tm-pn.h

早期freebsd实现

   to be actual register numbers as far as the user is concerned
   but do serve to get the desired values when passed to read_register.  */
#define R1_REGNUM	1	/* Gr1 => return address of caller */
#define R4_REGNUM	4	/* Gr4 => register save area */
#define R5_REGNUM	5	/* Gr5 => register save area */
#define R6_REGNUM	6	/* Gr6 => register save area */
#define R7_REGNUM	7	/* Gr7 => register save area */
#define B1_REGNUM	9	/* Br1 => start of this code routine */
#define FP_REGNUM	10	/* Br2 == (sp) */
#define AP_REGNUM	11	/* Br3 == (ap) */
#define SP_REGNUM 	16	/* A copy of Br2 saved in trap */
#define PS_REGNUM 	17	/* Contains processor status */
#define PC_REGNUM 	18	/* Contains program counter */

/* Total amount of space needed to store our copies of the machine's
   register state, the array `registers'.  */
#define REGISTER_BYTES			(NUM_GEN_REGS*4 + NUM_CPU_REGS*4)

/* Index within `registers' of the first byte of the space for
   register N.  */
#define REGISTER_BYTE(N)  		((N) * 4)

/* Number of bytes of storage in the actual machine representation
   for register N.  On the PN, all normal regs are 4 bytes. */
#define REGISTER_RAW_SIZE(N) 		(4)

/* Number of bytes of storage in the program's representation
   for register N.  On the PN, all regs are 4 bytes. */
#define REGISTER_VIRTUAL_SIZE(N)	(4)

/* Largest value REGISTER_RAW_SIZE can have.  */
#define MAX_REGISTER_RAW_SIZE		(4)

/* Largest value REGISTER_VIRTUAL_SIZE can have.  */
#define MAX_REGISTER_VIRTUAL_SIZE	(4)

/* Nonzero if register N requires conversion
   from raw format to virtual format.  */
#define REGISTER_CONVERTIBLE(N)		(0)

/* Convert data from raw format for register REGNUM
   to virtual format for register REGNUM.  */
#define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO)	\
	bcopy ((FROM), (TO), REGISTER_RAW_SIZE(REGNUM));

/* Convert data from virtual format for register REGNUM
   to raw format for register REGNUM.  */
#define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO)	\
	bcopy ((FROM), (TO), REGISTER_VIRTUAL_SIZE(REGNUM));

/* Return the GDB type object for the "standard" data type
   of data in register N.  */
#define REGISTER_VIRTUAL_TYPE(N)	(builtin_type_int)

/* Store the address of the place in which to copy the structure the
   subroutine will return.  This is called from call_function.

   On this machine this is a no-op, because gcc isn't used on it
   yet.  So this calling convention is not used. */

#define STORE_STRUCT_RETURN(ADDR, SP)

/* Extract from an arrary REGBUF containing the (raw) register state
   a function return value of type TYPE, and copy that, in virtual format,
   into VALBUF. */

#define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
	bcopy (REGBUF, VALBUF, TYPE_LENGTH (TYPE))

/* Write into appropriate registers a function return value
   of type TYPE, given in virtual format.  */

#define STORE_RETURN_VALUE(TYPE,VALBUF) \
	write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))

/* Extract from an array REGBUF containing the (raw) register state
   the address in which a function should return its structure value,
   as a CORE_ADDR (or an expression that can be used as one).  */

#define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(int *)(REGBUF))


/* Describe the pointer in each stack frame to the previous stack frame
   (its caller).  */

/* FRAME_CHAIN takes a frame's nominal address
   and produces the frame's chain-pointer.

   However, if FRAME_CHAIN_VALID returns zero,
   it means the given frame is the outermost one and has no caller.  */

/* In the case of the NPL, the frame's norminal address is Br2 and the 
   previous routines frame is up the stack X bytes, where X is the
   value stored in the code function header xA(Br1). */
#define FRAME_CHAIN(thisframe)		(findframe(thisframe))

#define FRAME_CHAIN_VALID(chain, thisframe) \
        (chain != 0 && chain != (thisframe)->frame)

/* Define other aspects of the stack frame on NPL.  */
#define FRAME_SAVED_PC(frame) \
	(read_memory_integer ((frame)->frame + 8, 4))

#define FRAME_ARGS_ADDRESS(fi) \
	((fi)->next_frame ? \
	 read_memory_integer ((fi)->frame + 12, 4) : \
	 read_register (AP_REGNUM))

