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Started main clean-up of version 1.6
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* Fixed all compiler warnings
* Killed union usage
* Started using C99 fixed width types
* Started normalization of whitespace width in listing
* Simplified internal addresses computations
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@tcarmelveilleux
tcarmelveilleux committed Jul 24, 2014
1 parent e19fc45 commit 7985830
Showing 1 changed file with 79 additions and 77 deletions.
156 changes: 79 additions & 77 deletions dcc6502.c
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Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,8 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <ctype.h>

#define VERSION_INFO "v1.6"
#define NUMBER_OPCODES 151
Expand All @@ -46,26 +48,16 @@
#define RELAT 11 /* Relative */
#define ACCUM 12 /* Accumulator */

#define LSB_FIRST

typedef struct OPcode {
unsigned char number; /* Number of the opcode */
unsigned char name; /* Index in the name table */
unsigned char addressing; /* Addressing mode */
unsigned char cycles; /* Number of cycles */
unsigned char cross_page; /* 1 if cross-page boundaries affect cycles */
uint8_t number; /* Number of the opcode */
unsigned int name; /* Index in the name table */
// FIXME: Transform toe num
unsigned int addressing; /* Addressing mode */
unsigned int cycles; /* Number of cycles */
unsigned int cross_page; /* 1 if cross-page boundaries affect cycles */
} OPcode;

// FIXME: Stop using the needless union and become native-endianness-agnostic
typedef union
{
#ifdef LSB_FIRST
struct { unsigned char l, h; } B;
#else
struct { byte h, l; } B;
#endif
unsigned short W;
} word;
typedef uint16_t word;

char name_table[56][4] = {
"ADC", "AND", "ASL", "BCC", "BCS", "BEQ", "BIT", "BMI", "BNE", "BPL",
Expand Down Expand Up @@ -288,20 +280,20 @@ OPcode opcode_table[NUMBER_OPCODES] = {

// FIXME: use stdint types
// FIXME: use g_ nomenclature for globals
unsigned short org; /* Origin of addresses */
char hex_output = 0; /* 1 if hex output is desired at beginning of line */
char cycle_counting = 0; /* 1 if we want cycle counting */
char nes_mode = 0; /* 1 if NES commenting and warnings are enabled */
uint16_t org; /* Origin of addresses */
int hex_output = 0; /* 1 if hex output is desired at beginning of line */
int cycle_counting = 0; /* 1 if we want cycle counting */
int nes_mode = 0; /* 1 if NES commenting and warnings are enabled */
FILE *f; /* Input file */
unsigned char buffer[0xffff]; /* Memory buffer */
unsigned short PC = 0; /* Program counter */
unsigned short max = 0xffff; /* Maximum number of bytes to disassemble */
uint8_t buffer[0xffff]; /* Memory buffer */
uint16_t PC = 0; /* Program counter */
uint16_t max = 0xffff; /* Maximum number of bytes to disassemble */
char line[512];

/* This function emits a comment header with information about the file
being disassembled */

void emit_header(char *filename, int fsize, unsigned short org) {
void emit_header(char *filename, int fsize, uint16_t org) {
fprintf(stdout, "; Source generated by DCC6502 version %s\n", VERSION_INFO);
fprintf(stdout, "; For more info about DCC6502, see https://github.com/tcarmelveilleux/dcc6502\n");
fprintf(stdout, "; FILENAME: %s, File Size: %d, ORG: $%04X\n", filename, fsize, org);
Expand All @@ -312,16 +304,17 @@ void emit_header(char *filename, int fsize, unsigned short org) {
}

