Initial revision

1 files changed, 629 insertions, 0 deletions

diff --git a/gdb/m88k-tdep.c b/gdb/m88k-tdep.c
new file mode 100644
index 00000000000..f82cb764d06
--- /dev/null
+++ b/gdb/m88k-tdep.c
@@ -0,0 +1,629 @@
+/* Target-machine dependent code for Motorola 88000 series, for GDB.
+   Copyright 1988, 1990, 1991, 1994, 1995 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 "inferior.h"
+#include "value.h"
+#include "gdbcore.h"
+#include "symtab.h"
+#include "setjmp.h"
+#include "value.h"
+
+/* Size of an instruction */
+#define	BYTES_PER_88K_INSN	4
+
+void frame_find_saved_regs ();
+
+/* Is this target an m88110?  Otherwise assume m88100.  This has
+   relevance for the ways in which we screw with instruction pointers.  */
+
+int target_is_m88110 = 0;
+
+/* The m88k kernel aligns all instructions on 4-byte boundaries.  The
+   kernel also uses the least significant two bits for its own hocus
+   pocus.  When gdb receives an address from the kernel, it needs to
+   preserve those right-most two bits, but gdb also needs to be careful
+   to realize that those two bits are not really a part of the address
+   of an instruction.  Shrug.  */
+
+CORE_ADDR
+m88k_addr_bits_remove (addr)
+     CORE_ADDR addr;
+{
+  return ((addr) & ~3);
+}
+
+
+/* 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.
+
+   For us, the frame address is its stack pointer value, so we look up
+   the function prologue to determine the caller's sp value, and return it.  */
+
+CORE_ADDR
+frame_chain (thisframe)
+     struct frame_info *thisframe;
+{
+
+  frame_find_saved_regs (thisframe, (struct frame_saved_regs *) 0);
+  /* NOTE:  this depends on frame_find_saved_regs returning the VALUE, not
+ 	    the ADDRESS, of SP_REGNUM.  It also depends on the cache of
+	    frame_find_saved_regs results.  */
+  if (thisframe->fsr->regs[SP_REGNUM])
+    return thisframe->fsr->regs[SP_REGNUM];
+  else
+    return thisframe->frame;	/* Leaf fn -- next frame up has same SP. */
+}
+
+int
+frameless_function_invocation (frame)
+     struct frame_info *frame;
+{
+
+  frame_find_saved_regs (frame, (struct frame_saved_regs *) 0);
+  /* NOTE:  this depends on frame_find_saved_regs returning the VALUE, not
+ 	    the ADDRESS, of SP_REGNUM.  It also depends on the cache of
+	    frame_find_saved_regs results.  */
+  if (frame->fsr->regs[SP_REGNUM])
+    return 0;			/* Frameful -- return addr saved somewhere */
+  else
+    return 1;			/* Frameless -- no saved return address */
+}
+
+void
+init_extra_frame_info (fromleaf, frame)
+     int fromleaf;
+     struct frame_info *frame;
+{
+  frame->fsr = 0;			/* Not yet allocated */
+  frame->args_pointer = 0;		/* Unknown */
+  frame->locals_pointer = 0;	/* Unknown */
+}
+
+/* Examine an m88k 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 gcc 1.95, particularly
+   the routine output_prologue () in config/out-m88k.c.
+
+   subu r31,r31,n			# stack pointer update
+
+   (st rn,r31,offset)?			# save incoming regs
+   (st.d rn,r31,offset)?
+
+   (addu r30,r31,n)?			# frame pointer update
+
+   (pic sequence)?			# PIC code prologue
+
+   (or   rn,rm,0)?			# Move parameters to other regs
+*/
+
+/* Macros for extracting fields from instructions.  */
+
+#define BITMASK(pos, width) (((0x1 << (width)) - 1) << (pos))
+#define EXTRACT_FIELD(val, pos, width) ((val) >> (pos) & BITMASK (0, width))
+#define	SUBU_OFFSET(x)	((unsigned)(x & 0xFFFF))
+#define	ST_OFFSET(x)	((unsigned)((x) & 0xFFFF))
+#define	ST_SRC(x)	EXTRACT_FIELD ((x), 21, 5)
+#define	ADDU_OFFSET(x)	((unsigned)(x & 0xFFFF))
+
+/*
+ * prologue_insn_tbl is a table of instructions which may comprise a
+ * function prologue.  Associated with each table entry (corresponding
+ * to a single instruction or group of instructions), is an action.
