|
||
|
||
/* Functions declared and used only in this file */
|
||
|
||
static CORE_ADDR mcore_analyze_prologue (struct frame_info *fi, CORE_ADDR pc, int skip_prologue);
|
||
|
||
static struct frame_info *analyze_dummy_frame (CORE_ADDR pc, CORE_ADDR frame);
|
||
|
||
static int get_insn (CORE_ADDR pc);
|
||
|
||
/* Functions exported from this file */
|
||
|
||
int mcore_use_struct_convention (int gcc_p, struct type *type);
|
||
|
||
void _initialize_mcore (void);
|
||
|
||
void mcore_init_extra_frame_info (struct frame_info *fi);
|
||
|
||
CORE_ADDR mcore_frame_saved_pc (struct frame_info *fi);
|
||
|
||
CORE_ADDR mcore_find_callers_reg (struct frame_info *fi, int regnum);
|
||
|
||
CORE_ADDR mcore_frame_args_address (struct frame_info *fi);
|
||
|
||
CORE_ADDR mcore_frame_locals_address (struct frame_info *fi);
|
||
|
||
void mcore_virtual_frame_pointer (CORE_ADDR pc, long *reg, long *offset);
|
||
|
||
CORE_ADDR mcore_push_return_address (CORE_ADDR pc, CORE_ADDR sp);
|
||
|
||
CORE_ADDR mcore_push_arguments (int nargs, value_ptr * args, CORE_ADDR sp,
|
||
unsigned char struct_return, CORE_ADDR struct_addr);
|
||
|
||
void mcore_pop_frame (struct frame_info *fi);
|
||
|
||
CORE_ADDR mcore_skip_prologue (CORE_ADDR pc);
|
||
|
||
CORE_ADDR mcore_frame_chain (struct frame_info *fi);
|
||
|
||
unsigned char *mcore_breakpoint_from_pc (CORE_ADDR * bp_addr, int *bp_size);
|
||
|
||
int mcore_use_struct_convention (int gcc_p, struct type *type);
|
||
|
||
void mcore_store_return_value (struct type *type, char *valbuf);
|
||
|
||
CORE_ADDR mcore_extract_struct_value_address (char *regbuf);
|
||
|
||
void mcore_extract_return_value (struct type *type, char *regbuf, char *valbuf);
|
||
|
||
#ifdef MCORE_DEBUG
|
||
int mcore_debug = 0;
|
||
#endif
|
||
|
||
/* The registers of the Motorola MCore processors */
|
||
/* *INDENT-OFF* */
|
||
char *mcore_register_names[] =
|
||
{ "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
|
||
"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
|
||
"ar0", "ar1", "ar2", "ar3", "ar4", "ar5", "ar6", "ar7",
|
||
"ar8", "ar9", "ar10", "ar11", "ar12", "ar13", "ar14", "ar15",
|
||
"psr", "vbr", "epsr", "fpsr", "epc", "fpc", "ss0", "ss1",
|
||
"ss2", "ss3", "ss4", "gcr", "gsr", "cr13", "cr14", "cr15",
|
||
"cr16", "cr17", "cr18", "cr19", "cr20", "cr21", "cr22", "cr23",
|
||
"cr24", "cr25", "cr26", "cr27", "cr28", "cr29", "cr30", "cr31",
|
||
"pc" };
|
||
/* *INDENT-ON* */
|
||
|
||
|
||
|
||
/* Additional info that we use for managing frames */
|
||
struct frame_extra_info
|
||
{
|
||
/* A generic status word */
|
||
int status;
|
||
|
||
/* Size of this frame */
|
||
int framesize;
|
||
|
||
/* The register that is acting as a frame pointer, if
|
||
it is being used. This is undefined if status
|
||
does not contain the flag MY_FRAME_IN_FP. */
|
||
int fp_regnum;
|
||
};
|
||
|
||
/* frame_extra_info status flags */
|
||
|
||
/* The base of the current frame is actually in the stack pointer.
|
||
This happens when there is no frame pointer (MCore ABI does not
|
||
require a frame pointer) or when we're stopped in the prologue or
|
||
epilogue itself. In these cases, mcore_analyze_prologue will need
|
||
to update fi->frame before returning or analyzing the register
|
||
save instructions. */
|
||
#define MY_FRAME_IN_SP 0x1
|
||
|
||
/* The base of the current frame is in a frame pointer register.
|
||
This register is noted in frame_extra_info->fp_regnum.