/* This function appends cycle counting to the comment block */
void append_cycle(char *input, unsigned char entry, unsigned short arg, unsigned short cur_PC) {
void append_cycle(char *input, uint8_t entry, uint16_t arg, uint16_t cur_PC) {
char tmpstr[256];
int cycles = 0;

cycles = opcode_table[entry].cycles;
int cycles = opcode_table[entry].cycles;

sprintf(tmpstr, " Cycles: %d ", cycles);
// On page boundary crossing, instruction will take an extra cycle
if (opcode_table[entry].cross_page) {
strcat(tmpstr, "*!* ");
sprintf(tmpstr, " Cycles: %d/%d", cycles, cycles + 1);
} else {
sprintf(tmpstr, " Cycles: %d", cycles);
}

strcat(input, tmpstr);
}

Expand All @@ -331,7 +324,7 @@ void add_nes_str(char *instr, char *instr2) {
}

/* This function put NES-specific info in the comment block */
void append_nes(char *input, unsigned short arg) {
void append_nes(char *input, uint16_t arg) {
switch(arg) {
case 0x2000: add_nes_str(input, "PPU setup #1"); break;
case 0x2001: add_nes_str(input, "PPU setup #2"); break;
Expand Down Expand Up @@ -367,18 +360,24 @@ void append_nes(char *input, unsigned short arg) {
}
}

#define DUMP_FORMAT (hex_output ? "%-16s%-16s;" : "%-8s%-16s;")
#define HIGH_PART(val) (((val) >> 8) & 0xFFu)
#define LOW_PART(val) ((val) & 0xFFu)
#define LOAD_WORD(buffer, current_pc) ((uint16_t)buffer[(current_pc) + 1] | (((uint16_t)buffer[(current_pc) + 2]) << 8))

// FIXME: Refactor code to reduce line duplication and make more readable
/* This function disassembles the opcode at the PC and outputs it in *output */
void disassemble(char *output) {
unsigned char tmp_byte1, tmp_byte2, opcode;
char argument_signed;
uint8_t tmp_byte1, opcode;
char tmpstr[256], opcode_repr[256], hex_dump[256];
word tmp_word;
int i;
int entry = 0;
int found = 0;
int len = 0;
unsigned int current_addr = org + PC;

char tmpstr[256], tmpstr2[256], tmpstr3[256];

int i, entry, found = 0;

opcode = buffer[PC];
opcode = buffer[current_addr - org];

for (i = 0; i < NUMBER_OPCODES; i++) {
if (opcode == opcode_table[i].number) {
Expand All @@ -388,52 +387,56 @@ void disassemble(char *output) {
}

if (!found) {
sprintf(opcode_repr, ".byte $%02x", opcode);
if (hex_output) {
sprintf(tmpstr, "$%04X> %02X:\t.byte $%02x\t\t; INVALID OPCODE !!!\n", org+PC, opcode, opcode);
strncpy(output, tmpstr, 254);
sprintf(hex_dump, "$%04X> %02X:", current_addr, opcode);
len = sprintf(output, "%-16s%-16s; INVALID OPCODE !!!\n", hex_dump, opcode_repr);
} else {
sprintf(tmpstr, "$%04X\t.byte $%02x\t; INVALID OPCODE !!!\n", org+PC, opcode);
strncpy(output, tmpstr, 254);
sprintf(hex_dump, "$%04X", current_addr);
len = sprintf(output, "%-8s%-16s; INVALID OPCODE !!!\n", hex_dump, opcode_repr);
}
output += len;
} else {
switch (opcode_table[entry].addressing) {
case IMMED:
PC++;
tmp_byte1 = buffer[PC]; /* Get immediate value */
tmp_byte1 = buffer[PC + 1]; /* Get immediate value */

sprintf(opcode_repr, "%s #$%02x", name_table[opcode_table[entry].name], tmp_byte1);
if (hex_output) {
sprintf(tmpstr, "$%04X> %02X %02X:\t%s #$%02x\t;", org+PC-1, opcode, tmp_byte1, name_table[opcode_table[entry].name], tmp_byte1);
sprintf(hex_dump, "$%04X> %02X %02X:", current_addr, opcode, tmp_byte1);
} else {
sprintf(tmpstr, "$%04X\t%s #$%02x\t;", org+PC-1, name_table[opcode_table[entry].name], tmp_byte1);
sprintf(hex_dump, "$%04X", current_addr);
}
len = sprintf(output, DUMP_FORMAT, hex_dump, opcode_repr);
output += len;

