/* -*- c -*- */
/* Copyright (C) 2013-2014 Free Software Foundation, Inc.
Contributed by Red Hat.
Written by DJ Delorie.
This file is part of the GNU opcodes library.
This library 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 3, or (at your option)
any later version.
It 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., 51 Franklin Street - Fifth Floor, Boston,
MA 02110-1301, USA. */
#include "sysdep.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "ansidecl.h"
#include "opcode/msp430-decode.h"
static int trace = 0;
typedef struct
{
MSP430_Opcode_Decoded *msp430;
int (*getbyte)(void *);
void *ptr;
unsigned char *op;
int op_ptr;
int pc;
} LocalData;
#define AU ATTRIBUTE_UNUSED
#define GETBYTE() getbyte_swapped (ld)
#define B ((unsigned long) GETBYTE ())
static int
getbyte_swapped (LocalData *ld)
{
int b;
if (ld->op_ptr == ld->msp430->n_bytes)
{
do
{
b = ld->getbyte (ld->ptr);
ld->op [(ld->msp430->n_bytes++)^1] = b;
}
while (ld->msp430->n_bytes & 1);
}
return ld->op[ld->op_ptr++];
}
#define ID(x) msp430->id = x
#define OP(n, t, r, a) (msp430->op[n].type = t, \
msp430->op[n].reg = r, \
msp430->op[n].addend = a)
#define OPX(n, t, r1, r2, a) \
(msp430->op[n].type = t, \
msp430->op[n].reg = r1, \
msp430->op[n].reg2 = r2, \
msp430->op[n].addend = a)
#define SYNTAX(x) msp430->syntax = x
#define UNSUPPORTED() msp430->syntax = "*unknown*"
#define DC(c) OP (0, MSP430_Operand_Immediate, 0, c)
#define DR(r) OP (0, MSP430_Operand_Register, r, 0)
#define DM(r, a) OP (0, MSP430_Operand_Indirect, r, a)
#define DA(a) OP (0, MSP430_Operand_Indirect, MSR_None, a)
#define AD(r, ad) encode_ad (r, ad, ld, 0)
#define ADX(r, ad, x) encode_ad (r, ad, ld, x)
#define SC(c) OP (1, MSP430_Operand_Immediate, 0, c)
#define SR(r) OP (1, MSP430_Operand_Register, r, 0)
#define SM(r, a) OP (1, MSP430_Operand_Indirect, r, a)
#define SA(a) OP (1, MSP430_Operand_Indirect, MSR_None, a)
#define SI(r) OP (1, MSP430_Operand_Indirect_Postinc, r, 0)
#define AS(r, as) encode_as (r, as, ld, 0)
#define ASX(r, as, x) encode_as (r, as, ld, x)
#define BW(x) msp430->size = (x ? 8 : 16)
/* The last 20 is for SWPBX.Z and SXTX.A. */
#define ABW(a,x) msp430->size = (a ? ((x ? 8 : 16)) : (x ? 20 : 20))
#define IMMU(bytes) immediate (bytes, 0, ld)
#define IMMS(bytes) immediate (bytes, 1, ld)
/* Helper macros for known status bits settings. */
#define F_____ msp430->flags_1 = msp430->flags_0 = 0; msp430->flags_set = 0
#define F_VNZC msp430->flags_1 = msp430->flags_0 = 0; msp430->flags_set = 0x87
#define F_0NZC msp430->flags_1 = 0; msp430->flags_0 = 0x80; msp430->flags_set = 0x07
/* The chip is little-endian, but GETBYTE byte-swaps words because the
decoder is based on 16-bit "words" so *this* logic is big-endian. */
static int
immediate (int bytes, int sign_extend, LocalData *ld)
{
unsigned long i = 0;
switch (bytes)
{
case 1:
i |= B;
if (sign_extend && (i & 0x80))
i -= 0x100;
break;
case 2:
i |= B << 8;
i |= B;