|
||
|
||
Note that the existence of an FP might also indicate that the
|
||
function has called alloca. */
|
||
#define MY_FRAME_IN_FP 0x2
|
||
|
||
/* This flag is set to indicate that this frame is the top-most
|
||
frame. This tells frame chain not to bother trying to unwind
|
||
beyond this frame. */
|
||
#define NO_MORE_FRAMES 0x4
|
||
|
||
/* Instruction macros used for analyzing the prologue */
|
||
#define IS_SUBI0(x) (((x) & 0xfe0f) == 0x2400) /* subi r0,oimm5 */
|
||
#define IS_STM(x) (((x) & 0xfff0) == 0x0070) /* stm rf-r15,r0 */
|
||
#define IS_STWx0(x) (((x) & 0xf00f) == 0x9000) /* stw rz,(r0,disp) */
|
||
#define IS_STWxy(x) (((x) & 0xf000) == 0x9000) /* stw rx,(ry,disp) */
|
||
#define IS_MOVx0(x) (((x) & 0xfff0) == 0x1200) /* mov rn,r0 */
|
||
#define IS_LRW1(x) (((x) & 0xff00) == 0x7100) /* lrw r1,literal */
|
||
#define IS_MOVI1(x) (((x) & 0xf80f) == 0x6001) /* movi r1,imm7 */
|
||
#define IS_BGENI1(x) (((x) & 0xfe0f) == 0x3201) /* bgeni r1,imm5 */
|
||
#define IS_BMASKI1(x) (((x) & 0xfe0f) == 0x2C01) /* bmaski r1,imm5 */
|
||
#define IS_ADDI1(x) (((x) & 0xfe0f) == 0x2001) /* addi r1,oimm5 */
|
||
#define IS_SUBI1(x) (((x) & 0xfe0f) == 0x2401) /* subi r1,oimm5 */
|
||
#define IS_RSUBI1(x) (((x) & 0xfe0f) == 0x2801) /* rsubi r1,imm5 */
|
||
#define IS_NOT1(x) (((x) & 0xffff) == 0x01f1) /* not r1 */
|
||
#define IS_ROTLI1(x) (((x) & 0xfe0f) == 0x3801) /* rotli r1,imm5 */
|
||
#define IS_BSETI1(x) (((x) & 0xfe0f) == 0x3401) /* bseti r1,imm5 */
|
||
#define IS_BCLRI1(x) (((x) & 0xfe0f) == 0x3001) /* bclri r1,imm5 */
|
||
#define IS_IXH1(x) (((x) & 0xffff) == 0x1d11) /* ixh r1,r1 */
|
||
#define IS_IXW1(x) (((x) & 0xffff) == 0x1511) /* ixw r1,r1 */
|
||
#define IS_SUB01(x) (((x) & 0xffff) == 0x0510) /* subu r0,r1 */
|
||
#define IS_RTS(x) (((x) & 0xffff) == 0x00cf) /* jmp r15 */
|
||
|
||
#define IS_R1_ADJUSTER(x) \
|
||
(IS_ADDI1(x) || IS_SUBI1(x) || IS_ROTLI1(x) || IS_BSETI1(x) \
|
||
|| IS_BCLRI1(x) || IS_RSUBI1(x) || IS_NOT1(x) \
|
||
|| IS_IXH1(x) || IS_IXW1(x))
|
||
|
||
|
||
#ifdef MCORE_DEBUG
|
||
static void
|
||
mcore_dump_insn (char *commnt, CORE_ADDR pc, int insn)
|
||
{
|
||
if (mcore_debug)
|
||
{
|
||
printf_filtered ("MCORE: %s %08x %08x ",
|
||
commnt, (unsigned int) pc, (unsigned int) insn);
|
||
(*tm_print_insn) (pc, &tm_print_insn_info);
|
||
printf_filtered ("\n");
|
||
}
|
||
}
|
||
#define mcore_insn_debug(args) { if (mcore_debug) printf_filtered args; }
|
||
#else /* !MCORE_DEBUG */
|
||
#define mcore_dump_insn(a,b,c) {}
|
||
#define mcore_insn_debug(args) {}
|
||
#endif
|
||
|
||
/* Given the address at which to insert a breakpoint (BP_ADDR),
|
||
what will that breakpoint be?
|
||
|
||
For MCore, we have a breakpoint instruction. Since all MCore
|
||
instructions are 16 bits, this is all we need, regardless of
|
||
address. bpkt = 0x0000 */
|
||
|
||
unsigned char *
|
||
mcore_breakpoint_from_pc (CORE_ADDR * bp_addr, int *bp_size)
|
||
{
|
||
static char breakpoint[] =
|
||
{0x00, 0x00};
|
||
*bp_size = 2;
|
||
return breakpoint;
|
||
}
|
||
|
||
/* Helper function for several routines below. This funtion simply
|
||
sets up a fake, aka dummy, frame (not a _call_ dummy frame) that
|
||
we can analyze with mcore_analyze_prologue. */
|
||
|
||
static struct frame_info *
|
||
analyze_dummy_frame (CORE_ADDR pc, CORE_ADDR frame)
|
||
{
|
||
static struct frame_info *dummy = NULL;
|
||
|
||
if (dummy == NULL)
|
||
{
|
||
dummy = (struct frame_info *) xmalloc (sizeof (struct frame_info));
|
||
dummy->saved_regs = (CORE_ADDR *) xmalloc (SIZEOF_FRAME_SAVED_REGS);
|
||
dummy->extra_info =
|
||
(struct frame_extra_info *) xmalloc (sizeof (struct frame_extra_info));
|
||
}
|
||
|
||
dummy->next = NULL;
|
||
dummy->prev = NULL;
|
||
dummy->pc = pc;
|
||
dummy->frame = frame;
|
||
dummy->extra_info->status = 0;
|
||
dummy->extra_info->framesize = 0;
|
||
memset (dummy->saved_regs, '\000', SIZEOF_FRAME_SAVED_REGS);
|
||
mcore_analyze_prologue (dummy, 0, 0);
|
||
return dummy;
|
||
}
|
||
|
||
/* Function prologues on the Motorola MCore processors consist of:
|
||
|
||
- adjustments to the stack pointer (r1 used as scratch register)
|
||
- store word/multiples that use r0 as the base address
|
||
- making a copy of r0 into another register (a "frame" pointer)
|
||
|
||
Note that the MCore really doesn't have a real frame pointer.
