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disassemble even more instructions

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This commit is contained in:
Antoni Piasecki
2025-07-12 17:58:05 +02:00
parent 904ec6541f
commit 212f5aa9cc
1 changed files with 131 additions and 6 deletions
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137
mos6502.c
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@@ -36,6 +36,19 @@ void mos6502_disassemble(MOS6502 *m, size_t ins_count) {
case 0x00: {
printf("BRK\n");
} break;
case 0x08: {
printf("PHP\n");
} break;
case 0x09: {
printf("ORA #$%02X\n", m->memory[m->pc++]);
} break;
case 0x0A: {
printf("ASL A\n");
} break;
case 0x10: {
int8_t offset = m->memory[m->pc++];
printf("BPL $%04X\n", m->pc + offset);
} break;
case 0x18: {
printf("CLC\n");
} break;
@@ -43,21 +56,79 @@ void mos6502_disassemble(MOS6502 *m, size_t ins_count) {
READ_ADDR();
printf("JSR $%04X\n", addr);
} break;
case 0x28: {
printf("PLP\n");
} break;
case 0x29: {
printf("AND #$%02X\n", m->memory[m->pc++]);
} break;
case 0x2C: {
READ_ADDR();
printf("BIT $%04X\n", addr);
} break;
case 0x2E: {
READ_ADDR();
printf("ROL $%04X\n", addr);
} break;
case 0x30: {
int8_t offset = m->memory[m->pc++];
printf("BMI $%04X\n", m->pc + offset);
} break;
case 0x38: {
printf("SEC\n");
} break;
case 0x40: {
printf("RTI\n");
} break;
case 0x4C: {
READ_ADDR();
printf("JMP $%04X\n", addr);
} break;
case 0x48: {
printf("PHA\n");
} break;
case 0x49: {
printf("EOR #$%02X\n", m->memory[m->pc++]);
} break;
case 0x4A: {
printf("LSR A\n");
} break;
case 0x50: {
int8_t offset = m->memory[m->pc++];
printf("BVC $%04X\n", m->pc + offset);
} break;
case 0x60: {
printf("RTS\n");
} break;
case 0x68: {
printf("PLA\n");
} break;
case 0x69: {
printf("ADC #$%02X\n", m->memory[m->pc++]);
} break;
case 0x6E: {
READ_ADDR();
printf("ROR $%04X\n", addr);
} break;
case 0x70: {
int8_t offset = m->memory[m->pc++];
printf("BVS $%04X\n", m->pc + offset);
} break;
case 0x78: {
printf("SEI\n");
} break;
case 0x7D: {
READ_ADDR();
printf("ADC $%04X,X\n", addr);
} break;
case 0x85: {
printf("STA #$%02X\n", m->memory[m->pc++]);
printf("STA $%02X\n", m->memory[m->pc++]);
} break;
case 0x88: {
printf("DEY\n");
} break;
case 0x8A: {
printf("TXA\n");
} break;
case 0x8C: {
READ_ADDR();
@@ -75,19 +146,41 @@ void mos6502_disassemble(MOS6502 *m, size_t ins_count) {
int8_t offset = m->memory[m->pc++];
printf("BCC $%04X\n", m->pc + offset);
} break;
case 0x91: {
printf("STA ($%02X),Y\n", m->memory[m->pc++]);
} break;
case 0x98: {
printf("TYA\n");
} break;
case 0x99: {
READ_ADDR();
printf("STA $%04X,Y\n", addr);
} break;
case 0x9A: {
printf("TXS\n");
} break;
case 0x9D: {
READ_ADDR();
printf("STA $%04X,X\n", addr);
} break;
case 0xA0: {
printf("LDY #$%02X\n", m->memory[m->pc++]);
} break;
case 0xA1: {
printf("LDA ($%02X,X)\n", m->memory[m->pc++]);
} break;
case 0xA2: {
printf("LDX #$%02X\n", m->memory[m->pc++]);
} break;
case 0xA8: {
printf("TAY\n");
} break;
case 0xA9: {
printf("LDA #$%02X\n", m->memory[m->pc++]);
} break;
case 0xAA: {
printf("TAX\n");
} break;
case 0xAD: {
READ_ADDR();
printf("LDA $%04X\n", addr);
@@ -97,37 +190,69 @@ void mos6502_disassemble(MOS6502 *m, size_t ins_count) {
printf("BCS $%04X\n", m->pc + offset);
} break;
case 0xB1: {
printf("LDA (#$%02X),Y\n", m->memory[m->pc++]);
printf("LDA ($%02X,Y)\n", m->memory[m->pc++]);
} break;
case 0xB8: {
printf("CLV\n");
} break;
case 0xBA: {
printf("TSX\n");
} break;
case 0xBD: {
READ_ADDR();
printf("LDA $%04X,X\n", addr);
} break;
case 0xC0: {
printf("CPY #$%02X\n", m->memory[m->pc++]);
} break;
case 0xCA: {
printf("DEX\n");
} break;
case 0xC8: {
printf("INY\n");
} break;
case 0xC9: {
printf("CMP #$%02X\n", m->memory[m->pc++]);
} break;
case 0xCE: {
READ_ADDR();
printf("DEC $%04X\n", addr);
} break;
case 0xD0: {
int8_t offset = m->memory[m->pc++];
printf("BNE $%04X\n", m->pc + offset);
} break;
case 0xD8: {
printf("CLD\n");
} break;
case 0xE0: {
printf("CPX #$%02X\n", m->memory[m->pc++]);
} break;
case 0xE6: {
printf("INC $%02X\n", m->memory[m->pc++]);
} break;
case 0xE8: {
printf("INX\n");
} break;
case 0xE9: {
printf("SBC #$%02X\n", m->memory[m->pc++]);
} break;
case 0xEA: {
printf("NOP\n");
} break;
case 0xEE: {
READ_ADDR();
printf("INC $%04X\n", addr);
} break;
case 0xF0: {
int8_t offset = m->memory[m->pc++];
printf("BEQ $%04X\n", m->pc + offset);
} break;
case 0xF8: {
printf("SED\n");
} break;
default:
fprintf(stderr, "unrecognized opcode: %x\n", op);
fprintf(stderr, "unrecognized opcode: %02X\n", op);
exit(1);
}
}
@@ -136,8 +261,8 @@ void mos6502_disassemble(MOS6502 *m, size_t ins_count) {
void mos6502_free(MOS6502 m) { free(m.memory); }
int main(int argc, char *argv[]) {
if (argc < 2) {
fprintf(stderr, "Usage: %s <path>\n", argv[0]);
if (argc < 3) {
fprintf(stderr, "Usage: %s <path> <ins count>\n", argv[0]);
return 1;
}
@@ -152,7 +277,7 @@ int main(int argc, char *argv[]) {
m.memory[0x600 + i] = buffer[i];
}
mos6502_disassemble(&m, 103);
mos6502_disassemble(&m, atoi(argv[2]));
mos6502_free(m);
}