if (sign_extend && (i & 0x8000))
i -= 0x10000;
break;
case 3:
i |= B << 16;
i |= B << 8;
i |= B;
if (sign_extend && (i & 0x800000))
i -= 0x1000000;
break;
case 4:
i |= B << 24;
i |= B << 16;
i |= B << 8;
i |= B;
if (sign_extend && (i & 0x80000000ULL))
i -= 0x100000000ULL;
break;
default:
fprintf (stderr,
"Programmer error: immediate() called with invalid byte count %d\n",
bytes);
abort ();
}
return i;
}
/*
PC SP SR CG
As
00 Rn - - R2 #0
01 X(Rn) Sym - X(abs) #1
10 (Rn) - - #4 #2
11 (Rn++) #imm - #8 #-1
Ad
0 Rn - - - -
1 X(Rn) Sym - X(abs) - */
static void
encode_ad (int reg, int ad, LocalData *ld, int ext)
{
MSP430_Opcode_Decoded *msp430 = ld->msp430;
if (ad)
{
int x = IMMU(2) | (ext << 16);
switch (reg)
{
case 0: /* (PC) -> Symbolic. */
DA (x + ld->pc + ld->op_ptr - 2);
break;
case 2: /* (SR) -> Absolute. */
DA (x);
break;
default:
DM (reg, x);
break;
}
}
else
{
DR (reg);
}
}
static void
encode_as (int reg, int as, LocalData *ld, int ext)
{
MSP430_Opcode_Decoded *msp430 = ld->msp430;
int x;
switch (as)
{
case 0:
switch (reg)
{
case 3:
SC (0);
break;
default:
SR (reg);
break;
}
break;
case 1:
switch (reg)
{
case 0: /* PC -> Symbolic. */
x = IMMU(2) | (ext << 16);
SA (x + ld->pc + ld->op_ptr - 2);
break;
case 2: /* SR -> Absolute. */
x = IMMU(2) | (ext << 16);
SA (x);
break;
case 3:
SC (1);
break;
default:
x = IMMU(2) | (ext << 16);
SM (reg, x);
break;
}
break;
case 2:
switch (reg)
{
case 2:
SC (4);
break;
case 3:
SC (2);
break;
case MSR_None:
SA (0);
default:
SM (reg, 0);
break;
}
break;
case 3:
switch (reg)
{
case 0:
{
/* This fetch *is* the *PC++ that the opcode encodes :-) */
x = IMMU(2) | (ext << 16);
SC (x);
}
break;
case 2:
SC (8);
break;
case 3:
SC (-1);
break;
default:
SI (reg);
break;
}
break;
}
}
static void
encode_rep_zc (int srxt, int dsxt, LocalData *ld)
{
MSP430_Opcode_Decoded *msp430 = ld->msp430;
msp430->repeat_reg = srxt & 1;
msp430->repeats = dsxt;
msp430->zc = (srxt & 2) ? 1 : 0;
}
#define REPZC(s,d) encode_rep_zc (s, d, ld)
static int
dopc_to_id (int dopc)
{
switch (dopc)
{
case 4: return MSO_mov;
case 5: return MSO_add;
case 6: return MSO_addc;
case 7: return MSO_subc;
case 8: return MSO_sub;
case 9: return MSO_cmp;
case 10: return MSO_dadd;
case 11: return MSO_bit;
case 12: return MSO_bic;
case 13: return MSO_bis;
case 14: return MSO_xor;
case 15: return MSO_and;
default: return MSO_unknown;
}
}
static int
sopc_to_id (int sop, int c)
{
switch (sop * 2 + c)
{
case 0: return MSO_rrc;
case 1: return MSO_swpb;
case 2: return MSO_rra;
case 3: return MSO_sxt;
case 4: return MSO_push;
case 5: return MSO_call;
case 6: return MSO_reti;
default: return MSO_unknown;
}
}
int
msp430_decode_opcode (unsigned long pc,
MSP430_Opcode_Decoded *msp430,
int (*getbyte)(void *),
void *ptr)
{
LocalData lds, *ld = &lds;
unsigned char op_buf[20] = {0};
unsigned char *op = op_buf;
int raddr;
int al_bit;
int srxt_bits, dsxt_bits;
lds.msp430 = msp430;
lds.getbyte = getbyte;
lds.ptr = ptr;
