/**

 * $Id: armdasm.c,v 1.9 2005-12-28 22:49:26 nkeynes Exp $

 * 

 * armdasm.c    21 Aug 2004  - ARM7tdmi (ARMv4) disassembler

 *

 * Copyright (c) 2005 Nathan Keynes.

 *

 * 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.

 */

#include "aica/armcore.h"

#include "aica/armdasm.h"

#include <stdlib.h>

#define COND(ir) (ir>>28)

#define OPCODE(ir) ((ir>>20)&0x1F)

#define GRP(ir) ((ir>>26)&0x03)

#define IFLAG(ir) (ir&0x02000000)

#define SFLAG(ir) (ir&0x00100000)

#define PFLAG(ir) (ir&0x01000000)

#define UFLAG(ir) (ir&0x00800000)

#define BFLAG(ir) (ir&0x00400000)

#define WFLAG(ir) (ir&0x00200000)

#define LFLAG(ir) SFLAG(ir)

#define RN(ir) ((ir>>16)&0x0F)

#define RD(ir) ((ir>>12)&0x0F)

#define RS(ir) ((ir>>8)&0x0F)

#define RM(ir) (ir&0x0F)

#define IMM8(ir) (ir&0xFF)

#define IMM12(ir) (ir&0xFFF)

#define SHIFTIMM(ir) ((ir>>7)&0x1F)

#define IMMROT(ir) ((ir>>7)&0x1E)

#define SHIFT(ir) ((ir>>4)&0x07)

#define DISP24(ir) ((ir&0x00FFFFFF))

#define FSXC(ir) msrFieldMask[RN(ir)]

#define ROTIMM12(ir) ROTATE_RIGHT_LONG(IMM8(ir),IMMROT(ir))

#define SIGNEXT24(n) ((n&0x00800000) ? (n|0xFF000000) : (n&0x00FFFFFF))

const struct reg_desc_struct arm_reg_map[] = 

    { {"R0", REG_INT, &armr.r[0]}, {"R1", REG_INT, &armr.r[1]},

    {"R2", REG_INT, &armr.r[2]}, {"R3", REG_INT, &armr.r[3]},

    {"R4", REG_INT, &armr.r[4]}, {"R5", REG_INT, &armr.r[5]},

    {"R6", REG_INT, &armr.r[6]}, {"R7", REG_INT, &armr.r[7]},

    {"R8", REG_INT, &armr.r[8]}, {"R9", REG_INT, &armr.r[9]},

    {"R10",REG_INT, &armr.r[10]}, {"R11",REG_INT, &armr.r[11]},

    {"R12",REG_INT, &armr.r[12]}, {"R13",REG_INT, &armr.r[13]},

    {"R14",REG_INT, &armr.r[14]}, {"R15",REG_INT, &armr.r[15]},

    {"CPSR", REG_INT, &armr.cpsr}, {"SPSR", REG_INT, &armr.spsr},

    {NULL, 0, NULL} };

const struct cpu_desc_struct arm_cpu_desc = 

    { "ARM7", arm_disasm_instruction, arm_execute_instruction, arm_has_page,

      arm_set_breakpoint, arm_clear_breakpoint, arm_get_breakpoint, 4,

      (char *)&armr, sizeof(armr), arm_reg_map,

      &armr.r[15], &armr.icount };

const struct cpu_desc_struct armt_cpu_desc = 

    { "ARM7T", armt_disasm_instruction, arm_execute_instruction, arm_has_page,

      arm_set_breakpoint, arm_clear_breakpoint, arm_get_breakpoint, 2,

      (char*)&armr, sizeof(armr), arm_reg_map,

      &armr.r[15], &armr.icount };

char *conditionNames[] = { "EQ", "NE", "CS", "CC", "MI", "PL", "VS", "VC", 

                           "HI", "LS", "GE", "LT", "GT", "LE", "  " /*AL*/, "NV" };

                         /* fsxc */

char *msrFieldMask[] = { "", "c", "x", "xc", "s", "sc", "sx", "sxc",

	                     "f", "fc", "fx", "fxc", "fs", "fsc", "fsx", "fsxc" };

char *ldmModes[] = { "DA", "IA", "DB", "IB" };

#define UNIMP(ir) snprintf( buf, len, "???     " )

int arm_disasm_shift_operand( uint32_t ir, char *buf, int len )

{

	uint32_t operand, tmp;

	if( IFLAG(ir) == 0 ) {

		switch(SHIFT(ir)) {

		case 0: /* (Rm << imm) */

		    tmp = SHIFTIMM(ir);

		    if( tmp != 0 ) {

			return snprintf(buf, len, "R%d << %d", RM(ir), tmp );

		    } else {

			return snprintf(buf, len, "R%d", RM(ir));

