path: root/gdb/m88k-pinsn.c

/* This file has been modified by Data General Corporation, November 1989. */

#include <stdio.h>
#include "m88k-opcode.h"
#include "defs.h"
#include "symtab.h"

void sprint_address ();

/* Changed hashtab to hashtable to avoid naming conflict
   with libdc.o (used for tdesc) for m88k.
*/

INSTAB  *hashtable[HASHVAL] = {0};

/*
*		Disassemble an M88000 Instruction
*
*
*       This module decodes the first instruction in inbuf.  It uses the pc
*	to display pc-relative displacements.  It writes the disassembled
*	instruction in outbuf.
*
*			Revision History
*
*       Revision 1.0    11/08/85        Creation date by Motorola
*			05/11/89	R. Trawick adapted to GDB interface.
*/
#define MAXLEN 20

print_insn (memaddr, stream)
     CORE_ADDR memaddr;
     FILE *stream;
{
  unsigned char buffer[MAXLEN];
  /* should be expanded if disassembler prints symbol names */
  char outbuf[100];
  int n;

  /* Instruction addresses may have low two bits set. Clear them.	*/
  memaddr&= 0xfffffffc;
  read_memory (memaddr, buffer, MAXLEN);

  n = m88kdis ((int)memaddr, buffer, outbuf);

  fputs (outbuf, stream);

  return (n);
}

/*
 * disassemble the first instruction in 'inbuf'.
 * 'pc' should be the address of this instruction, it will
 *   be used to print the target address if this is a relative jump or call
 * 'outbuf' gets filled in with the disassembled instruction.  It should
 *   be long enough to hold the longest disassembled instruction.
 *   100 bytes is certainly enough, unless symbol printing is added later
 * The function returns the length of this instruction in bytes.
 */

int m88kdis( pc, inbuf, outbuf )

    int		pc;
    int	        *inbuf;
    char	*outbuf;

{   static		ihashtab_initialized = 0;
    int			instruction;
    unsigned int	opcode;
    INSTAB		*entry_ptr;
    int	        	opmask;
    int			class;

    instruction= *inbuf;

    if (!ihashtab_initialized) {
	init_disasm();
    }

    /* create a the appropriate mask to isolate the opcode */
    opmask= DEFMASK;
    class= instruction & DEFMASK;
    if ((class >= SFU0) && (class <= SFU7)) {
	if (instruction < SFU1) {
	    opmask= CTRLMASK;
	} else {
	    opmask= SFUMASK;
	}
    } else if (class == RRR) {
	opmask= RRRMASK;
    } else if (class == RRI10) {
	opmask= RRI10MASK;
    }

    /* isolate the opcode */
    opcode= instruction & opmask;

    /* search the hash table with the isolated opcode */
    for (entry_ptr= hashtable[ opcode % HASHVAL ];
	 (entry_ptr != NULL) && (entry_ptr->opcode != opcode);
	 entry_ptr= entry_ptr->next) {
    }

    if (entry_ptr == NULL) {
	sprintf( outbuf, "word\t%08x", instruction );
    } else {
	sprintf( outbuf, "%s\t", entry_ptr->mnemonic );
	sprintop( &outbuf[strlen(outbuf)], &(entry_ptr->op1), instruction, pc, 1 );
	sprintop( &outbuf[strlen(outbuf)], &(entry_ptr->op2), instruction, pc, 0 );
	sprintop( &outbuf[strlen(outbuf)], &(entry_ptr->op3), instruction, pc, 0 );
    }


    return 4;
}


/*
*                      Decode an Operand of an Instruction
*
*			Functional Description
*
*       This module formats and writes an operand of an instruction to buf
*       based on the operand specification.  When the first flag is set this
*       is the first operand of an instruction.  Undefined operand types
*       cause a <dis error> message.
*
*			Parameters
*	char	*buf		buffer where the operand may be printed
*       OPSPEC  *opptr          Pointer to an operand specification
*       UINT    inst            Instruction from which operand is extracted
*	UINT    pc		PC of instruction; used for pc-relative disp.
*       int     first           Flag which if nonzero indicates the first
*                               operand of an instruction
*
*			Output
*
*       The operand specified is extracted from the instruction and is
*       written to buf in the format specified. The operand is preceded
*       by a comma if it is not the first operand of an instruction and it
*       is not a register indirect form.  Registers are preceded by 'r' and
*       hex values by '0x'.
*
*			Revision History
*
*       Revision 1.0    11/08/85        Creation date
*/

sprintop( buf, opptr, inst, pc, first )

   char   *buf;
   OPSPEC *opptr;
   UINT   inst;
   int	  pc;
   int    first;

