/* Parameters for targeting on a Gould NP1, for GDB, the GNU debugger.
   Copyright 1986, 1987, 1989, 1991, 1993 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.  */

#define GOULD_NPL

#define TARGET_BYTE_ORDER BIG_ENDIAN

/* N_ENTRY appears in libraries on Gould machines.
   Don't know what 0xa4 is; it's mentioned in stab.h
   but only in the sdb symbol list.  */
#define IGNORE_SYMBOL(type) (type == N_ENTRY || type == 0xa4)

/* We don't want the extra gnu symbols on the machine;
   they will interfere with the shared segment symbols.  */
#define NO_GNU_STABS

/* Macro for text-offset and data info (in NPL a.out format).  */
#define	TEXTINFO						\
        text_offset = N_TXTOFF (exec_coffhdr, exec_aouthdr);	\
        exec_data_offset = N_TXTOFF (exec_coffhdr, exec_aouthdr)\
                + exec_aouthdr.a_text

/* Macro for number of symbol table entries */
#define NUMBER_OF_SYMBOLS					\
	(coffhdr.f_nsyms)

/* Macro for file-offset of symbol table (in NPL a.out format).  */
#define SYMBOL_TABLE_OFFSET					\
	N_SYMOFF (coffhdr)

/* Macro for file-offset of string table (in NPL a.out format).  */
#define STRING_TABLE_OFFSET					\
	(N_STROFF (coffhdr))

/* Macro to store the length of the string table data in INTO.  */
#define READ_STRING_TABLE_SIZE(INTO)				\
	{ INTO = hdr.a_stsize; }

/* Macro to declare variables to hold the file's header data.  */
#define DECLARE_FILE_HEADERS  struct exec hdr;			\
			      FILHDR coffhdr

/* Macro to read the header data from descriptor DESC and validate it.
   NAME is the file name, for error messages.  */
#define READ_FILE_HEADERS(DESC, NAME)				\
{ val = myread (DESC, &coffhdr, sizeof coffhdr);		\
  if (val < 0)							\
    perror_with_name (NAME);					\
  val = myread (DESC, &hdr, sizeof hdr);			\
  if (val < 0)							\
    perror_with_name (NAME);					\
  if (coffhdr.f_magic != GNP1MAGIC)				\
    error ("File \"%s\" not in coff executable format.", NAME);	\
  if (N_BADMAG (hdr))						\
    error ("File \"%s\" not in executable format.", NAME); }

/* Define COFF and other symbolic names needed on NP1 */
#define	NS32GMAGIC	GNP1MAGIC
#define	NS32SMAGIC	GPNMAGIC

/* Address of blocks in N_LBRAC and N_RBRAC symbols are absolute addresses,
   not relative to start of source address.  */
#define BLOCK_ADDRESS_ABSOLUTE

/* Offset from address of function to start of its code.
   Zero on most machines.  */
#define FUNCTION_START_OFFSET	8

/* Advance PC across any function entry prologue instructions
   to reach some "real" code.  One NPL we can have one two startup
   sequences depending on the size of the local stack:

   Either:
      "suabr b2, #"
   of
      "lil r4, #", "suabr b2, #(r4)"

   "lwbr b6, #", "stw r1, 8(b2)"
   Optional "stwbr b3, c(b2)"
   Optional "trr r2,r7"      (Gould first argument register passing)
     or
   Optional "stw r2,8(b3)"   (Gould first argument register passing)
 */
#define SKIP_PROLOGUE(pc) { 						\
	register int op = read_memory_integer ((pc), 4);		\
	if ((op & 0xffff0000) == 0xFA0B0000) { 				\
	    pc += 4;							\
	    op = read_memory_integer ((pc), 4);				\
	    if ((op & 0xffff0000) == 0x59400000) {			\
		pc += 4;						\
	        op = read_memory_integer ((pc), 4);			\
		if ((op & 0xffff0000) == 0x5F000000) {			\
		    pc += 4;						\
	            op = read_memory_integer ((pc), 4);			\
		    if (op == 0xD4820008) {				\
		    	pc += 4;					\
	            	op = read_memory_integer ((pc), 4);		\
		    	if (op == 0x5582000C) {				\
		    	    pc += 4;					\
	                    op = read_memory_integer ((pc), 2);		\
		            if (op == 0x2fa0) {				\
		    	        pc += 2;				\
		            } else {					\
	                        op = read_memory_integer ((pc), 4);	\
		                if (op == 0xd5030008) {			\
		    	            pc += 4;				\
		                }					\
		            }						\
		        } else {					\
	                    op = read_memory_integer ((pc), 2);		\
		            if (op == 0x2fa0) {				\
		    	        pc += 2;				\
		            }						\
		        }						\
		    }							\
		}							\
	    }								\
	} 								\
	if ((op & 0xffff0000) == 0x59000000) { 				\
	    pc += 4;							\
	    op = read_memory_integer ((pc), 4);				\
	    if ((op & 0xffff0000) == 0x5F000000) {			\
		pc += 4;						\
	        op = read_memory_integer ((pc), 4);			\
		if (op == 0xD4820008) {					\
		    pc += 4;						\
	            op = read_memory_integer ((pc), 4);			\
		    if (op == 0x5582000C) {				\
		    	pc += 4;					\
	                op = read_memory_integer ((pc), 2);		\
		        if (op == 0x2fa0) {				\
		    	    pc += 2;					\
		        } else {					\
	                    op = read_memory_integer ((pc), 4);		\
		            if (op == 0xd5030008) {			\
		    	        pc += 4;				\
		            }						\
		        }						\
		    } else {						\
	                op = read_memory_integer ((pc), 2);		\
		        if (op == 0x2fa0) {				\
		    	    pc += 2;					\
		        }						\
		    }							\
		}							\
	    }								\
	} 								\
}