		    }

		case 1: /* (Rm << Rs) */

			return snprintf(buf, len, "R%d << R%d", RM(ir), RS(ir) );

		case 2: /* (Rm >> imm) */

			return snprintf(buf, len, "R%d >> %d", RM(ir), SHIFTIMM(ir) );

		case 3: /* (Rm >> Rs) */

			return snprintf(buf, len, "R%d >> R%d", RM(ir), RS(ir) );

		case 4: /* (Rm >>> imm) */

			return snprintf(buf, len, "R%d >>> %d", RM(ir), SHIFTIMM(ir) );

		case 5: /* (Rm >>> Rs) */

			return snprintf(buf, len, "R%d >>> R%d", RM(ir), RS(ir) );

		case 6:

			tmp = SHIFTIMM(ir);

			if( tmp == 0 ) /* RRX aka rotate with carry */

				return snprintf(buf, len, "R%d roc 1", RM(ir) );

			else

				return snprintf(buf, len, "R%d rot %d", RM(ir), SHIFTIMM(ir) );

		case 7:

			return snprintf(buf, len, "R%d rot R%d", RM(ir), RS(ir) );

		}

	} else {

		operand = IMM8(ir);

		tmp = IMMROT(ir);

		operand = ROTATE_RIGHT_LONG(operand, tmp);

		return snprintf(buf, len, "#%08Xh", operand );

	}

}

static int arm_disasm_address_index( uint32_t ir, char *buf, int len )

{

	uint32_t tmp;

	switch(SHIFT(ir)) {

	case 0: /* (Rm << imm) */

	    tmp = SHIFTIMM(ir);

	    if( tmp != 0 ) {

		return snprintf( buf, len, "R%d << %d", RM(ir), tmp );

	    } else {

		return snprintf( buf, len, "R%d", RM(ir) );

	    }

	case 2: /* (Rm >> imm) */

		return snprintf( buf, len, "R%d >> %d", RM(ir), SHIFTIMM(ir) );

	case 4: /* (Rm >>> imm) */

		return snprintf( buf, len, "R%d >>> %d", RM(ir), SHIFTIMM(ir) );

	case 6:

		tmp = SHIFTIMM(ir);

		if( tmp == 0 ) /* RRX aka rotate with carry */

			return snprintf( buf, len, "R%d roc 1", RM(ir) );

		else

			return snprintf( buf, len, "R%d rot %d", RM(ir), tmp );

	default: 

		return UNIMP(ir);

	}

}

static int arm_disasm_address_operand( uint32_t ir, char *buf, int len,  int pc )

{

    char  shift[32];

	char sign = UFLAG(ir) ? '+' : '-';

	/* I P U . W */

	switch( (ir>>21)&0x19 ) {

	case 0: /* Rn -= imm offset (post-indexed) [5.2.8 A5-28] */

	case 1:

		return snprintf( buf, len, "[R%d], R%d %c= #%04Xh", RN(ir), RN(ir), sign, IMM12(ir) );

	case 8: /* Rn - imm offset  [5.2.2 A5-20] */

	    if( RN(ir) == 15 ) { /* PC relative - decode here */

		uint32_t addr = pc + 8 + (UFLAG(ir) ? IMM12(ir) : -IMM12(ir));

		return snprintf( buf, len, "[$%08Xh] <- #%08Xh", addr,

				 arm_read_long( addr ) );

	    } else {

		return snprintf( buf, len, "[R%d %c #%04Xh]", RN(ir), sign, IMM12(ir) );

	    }

	case 9: /* Rn -= imm offset (pre-indexed)  [5.2.5 A5-24] */

		return snprintf( buf, len, "[R%d %c= #%04Xh]", RN(ir), sign, IMM12(ir) );

	case 16: /* Rn -= Rm (post-indexed)  [5.2.10 A5-32 ] */

	case 17:

		arm_disasm_address_index( ir, shift, sizeof(shift) );

		return snprintf( buf, len, "[R%d], R%d %c= %s", RN(ir), RN(ir), sign, shift );

	case 24: /* Rn - Rm  [5.2.4 A5-23] */

		arm_disasm_address_index( ir, shift, sizeof(shift) );

		return snprintf( buf, len, "[R%d %c %s]", RN(ir), sign, shift );

	case 25: /* RN -= Rm (pre-indexed)  [5.2.7 A5-26] */

		arm_disasm_address_index( ir, shift, sizeof(shift) );

		return snprintf( buf, len, "[R%d %c= %s]", RN(ir), sign, shift );

	default:

		return UNIMP(ir); /* Unreachable */

	}

}

uint32_t arm_disasm_instruction( uint32_t pc, char *buf, int len, char *opcode )