{  int	  extracted_field;
   char	  *cond_mask_sym;
   char	  cond_mask_sym_buf[6];

   if (opptr->width == 0)
      return;

   switch(opptr->type) {
      case CRREG:
		       if (!first)
			   *buf++= ',';
		       sprintf( buf, "cr%d", UEXT(inst,opptr->offset,opptr->width));
		       break;

      case FCRREG:
		       if (!first)
			   *buf++= ',';
		       sprintf( buf, "fcr%d", UEXT(inst,opptr->offset,opptr->width));
		       break;

      case REGSC:
		       sprintf( buf, "[r%d]", UEXT(inst,opptr->offset,opptr->width));
		       break;

      case REG:
		       if (!first)
			   *buf++= ',';
		       sprintf( buf, "r%d", UEXT(inst,opptr->offset,opptr->width));
		       break;

      case HEX:
		        if (!first)
			   *buf++= ',';
		        extracted_field= UEXT(inst, opptr->offset, opptr->width);
		        if (extracted_field == 0) {
			    sprintf( buf, "0" );
		        } else {
			    sprintf( buf, "0x%02x", extracted_field );
		        }
		        break;

      case CONDMASK:
		        if (!first)
			   *buf++= ',';
		        extracted_field= UEXT(inst, opptr->offset, opptr->width);
		        switch (extracted_field & 0x0f) {
			  case 0x1:	cond_mask_sym= "gt0";
					break;
			  case 0x2:	cond_mask_sym= "eq0";
					break;
			  case 0x3:	cond_mask_sym= "ge0";
					break;
			  case 0xc:	cond_mask_sym= "lt0";
					break;
			  case 0xd:	cond_mask_sym= "ne0";
					break;
			  case 0xe:	cond_mask_sym= "le0";
					break;
			  default:	cond_mask_sym= cond_mask_sym_buf;
					sprintf( cond_mask_sym_buf,
						 "%x",
						 extracted_field );
					break;
			}
			strcpy( buf, cond_mask_sym );
			break;
			
      case PCREL:
		        if (!first)
			   *buf++= ',';
			sprint_address( pc + 4*(SEXT(inst,opptr->offset,opptr->width)),
					buf );
		        break;

      case CONT:
		       sprintf( buf,
				"%d,r%d",
				UEXT(inst,opptr->offset,5),
			        UEXT(inst,(opptr->offset)+5,5) );
		       break;

      case BF:
		       if (!first)
			   *buf++= ',';
		       sprintf( buf,
				"%d<%d>",
				UEXT(inst,(opptr->offset)+5,5),
			        UEXT(inst,opptr->offset,5));
		       break;

      default:
		       sprintf( buf, "<dis error: %08x>", inst );
    }

}

/*
*                 Initialize the Disassembler Instruction Table
*
*       Initialize the hash table and instruction table for the disassembler.
*       This should be called once before the first call to disasm().
*
*			Parameters
*
*			Output
*
*       If the debug option is selected, certain statistics about the hashing
*       distribution are written to stdout.
*
*			Revision History
*
*       Revision 1.0    11/08/85        Creation date
*/

init_disasm()
{
   int i,size;

   for (i=0 ; i < HASHVAL ; i++)
      hashtable[i] = NULL;

   for (i=0, size =  sizeof(instructions) / sizeof(INSTAB) ; i < size ;
       install(&instructions[i++]));

}

/*
*       Insert an instruction into the disassembler table by hashing the
*       opcode and inserting it into the linked list for that hash value.
*
*			Parameters
*
*       INSTAB *instptr         Pointer to the entry in the instruction table
*                               to be installed
*
*       Revision 1.0    11/08/85        Creation date
*			05/11/89	R. TRAWICK ADAPTED FROM MOTOROLA
*/

install(instptr)
   INSTAB *instptr;
{
   UINT i;

   i = (instptr->opcode) % HASHVAL;
   instptr->next = hashtable[i];
   hashtable[i] = instptr;
}


/* adapted from print_address in printcmd by R. Trawick 5/15/89.  The two should
   be combined.
 */

void sprint_address (addr, buffer)

     CORE_ADDR  addr;
     char	*buffer;

{
	register int	i;
	struct symbol	*fs;
	char		*name;
	int		name_location;

	sprintf ( buffer, "0x%x", addr);

	fs = find_pc_function (addr);

	if (!fs) {
	    i = find_pc_misc_function (addr);

	    if (i < 0) return;	/* If nothing comes through, don't
				   print anything symbolic */

	    name = misc_function_vector[i].name;
	    name_location = misc_function_vector[i].address;
	} else {
	    name = fs->name;
	    name_location = BLOCK_START (SYMBOL_BLOCK_VALUE (fs));
	}

	if (addr - name_location)
	    sprintf (buffer, " <%s+%d>", name, addr - name_location);
	else
	    sprintf (buffer, " <%s>", name);
}