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159 lines (151 loc) · 6.25 KB
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disassembler.c
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159 lines (151 loc) · 6.25 KB
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#include <stdio.h>
#include <stdint.h>
int main(int argc, char **argv) {
if (argv[1] == NULL) {
printf("ROM file required as argument.\n");
return -1;
}
char *filename = argv[1];
FILE *rom_file = fopen(filename, "rb");
fseek(rom_file, 0, SEEK_END);
unsigned int size = ftell(rom_file);
uint8_t rom_bytes[size];
uint16_t address = 0x0000;
rewind(rom_file);
for (int i = 0; i < size; i++) {
fread(&rom_bytes[i], 1, 1, rom_file);
}
fclose(rom_file);
for (int i = 0; i < size; i+= 2) {
uint16_t instruction = (uint16_t)rom_bytes[i] << 8 | rom_bytes[i+1];
printf("%04X\t", address);
printf("%04X\t", instruction);
switch ((instruction & 0xF000) >> 12) {
case 0x0:
switch (instruction & 0x0FFF) {
case 0x0E0:
printf("Clear screen\n");
break;
case 0x0EE:
printf("Return\n");
break;
case 0x000:
printf("NO-OP\n");
break;
default:
printf("COSMAC Call %03X\n", instruction & 0x0FFF);
break;
}
break;
case 0x1:
printf("JMP %03X\n", instruction & 0x0FFF);
break;
case 0x2:
printf("Call %03X\n", instruction & 0x0FFF);
break;
case 0x3:
printf("SE V[%X], %02X\n", (instruction & 0x0F00) >> 8, instruction & 0x00FF);
break;
case 0x4:
printf("SNE V[%X], %02X\n", (instruction & 0x0F00) >> 8, instruction & 0x00FF);
break;
case 0x5:
printf("SE V[%X], V[%X]\n", instruction & 0x0F00, instruction & 0x0F00);
break;
case 0x6:
printf("MOV V[%X], %02X\n", (instruction & 0x0F00) >> 8, instruction & 0x00FF);
break;
case 0x7:
printf("ADD V[%X] %02X\n", instruction & 0x0F00, instruction & 0x00FF);
break;
case 0x8:
switch (instruction & 0x000F) {
case 0x0:
printf("MOV V[%X], V[%X]\n", (instruction & 0x0F00) >> 8, (instruction & 0x00F0) >> 4);
break;
case 0x1:
printf("OREQ V[%X], V[%X]\n", (instruction & 0x0F00) >> 8, (instruction & 0x00F0) >> 4);
break;
case 0x2:
printf("ANDEQ V[%X], V[%X]\n", (instruction & 0x0F00) >> 8, (instruction & 0x00F0) >> 4);
break;
case 0x3:
printf("XOREQ V[%X], V[%X]\n", (instruction & 0x0F00) >> 8, (instruction & 0x00F0) >> 4);
break;
case 0x4:
printf("ADD V[%X], V[%X]\n", (instruction & 0x0F00) >> 8, (instruction & 0x00F0) >> 4);
break;
case 0x5:
printf("SUB V[%X], V[%X]\n", (instruction & 0x0F00) >> 8, (instruction & 0x00F0) >> 4);
break;
case 0x6:
printf("RSHIFT V[%X]\n", (instruction & 0x0F00) >> 8);
break;
case 0x7:
printf("SUBEQ V[%X], V[%X]\n", (instruction & 0x0F00) >> 8, (instruction & 0x00F0) >> 4);
break;
case 0xE:
printf("LSHIFT V[%X]\n", (instruction & 0x0F00) >> 8);
break;
}
break;
case 0x9:
printf("SNE V[%X], V[%X]\n", (instruction & 0x0F00) >> 8, (instruction & 0x00F0) >> 4);
break;
case 0xA:
printf("MOV I, %03X\n", instruction & 0x0FFF);
break;
case 0xB:
printf("JMP %03X; Plus V[0]\n", instruction & 0x0FFF);
break;
case 0xC:
printf("ANDRAND V[%X], %02X\n", (instruction & 0x0F00) >> 8, instruction & 0x00FF);
break;
case 0xD:
printf("DRAW V[%X], V[%X], %X\n", (instruction & 0x0F00) >> 8, (instruction & 0x00F0) >> 4, instruction & 0x000F);
break;
case 0xE:
switch (instruction & 0x00FF) {
case 0x9E:
printf("JKEQ V[%X], KEY\n", (instruction & 0x0F00) >> 8);
break;
case 0xA1:
printf("JKNEQ V[%X], KEY\n", (instruction & 0x0F00) >> 8);
break;
}
break;
case 0xF:
switch (instruction & 0x00FF) {
case 0x07:
printf("MOV V[%X], DTIMER\n", (instruction & 0x0F00) >> 8);
break;
case 0x0A:
printf("GETKEY V[%X], KEY\n", (instruction & 0x0F00) >> 8);
break;
case 0x15:
printf("MOV DTIMER, V[%X]\n", (instruction & 0x0F00) >> 8);
break;
case 0x18:
printf("MOV STIMER, V[%X]\n", (instruction & 0x0F00) >> 8);
break;
case 0x1E:
printf("ADD I, V[%X]\n", (instruction & 0x0F00) >> 8);
break;
case 0x29:
printf("MOV I, SPRITELOC(V[%X])\n", (instruction & 0x0F00) >> 8);
break;
case 0x33:
printf("MOV I, BCD(V[%X])\n", (instruction & 0x0F00) >> 8);
break;
case 0x55:
printf("REGDMP V[%X])\n", (instruction & 0x0F00) >> 8);
break;
case 0x65:
printf("REGFILL V[%X]\n", (instruction & 0x0F00) >> 8);
break;
}
break;
}
address += 2;
}
}