{

    char operand[64];

    uint32_t ir = arm_read_long(pc);

    int i,j;

    sprintf( opcode, "%02X %02X %02X %02X", ir&0xFF, (ir>>8) & 0xFF,

	     (ir>>16)&0xFF, (ir>>24) );

    if( COND(ir) == 0x0F ) {

    	UNIMP(ir);

    	return pc+4;

    }

    char *cond = conditionNames[COND(ir)];

	switch( GRP(ir) ) {

	case 0:

		if( (ir & 0x0D900000) == 0x01000000 ) {

			/* Instructions that aren't actual data processing */

			switch( ir & 0x0FF000F0 ) {

			case 0x01200010: /* BXcc */

				snprintf(buf, len, "BX%s     R%d", cond, RM(ir));

				break;

			case 0x01000000: /* MRS Rd, CPSR */

				snprintf(buf, len, "MRS%s    R%d, CPSR", cond, RD(ir));

				break;

			case 0x01400000: /* MRS Rd, SPSR */

				snprintf(buf, len, "MRS%s    R%d, SPSR", cond, RD(ir));

				break;

			case 0x01200000: /* MSR CPSR, Rm */

				snprintf(buf, len, "MSR%s    CPSR_%s, R%d", cond, FSXC(ir), RM(ir));

				break;

			case 0x01600000: /* MSR SPSR, Rm */

				snprintf(buf, len, "MSR%s    SPSR_%s, R%d", cond, FSXC(ir), RM(ir));

				break;

			case 0x03200000: /* MSR CPSR, imm */

				snprintf(buf, len, "MSR%s    CPSR_%s, #%08X", cond, FSXC(ir), ROTIMM12(ir));

				break;

			case 0x03600000: /* MSR SPSR, imm */

				snprintf(buf, len, "MSR%s    SPSR_%s, #%08X", cond, FSXC(ir), ROTIMM12(ir));

				break;

			default:

				UNIMP();

			}

		} else if( (ir & 0x0E000090) == 0x00000090 ) {

			/* Neither are these */

			switch( (ir>>5)&0x03 ) {

			case 0:

				/* Arithmetic extension area */

				switch(OPCODE(ir)) {

				case 0: /* MUL */

					snprintf(buf,len, "MUL%s    R%d, R%d, R%d", cond, RN(ir), RM(ir), RS(ir) );

					break;

				case 1: /* MULS */

					break;

				case 2: /* MLA */

					snprintf(buf,len, "MLA%s    R%d, R%d, R%d, R%d", cond, RN(ir), RM(ir), RS(ir), RD(ir) );

					break;

				case 3: /* MLAS */

					break;

				case 8: /* UMULL */

					snprintf(buf,len, "UMULL%s  R%d, R%d, R%d, R%d", cond, RD(ir), RN(ir), RM(ir), RS(ir) );

					break;

				case 9: /* UMULLS */

					break;

				case 10: /* UMLAL */

					snprintf(buf,len, "UMLAL%s  R%d, R%d, R%d, R%d", cond, RD(ir), RN(ir), RM(ir), RS(ir) );

					break;

				case 11: /* UMLALS */

					break;

				case 12: /* SMULL */

					snprintf(buf,len, "SMULL%s  R%d, R%d, R%d, R%d", cond, RD(ir), RN(ir), RM(ir), RS(ir) );

					break;

				case 13: /* SMULLS */

					break;

				case 14: /* SMLAL */

					snprintf(buf,len, "SMLAL%s  R%d, R%d, R%d, R%d", cond, RD(ir), RN(ir), RM(ir), RS(ir) );

					break;

				case 15: /* SMLALS */

					break;

				case 16: /* SWP */

					snprintf(buf,len, "SWP%s    R%d, R%d, [R%d]", cond, RD(ir), RN(ir), RM(ir) );

					break;

				case 20: /* SWPB */

					snprintf(buf,len, "SWPB%s   R%d, R%d, [R%d]", cond, RD(ir), RN(ir), RM(ir) );

					break;

				default:

					UNIMP(ir);

				}

				break;

			case 1:

				if( LFLAG(ir) ) {

					/* LDRH */

				} else {

					/* STRH */

				}

				UNIMP(ir);

				break;

			case 2:

				if( LFLAG(ir) ) {

					/* LDRSB */

				} else {

				}

				UNIMP(ir);

				break;

			case 3:

				if( LFLAG(ir) ) {

					/* LDRSH */

				} else {

				}

				UNIMP(ir);

				break;