|
||
Instead, the compiler may copy the SP into a register (usually
|
||
r8) to act as an arg pointer. For our target-dependent purposes,
|
||
the frame info's "frame" member will be the beginning of the
|
||
frame. The SP could, in fact, point below this.
|
||
|
||
The prologue ends when an instruction fails to meet either of
|
||
the first two criteria or when an FP is made. We make a special
|
||
exception for gcc. When compiling unoptimized code, gcc will
|
||
setup stack slots. We need to make sure that we skip the filling
|
||
of these stack slots as much as possible. This is only done
|
||
when SKIP_PROLOGUE is set, so that it does not mess up
|
||
backtraces. */
|
||
|
||
/* Analyze the prologue of frame FI to determine where registers are saved,
|
||
the end of the prologue, etc. Return the address of the first line
|
||
of "real" code (i.e., the end of the prologue). */
|
||
|
||
static CORE_ADDR
|
||
mcore_analyze_prologue (struct frame_info *fi, CORE_ADDR pc, int skip_prologue)
|
||
{
|
||
CORE_ADDR func_addr, func_end, addr, stop;
|
||
CORE_ADDR stack_size;
|
||
int insn, rn;
|
||
int status, fp_regnum, flags;
|
||
int framesize;
|
||
int register_offsets[NUM_REGS];
|
||
char *name;
|
||
|
||
/* If provided, use the PC in the frame to look up the
|
||
start of this function. */
|
||
pc = (fi == NULL ? pc : fi->pc);
|
||
|
||
/* Find the start of this function. */
|
||
status = find_pc_partial_function (pc, &name, &func_addr, &func_end);
|
||
|
||
/* If the start of this function could not be found or if the debbuger
|
||
is stopped at the first instruction of the prologue, do nothing. */
|
||
if (status == 0)
|
||
return pc;
|
||
|
||
/* If the debugger is entry function, give up. */
|
||
if (func_addr == entry_point_address ())
|
||
{
|
||
if (fi != NULL)
|
||
fi->extra_info->status |= NO_MORE_FRAMES;
|
||
return pc;
|
||
}
|
||
|
||
/* At the start of a function, our frame is in the stack pointer. */
|
||
flags = MY_FRAME_IN_SP;
|
||
|
||
/* Start decoding the prologue. We start by checking two special cases:
|
||
|
||
1. We're about to return
|
||
2. We're at the first insn of the prologue.
|
||
|
||
If we're about to return, our frame has already been deallocated.
|
||
If we are stopped at the first instruction of a prologue,
|
||
then our frame has not yet been set up. */
|
||
|
||
/* Get the first insn from memory (all MCore instructions are 16 bits) */
|
||
mcore_insn_debug (("MCORE: starting prologue decoding\n"));
|
||
insn = get_insn (pc);
|
||
mcore_dump_insn ("got 1: ", pc, insn);
|
||
|
||
/* Check for return. */
|
||
if (fi != NULL && IS_RTS (insn))
|
||
{
|
||
mcore_insn_debug (("MCORE: got jmp r15"));
|
||
if (fi->next == NULL)
|
||
fi->frame = read_sp ();
|
||
return fi->pc;
|
||
}
|
||
|
||
/* Check for first insn of prologue */
|
||
if (fi != NULL && fi->pc == func_addr)
|
||
{
|
||
if (fi->next == NULL)
|
||
fi->frame = read_sp ();
|
||
return fi->pc;
|
||
}
|
||
|
||
/* Figure out where to stop scanning */
|
||
stop = (fi ? fi->pc : func_end);
|
||
|
||
/* Don't walk off the end of the function */
|
||
stop = (stop > func_end ? func_end : stop);
|
||
|
||
/* REGISTER_OFFSETS will contain offsets, from the top of the frame
|
||
(NOT the frame pointer), for the various saved registers or -1
|
||
if the register is not saved. */
|
||
for (rn = 0; rn < NUM_REGS; rn++)
|
||
register_offsets[rn] = -1;
|
||
|
||
/* Analyze the prologue. Things we determine from analyzing the
|
||
prologue include:
|
||
* the size of the frame
|
||
* where saved registers are located (and which are saved)
|
||
* FP used? */
|
||
mcore_insn_debug (("MCORE: Scanning prologue: func_addr=0x%x, stop=0x%x\n",
|
||
(unsigned int) func_addr, (unsigned int) stop));
|
||
|
||
framesize = 0;
|
||
for (addr = func_addr; addr < stop; addr += 2)
|
||
{
|
||
/* Get next insn */
|
||
insn = get_insn (addr);
