AtomBusMon/firmware/dis6502.c
David Banks 0c0fde6a32 Working Z80 memory access and disassembler in the small GODIL, incremented version to 0.44
Change-Id: I718be7476ec330743c206e737389856fc4b41fc8
2015-06-28 19:42:25 +01:00

264 lines
6.4 KiB
C

#include "AtomBusMon.h"
enum
{
IMP, IMPA, MARK2, BRA, IMM, ZP, ZPX, ZPY, INDX, INDY, IND, MARK3, ABS, ABSX, ABSY, IND16, IND1X
};
enum
{
I_ADC,
I_AND,
I_ASL,
I_BCC,
I_BCS,
I_BEQ,
I_BIT,
I_BMI,
I_BNE,
I_BPL,
I_BRA,
I_BRK,
I_BVC,
I_BVS,
I_CLC,
I_CLD,
I_CLI,
I_CLV,
I_CMP,
I_CPX,
I_CPY,
I_DEC,
I_DEX,
I_DEY,
I_EOR,
I_INC,
I_INX,
I_INY,
I_JMP,
I_JSR,
I_LDA,
I_LDX,
I_LDY,
I_LSR,
I_NOP,
I_ORA,
I_PHA,
I_PHP,
I_PHX,
I_PHY,
I_PLA,
I_PLP,
I_PLX,
I_PLY,
I_ROL,
I_ROR,
I_RTI,
I_RTS,
I_SBC,
I_SEC,
I_SED,
I_SEI,
I_STA,
I_STP,
I_STX,
I_STY,
I_STZ,
I_TAX,
I_TAY,
I_TRB,
I_TSB,
I_TSX,
I_TXA,
I_TXS,
I_TYA,
I_WAI,
I_XXX
};
char *opStrings[67] = {
"ADC",
"AND",
"ASL",
"BCC",
"BCS",
"BEQ",
"BIT",
"BMI",
"BNE",
"BPL",
"BRA",
"BRK",
"BVC",
"BVS",
"CLC",
"CLD",
"CLI",
"CLV",
"CMP",
"CPX",
"CPY",
"DEC",
"DEX",
"DEY",
"EOR",
"INC",
"INX",
"INY",
"JMP",
"JSR",
"LDA",
"LDX",
"LDY",
"LSR",
"NOP",
"ORA",
"PHA",
"PHP",
"PHX",
"PHY",
"PLA",
"PLP",
"PLX",
"PLY",
"ROL",
"ROR",
"RTI",
"RTS",
"SBC",
"SEC",
"SED",
"SEI",
"STA",
"STP",
"STX",
"STY",
"STZ",
"TAX",
"TAY",
"TRB",
"TSB",
"TSX",
"TXA",
"TXS",
"TYA",
"WAI",
"---"
};
unsigned char dopname[256] =
{
/*00*/ I_BRK, I_ORA, I_XXX, I_XXX, I_TSB, I_ORA, I_ASL, I_XXX, I_PHP, I_ORA, I_ASL, I_XXX, I_TSB, I_ORA, I_ASL, I_XXX,
/*10*/ I_BPL, I_ORA, I_ORA, I_XXX, I_TRB, I_ORA, I_ASL, I_XXX, I_CLC, I_ORA, I_INC, I_XXX, I_TRB, I_ORA, I_ASL, I_XXX,
/*20*/ I_JSR, I_AND, I_XXX, I_XXX, I_BIT, I_AND, I_ROL, I_XXX, I_PLP, I_AND, I_ROL, I_XXX, I_BIT, I_AND, I_ROL, I_XXX,
/*30*/ I_BMI, I_AND, I_AND, I_XXX, I_BIT, I_AND, I_ROL, I_XXX, I_SEC, I_AND, I_DEC, I_XXX, I_BIT, I_AND, I_ROL, I_XXX,
/*40*/ I_RTI, I_EOR, I_XXX, I_XXX, I_XXX, I_EOR, I_LSR, I_XXX, I_PHA, I_EOR, I_LSR, I_XXX, I_JMP, I_EOR, I_LSR, I_XXX,
/*50*/ I_BVC, I_EOR, I_EOR, I_XXX, I_XXX, I_EOR, I_LSR, I_XXX, I_CLI, I_EOR, I_PHY, I_XXX, I_XXX, I_EOR, I_LSR, I_XXX,
/*60*/ I_RTS, I_ADC, I_XXX, I_XXX, I_STZ, I_ADC, I_ROR, I_XXX, I_PLA, I_ADC, I_ROR, I_XXX, I_JMP, I_ADC, I_ROR, I_XXX,
/*70*/ I_BVS, I_ADC, I_ADC, I_XXX, I_STZ, I_ADC, I_ROR, I_XXX, I_SEI, I_ADC, I_PLY, I_XXX, I_JMP, I_ADC, I_ROR, I_XXX,
/*80*/ I_BRA, I_STA, I_XXX, I_XXX, I_STY, I_STA, I_STX, I_XXX, I_DEY, I_BIT, I_TXA, I_XXX, I_STY, I_STA, I_STX, I_XXX,
/*90*/ I_BCC, I_STA, I_STA, I_XXX, I_STY, I_STA, I_STX, I_XXX, I_TYA, I_STA, I_TXS, I_XXX, I_STZ, I_STA, I_STZ, I_XXX,
/*A0*/ I_LDY, I_LDA, I_LDX, I_XXX, I_LDY, I_LDA, I_LDX, I_XXX, I_TAY, I_LDA, I_TAX, I_XXX, I_LDY, I_LDA, I_LDX, I_XXX,
/*B0*/ I_BCS, I_LDA, I_LDA, I_XXX, I_LDY, I_LDA, I_LDX, I_XXX, I_CLV, I_LDA, I_TSX, I_XXX, I_LDY, I_LDA, I_LDX, I_XXX,
/*C0*/ I_CPY, I_CMP, I_XXX, I_XXX, I_CPY, I_CMP, I_DEC, I_XXX, I_INY, I_CMP, I_DEX, I_WAI, I_CPY, I_CMP, I_DEC, I_XXX,