lds.op = op;
lds.op_ptr = 0;
lds.pc = pc;
memset (msp430, 0, sizeof (*msp430));
/* These are overridden by an extension word. */
al_bit = 1;
srxt_bits = 0;
dsxt_bits = 0;
post_extension_word:
;
/* 430X extention word. */
/** 0001 1srx t l 00 dsxt 430x */
al_bit = l;
srxt_bits = srx * 2 + t;
dsxt_bits = dsxt;
op = op_buf + lds.op_ptr;
msp430->ofs_430x = 1;
goto post_extension_word;
/* double-op insns:
opcode:4 sreg:4 Ad:1 BW:1 As:2 Dreg:4
single-op insn:
opcode:9 BW:1 Ad:2 DSreg:4
jumps:
opcode:3 Cond:3 pcrel:10. */
/* Double-Operand "opcode" fields. */
/** VARY dopc 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111 */
/** dopc sreg a b as dreg %D%b %1,%0 */
ID (dopc_to_id (dopc)); ASX (sreg, as, srxt_bits); ADX (dreg, a, dsxt_bits); ABW (al_bit, b);
if (a == 0 && as == 0)
REPZC (srxt_bits, dsxt_bits);
switch (msp430->id)
{
case MSO_mov: F_____; break;
case MSO_add: F_VNZC; break;
case MSO_addc: F_VNZC; break;
case MSO_subc: F_VNZC; break;
case MSO_sub: F_VNZC; break;
case MSO_cmp: F_VNZC; break;
case MSO_dadd: F_VNZC; break;
case MSO_bit: F_0NZC; break;
case MSO_bic: F_____; break;
case MSO_bis: F_____; break;
case MSO_xor: F_VNZC; break;
case MSO_and: F_0NZC; break;
default: break;
}
/** 0001 00so c b ad dreg %S%b %1 */
ID (sopc_to_id (so,c)); ASX (dreg, ad, srxt_bits); ABW (al_bit, b);
if (ad == 0)
REPZC (srxt_bits, dsxt_bits);
/* The helper functions encode for source, but it's
both source and dest, with a few documented exceptions. */
msp430->op[0] = msp430->op[1];
/* RETI ignores the operand. */
if (msp430->id == MSO_reti)
msp430->syntax = "%S";
switch (msp430->id)
{
case MSO_rrc: F_VNZC; break;
case MSO_swpb: F_____; break;
case MSO_rra: F_0NZC; break;
case MSO_sxt: F_0NZC; break;
case MSO_push: F_____; break;
case MSO_call: F_____; break;
case MSO_reti: F_VNZC; break;
default: break;
}
/* 20xx 0010 0000 ---- ----
3cxx 0011 1100 ---- ----
001j mp-- ---- ----. */
/** 001jmp aa addrlsbs %J %1 */
raddr = (aa << 9) | (addrlsbs << 1);
if (raddr & 0x400)
raddr = raddr - 0x800;
/* This is a pc-relative jump, but we don't use SM because that
would load the target address from the memory at X(PC), not use
PC+X *as* the address. So we use SC to use the address, not the
data at that address. */
ID (MSO_jmp); SC (pc + raddr + msp430->n_bytes);
msp430->cond = jmp;
/* Extended instructions. */
/** 0000 srcr 0000 dstr MOVA @%1, %0 */
ID (MSO_mov); SM (srcr, 0); DR (dstr);
msp430->size = 20;
msp430->ofs_430x = 1;
/** 0000 srcr 0001 dstr MOVA @%1+, %0 */
ID (MSO_mov); SI (srcr); DR (dstr);
msp430->size = 20;
msp430->ofs_430x = 1;
/** 0000 srcr 0010 dstr MOVA &%1, %0 */
ID (MSO_mov); SA ((srcr << 16) + IMMU(2)); DR (dstr);
msp430->size = 20;
msp430->ofs_430x = 1;
/** 0000 srcr 0011 dstr MOVA %1, %0 */
ID (MSO_mov); SM (srcr, IMMS(2)); DR (dstr);
msp430->size = 20;
msp430->ofs_430x = 1;
/** 0000 srcr 0110 dstr MOVA %1, &%0 */
ID (MSO_mov); SR (srcr); DA ((dstr << 16) + IMMU(2));