|
||
mcore_dump_insn ("got 2: ", addr, insn);
|
||
|
||
if (IS_SUBI0 (insn))
|
||
{
|
||
int offset = 1 + ((insn >> 4) & 0x1f);
|
||
mcore_insn_debug (("MCORE: got subi r0,%d; continuing\n", offset));
|
||
framesize += offset;
|
||
continue;
|
||
}
|
||
else if (IS_STM (insn))
|
||
{
|
||
/* Spill register(s) */
|
||
int offset;
|
||
int start_register;
|
||
|
||
/* BIG WARNING! The MCore ABI does not restrict functions
|
||
to taking only one stack allocation. Therefore, when
|
||
we save a register, we record the offset of where it was
|
||
saved relative to the current framesize. This will
|
||
then give an offset from the SP upon entry to our
|
||
function. Remember, framesize is NOT constant until
|
||
we're done scanning the prologue. */
|
||
start_register = (insn & 0xf);
|
||
mcore_insn_debug (("MCORE: got stm r%d-r15,(r0)\n", start_register));
|
||
|
||
for (rn = start_register, offset = 0; rn <= 15; rn++, offset += 4)
|
||
{
|
||
register_offsets[rn] = framesize - offset;
|
||
mcore_insn_debug (("MCORE: r%d saved at 0x%x (offset %d)\n", rn,
|
||
register_offsets[rn], offset));
|
||
}
|
||
mcore_insn_debug (("MCORE: continuing\n"));
|
||
continue;
|
||
}
|
||
else if (IS_STWx0 (insn))
|
||
{
|
||
/* Spill register: see note for IS_STM above. */
|
||
int imm;
|
||
|
||
rn = (insn >> 8) & 0xf;
|
||
imm = (insn >> 4) & 0xf;
|
||
register_offsets[rn] = framesize - (imm << 2);
|
||
mcore_insn_debug (("MCORE: r%d saved at offset 0x%x\n", rn, register_offsets[rn]));
|
||
mcore_insn_debug (("MCORE: continuing\n"));
|
||
continue;
|
||
}
|
||
else if (IS_MOVx0 (insn))
|
||
{
|
||
/* We have a frame pointer, so this prologue is over. Note
|
||
the register which is acting as the frame pointer. */
|
||
flags |= MY_FRAME_IN_FP;
|
||
flags &= ~MY_FRAME_IN_SP;
|
||
fp_regnum = insn & 0xf;
|
||
mcore_insn_debug (("MCORE: Found a frame pointer: r%d\n", fp_regnum));
|
||
|
||
/* If we found an FP, we're at the end of the prologue. */
|
||
mcore_insn_debug (("MCORE: end of prologue\n"));
|
||
if (skip_prologue)
|
||
continue;
|
||
|
||
/* If we're decoding prologue, stop here. */
|
||
addr += 2;
|
||
break;
|
||
}
|
||
else if (IS_STWxy (insn) && (flags & MY_FRAME_IN_FP) && ((insn & 0xf) == fp_regnum))
|
||
{
|
||
/* Special case. Skip over stack slot allocs, too. */
|
||
mcore_insn_debug (("MCORE: push arg onto stack.\n"));
|
||
continue;
|
||
}
|
||
else if (IS_LRW1 (insn) || IS_MOVI1 (insn)
|
||
|| IS_BGENI1 (insn) || IS_BMASKI1 (insn))
|
||
{
|
||
int adjust = 0;
|
||
int offset = 0;
|
||
int insn2;
|
||
|
||
mcore_insn_debug (("MCORE: looking at large frame\n"));
|
||
if (IS_LRW1 (insn))
|
||
{
|
||
adjust =
|
||
read_memory_integer ((addr + 2 + ((insn & 0xff) << 2)) & 0xfffffffc, 4);
|
||
}
|
||
else if (IS_MOVI1 (insn))
|
||
adjust = (insn >> 4) & 0x7f;
|
||
else if (IS_BGENI1 (insn))
|
||
adjust = 1 << ((insn >> 4) & 0x1f);
|
||
else /* IS_BMASKI (insn) */
|
||
adjust = (1 << (adjust >> 4) & 0x1f) - 1;
|
||
|
||
mcore_insn_debug (("MCORE: base framesize=0x%x\n", adjust));
|
||
|
||
/* May have zero or more insns which modify r1 */
|
||
mcore_insn_debug (("MCORE: looking for r1 adjusters...\n"));
|
||
offset = 2;
|
||
insn2 = get_insn (addr + offset);
|
||
while (IS_R1_ADJUSTER (insn2))
|
||
{
|
||
int imm;
|
||
|
||
imm = (insn2 >> 4) & 0x1f;
|
||
mcore_dump_insn ("got 3: ", addr + offset, insn);
|
||
if (IS_ADDI1 (insn2))
|
||
{
|
||
adjust += (imm + 1);
|
||
mcore_insn_debug (("MCORE: addi r1,%d\n", imm + 1));
|
||
}
|
||
else if (IS_SUBI1 (insn2))
|
||
{
|
||
adjust -= (imm + 1);
|
||
mcore_insn_debug (("MCORE: subi r1,%d\n", imm + 1));
|
||
}
|
||
else if (IS_RSUBI1 (insn2))
|
||
{
|
||
adjust = imm - adjust;
|
||
mcore_insn_debug (("MCORE: rsubi r1,%d\n", imm + 1));
|
||
}
|
||
else if (IS_NOT1 (insn2))
|
||
{
|
||
adjust = ~adjust;
|
||
mcore_insn_debug (("MCORE: not r1\n"));
|
||
}
|
||