+ * This action is used by examine_prologue (below) to determine
+ * the state of certain machine registers and where the stack frame lives.
+ */
+
+enum prologue_insn_action {
+  PIA_SKIP,			/* don't care what the instruction does */
+  PIA_NOTE_ST,			/* note register stored and where */
+  PIA_NOTE_STD,			/* note pair of registers stored and where */
+  PIA_NOTE_SP_ADJUSTMENT,	/* note stack pointer adjustment */
+  PIA_NOTE_FP_ASSIGNMENT,	/* note frame pointer assignment */
+  PIA_NOTE_PROLOGUE_END,	/* no more prologue */
+};
+
+struct prologue_insns {
+    unsigned long insn;
+    unsigned long mask;
+    enum prologue_insn_action action;
+};
+
+struct prologue_insns prologue_insn_tbl[] = {
+  /* Various register move instructions */
+  { 0x58000000, 0xf800ffff, PIA_SKIP },		/* or/or.u with immed of 0 */
+  { 0xf4005800, 0xfc1fffe0, PIA_SKIP },		/* or rd, r0, rs */
+  { 0xf4005800, 0xfc00ffff, PIA_SKIP },		/* or rd, rs, r0 */
+
+  /* Stack pointer setup: "subu sp, sp, n" where n is a multiple of 8 */
+  { 0x67ff0000, 0xffff0007, PIA_NOTE_SP_ADJUSTMENT },
+
+  /* Frame pointer assignment: "addu r30, r31, n" */
+  { 0x63df0000, 0xffff0000, PIA_NOTE_FP_ASSIGNMENT },
+
+  /* Store to stack instructions; either "st rx, sp, n" or "st.d rx, sp, n" */
+  { 0x241f0000, 0xfc1f0000, PIA_NOTE_ST },	/* st rx, sp, n */
+  { 0x201f0000, 0xfc1f0000, PIA_NOTE_STD },	/* st.d rs, sp, n */
+
+  /* Instructions needed for setting up r25 for pic code. */
+  { 0x5f200000, 0xffff0000, PIA_SKIP },		/* or.u r25, r0, offset_high */
+  { 0xcc000002, 0xffffffff, PIA_SKIP },		/* bsr.n Lab */
+  { 0x5b390000, 0xffff0000, PIA_SKIP },		/* or r25, r25, offset_low */
+  { 0xf7396001, 0xffffffff, PIA_SKIP },		/* Lab: addu r25, r25, r1 */
+
+  /* Various branch or jump instructions which have a delay slot -- these
+     do not form part of the prologue, but the instruction in the delay
+     slot might be a store instruction which should be noted. */
+  { 0xc4000000, 0xe4000000, PIA_NOTE_PROLOGUE_END }, 
+  					/* br.n, bsr.n, bb0.n, or bb1.n */
+  { 0xec000000, 0xfc000000, PIA_NOTE_PROLOGUE_END }, /* bcnd.n */
+  { 0xf400c400, 0xfffff7e0, PIA_NOTE_PROLOGUE_END } /* jmp.n or jsr.n */
+
+};
+
+
+/* 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. */
+
+#define NEXT_PROLOGUE_INSN(addr, lim, pword1) \
+  (((addr) < (lim)) ? next_insn (addr, pword1) : 0)
+
+/* Read the m88k 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 instruction
+   is stored at 'pword1'.  */
+
+CORE_ADDR
+next_insn (memaddr, pword1)
+     unsigned long *pword1;
+     CORE_ADDR memaddr;
+{
+  *pword1 = read_memory_integer (memaddr, BYTES_PER_88K_INSN);
+  return memaddr + BYTES_PER_88K_INSN;
+}
+
+/* Read a register from frames called by us (or from the hardware regs).  */
+
+static int
+read_next_frame_reg(frame, regno)
+     struct frame_info *frame;
+     int regno;
+{
+  for (; frame; frame = frame->next) {
+      if (regno == SP_REGNUM)
+	return FRAME_FP (frame);
+      else if (frame->fsr->regs[regno])
+	return read_memory_integer(frame->fsr->regs[regno], 4);
+  }
+  return read_register(regno);
+}
+
+/* Examine the prologue of a function.  `ip' points to the first instruction.
