libzel/include/zel/z80_instructions.h

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2017-08-12 13:12:35 -05:00
/* Copyright (c) 2008 Steve Checkoway
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/*! \file
*
* Functions for decoding and disassembling z80 instructions.
* \author Steve Checkoway
* \version 0.1
* \date 2008
*/
#ifndef ZEL_Z80_INSTRUCTIONS_H
#define ZEL_Z80_INSTRUCTIONS_H
#define _GNU_SOURCE
#include <sys/types.h>
#include <sys/param.h>
#include <stdlib.h>
#include <stdint.h>
#ifdef __cplusplus
extern "C" {
#else
#include <stdbool.h>
#endif
#include <zel/z80_types.h>
/*! The type of a z80 instruction. Many z80 instructions are similar
* and share a common type. For example, <code>add a,b</code> and
* <code>add a,c</code> have the same type.
*
* The type of each instruction can be decoded as follows. Given an
* instruction \c FOO_BAR_BAZ, \c FOO is the mnemonic, \c BAR is the
* type of the first operand and \c BAZ is the type of the second. The
* operand types are as follows:
* - \c N 8 bit immediate
* - \c NN 16 bit immediate
* - \c I 8 bit signed displacement from an index register
* - \c R 8 bit register
* - \c RR 16 bit paired register
* - \c MRR 16 bit paired register used as an address
* - \c MNN 16 bit immediate used as an address
*/
typedef enum
{
#include <zel/z80_types.tab>
//! \includedoc z80_types.tab
} InstructionType;
#ifndef BYTE_ORDER
#error define BYTE_ORDER
#endif
#if BYTE_ORDER == BIG_ENDIAN
/*! Register values for the 8 bit registers which comprise the 16 bit
* paired registers.
*/
enum
{
REG_B, //!< z80 register b.
REG_C, //!< z80 register c.
REG_D, //!< z80 register d.
REG_E, //!< z80 register e.
REG_H, //!< z80 register h.
REG_L, //!< z80 register l.
REG_A, //!< z80 register a.
REG_F, //!< z80 register f.
REG_IXH, //!< z80 register ixh.
REG_IXL, //!< z80 register ixl.
REG_IYH, //!< z80 register iyh.
REG_IYL, //!< z80 register iyl.
REG_PCH, //!< z80 register pch.
REG_PCL, //!< z80 register pcl.
/* No REG_SPH */
/* No REG_SPL */
/* No REG_BP */
/* No REG_CP */
/* No REG_DP */
/* No REG_EP */
/* No REG_HP */
/* No REG_LP */
/* No REG_AP */
/* No REG_FP */
REG_I = 24, //!< z80 register I. Interrupt page address register.
REG_R, //!< z80 register r. Memory refresh register.
INV = 0xff, //!< Invalid.
};
#elif BYTE_ORDER == LITTLE_ENDIAN
/*! Register values for the 8 bit registers which comprise the 16 bit
* paired registers.
*/
enum
{
REG_C, //!< z80 register c.
REG_B, //!< z80 register b.
REG_E, //!< z80 register e.
REG_D, //!< z80 register d.
REG_L, //!< z80 register l.
REG_H, //!< z80 register h.
REG_F, //!< z80 register f.
REG_A, //!< z80 register a.
REG_IXL, //!< z80 register ixl.
REG_IXH, //!< z80 register ixh.
REG_IYL, //!< z80 register iyl.
REG_IYH, //!< z80 register iyh.
REG_PCL, //!< z80 register pcl.
REG_PCH, //!< z80 register pch.
/* No single byte regs */
REG_R = 24, //!< z80 register r. Memory refresh register.
REG_I, //!< z80 register I. Interrupt page address register.
INV = 0xff, //!< Invalid.
};
#else
#error What endianness are you using?
#endif
/*! Condition flag bits as stored in register \c f.
* The flags \c x and \c y are listed as unspecified by the z80 CPU
* User's Manual but they are modified by a number of instructions.
*/
enum
{
FLAG_C, //!< Carry flag.
FLAG_N, //!< Add/subtract flag.
FLAG_P, //!< Parity/overflow flag (P/V).
FLAG_X, //!< Flag 3.
FLAG_H, //!< Half-carry flag.
FLAG_Y, //!< Flag 5.
FLAG_Z, //!< Zero flag.
