6502
/
dcc6502
mirror of https://github.com/tcarmelveilleux/dcc6502.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

Refactored disassembly code to combine steps

This commit is contained in:
Tennessee Carmel-Veilleux 2014-07-24 16:40:08 -04:00
parent 7985830ecd
commit 4c9a2daeb4
1 changed files with 38 additions and 108 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

146
dcc6502.c
View File

@ -43,8 +43,8 @@
#define ABSIY 6 /* Absolute indexed with Y */
#define ZEPIX 7 /* Zero page indexed with X */
#define ZEPIY 8 /* Zero page indexed with Y */
#define INDIN 9 /* Indexed indirect (with x) */
#define ININD 10 /* Indirect indexed (with y) */
#define INDIN 9 /* Indexed indirect (with X) */
#define ININD 10 /* Indirect indexed (with Y) */
#define RELAT 11 /* Relative */
#define ACCUM 12 /* Accumulator */
@ -304,7 +304,7 @@ void emit_header(char *filename, int fsize, uint16_t org) {
}
/* This function appends cycle counting to the comment block */
void append_cycle(char *input, uint8_t entry, uint16_t arg, uint16_t cur_PC) {
char *append_cycle(char *input, uint8_t entry) {
char tmpstr[256];
int cycles = opcode_table[entry].cycles;
@ -316,6 +316,7 @@ void append_cycle(char *input, uint8_t entry, uint16_t arg, uint16_t cur_PC) {
}
strcat(input, tmpstr);
return (input + strlen(input));
}
void add_nes_str(char *instr, char *instr2) {
@ -368,14 +369,13 @@ void append_nes(char *input, uint16_t arg) {
// 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) {
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;
uint8_t tmp_byte1, opcode;
word tmp_word = 0;
uint16_t current_addr = org + PC;
opcode = buffer[current_addr - org];
@ -390,12 +390,11 @@ void disassemble(char *output) {
sprintf(opcode_repr, ".byte $%02x", opcode);
if (hex_output) {
sprintf(hex_dump, "$%04X> %02X:", current_addr, opcode);
len = sprintf(output, "%-16s%-16s; INVALID OPCODE !!!\n", hex_dump, opcode_repr);
sprintf(output, "%-16s%-16s; INVALID OPCODE !!!\n", hex_dump, opcode_repr);
} else {
sprintf(hex_dump, "$%04X", current_addr);
len = sprintf(output, "%-8s%-16s; INVALID OPCODE !!!\n", hex_dump, opcode_repr);
sprintf(output, "%-8s%-16s; INVALID OPCODE !!!\n", hex_dump, opcode_repr);
}
output += len;
} else {
switch (opcode_table[entry].addressing) {
case IMMED:
@ -407,38 +406,24 @@ void disassemble(char *output) {
} else {
sprintf(hex_dump, "$%04X", current_addr);
}
len = sprintf(output, DUMP_FORMAT, hex_dump, opcode_repr);
output += len;
sprintf(output, DUMP_FORMAT, hex_dump, opcode_repr);
/* Add cycle count if necessary */
if (cycle_counting) {
append_cycle(output, entry, current_addr, current_addr);
}
PC++;
break;
case ABSOL:
/* Get address */
tmp_word = LOAD_WORD(buffer, PC);
if (hex_output)
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;", 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, current_addr);
sprintf(opcode_repr, "%s $%02X%02X", name_table[opcode_table[entry].name], HIGH_PART(tmp_word), LOW_PART(tmp_word));
if (hex_output) {
sprintf(hex_dump, "$%04X> %02X %02X%02X:", current_addr, opcode, LOW_PART(tmp_word), HIGH_PART(tmp_word));
} else {
sprintf(hex_dump, "$%04X", current_addr);
}
sprintf(output, DUMP_FORMAT, hex_dump, opcode_repr);
/* Add NES port info if necessary */
if (nes_mode) {
append_nes(tmpstr, tmp_word);
}
strncpy(output, tmpstr, 254);
PC += 2;
break;
case ZEROP:
PC++;
tmp_byte1 = buffer[PC]; /* Get low byte of address */
@ -448,15 +433,8 @@ void disassemble(char *output) {
} else {
sprintf(tmpstr, "$%04X\t%s $%02X\t\t;", org+PC-1, name_table[opcode_table[entry].name], tmp_byte1);
}
/* Add cycle count if necessary */
if (cycle_counting) {
append_cycle(tmpstr, entry, org+PC-1, org+PC-1);
}
strncpy(output, tmpstr, 254);
break;
case IMPLI:
if (hex_output) {
sprintf(tmpstr, "$%04X> %02X:\t%s\t\t;", org+PC, opcode, name_table[opcode_table[entry].name]);
@ -464,14 +442,8 @@ void disassemble(char *output) {
sprintf(tmpstr, "$%04X\t%s\t\t;", org+PC, name_table[opcode_table[entry].name]);
}
/* Add cycle count if necessary */
if (cycle_counting) {
append_cycle(tmpstr, entry, org+PC, org+PC);
}
strncpy(output, tmpstr, 254);
break;
case INDIA:
PC++;