else if (IS_ROTLI1 (insn2))
|
||
{
|
||
adjust <<= imm;
|
||
mcore_insn_debug (("MCORE: rotli r1,%d\n", imm + 1));
|
||
}
|
||
else if (IS_BSETI1 (insn2))
|
||
{
|
||
adjust |= (1 << imm);
|
||
mcore_insn_debug (("MCORE: bseti r1,%d\n", imm));
|
||
}
|
||
else if (IS_BCLRI1 (insn2))
|
||
{
|
||
adjust &= ~(1 << imm);
|
||
mcore_insn_debug (("MCORE: bclri r1,%d\n", imm));
|
||
}
|
||
else if (IS_IXH1 (insn2))
|
||
{
|
||
adjust *= 3;
|
||
mcore_insn_debug (("MCORE: ix.h r1,r1\n"));
|
||
}
|
||
else if (IS_IXW1 (insn2))
|
||
{
|
||
adjust *= 5;
|
||
mcore_insn_debug (("MCORE: ix.w r1,r1\n"));
|
||
}
|
||
|
||
offset += 2;
|
||
insn2 = get_insn (addr + offset);
|
||
};
|
||
|
||
mcore_insn_debug (("MCORE: done looking for r1 adjusters\n"));
|
||
|
||
/* If the next insn adjusts the stack pointer, we keep everything;
|
||
if not, we scrap it and we've found the end of the prologue. */
|
||
if (IS_SUB01 (insn2))
|
||
{
|
||
addr += offset;
|
||
framesize += adjust;
|
||
mcore_insn_debug (("MCORE: found stack adjustment of 0x%x bytes.\n", adjust));
|
||
mcore_insn_debug (("MCORE: skipping to new address 0x%x\n", addr));
|
||
mcore_insn_debug (("MCORE: continuing\n"));
|
||
continue;
|
||
}
|
||
|
||
/* None of these instructions are prologue, so don't touch
|
||
anything. */
|
||
mcore_insn_debug (("MCORE: no subu r1,r0, NOT altering framesize.\n"));
|
||
break;
|
||
}
|
||
|
||
/* This is not a prologue insn, so stop here. */
|
||
mcore_insn_debug (("MCORE: insn is not a prologue insn -- ending scan\n"));
|
||
break;
|
||
}
|
||
|
||
mcore_insn_debug (("MCORE: done analyzing prologue\n"));
|
||
mcore_insn_debug (("MCORE: prologue end = 0x%x\n", addr));
|
||
|
||
/* Save everything we have learned about this frame into FI. */
|
||
if (fi != NULL)
|
||
{
|
||
fi->extra_info->framesize = framesize;
|
||
fi->extra_info->fp_regnum = fp_regnum;
|
||
fi->extra_info->status = flags;
|
||
|
||
/* Fix the frame pointer. When gcc uses r8 as a frame pointer,
|
||
it is really an arg ptr. We adjust fi->frame to be a "real"
|
||
frame pointer. */
|
||
if (fi->next == NULL)
|
||
{
|
||
if (fi->extra_info->status & MY_FRAME_IN_SP)
|
||
fi->frame = read_sp () + framesize;
|
||
else
|
||
fi->frame = read_register (fp_regnum) + framesize;
|
||
}
|
||
|
||
/* Note where saved registers are stored. The offsets in REGISTER_OFFSETS
|
||
are computed relative to the top of the frame. */
|
||
for (rn = 0; rn < NUM_REGS; rn++)
|
||
{
|
||
if (register_offsets[rn] >= 0)
|
||
{
|
||
fi->saved_regs[rn] = fi->frame - register_offsets[rn];
|
||
mcore_insn_debug (("Saved register %s stored at 0x%08x, value=0x%08x\n",
|
||
mcore_register_names[rn], fi->saved_regs[rn],
|
||
read_memory_integer (fi->saved_regs[rn], 4)));
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Return addr of first non-prologue insn. */
|
||
return addr;
|
||
}
|
||
|
||
/* Given a GDB frame, determine the address of the calling function's frame.
|
||
This will be used to create a new GDB frame struct, and then
|
||
INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame. */
|
||
|
||
CORE_ADDR
|
||
mcore_frame_chain (struct frame_info * fi)
|
||
{
|
||
struct frame_info *dummy;
|
||
CORE_ADDR callers_addr;
|
||
|
||
/* Analyze the prologue of this function. */
|
||
if (fi->extra_info->status == 0)
|
||
mcore_analyze_prologue (fi, 0, 0);
|
||
|
||
/* If mcore_analyze_prologue set NO_MORE_FRAMES, quit now. */
|
||
if (fi->extra_info->status & NO_MORE_FRAMES)
|
||
return 0;
|
||
|
||
/* Now that we've analyzed our prologue, we can start to ask
|
||
for information about our caller. The easiest way to do
|
||
this is to analyze our caller's prologue.
|
||
|
||
If our caller has a frame pointer, then we need to find
|
||
the value of that register upon entry to our frame.
|
||
This value is either in fi->saved_regs[rn] if it's saved,
|
||
or it's still in a register.