/* 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.  True on NPL! Return address is in R1.
   The true return address is REALLY 4 past that location! */
#define SAVED_PC_AFTER_CALL(frame) \
	(read_register(R1_REGNUM) + 4)

/* Address of end of stack space.  */
#define STACK_END_ADDR 		0x7fffc000

/* Stack grows downward.  */
#define INNER_THAN 		<

/* Sequence of bytes for breakpoint instruction.
   This is padded out to the size of a machine word.  When it was just
   {0x28, 0x09} it gave problems if hit breakpoint on returning from a
   function call.  */
#define BREAKPOINT 		{0x28, 0x09, 0x0, 0x0}

/* Amount PC must be decremented by after a breakpoint.
   This is often the number of bytes in BREAKPOINT
   but not always.  */
#define DECR_PC_AFTER_BREAK	2

/* Nonzero if instruction at PC is a return instruction. "bu 4(r1)" */
#define ABOUT_TO_RETURN(pc)	(read_memory_integer (pc, 4) == 0x40100004)

/* Return 1 if P points to an invalid floating point value.  */
#define INVALID_FLOAT(p, len) 	((*(short *)p & 0xff80) == 0x8000)

/* Say how long (ordinary) registers are.  This is a piece of bogosity
   used in push_word and a few other places; REGISTER_RAW_SIZE is the
   real way to know how big a register is.  */

#define REGISTER_SIZE 4

/* Size of bytes of vector register (NP1 only), 32 elements * sizeof(int) */
#define VR_SIZE			128

/* Number of machine registers */
#define NUM_REGS 		27
#define NUM_GEN_REGS		16
#define NUM_CPU_REGS		4
#define NUM_VECTOR_REGS		7

/* Initializer for an array of names of registers.
   There should be NUM_REGS strings in this initializer.  */
#define REGISTER_NAMES { \
  "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", \
  "b0", "b1", "b2", "b3", "b4", "b5", "b6", "b7", \
  "sp", "ps", "pc", "ve", \
  "v1", "v2", "v3", "v4", "v5", "v6", "v7", \
}

/* Register numbers of various important registers.
   Note that some of these values are "real" register numbers,
   and correspond to the general registers of the machine,
   and some are "phony" register numbers which are too large
   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 R2_REGNUM	2	/* Gr2 => return value from function */
#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 SP_REGNUM	10	/* Br2 == (sp) */
#define AP_REGNUM	11	/* Br3 == (ap) */
#define FP_REGNUM 	16	/* A copy of Br2 saved in trap */
#define PS_REGNUM 	17	/* Contains processor status */
#define PC_REGNUM 	18	/* Contains program counter */
#define VE_REGNUM 	19	/* Vector end (user setup) register */
#define V1_REGNUM 	20	/* First vector register */
#define V7_REGNUM 	26	/* First vector register */

/* 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_VECTOR_REGS*VR_SIZE + NUM_CPU_REGS*4)

/* Index within `registers' of the first byte of the space for
   register N.  */
#define REGISTER_BYTE(N)  \
	(((N) < V1_REGNUM) ? ((N) * 4) : (((N) - V1_REGNUM) * VR_SIZE) + 80)

/* Number of bytes of storage in the actual machine representation
   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

/* 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) \
	memcpy (VALBUF, ((int *)(REGBUF)) + 2, 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 ? \
	 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)		\
{                                                                       \
  memset (&frame_saved_regs, '\0', 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.  */
/* FIXME: Should be using {store,extract}_unsigned_integer.  */

#define POP_FRAME  \
{ CORE_ADDR sp = read_register(SP_REGNUM);             \
  ULONGEST reg;                                   \
  int regnum;                                          \
  for(regnum = 0;regnum < FP_REGNUM;regnum++){         \
    sp-=REGISTER_SIZE;                         \
    read_memory(sp,&reg,REGISTER_SIZE);        \
    write_register(regnum,reg);}                       \
  sp-=REGISTER_SIZE;                           \
  read_memory(sp,&reg,REGISTER_SIZE);          \
  write_register(PS_REGNUM,reg);                       \
  sp-=REGISTER_SIZE;                           \
  read_memory(sp,&reg,REGISTER_SIZE);          \
  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       |
*/