/* Add cycle count if necessary */
if (cycle_counting) {
append_cycle(tmpstr, entry, org+PC-1, org+PC-1);
append_cycle(output, entry, current_addr, current_addr);
}
strncpy(output, tmpstr, 254);
PC++;
break;

case ABSOL:
PC++;
tmp_word.B.l = buffer[PC]; /* Get low byte of address */
PC++;
tmp_word.B.h = buffer[PC]; /* Get high byte of address */
/* Get address */
tmp_word = LOAD_WORD(buffer, PC);

if (hex_output)
sprintf(tmpstr, "$%04X> %02X %02X%02X:\t%s $%02X%02X\t;", org+PC-2, opcode, tmp_word.B.l, tmp_word.B.h, name_table[opcode_table[entry].name], tmp_word.B.h, tmp_word.B.l);
sprintf(tmpstr, "$%04X> %02X %02X%02X:\t%s $%02X%02X\t;", current_addr, opcode, LOW_PART(tmp_word), HIGH_PART(tmp_word), name_table[opcode_table[entry].name], HIGH_PART(tmp_word), LOW_PART(tmp_word));
else
sprintf(tmpstr, "$%04X\t%s $%02X%02X\t;", org+PC-2, name_table[opcode_table[entry].name], tmp_word.B.h, tmp_word.B.l);
sprintf(tmpstr, "$%04X\t%s $%02X%02X\t;", current_addr, name_table[opcode_table[entry].name], HIGH_PART(tmp_word), LOW_PART(tmp_word));

/* Add cycle count if necessary */
if (cycle_counting) {
append_cycle(tmpstr, entry, tmp_word.W, org+PC-2);
append_cycle(tmpstr, entry, tmp_word, current_addr);
}

/* Add NES port info if necessary */
if (nes_mode) {
append_nes(tmpstr, tmp_word.W);
append_nes(tmpstr, tmp_word);
}
strncpy(output, tmpstr, 254);
PC += 2;
break;

case ZEROP:
Expand Down Expand Up @@ -471,69 +474,66 @@ void disassemble(char *output) {

case INDIA:
PC++;
tmp_word.B.l = buffer[PC]; /* Get low byte of address */
PC++;
tmp_word.B.h = buffer[PC]; /* Get high byte of address */
tmp_word = LOAD_WORD(buffer, PC-2);

if (hex_output) {
sprintf(tmpstr, "$%04X> %02X %02X%02X:\t%s ($%02X%02X)\t;", org+PC-2, opcode, tmp_word.B.l, tmp_word.B.h, name_table[opcode_table[entry].name], tmp_word.B.h, tmp_word.B.l);
sprintf(tmpstr, "$%04X> %02X %02X%02X:\t%s ($%02X%02X)\t;", org+PC-2, opcode, LOW_PART(tmp_word), HIGH_PART(tmp_word), name_table[opcode_table[entry].name], HIGH_PART(tmp_word), LOW_PART(tmp_word));
} else {
sprintf(tmpstr, "$%04X\t%s ($%02X%02X)\t;", org+PC-2, name_table[opcode_table[entry].name], tmp_word.B.h, tmp_word.B.l);
sprintf(tmpstr, "$%04X\t%s ($%02X%02X)\t;", org+PC-2, name_table[opcode_table[entry].name], HIGH_PART(tmp_word), LOW_PART(tmp_word));
}

