tm-np1.h

早期freebsd实现

   for register N.  On the NP1, all normal regs are 4 bytes, but
   the vector registers are VR_SIZE*4 bytes long. */
#define REGISTER_RAW_SIZE(N) \
	(((N) < V1_REGNUM) ? 4 : VR_SIZE)

/* Number of bytes of storage in the program's representation
   for register N.  On the NP1, all regs are 4 bytes. */
#define REGISTER_VIRTUAL_SIZE(N) \
	(((N) < V1_REGNUM) ? 4 : VR_SIZE)

/* Largest value REGISTER_RAW_SIZE can have.  */
#define MAX_REGISTER_RAW_SIZE		VR_SIZE

/* Largest value REGISTER_VIRTUAL_SIZE can have.  */
#define MAX_REGISTER_VIRTUAL_SIZE	VR_SIZE

/* 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)	\
  ((N) > VE_REGNUM ? builtin_type_np1_vector : builtin_type_int)
extern struct type *builtin_type_np1_vector;

/* 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) push_word(SP + 8, ADDR)

/* 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 (((int *)(REGBUF)) + 2, 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 (REGISTER_BYTE (R2_REGNUM), 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) + 2))

/* Both gcc and cc return small structs in registers (i.e. in GDB
   terminology, small structs don't use the struct return convention).  */
#define USE_STRUCT_CONVENTION(gcc_p, type) (TYPE_LENGTH(type) > 8)

/* 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)

/* 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[SP_REGNUM] = framechain (frame_info);         \
  (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.  */

#define CALL_DUMMY_LOCATION	BEFORE_TEXT_END
#define	NEED_TEXT_START_END

/* 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;                               \
  for (regnum = 0; regnum < FP_REGNUM; regnum++)     \
    sp = push_word (sp, read_register (regnum));     \
  sp = push_word (sp, read_register (PS_REGNUM));    \
  sp = push_word (sp, read_register (PC_REGNUM));    \
  write_register (SP_REGNUM, sp);}

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

#define POP_FRAME  \
{ CORE_ADDR sp = read_register(SP_REGNUM);             \
  REGISTER_TYPE reg;                                   \
  int regnum;                                          \
  for(regnum = 0;regnum < FP_REGNUM;regnum++){         \
    sp-=sizeof(REGISTER_TYPE);                         \
    read_memory(sp,&reg,sizeof(REGISTER_TYPE));        \
    write_register(regnum,reg);}                       \
  sp-=sizeof(REGISTER_TYPE);                           \
  read_memory(sp,&reg,sizeof(REGISTER_TYPE));          \
  write_register(PS_REGNUM,reg);                       \
  sp-=sizeof(REGISTER_TYPE);                           \
  read_memory(sp,&reg,sizeof(REGISTER_TYPE));          \
  write_register(PC_REGNUM,reg);}

/* MJD - Size of dummy frame pushed onto stack by PUSH_DUMMY_FRAME */

#define DUMMY_FRAME_SIZE (0x48)

/* MJD - The sequence of words in the instructions is
   halt
   halt
   halt
   halt
   subr    b2,stack size,0             grab stack space for dummy call
   labr    b3,x0(b2),0                 set AP_REGNUM to point at arguments
   lw      r2,x8(b3),0                 load r2 with first argument    
   lwbr    b1,arguments size(b2),0     load address of function to be called
   brlnk   r1,x8(b1),0                 call function
   halt
   halt
   labr    b2,stack size(b2),0         give back stack
   break                               break
   */

#define CALL_DUMMY {0x00000000,  \
		    0x00000000,  \
		    0x59000000,  \
		    0x598a0000,  \
		    0xb5030008,  \
		    0x5c820000,  \
		    0x44810008,  \
		    0x00000000,  \
		    0x590a0000,  \
		    0x28090000 }

#define CALL_DUMMY_LENGTH 40

#define CALL_DUMMY_START_OFFSET 8

#define CALL_DUMMY_STACK_ADJUST 8

/* MJD - Fixup CALL_DUMMY for the specific function call.
   OK heres the problems
   1) On a trap there are two copies of the stack pointer, one in SP_REGNUM
      which is read/write and one in FP_REGNUM which is only read. It seems
      that when restarting the GOULD NP1 uses FP_REGNUM's value.
   2) Loading function address into b1 looks a bit difficult if bigger than
      0x0000fffc, infact from what I can tell the compiler sets up table of
      function address in base3 through which function calls are referenced.

   OK my solutions
     Calculate the size of the dummy stack frame and do adjustments of
     SP_REGNUM in the dummy call.
     Push function address onto the stack and load it in the dummy call
 */

#define FIX_CALL_DUMMY(dummyname, sp, fun, nargs, args, type, gcc_p) \
  {   int i;\
      int arg_len = 0, total_len;\
      old_sp = push_word(old_sp,fun);\
      for(i = nargs - 1;i >= 0;i--)\
	arg_len += TYPE_LENGTH (VALUE_TYPE (value_arg_coerce (args[i])));\
      if(struct_return)\
	arg_len += TYPE_LENGTH(value_type);\
      total_len = DUMMY_FRAME_SIZE+CALL_DUMMY_STACK_ADJUST+4+arg_len;\
      dummyname[0] += total_len;\
      dummyname[2] += total_len;\
      dummyname[5] += arg_len+CALL_DUMMY_STACK_ADJUST;\
      dummyname[8] += total_len;}

/* MJD - So the stack should end up looking like this

                   | Normal stack frame  |
                   | from normal program |
                   | flow                |
                   +---------------------+ <- Final sp - 0x08 - argument size
                   |                     |    - 0x4 - dummy_frame_size
                   | Pushed dummy frame  |
                   |  b0-b7, r0-r7       |
                   |  pc and ps          |
                   |                     |
                   +---------------------+
                   | Function address    |
                   +---------------------+ <- Final sp - 0x8 - arguments size
                   |                     |
                   |                     |
                   |                     |
                   |  Arguments to       |
                   |       Function      |
                   |                     |
                   |                     |
                   |                     |
                   +---------------------+ <- Final sp - 0x8
                   | Dummy_stack_adjust  |
                   +---------------------+ <- Final sp
                   |                     |
                   | where call will     |
                   |   build frame       |
*/