/*D0*/ I_BNE, I_CMP, I_CMP, I_XXX, I_XXX, I_CMP, I_DEC, I_XXX, I_CLD, I_CMP, I_PHX, I_STP, I_XXX, I_CMP, I_DEC, I_XXX,
/*E0*/ I_CPX, I_SBC, I_XXX, I_XXX, I_CPX, I_SBC, I_INC, I_XXX, I_INX, I_SBC, I_NOP, I_XXX, I_CPX, I_SBC, I_INC, I_XXX,
/*F0*/ I_BEQ, I_SBC, I_SBC, I_XXX, I_XXX, I_SBC, I_INC, I_XXX, I_SED, I_SBC, I_PLX, I_XXX, I_XXX, I_SBC, I_INC, I_XXX
};
unsigned char dopaddr[256] =
{
/*00*/ IMP, INDX, IMP, IMP, ZP, ZP, ZP, IMP, IMP, IMM, IMPA, IMP, ABS, ABS, ABS, IMP,
/*10*/ BRA, INDY, IND, IMP, ZP, ZPX, ZPX, IMP, IMP, ABSY, IMPA, IMP, ABS, ABSX, ABSX, IMP,
/*20*/ ABS, INDX, IMP, IMP, ZP, ZP, ZP, IMP, IMP, IMM, IMPA, IMP, ABS, ABS, ABS, IMP,
/*30*/ BRA, INDY, IND, IMP, ZPX, ZPX, ZPX, IMP, IMP, ABSY, IMPA, IMP, ABSX, ABSX, ABSX, IMP,
/*40*/ IMP, INDX, IMP, IMP, ZP, ZP, ZP, IMP, IMP, IMM, IMPA, IMP, ABS, ABS, ABS, IMP,
/*50*/ BRA, INDY, IND, IMP, ZP, ZPX, ZPX, IMP, IMP, ABSY, IMP, IMP, ABS, ABSX, ABSX, IMP,
/*60*/ IMP, INDX, IMP, IMP, ZP, ZP, ZP, IMP, IMP, IMM, IMPA, IMP, IND16, ABS, ABS, IMP,
/*70*/ BRA, INDY, IND, IMP, ZPX, ZPX, ZPX, IMP, IMP, ABSY, IMP, IMP, IND1X, ABSX, ABSX, IMP,
/*80*/ BRA, INDX, IMP, IMP, ZP, ZP, ZP, IMP, IMP, IMM, IMP, IMP, ABS, ABS, ABS, IMP,
/*90*/ BRA, INDY, IND, IMP, ZPX, ZPX, ZPY, IMP, IMP, ABSY, IMP, IMP, ABS, ABSX, ABSX, IMP,
/*A0*/ IMM, INDX, IMM, IMP, ZP, ZP, ZP, IMP, IMP, IMM, IMP, IMP, ABS, ABS, ABS, IMP,
/*B0*/ BRA, INDY, IND, IMP, ZPX, ZPX, ZPY, IMP, IMP, ABSY, IMP, IMP, ABSX, ABSX, ABSY, IMP,
/*C0*/ IMM, INDX, IMP, IMP, ZP, ZP, ZP, IMP, IMP, IMM, IMP, IMP, ABS, ABS, ABS, IMP,
/*D0*/ BRA, INDY, IND, IMP, ZP, ZPX, ZPX, IMP, IMP, ABSY, IMP, IMP, ABS, ABSX, ABSX, IMP,
/*E0*/ IMM, INDX, IMP, IMP, ZP, ZP, ZP, IMP, IMP, IMM, IMP, IMP, ABS, ABS, ABS, IMP,
/*F0*/ BRA, INDY, IND, IMP, ZP, ZPX, ZPX, IMP, IMP, ABSY, IMP, IMP, ABS, ABSX, ABSX, IMP
};
unsigned int disassemble(unsigned int addr)
{
unsigned int temp;
unsigned int op = readByteInc();
int mode = dopaddr[op];
unsigned int p1 = (mode > MARK2) ? readByteInc() : 0;
unsigned int p2 = (mode > MARK3) ? readByteInc() : 0;
log0("%04X : %s ", addr, opStrings[dopname[op]]);
switch (mode)
{
case IMP:
log0(" ");
break;
case IMPA:
log0("A ");
break;
case BRA:
temp = addr + 2 + (signed char)p1;
log0("%04X ", temp);
addr++;
break;
case IMM:
log0("#%02X ", p1);
addr++;
break;
case ZP:
log0("%02X ", p1);
addr++;
break;
case ZPX:
log0("%02X,X ", p1);
addr++;
break;
case ZPY:
log0("%02X,Y ", p1);
addr++;
break;
case IND:
log0("(%02X) ", p1);
addr++;
break;
case INDX:
log0("(%02X,X) ", p1);
addr++;
break;
case INDY:
log0("(%02X),Y ", p1);
addr++;
break;
case ABS:
log0("%02X%02X ", p2, p1);
addr += 2;
break;
case ABSX:
log0("%02X%02X,X ", p2, p1);
addr += 2;
break;
case ABSY:
log0("%02X%02X,Y ", p2, p1);
addr += 2;
break;
case IND16:
log0("(%02X%02X) ", p2, p1);
addr += 2;
break;
case IND1X:
log0("(%02X%02X,X)", p2, p1);
addr += 2;
break;
}
log0("\n");
addr++;
return addr;
}