/* Add cycle count if necessary */
if (cycle_counting) {
append_cycle(tmpstr, entry, tmp_word.W, org+PC-2);
append_cycle(tmpstr, entry, tmp_word, org+PC-2);
}

strncpy(output, tmpstr, 254);
break;

case ABSIX:
PC++;
tmp_word.B.l = buffer[PC]; /* Get low byte of address */
PC++;
tmp_word.B.h = buffer[PC]; /* Get high byte of address */
tmp_word = LOAD_WORD(buffer, PC-2);

if (hex_output) {
sprintf(tmpstr, "$%04X> %02X %02X%02X:\t%s $%02X%02X,X\t;", org+PC-2, opcode, tmp_word.B.l, tmp_word.B.h, name_table[opcode_table[entry].name], tmp_word.B.h, tmp_word.B.l);
sprintf(tmpstr, "$%04X> %02X %02X%02X:\t%s $%02X%02X,X\t;", org+PC-2, opcode, LOW_PART(tmp_word), HIGH_PART(tmp_word), name_table[opcode_table[entry].name], HIGH_PART(tmp_word), LOW_PART(tmp_word));
} else {
sprintf(tmpstr, "$%04X\t%s $%02X%02X,X\t;", org+PC-2, name_table[opcode_table[entry].name], tmp_word.B.h, tmp_word.B.l);
sprintf(tmpstr, "$%04X\t%s $%02X%02X,X\t;", org+PC-2, name_table[opcode_table[entry].name], HIGH_PART(tmp_word), LOW_PART(tmp_word));
}

/* Add cycle count if necessary */
if (cycle_counting) {
append_cycle(tmpstr, entry, tmp_word.W, org+PC-2);
append_cycle(tmpstr, entry, tmp_word, org+PC-2);
}

/* Add NES port info if necessary */
if (nes_mode) {
append_nes(tmpstr, tmp_word.W);
append_nes(tmpstr, tmp_word);
}

strncpy(output, tmpstr, 254);
break;

case ABSIY:
PC++;
tmp_word.B.l = buffer[PC]; /* Get low byte of address */
PC++;
tmp_word.B.h = buffer[PC]; /* Get high byte of address */
tmp_word = LOAD_WORD(buffer, PC-2);

if (hex_output) {
sprintf(tmpstr, "$%04X> %02X %02X%02X:\t%s $%02X%02X,Y\t;", org+PC-2, opcode, tmp_word.B.l, tmp_word.B.h, name_table[opcode_table[entry].name], tmp_word.B.h, tmp_word.B.l);
sprintf(tmpstr, "$%04X> %02X %02X%02X:\t%s $%02X%02X,Y\t;", org+PC-2, opcode, LOW_PART(tmp_word), HIGH_PART(tmp_word), name_table[opcode_table[entry].name], HIGH_PART(tmp_word), LOW_PART(tmp_word));
} else {
sprintf(tmpstr, "$%04X\t%s $%02X%02X,Y\t;", org+PC-2, name_table[opcode_table[entry].name], tmp_word.B.h, tmp_word.B.l);
sprintf(tmpstr, "$%04X\t%s $%02X%02X,Y\t;", org+PC-2, name_table[opcode_table[entry].name], HIGH_PART(tmp_word), LOW_PART(tmp_word));
}

/* Add cycle count if necessary */
if (cycle_counting) {
append_cycle(tmpstr, entry, tmp_word.W, org+PC-2);
append_cycle(tmpstr, entry, tmp_word, org+PC-2);
}

/* Add NES port info if necessary */
if (nes_mode) {
append_nes(tmpstr, tmp_word.W);
append_nes(tmpstr, tmp_word);
}

strncpy(output, tmpstr, 254);
Expand Down Expand Up @@ -660,6 +660,7 @@ void usage_helper(char *str) {
fprintf(stderr, "\t%s\n", str);
}

// FIXME: add command line sample
void usage(void) {
usage_helper("-? -> Show this help message");
usage_helper("-oXXXX -> Set the origin (ORG) [dfl: $8000]");
Expand All @@ -672,11 +673,12 @@ void usage(void) {
}

// FIXME: DE-KLUDGIFY THIS :D
unsigned short hex2int (char *str, unsigned short dfl) {
uint16_t hex2int (char *str, uint16_t dfl) {
char HEX_digits[16] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
int i, j;
char c, k, shift;
unsigned short tmp = 0;
char k = 0;
char c, shift;
uint16_t tmp = 0;

shift = 0;
for (i = 5; i >= 2; i--) {
Expand Down

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