|
||
|
||
If our caller does not have a frame pointer, then his frame base
|
||
is <our base> + -<caller's frame size>. */
|
||
dummy = analyze_dummy_frame (FRAME_SAVED_PC (fi), fi->frame);
|
||
|
||
if (dummy->extra_info->status & MY_FRAME_IN_FP)
|
||
{
|
||
int fp = dummy->extra_info->fp_regnum;
|
||
|
||
/* Our caller has a frame pointer. */
|
||
if (fi->saved_regs[fp] != 0)
|
||
{
|
||
/* The "FP" was saved on the stack. Don't forget to adjust
|
||
the "FP" with the framesize to get a real FP. */
|
||
callers_addr = read_memory_integer (fi->saved_regs[fp], REGISTER_SIZE)
|
||
+ dummy->extra_info->framesize;
|
||
}
|
||
else
|
||
{
|
||
/* It's still in the register. Don't forget to adjust
|
||
the "FP" with the framesize to get a real FP. */
|
||
callers_addr = read_register (fp) + dummy->extra_info->framesize;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* Our caller does not have a frame pointer. */
|
||
callers_addr = fi->frame + dummy->extra_info->framesize;
|
||
}
|
||
|
||
return callers_addr;
|
||
}
|
||
|
||
/* Skip the prologue of the function at PC. */
|
||
|
||
CORE_ADDR
|
||
mcore_skip_prologue (CORE_ADDR pc)
|
||
{
|
||
CORE_ADDR func_addr, func_end;
|
||
struct symtab_and_line sal;
|
||
|
||
/* If we have line debugging information, then the end of the
|
||
prologue should be the first assembly instruction of the first
|
||
source line */
|
||
if (find_pc_partial_function (pc, NULL, &func_addr, &func_end))
|
||
{
|
||
sal = find_pc_line (func_addr, 0);
|
||
if (sal.end && sal.end < func_end)
|
||
return sal.end;
|
||
}
|
||
|
||
return mcore_analyze_prologue (NULL, pc, 1);
|
||
}
|
||
|
||
/* Return the address at which function arguments are offset. */
|
||
CORE_ADDR
|
||
mcore_frame_args_address (struct frame_info * fi)
|
||
{
|
||
return fi->frame - fi->extra_info->framesize;
|
||
}
|
||
|
||
CORE_ADDR
|
||
mcore_frame_locals_address (struct frame_info * fi)
|
||
{
|
||
return fi->frame - fi->extra_info->framesize;
|
||
}
|
||
|
||
/* Return the frame pointer in use at address PC. */
|
||
|
||
void
|
||
mcore_virtual_frame_pointer (CORE_ADDR pc, long *reg, long *offset)
|
||
{
|
||
struct frame_info *dummy = analyze_dummy_frame (pc, 0);
|
||
if (dummy->extra_info->status & MY_FRAME_IN_SP)
|
||
{
|
||
*reg = SP_REGNUM;
|
||
*offset = 0;
|
||
}
|
||
else
|
||
{
|
||
*reg = dummy->extra_info->fp_regnum;
|
||
*offset = 0;
|
||
}
|
||
}
|
||
|
||
/* Find the value of register REGNUM in frame FI. */
|
||
|
||
CORE_ADDR
|
||
mcore_find_callers_reg (struct frame_info *fi, int regnum)
|
||
{
|
||
for (; fi != NULL; fi = fi->next)
|
||
{
|
||
if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
|
||
return generic_read_register_dummy (fi->pc, fi->frame, regnum);
|
||
else if (fi->saved_regs[regnum] != 0)
|
||
return read_memory_integer (fi->saved_regs[regnum],
|
||
REGISTER_SIZE);
|
||
}
|
||
|
||
return read_register (regnum);
|
||
}
|
||
|
||
/* Find the saved pc in frame FI. */
|
||
|
||
CORE_ADDR
|
||
mcore_frame_saved_pc (struct frame_info * fi)
|
||
{
|
||
|
||
if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
|
||
return generic_read_register_dummy (fi->pc, fi->frame, PC_REGNUM);
|
||
else
|
||
return mcore_find_callers_reg (fi, PR_REGNUM);
|
||
}
|
||
|
||
/* INFERIOR FUNCTION CALLS */
|
||
|
||
/* This routine gets called when either the user uses the "return"
|
||
command, or the call dummy breakpoint gets hit. */
|
||
|
||
void
|
||
mcore_pop_frame (struct frame_info *fi)
|
||
{
|
||
int rn;
|
||
|
||
if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
|
||
generic_pop_dummy_frame ();
|
||
else
|
||
{
|
||
/* Write out the PC we saved. */
|
||
write_register (PC_REGNUM, FRAME_SAVED_PC (fi));
|
||
|
||
/* Restore any saved registers. */
|
||
for (rn = 0; rn < NUM_REGS; rn++)
|
||
{
|
||
if (fi->saved_regs[rn] != 0)
|
||
{
|
||
ULONGEST value;
|
||
|
||
value = read_memory_unsigned_integer (fi->saved_regs[rn],
|
||
REGISTER_SIZE);
|
||
write_register (rn, value);
|
||
}
|
||
}
|
||
|
||
/* Actually cut back the stack. */
|
||
write_register (SP_REGNUM, FRAME_FP (fi));
|
||
}
|
||
|
||
/* Finally, throw away any cached frame information. */
|
||
flush_cached_frames ();
|
||
}
|
||
|
||
/* Setup arguments and PR for a call to the target. First six arguments
|
||
go in FIRST_ARGREG -> LAST_ARGREG, subsequent args go on to the stack.
|
||
|
||
* Types with lengths greater than REGISTER_SIZE may not be split
|
||
between registers and the stack, and they must start in an even-numbered
|
||
register. Subsequent args will go onto the stack.
|
||
|
||
* Structs may be split between registers and stack, left-aligned.