PC++;
@ -483,14 +455,8 @@ void disassemble(char *output) {
sprintf(tmpstr, "$%04X\t%s ($%02X%02X)\t;", org+PC-2, name_table[opcode_table[entry].name], HIGH_PART(tmp_word), LOW_PART(tmp_word));
}
/* Add cycle count if necessary */
if (cycle_counting) {
append_cycle(tmpstr, entry, tmp_word, org+PC-2);
}
strncpy(output, tmpstr, 254);
break;
case ABSIX:
PC++;
PC++;
@ -502,19 +468,8 @@ void disassemble(char *output) {
sprintf(tmpstr, "$%04X\t%s $%02X%02X,X\t;", org+PC-2, name_table[opcode_table[entry].name], HIGH_PART(tmp_word), LOW_PART(tmp_word));
}
/* Add cycle count if necessary */
if (cycle_counting) {
append_cycle(tmpstr, entry, tmp_word, org+PC-2);
}
/* Add NES port info if necessary */
if (nes_mode) {
append_nes(tmpstr, tmp_word);
}
strncpy(output, tmpstr, 254);
break;
case ABSIY:
PC++;
PC++;
@ -526,19 +481,8 @@ void disassemble(char *output) {
sprintf(tmpstr, "$%04X\t%s $%02X%02X,Y\t;", org+PC-2, name_table[opcode_table[entry].name], HIGH_PART(tmp_word), LOW_PART(tmp_word));
}
/* Add cycle count if necessary */
if (cycle_counting) {
append_cycle(tmpstr, entry, tmp_word, org+PC-2);
}
/* Add NES port info if necessary */
if (nes_mode) {
append_nes(tmpstr, tmp_word);
}
strncpy(output, tmpstr, 254);
break;
case ZEPIX:
PC++;
tmp_byte1 = buffer[PC]; /* Get low byte of address */
@ -549,14 +493,8 @@ void disassemble(char *output) {
sprintf(tmpstr, "$%04X\t%s $%02X,X\t;", org+PC-1, name_table[opcode_table[entry].name], tmp_byte1);
}
/* Add cycle count if necessary */
if (cycle_counting) {
append_cycle(tmpstr, entry, org+PC-1, org+PC-1);
}
strncpy(output, tmpstr, 254);
break;
case ZEPIY:
PC++;
tmp_byte1 = buffer[PC]; /* Get low byte of address */
@ -567,14 +505,8 @@ void disassemble(char *output) {
sprintf(tmpstr, "$%04X\t%s $%02X,Y\t;", org+PC-1, name_table[opcode_table[entry].name], tmp_byte1);
}
/* Add cycle count if necessary */
if (cycle_counting) {
append_cycle(tmpstr, entry, org+PC-1, org+PC-1);
}
strncpy(output, tmpstr, 254);
break;
case INDIN:
PC++;
tmp_byte1 = buffer[PC]; /* Get low byte of address */
@ -585,14 +517,8 @@ void disassemble(char *output) {
sprintf(tmpstr, "$%04X\t%s ($%02X,X)\t;", org+PC-1, name_table[opcode_table[entry].name], tmp_byte1);
}
/* Add cycle count if necessary */
if (cycle_counting) {
append_cycle(tmpstr, entry, org+PC-1, org+PC-1);
}
strncpy(output, tmpstr, 254);
break;
case ININD:
PC++;
tmp_byte1 = buffer[PC]; /* Get low byte of address */
@ -603,32 +529,21 @@ void disassemble(char *output) {
sprintf(tmpstr, "$%04X\t%s ($%02X),Y\t;", org+PC-1, name_table[opcode_table[entry].name], tmp_byte1);
}
/* Add cycle count if necessary */
if (cycle_counting) {
append_cycle(tmpstr, entry, org+PC-1, org+PC-1);
}
strncpy(output, tmpstr, 254);
break;
case RELAT:
PC++;
tmp_byte1 = buffer[PC]; /* Get relative modifier */
// FIXME: Resolve undefined behavior of cast for signed relative addressing
if (hex_output) {
sprintf(tmpstr, "$%04X> %02X %02X:\t%s $%04X\t\t;", org+PC-1, opcode, tmp_byte1, name_table[opcode_table[entry].name], (org+PC)+(signed char)(tmp_byte1)+1);
} else {
sprintf(tmpstr, "$%04X\t%s $%04X\t;", org+PC-1, name_table[opcode_table[entry].name], (org+PC)+(signed char)(tmp_byte1)+1);
}
/* Add cycle count if necessary */
if (cycle_counting) {
append_cycle(tmpstr, entry, org+PC, org+PC);
}
strncpy(output, tmpstr, 254);
break;
case ACCUM:
if (hex_output) {
sprintf(tmpstr, "$%04X> %02X:\t%s A\t\t;", org+PC, opcode, name_table[opcode_table[entry].name]);
@ -636,17 +551,32 @@ void disassemble(char *output) {
sprintf(tmpstr, "$%04X\t%s A\t\t;", org+PC, name_table[opcode_table[entry].name]);
}
/* Add cycle count if necessary */
if (cycle_counting) {
append_cycle(tmpstr, entry, org+PC, org+PC);
}
strncpy(output, tmpstr, 254);
break;
default:
break;
}
output += strlen(output);
/* Add cycle count if necessary */
if (cycle_counting) {
output = append_cycle(output, entry);
}
/* Add NES port info if necessary */
switch (opcode_table[entry].addressing) {
case ABSOL:
case ABSIX:
case ABSIY:
if (nes_mode) {
append_nes(output, tmp_word);
}
break;
default:
/* Other addressing modes: not enough info to add NES register annotation */
break;
}
}
}