+   `limit' is the limit of the prologue (e.g. the addr of the first 
+   linenumber, or perhaps the program counter if we're stepping through).
+   `frame_sp' is the stack pointer value in use in this frame.  
+   `fsr' is a pointer to a frame_saved_regs structure into which we put
+   info about the registers saved by this frame.  
+   `fi' is a struct frame_info pointer; we fill in various fields in it
+   to reflect the offsets of the arg pointer and the locals pointer.  */
+
+static CORE_ADDR
+examine_prologue (ip, limit, frame_sp, fsr, fi)
+     register CORE_ADDR ip;
+     register CORE_ADDR limit;
+     CORE_ADDR frame_sp;
+     struct frame_saved_regs *fsr;
+     struct frame_info *fi;
+{
+  register CORE_ADDR next_ip;
+  register int src;
+  unsigned int insn;
+  int size, offset;
+  char must_adjust[32];		/* If set, must adjust offsets in fsr */
+  int sp_offset = -1;		/* -1 means not set (valid must be mult of 8) */
+  int fp_offset = -1;		/* -1 means not set */
+  CORE_ADDR frame_fp;
+  CORE_ADDR prologue_end = 0;
+
+  memset (must_adjust, '\0', sizeof (must_adjust));
+  next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn);
+
+  while (next_ip)
+    {
+      struct prologue_insns *pip; 
+
+      for (pip=prologue_insn_tbl; (insn & pip->mask) != pip->insn; )
+	  if (++pip >= prologue_insn_tbl + sizeof prologue_insn_tbl)
+	      goto end_of_prologue_found;	/* not a prologue insn */
+
+      switch (pip->action)
+	{
+	  case PIA_NOTE_ST:
+	  case PIA_NOTE_STD:
+	    if (sp_offset != -1) {
+		src = ST_SRC (insn);
+		offset = ST_OFFSET (insn);
+		must_adjust[src] = 1;
+		fsr->regs[src++] = offset;	/* Will be adjusted later */
+		if (pip->action == PIA_NOTE_STD && src < 32)
+		  {
+		    offset += 4;
+		    must_adjust[src] = 1;
+		    fsr->regs[src++] = offset;
+		  }
+	    }
+	    else
+		goto end_of_prologue_found;
+	    break;
+	  case PIA_NOTE_SP_ADJUSTMENT:
+	    if (sp_offset == -1)
+		sp_offset = -SUBU_OFFSET (insn);
+	    else
+		goto end_of_prologue_found;
+	    break;
+	  case PIA_NOTE_FP_ASSIGNMENT:
+	    if (fp_offset == -1)
+		fp_offset = ADDU_OFFSET (insn);
+	    else
+		goto end_of_prologue_found;
+	    break;
+	  case PIA_NOTE_PROLOGUE_END:
+	    if (!prologue_end)
+		prologue_end = ip;
+	    break;
+	  case PIA_SKIP:
+	  default :
+	    /* Do nothing */
+	    break;
+	}
+
+      ip = next_ip;
+      next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn);
+    }
+
+end_of_prologue_found:
+
+    if (prologue_end)
+	ip = prologue_end;
+
+  /* We're done with the prologue.  If we don't care about the stack
+     frame itself, just return.  (Note that fsr->regs has been trashed,
+     but the one caller who calls with fi==0 passes a dummy there.)  */
+
+  if (fi == 0)
+    return ip;
+
+  /*
+     OK, now we have:
+
+     	sp_offset	original (before any alloca calls) displacement of SP
+			(will be negative).
+
+	fp_offset	displacement from original SP to the FP for this frame
+			or -1.
+
+	fsr->regs[0..31]	displacement from original SP to the stack
+				location where reg[0..31] is stored.
+
+	must_adjust[0..31]	set if corresponding offset was set.
+
+     If alloca has been called between the function prologue and the current
+     IP, then the current SP (frame_sp) will not be the original SP as set by
+     the function prologue.  If the current SP is not the original SP, then the
+     compiler will have allocated an FP for this frame, fp_offset will be set,
+     and we can use it to calculate the original SP.