|
||
|
||
* If the function returns a struct which will not fit into registers (it's
|
||
more than eight bytes), we must allocate for that, too. Gdb will tell
|
||
us where this buffer is (STRUCT_ADDR), and we simply place it into
|
||
FIRST_ARGREG, since the MCORE treats struct returns (of less than eight
|
||
bytes) as hidden first arguments. */
|
||
|
||
CORE_ADDR
|
||
mcore_push_arguments (int nargs, value_ptr * args, CORE_ADDR sp,
|
||
unsigned char struct_return, CORE_ADDR struct_addr)
|
||
{
|
||
int argreg;
|
||
int argnum;
|
||
struct stack_arg
|
||
{
|
||
int len;
|
||
char *val;
|
||
}
|
||
*stack_args;
|
||
int nstack_args = 0;
|
||
|
||
stack_args = (struct stack_arg *) alloca (nargs * sizeof (struct stack_arg));
|
||
|
||
argreg = FIRST_ARGREG;
|
||
|
||
/* Align the stack. This is mostly a nop, but not always. It will be needed
|
||
if we call a function which has argument overflow. */
|
||
sp &= ~3;
|
||
|
||
/* If this function returns a struct which does not fit in the
|
||
return registers, we must pass a buffer to the function
|
||
which it can use to save the return value. */
|
||
if (struct_return)
|
||
write_register (argreg++, struct_addr);
|
||
|
||
/* FIXME: what about unions? */
|
||
for (argnum = 0; argnum < nargs; argnum++)
|
||
{
|
||
char *val = (char *) VALUE_CONTENTS (args[argnum]);
|
||
int len = TYPE_LENGTH (VALUE_TYPE (args[argnum]));
|
||
struct type *type = VALUE_TYPE (args[argnum]);
|
||
int olen;
|
||
|
||
mcore_insn_debug (("MCORE PUSH: argreg=%d; len=%d; %s\n",
|
||
argreg, len, TYPE_CODE (type) == TYPE_CODE_STRUCT ? "struct" : "not struct"));
|
||
/* Arguments larger than a register must start in an even
|
||
numbered register. */
|
||
olen = len;
|
||
|
||
if (TYPE_CODE (type) != TYPE_CODE_STRUCT && len > REGISTER_SIZE && argreg % 2)
|
||
{
|
||
mcore_insn_debug (("MCORE PUSH: %d > REGISTER_SIZE: and %s is not even\n",
|
||
len, mcore_register_names[argreg]));
|
||
argreg++;
|
||
}
|
||
|
||
if ((argreg <= LAST_ARGREG && len <= (LAST_ARGREG - argreg + 1) * REGISTER_SIZE)
|
||
|| (TYPE_CODE (type) == TYPE_CODE_STRUCT))
|
||
{
|
||
/* Something that will fit entirely into registers (or a struct
|
||
which may be split between registers and stack). */
|
||
mcore_insn_debug (("MCORE PUSH: arg %d going into regs\n", argnum));
|
||
|
||
if (TYPE_CODE (type) == TYPE_CODE_STRUCT && olen < REGISTER_SIZE)
|
||
{
|
||
/* Small structs must be right aligned within the register,
|
||
the most significant bits are undefined. */
|
||
write_register (argreg, extract_unsigned_integer (val, len));
|
||
argreg++;
|
||
len = 0;
|
||
}
|
||
|
||
while (len > 0 && argreg <= LAST_ARGREG)
|
||
{
|
||
write_register (argreg, extract_unsigned_integer (val, REGISTER_SIZE));
|
||
argreg++;
|
||
val += REGISTER_SIZE;
|
||
len -= REGISTER_SIZE;
|
||
}
|
||
|
||
/* Any remainder for the stack is noted below... */
|
||
}
|
||
else if (TYPE_CODE (VALUE_TYPE (args[argnum])) != TYPE_CODE_STRUCT
|
||
&& len > REGISTER_SIZE)
|
||
{
|
||
/* All subsequent args go onto the stack. */
|
||
mcore_insn_debug (("MCORE PUSH: does not fit into regs, going onto stack\n"));
|
||
argnum = LAST_ARGREG + 1;
|
||
}
|
||
|
||
if (len > 0)
|
||
{
|
||
/* Note that this must be saved onto the stack */
|
||
mcore_insn_debug (("MCORE PUSH: adding arg %d to stack\n", argnum));
|
||
stack_args[nstack_args].val = val;
|
||
stack_args[nstack_args].len = len;
|
||
nstack_args++;
|
||
}
|
||
|
||
}
|
||
|
||
/* We're done with registers and stack allocation. Now do the actual
|
||
stack pushes. */
|
||
while (nstack_args--)
|
||
{
|
||
sp -= stack_args[nstack_args].len;
|
||
write_memory (sp, stack_args[nstack_args].val, stack_args[nstack_args].len);
|
||
}
|
||
|
||
/* Return adjusted stack pointer. */
|
||
return sp;
|
||
}
|
||
|
||
/* Store the return address for the call dummy. For MCore, we've
|
||
opted to use generic call dummies, so we simply store the
|
||
CALL_DUMMY_ADDRESS into the PR register (r15). */
|
||
|
||
CORE_ADDR
|
||
mcore_push_return_address (CORE_ADDR pc, CORE_ADDR sp)
|
||
{
|
||
write_register (PR_REGNUM, CALL_DUMMY_ADDRESS ());
|
||
return sp;
|
||
}
|
||
|
||
/* Setting/getting return values from functions.
|
||
|
||
The Motorola MCore processors use r2/r3 to return anything
|
||
not larger than 32 bits. Everything else goes into a caller-
|
||
supplied buffer, which is passed in via a hidden first
|
||
argument.