msp430->size = 20;
msp430->ofs_430x = 1;
/** 0000 srcr 0111 dstr MOVA %1, &%0 */
ID (MSO_mov); SR (srcr); DM (dstr, IMMS(2));
msp430->size = 20;
msp430->ofs_430x = 1;
/** 0000 srcr 1000 dstr MOVA %1, %0 */
ID (MSO_mov); SC ((srcr << 16) + IMMU(2)); DR (dstr);
msp430->size = 20;
msp430->ofs_430x = 1;
/** 0000 srcr 1001 dstr CMPA %1, %0 */
ID (MSO_cmp); SC ((srcr << 16) + IMMU(2)); DR (dstr);
msp430->size = 20;
msp430->ofs_430x = 1;
F_VNZC;
/** 0000 srcr 1010 dstr ADDA %1, %0 */
ID (MSO_add); SC ((srcr << 16) + IMMU(2)); DR (dstr);
msp430->size = 20;
msp430->ofs_430x = 1;
F_VNZC;
/** 0000 srcr 1011 dstr SUBA %1, %0 */
ID (MSO_sub); SC ((srcr << 16) + IMMU(2)); DR (dstr);
msp430->size = 20;
msp430->ofs_430x = 1;
F_VNZC;
/** 0000 srcr 1011 dstr SUBA %1, %0 */
ID (MSO_sub); SC ((srcr << 16) + IMMU(2)); DR (dstr);
msp430->size = 20;
msp430->ofs_430x = 1;
F_VNZC;
/** 0000 srcr 1100 dstr MOVA %1, %0 */
ID (MSO_mov); SR (srcr); DR (dstr);
msp430->size = 20;
msp430->ofs_430x = 1;
/** 0000 srcr 1101 dstr CMPA %1, %0 */
ID (MSO_cmp); SR (srcr); DR (dstr);
msp430->size = 20;
msp430->ofs_430x = 1;
F_VNZC;
/** 0000 srcr 1110 dstr ADDA %1, %0 */
ID (MSO_add); SR (srcr); DR (dstr);
msp430->size = 20;
msp430->ofs_430x = 1;
F_VNZC;
/** 0000 srcr 1111 dstr SUBA %1, %0 */
ID (MSO_sub); SR (srcr); DR (dstr);
msp430->size = 20;
msp430->ofs_430x = 1;
F_VNZC;
/** 0000 bt00 010w dstr RRCM.A %c, %0 */
ID (MSO_rrc); DR (dstr); SR (dstr);
msp430->repeats = bt;
msp430->size = w ? 16 : 20;
msp430->ofs_430x = 1;
F_0NZC;
/** 0000 bt01 010w dstr RRAM.A %c, %0 */
ID (MSO_rra); DR (dstr); SR (dstr);
msp430->repeats = bt;
msp430->size = w ? 16 : 20;
msp430->ofs_430x = 1;
F_0NZC;
/** 0000 bt10 010w dstr RLAM.A %c, %0 */
ID (MSO_add); DR (dstr); SR (dstr);
msp430->repeats = bt;
msp430->size = w ? 16 : 20;
msp430->ofs_430x = 1;
F_0NZC;
/** 0000 bt11 010w dstr RRUM.A %c, %0 */
ID (MSO_rru); DR (dstr); SR (dstr);
msp430->repeats = bt;
msp430->size = w ? 16 : 20;
msp430->ofs_430x = 1;
F_0NZC;
/** 0001 0011 0000 0000 RETI */
ID (MSO_reti);
msp430->size = 20;
msp430->ofs_430x = 1;
/** 0001 0011 01as dstr CALLA %0 */
ID (MSO_call); AS (dstr, as);
msp430->size = 20;
msp430->ofs_430x = 1;
/** 0001 0011 1000 extb CALLA %0 */
ID (MSO_call); SA (IMMU(2) | (extb << 16));
msp430->size = 20;
msp430->ofs_430x = 1;
/** 0001 0011 1001 extb CALLA %0 */
raddr = IMMU(2) | (extb << 16);
if (raddr & 0x80000)
raddr -= 0x100000;
ID (MSO_call); SA (pc + raddr + msp430->n_bytes);
msp430->size = 20;
msp430->ofs_430x = 1;
/** 0001 0011 1011 extb CALLA %0 */
ID (MSO_call); SC (IMMU(2) | (extb << 16));
msp430->size = 20;
msp430->ofs_430x = 1;
/** 0001 010w bits srcr PUSHM.A %0 */
ID (MSO_push); SR (srcr);
msp430->size = w ? 16 : 20;
msp430->repeats = bits;
msp430->ofs_430x = 1;
/** 0001 011w bits dstr POPM.A %0 */
ID (MSO_pop); DR (dstr);
msp430->size = w ? 16 : 20;
msp430->repeats = bits;
msp430->ofs_430x = 1;
/** */
return msp430->n_bytes;
}