+
+     Then, we figure out where the arguments and locals are, and relocate the
+     offsets in fsr->regs to absolute addresses.  */
+
+  if (fp_offset != -1) {
+    /* We have a frame pointer, so get it, and base our calc's on it.  */
+    frame_fp = (CORE_ADDR) read_next_frame_reg (fi->next, ACTUAL_FP_REGNUM);
+    frame_sp = frame_fp - fp_offset;
+  } else {
+    /* We have no frame pointer, therefore frame_sp is still the same value
+       as set by prologue.  But where is the frame itself?  */
+    if (must_adjust[SRP_REGNUM]) {
+      /* Function header saved SRP (r1), the return address.  Frame starts
+	 4 bytes down from where it was saved.  */
+      frame_fp = frame_sp + fsr->regs[SRP_REGNUM] - 4;
+      fi->locals_pointer = frame_fp;
+    } else {
+      /* Function header didn't save SRP (r1), so we are in a leaf fn or
+	 are otherwise confused.  */
+      frame_fp = -1;
+    }
+  }
+
+  /* The locals are relative to the FP (whether it exists as an allocated
+     register, or just as an assumed offset from the SP) */
+  fi->locals_pointer = frame_fp;
+
+  /* The arguments are just above the SP as it was before we adjusted it
+     on entry.  */
+  fi->args_pointer = frame_sp - sp_offset;
+
+  /* Now that we know the SP value used by the prologue, we know where
+     it saved all the registers.  */
+  for (src = 0; src < 32; src++)
+    if (must_adjust[src])
+      fsr->regs[src] += frame_sp;
+ 
+  /* The saved value of the SP is always known.  */
+  /* (we hope...) */
+  if (fsr->regs[SP_REGNUM] != 0 
+   && fsr->regs[SP_REGNUM] != frame_sp - sp_offset)
+    fprintf_unfiltered(gdb_stderr, "Bad saved SP value %x != %x, offset %x!\n",
+        fsr->regs[SP_REGNUM],
+	frame_sp - sp_offset, sp_offset);
+
+  fsr->regs[SP_REGNUM] = frame_sp - sp_offset;
+
+  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,
+			    (struct frame_info *)0 ));
+}
+
+/* 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 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.  In the case where the PC is not in
+	 the function prologue, we set limit to two instructions beyond
+	 where the prologue ends in case if any of the prologue instructions
+	 were moved into a delay slot of a branch instruction. */
+         
+      ip = get_pc_function_start (fi->pc);
+      sal = find_pc_line (ip, 0);
+      limit = (sal.end && sal.end < fi->pc) ? sal.end + 2 * BYTES_PER_88K_INSN 
+					    : fi->pc;
+
+      /* This will fill in fields in *fi as well as in cache_fsr.  */
+#ifdef SIGTRAMP_FRAME_FIXUP
+      if (fi->signal_handler_caller)
+	SIGTRAMP_FRAME_FIXUP(fi->frame);
+#endif
+      examine_prologue (ip, limit, fi->frame, cache_fsr, fi);
+#ifdef SIGTRAMP_SP_FIXUP
+      if (fi->signal_handler_caller && fi->fsr->regs[SP_REGNUM])
+	SIGTRAMP_SP_FIXUP(fi->fsr->regs[SP_REGNUM]);
+#endif
+    }
+
+  if (fsr)
+    *fsr = *fi->fsr;
+}
+
+/* Return the address of the locals block for the frame
+   described by FI.  Returns 0 if the address is unknown.
+   NOTE!  Frame locals are referred to by negative offsets from the
+   argument pointer, so this is the same as frame_args_address().  */
+
+CORE_ADDR
+frame_locals_address (fi)
+     struct frame_info *fi;
+{
+  struct frame_saved_regs fsr;
+
+  if (fi->args_pointer)	/* Cached value is likely there.  */
+    return fi->args_pointer;
+
+  /* Nope, generate it.  */
+
+  get_frame_saved_regs (fi, &fsr);
+
+  return fi->args_pointer;
+}
+
+/* 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)
+     struct frame_info *fi;
+{
+  struct frame_saved_regs fsr;
+
+  if (fi->args_pointer)		/* Cached value is likely there.  */
+    return fi->args_pointer;
+
+  /* Nope, generate it.  */
+
+  get_frame_saved_regs (fi, &fsr);
+
+  return fi->args_pointer;
+}
+
+/* Return the saved PC from this frame.