FLAG_S, //!< Sign flag.
};
/*! Condition flags. The condition is met if the corresponding flag is
* set appropriately.
*/
enum
{
COND_NZ = -FLAG_Z-1, //!< Flag Z is reset.
COND_Z = FLAG_Z, //!< Flag Z is set.
COND_NC = -FLAG_C-1, //!< Flag C is reset.
COND_C = FLAG_C, //!< Flag C is set.
COND_PO = -FLAG_P-1, //!< Flag P/V is reset.
COND_PE = FLAG_P, //!< Flag P/V is set.
COND_P = -FLAG_S-1, //!< Flag S is reset.
COND_M = FLAG_S, //!< Flag S is set.
};
/* Exactly two instructions contain both an offset and an immediate:
* dd36 d n: ld (ix+d),n
* fd36 d n: ld (iy+d),n */
/*! Describes the layout of the operands for an instruction. */
enum
{
TYPE_NONE, //!< No operands.
TYPE_IMM_N, //!< 8 bit immediate.
TYPE_IMM_NN, //!< 16 bit immediate.
TYPE_OFFSET, //!< 8 bit signed offset.
TYPE_DISP, //!< 8 bit signed offset - 2.
TYPE_OFFSET_IMM_N, //!< 8 bit signed offset and 8 bit immediate.
};
// 4 (3) words native sized words on 32 (64) bit machine.
/*! Uniform template for the instruction tables.
* \headerfile z80_instructions.h zel/z80_instructions.h
*/
typedef struct
{
InstructionType type; //!< Type of the instruction.
int16_t operand1; //!< Type of the first operand, if any.
int16_t operand2; //!< Type of the second operand, if any.
int16_t extra; //!< Type of third operand or tstates when a branch is taken, if applicable.
uint8_t tstates; //!< Base number of clock ticks the instruction takes.
uint8_t operand_types; //!< Operand layout in memory for the instruction.
const char *format; //!< Format specifier string for disassembly.
} InstructionTemplate;
/*! Completely describes an instruction.
* \headerfile z80_instructions.h zel/z80_instructions.h
*/
typedef struct
{
const InstructionTemplate *IT; //!< Template for the instruction.
unsigned int immediate; //!< Immediate value, if any.
unsigned int additional_tstates;//!< Additional clock ticks.
unsigned int r_increment; //!< Amount by which the \c r register is incremented.
int offset; //!< Offset, if any.
} Instruction;
/*! Instruction table for unprefixed instructions. */
extern const InstructionTemplate Unprefixed[256];
/*! Instruction table for cb prefixed instructions. */
extern const InstructionTemplate CB_Prefixed[256];
/*! Instruction table for dd prefixed instructions. */
extern const InstructionTemplate DD_Prefixed[256];
/*! Instruction table for ddcb prefixed instructions. */
extern const InstructionTemplate DDCB_Prefixed[256];
/*! Instruction table for ed prefixed instructions. */
extern const InstructionTemplate ED_Prefixed[256];
/*! Instruction table for fd prefixed instructions. */
extern const InstructionTemplate FD_Prefixed[256];
/*! Instruction table for fdcb prefixed instructions. */
extern const InstructionTemplate FDCB_Prefixed[256];
/*! Memory reading callback.
* \param addr The address to read.
* \param data Callback data from IF_ID().
* \return The value at address \a addr.
*/
typedef byte (*ReadMemFunction)(word addr, void *data);
/*! Instruction fetch and instruction decode. Fetchs and decodes the
* instruction pointed to by \a address into \a *inst.
* \param inst Pointer to an \c Instruction. \a *inst is set to the
* decoded instruction.
* \param address The address of the instruction.
* \param ReadMem Called repeatedly to get bytes of the instruction.
* \a data is passed as the \c data argument.
* \param data Arbitrary data passed to the \a ReadMem callback.
* \return The length of the instruction.
*/
int IF_ID( Instruction *inst, word address, ReadMemFunction ReadMem, void *data );
/*! Disassemble the instruction pointed to by \a inst into \a buffer.
* \param inst Pointer to an \c Instruction.
* \param buffer Buffer into which the disassembly is written. It must
* be large enough to hold 25 bytes.
*/
void DisassembleInstruction( const Instruction *inst, char *buffer );
#ifdef __cplusplus
}
#endif
#endif