|
||
|
||
For gdb, this leaves us two routes, based on what
|
||
USE_STRUCT_CONVENTION (mcore_use_struct_convention) returns.
|
||
If this macro returns 1, gdb will call STORE_STRUCT_RETURN and
|
||
EXTRACT_STRUCT_VALUE_ADDRESS.
|
||
|
||
If USE_STRUCT_CONVENTION retruns 0, then gdb uses STORE_RETURN_VALUE
|
||
and EXTRACT_RETURN_VALUE to store/fetch the functions return value. */
|
||
|
||
/* Should we use EXTRACT_STRUCT_VALUE_ADDRESS instead of
|
||
EXTRACT_RETURN_VALUE? GCC_P is true if compiled with gcc
|
||
and TYPE is the type (which is known to be struct, union or array). */
|
||
|
||
int
|
||
mcore_use_struct_convention (int gcc_p, struct type *type)
|
||
{
|
||
return (TYPE_LENGTH (type) > 8);
|
||
}
|
||
|
||
/* Where is the return value saved? For MCore, a pointer to
|
||
this buffer was passed as a hidden first argument, so
|
||
just return that address. */
|
||
|
||
CORE_ADDR
|
||
mcore_extract_struct_value_address (char *regbuf)
|
||
{
|
||
return extract_address (regbuf + REGISTER_BYTE (FIRST_ARGREG), REGISTER_SIZE);
|
||
}
|
||
|
||
/* Given a function which returns a value of type TYPE, extract the
|
||
the function's return value and place the result into VALBUF.
|
||
REGBUF is the register contents of the target. */
|
||
|
||
void
|
||
mcore_extract_return_value (struct type *type, char *regbuf, char *valbuf)
|
||
{
|
||
/* Copy the return value (starting) in RETVAL_REGNUM to VALBUF. */
|
||
/* Only getting the first byte! if len = 1, we need the last byte of
|
||
the register, not the first. */
|
||
memcpy (valbuf, regbuf + REGISTER_BYTE (RETVAL_REGNUM) +
|
||
(TYPE_LENGTH (type) < 4 ? 4 - TYPE_LENGTH (type) : 0), TYPE_LENGTH (type));
|
||
}
|
||
|
||
/* Store the return value in VALBUF (of type TYPE) where the caller
|
||
expects to see it.
|
||
|
||
Values less than 32 bits are stored in r2, right justified and
|
||
sign or zero extended.
|
||
|
||
Values between 32 and 64 bits are stored in r2 (most
|
||
significant word) and r3 (least significant word, left justified).
|
||
Note that this includes structures of less than eight bytes, too. */
|
||
|
||
void
|
||
mcore_store_return_value (struct type *type, char *valbuf)
|
||
{
|
||
int value_size;
|
||
int return_size;
|
||
int offset;
|
||
char *zeros;
|
||
|
||
value_size = TYPE_LENGTH (type);
|
||
|
||
/* Return value fits into registers. */
|
||
return_size = (value_size + REGISTER_SIZE - 1) & ~(REGISTER_SIZE - 1);
|
||
offset = REGISTER_BYTE (RETVAL_REGNUM) + (return_size - value_size);
|
||
zeros = alloca (return_size);
|
||
memset (zeros, 0, return_size);
|
||
|
||
write_register_bytes (REGISTER_BYTE (RETVAL_REGNUM), zeros, return_size);
|
||
write_register_bytes (offset, valbuf, value_size);
|
||
}
|
||
|
||
/* Initialize our target-dependent "stuff" for this newly created frame.
|
||
|
||
This includes allocating space for saved registers and analyzing
|
||
the prologue of this frame. */
|
||
|
||
void
|
||
mcore_init_extra_frame_info (struct frame_info *fi)
|
||
{
|
||
if (fi->next)
|
||
fi->pc = FRAME_SAVED_PC (fi->next);
|
||
|
||
frame_saved_regs_zalloc (fi);
|
||
|
||
fi->extra_info = (struct frame_extra_info *)
|
||
frame_obstack_alloc (sizeof (struct frame_extra_info));
|
||
fi->extra_info->status = 0;
|
||
fi->extra_info->framesize = 0;
|
||
|
||
if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
|
||
{
|
||
/* We need to setup fi->frame here because run_stack_dummy gets it wrong
|
||
by assuming it's always FP. */
|
||
fi->frame = generic_read_register_dummy (fi->pc, fi->frame, SP_REGNUM);
|
||
}
|
||
else
|
||
mcore_analyze_prologue (fi, 0, 0);
|
||
}
|
||
|
||
/* Get an insturction from memory. */
|
||
|
||
static int
|
||
get_insn (CORE_ADDR pc)
|
||
{
|
||
char buf[4];
|
||
int status = read_memory_nobpt (pc, buf, 2);
|
||
if (status != 0)
|
||
return 0;
|
||
|
||
return extract_unsigned_integer (buf, 2);
|
||
}
|
||
|
||
void
|
||
_initialize_mcore_tdep (void)
|
||
{
|
||
extern int print_insn_mcore (bfd_vma, disassemble_info *);
|
||
tm_print_insn = print_insn_mcore;
|
||
|
||
#ifdef MCORE_DEBUG
|
||
add_show_from_set (add_set_cmd ("mcoredebug", no_class,
|
||
var_boolean, (char *) &mcore_debug,
|
||
"Set mcore debugging.\n", &setlist),
|
||
&showlist);
|
||
#endif
|
||
}
|