+
+   If the frame has a memory copy of SRP_REGNUM, use that.  If not,
+   just use the register SRP_REGNUM itself.  */
+
+CORE_ADDR
+frame_saved_pc (frame)
+     struct frame_info *frame;
+{
+  return read_next_frame_reg(frame, SRP_REGNUM);
+}
+
+
+#define DUMMY_FRAME_SIZE 192
+
+static void
+write_word (sp, word)
+     CORE_ADDR sp;
+     ULONGEST word;
+{
+  register int len = REGISTER_SIZE;
+  char buffer[MAX_REGISTER_RAW_SIZE];
+
+  store_unsigned_integer (buffer, len, word);
+  write_memory (sp, buffer, len);
+}
+
+void
+m88k_push_dummy_frame()
+{
+  register CORE_ADDR sp = read_register (SP_REGNUM);
+  register int rn;
+  int offset;
+
+  sp -= DUMMY_FRAME_SIZE;	/* allocate a bunch of space */
+
+  for (rn = 0, offset = 0; rn <= SP_REGNUM; rn++, offset+=4)
+    write_word (sp+offset, read_register(rn));
+  
+  write_word (sp+offset, read_register (SXIP_REGNUM));
+  offset += 4;
+
+  write_word (sp+offset, read_register (SNIP_REGNUM));
+  offset += 4;
+
+  write_word (sp+offset, read_register (SFIP_REGNUM));
+  offset += 4;
+
+  write_word (sp+offset, read_register (PSR_REGNUM));
+  offset += 4;
+
+  write_word (sp+offset, read_register (FPSR_REGNUM));
+  offset += 4;
+
+  write_word (sp+offset, read_register (FPCR_REGNUM));
+  offset += 4;
+
+  write_register (SP_REGNUM, sp);
+  write_register (ACTUAL_FP_REGNUM, sp);
+}
+
+void
+pop_frame ()
+{
+  register struct frame_info *frame = get_current_frame ();
+  register CORE_ADDR fp;
+  register int regnum;
+  struct frame_saved_regs fsr;
+
+  fp = FRAME_FP (frame);
+  get_frame_saved_regs (frame, &fsr);
+
+  if (PC_IN_CALL_DUMMY (read_pc (), read_register (SP_REGNUM), FRAME_FP (fi)))
+    {
+      /* FIXME: I think get_frame_saved_regs should be handling this so
+	 that we can deal with the saved registers properly (e.g. frame
+	 1 is a call dummy, the user types "frame 2" and then "print $ps").  */
+      register CORE_ADDR sp = read_register (ACTUAL_FP_REGNUM);
+      int offset;
+
+      for (regnum = 0, offset = 0; regnum <= SP_REGNUM; regnum++, offset+=4)
+	(void) write_register (regnum, read_memory_integer (sp+offset, 4));
+  
+      write_register (SXIP_REGNUM, read_memory_integer (sp+offset, 4));
+      offset += 4;
+
+      write_register (SNIP_REGNUM, read_memory_integer (sp+offset, 4));
+      offset += 4;
+
+      write_register (SFIP_REGNUM, read_memory_integer (sp+offset, 4));
+      offset += 4;
+
+      write_register (PSR_REGNUM, read_memory_integer (sp+offset, 4));
+      offset += 4;
+
+      write_register (FPSR_REGNUM, read_memory_integer (sp+offset, 4));
+      offset += 4;
+
+      write_register (FPCR_REGNUM, read_memory_integer (sp+offset, 4));
+      offset += 4;
+
+    }
+  else 
+    {
+      for (regnum = FP_REGNUM ; regnum > 0 ; regnum--)
+	  if (fsr.regs[regnum])
+	      write_register (regnum,
+			      read_memory_integer (fsr.regs[regnum], 4));
+      write_pc (frame_saved_pc (frame));
+    }
+  reinit_frame_cache ();
+}
+
+void
+_initialize_m88k_tdep ()
+{
+  tm_print_insn = print_insn_m88k;
+}