			}

		} else {

			/* Data processing */

			switch(OPCODE(ir)) {

			case 0: /* AND Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "AND%s    R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 1: /* ANDS Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "ANDS%s   R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 2: /* EOR Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "EOR%s    R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 3: /* EORS Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "EORS%s   R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 4: /* SUB Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "SUB%s    R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 5: /* SUBS Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "SUBS%s   R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 6: /* RSB Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "RSB%s    R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 7: /* RSBS Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "RSBS%s   R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 8: /* ADD Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "ADD%s    R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 9: /* ADDS Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "ADDS%s   R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 10: /* ADC Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "ADC%s    R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 11: /* ADCS Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "ADCS%s   R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 12: /* SBC Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "SBC%s    R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 13: /* SBCS Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "SBCS%s   R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 14: /* RSC Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "RSC%s    R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 15: /* RSCS Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "RSCS%s   R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 17: /* TST Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "TST%s    R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 19: /* TEQ Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "TEQ%s    R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 21: /* CMP Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "CMP%s    R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 23: /* CMN Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "CMN%s    R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 24: /* ORR Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "ORR%s    R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 25: /* ORRS Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "ORRS%s   R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 26: /* MOV Rd, operand */

			    if( ir == 0xE1A00000 ) {

				/* Not technically a different instruction,

				 * but this one is commonly used as a NOP,

				 * so... 

				 */

				snprintf(buf, len, "NOP");

			    } else {

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "MOV%s    R%d, %s", cond, RD(ir), operand);

			    }

			    break;

			case 27: /* MOVS Rd, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "MOVS%s   R%d, %s", cond, RD(ir), operand);

				break;

			case 28: /* BIC Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "BIC%s    R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 29: /* BICS Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "BICS%s   R%d, R%d, %s", cond, RD(ir), RN(ir), operand);

				break;

			case 30: /* MVN Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "MVN%s    R%d, %s", cond, RD(ir), operand);

				break;

			case 31: /* MVNS Rd, Rn, operand */

				arm_disasm_shift_operand(ir, operand, sizeof(operand));

				snprintf(buf, len, "MVNS%s   R%d, %s", cond, RD(ir), operand);

				break;

			default:

				UNIMP(ir);

			}

		}

		break;

	case 1: /* Load/store */

	    arm_disasm_address_operand( ir, operand, sizeof(operand), pc );

		switch( (ir>>20)&0x17 ) {

			case 0:

			case 16:

			case 18:

				snprintf(buf, len, "STR%s    R%d, %s", cond, RD(ir), operand );

				break;

			case 1:

			case 17:

			case 19:

				snprintf(buf, len, "LDR%s    R%d, %s", cond, RD(ir), operand );

				break;

			case 2:

				snprintf(buf, len, "STRT%s   R%d, %s", cond, RD(ir), operand );

				break;

			case 3:

				snprintf(buf, len, "LDRT%s   R%d, %s", cond, RD(ir), operand );

				break;

			case 4:

			case 20:

			case 22:

				snprintf(buf, len, "STRB%s   R%d, %s", cond, RD(ir), operand );

				break;

			case 5:

			case 21:

			case 23:

				snprintf(buf, len, "LDRB%s   R%d, %s", cond, RD(ir), operand );

				break;

			case 6:

				snprintf(buf, len, "STRBT%s  R%d, %s", cond, RD(ir), operand );

				break;

			case 7: 

				snprintf(buf, len, "LDRBT%s  R%d, %s", cond, RD(ir), operand );

				break;

		}

		break;

	case 2: 

	    if( (ir & 0x02000000) == 0x02000000 ) {

		int32_t offset = SIGNEXT24(ir&0x00FFFFFF) << 2;

		if( (ir & 0x01000000) == 0x01000000 ) { 

		    snprintf( buf, len, "BL%s     $%08Xh", cond, pc + offset + 8 );

		} else {

		    snprintf( buf, len, "B%s      $%08Xh", cond, pc + offset + 8 );

		}

	    } else {

		/* Load/store multiple */

		j = snprintf( buf, len, LFLAG(ir) ? "LDM%s%s  R%d%c,":"STM%s%s  R%d%c,", 

			      ldmModes[(ir>>23)&0x03], cond, RN(ir), WFLAG(ir)?'!':' ' );

		buf += j;

		len -= j;

		for( i = 0; i<16 && len > 2; i++ ) {

		    if( ir & (1<<i) ) {

			j = snprintf( buf, len, "R%d", i );

			buf+=j;

			len-=j;

		    }

		}

		if( BFLAG(ir) && len > 0 ) {

			buf[0] = '^';

			buf[1] = '\0';

		}

	    }

	    break;

	case 3: /* Copro */

	    if( (ir & 0x0F000000) == 0x0F000000 ) {

		snprintf( buf, len, "SWI%s    #%08Xh", SIGNEXT24(ir) );

	    } else {

		UNIMP(ir);

	    }

	    break;

	}

	return pc+4;

}

uint32_t armt_disasm_instruction( uint32_t pc, char *buf, int len, char *opcode )

{

    uint32_t ir = arm_read_word(pc);

    sprintf( opcode, "%02X %02X", ir&0xFF, (ir>>8) );

    UNIMP(ir);

    return pc+2;

}