#define FRAME_LOCALS_ADDRESS(fi)	((fi)->frame + 80)

/* Set VAL to the number of args passed to frame described by FI.
   Can set VAL to -1, meaning no way to tell.  */

/* We can check the stab info to see how
   many arg we have.  No info in stack will tell us */
#define FRAME_NUM_ARGS(val,fi)		(val = findarg(fi))

/* Return number of bytes at start of arglist that are not really args.  */
#define FRAME_ARGS_SKIP			8

/* 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.  */

#define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs)		\
{                                                                       \
  bzero (&frame_saved_regs, sizeof frame_saved_regs);			\
  (frame_saved_regs).regs[PC_REGNUM] = (frame_info)->frame + 8;		\
  (frame_saved_regs).regs[R4_REGNUM] = (frame_info)->frame + 0x30;	\
  (frame_saved_regs).regs[R5_REGNUM] = (frame_info)->frame + 0x34;	\
  (frame_saved_regs).regs[R6_REGNUM] = (frame_info)->frame + 0x38;	\
  (frame_saved_regs).regs[R7_REGNUM] = (frame_info)->frame + 0x3C;	\
}

/* Things needed for making the inferior call functions.  */

/* Push an empty stack frame, to record the current PC, etc.  */

#define PUSH_DUMMY_FRAME \
{ register CORE_ADDR sp = read_register (SP_REGNUM);			\
  register int regnum;							\
  sp = push_word (sp, read_register (PC_REGNUM));			\
  sp = push_word (sp, read_register (FP_REGNUM));			\
  write_register (FP_REGNUM, sp);					\
  for (regnum = FP_REGNUM - 1; regnum >= 0; regnum--)			\
    sp = push_word (sp, read_register (regnum));			\
  sp = push_word (sp, read_register (PS_REGNUM));			\
  write_register (SP_REGNUM, sp);  }

/* Discard from the stack the innermost frame, 
   restoring all saved registers.  */

#define POP_FRAME  \
{ register FRAME frame = get_current_frame ();			 \
  register CORE_ADDR fp;					 \
  register int regnum;						 \
  struct frame_saved_regs fsr;					 \
  struct frame_info *fi;					 \
  fi = get_frame_info (frame);					 \
  fp = fi->frame;						 \
  get_frame_saved_regs (fi, &fsr);				 \
  for (regnum = FP_REGNUM - 1; regnum >= 0; regnum--)		 \
    if (fsr.regs[regnum])					 \
      write_register (regnum, read_memory_integer (fsr.regs[regnum], 4)); \
  if (fsr.regs[PS_REGNUM])					 \
    write_register (PS_REGNUM, read_memory_integer (fsr.regs[PS_REGNUM], 4)); \
  write_register (FP_REGNUM, read_memory_integer (fp, 4));	 \
  write_register (PC_REGNUM, read_memory_integer (fp + 4, 4));   \
  write_register (SP_REGNUM, fp + 8);				 \
  flush_cached_frames ();					 \
  set_current_frame ( create_new_frame (read_register (FP_REGNUM),\
					read_pc ())); }

/* This sequence of words is the instructions:
     halt
     halt
     halt
     halt
     suabr	b2, #<stacksize>
     lwbr	b6, #con
     stw	r1, 8(b2)	- save caller address, do we care?
     lw		r2, 60(b2)	- arg1
     labr	b3, 50(b2)
     std	r4, 30(b2)	- save r4-r7
     std	r6, 38(b2)
     lwbr	b1, #<func>	- load function call address
     brlnk	r1, 8(b1)	- call function
     halt
     halt
     ld		r4, 30(b2)	- restore r4-r7
     ld		r6, 38(b2)

   Setup our stack frame, load argumemts, call and then restore registers.
*/

/* FIXME:  The below defines an m68k CALL_DUMMY, which looks nothing like what
   is documented above. */

#define CALL_DUMMY {0xf227e0ff, 0x48e7fffc, 0x426742e7, 0x4eb93232, 0x3232dffc, 0x69696969, 0x4e4f4e71}

#define CALL_DUMMY_LENGTH 28

#define CALL_DUMMY_START_OFFSET 12

/* Insert the specified number of args and function address
   into a call sequence of the above form stored at DUMMYNAME.  */

#define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p)     \
{ *(int *)((char *) dummyname + 20) = nargs * 4;  \
  *(int *)((char *) dummyname + 14) = fun; }