/**************************************************************************/
/* EightBall Disassembler */
/* */
/* The Eight Bit Algorithmic Language */
/* For Apple IIe/c/gs (64K), Commodore 64, VIC-20 +32K RAM expansion */
/* (also builds for Linux as 32 bit executable (gcc -m32) only) */
/* */
/* Compiles with cc65 v2.15 for VIC-20, C64, Apple II */
/* and gcc 7.3 for Linux */
/* */
/* cc65: Define symbol VIC20 to build for Commodore VIC-20 + 32K. */
/* Define symbol C64 to build for Commodore 64. */
/* Define symbol A2E to build for Apple //e. */
/* */
/* Copyright Bobbi Webber-Manners 2018 */
/* EightBall VM disassembler */
/* */
/* Formatted with indent -kr -nut */
/**************************************************************************/
/**************************************************************************/
/* GNU PUBLIC LICENCE v3 OR LATER */
/* */
/* This program is free software: you can redistribute it and/or modify */
/* it under the terms of the GNU General Public License as published by */
/* the Free Software Foundation, either version 3 of the License, or */
/* (at your option) any later version. */
/* */
/* This program is distributed in the hope that it will be useful, */
/* but WITHOUT ANY WARRANTY; without even the implied warranty of */
/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the */
/* GNU General Public License for more details. */
/* */
/* You should have received a copy of the GNU General Public License */
/* along with this program. If not, see . */
/* */
/**************************************************************************/
#include "eightballvm.h"
#include "eightballutils.h"
#include
#include
#include
#ifdef A2E
#include
#endif
/* Order must match enum bytecode */
char *bytecodenames[] = {
"END",
"LDI",
"LDAW",
"LDAWI",
"LDAB",
"LDABI",
"STAW",
"STAWI",
"STAB",
"STABI",
"LDRW",
"LDRWI",
"LDRB",
"LDRBI",
"STRW",
"STRWI",
"STRB",
"STRBI",
"SWP",
"DUP",
"DUP2",
"DRP",
"OVER",
"PICK",
"POPW",
"POPB",
"PSHW",
"PSHB",
"DISC",
"SPFP",
"FPSP",
"ATOR",
"RTOA",
"INC",
"DEC",
"ADD",
"SUB",
"MUL",
"DIV",
"MOD",
"NEG",
"GT",
"GTE",
"LT",
"LTE",
"EQL",
"NEQL",
"AND",
"OR",
"NOT",
"BAND",
"BOR",
"BXOR",
"BNOT",
"LSH",
"RSH",
"JMP",
"JMPI",
"BRC",
"BRCI",
"JSR",
"JSRI",
"RTS",
"PRDEC",
"PRHEX",
"PRCH",
"PRSTR",
"PRMSG",
"KBDCH",
"KBDLN"
};
/*
* Call stack grows down from top of memory.
* If it hits CALLSTACKLIM then VM will quit with error
*/
#ifdef __GNUC__
#define MEMORYSZ (64 * 1024)
#else
/* Has to be 64K minus a byte otherwise winds up being zero! */
#define MEMORYSZ (64 * 1024) - 1
#endif
#ifdef __GNUC__
unsigned char memory[MEMORYSZ];
#else
unsigned char *memory = 0;
#endif
#ifdef __GNUC__
#define UINT16 unsigned short
#else
#define UINT16 unsigned int
#endif
UINT16 pc = RTPCSTART; /* Program counter */
UINT16 lastpc;
/*
* Print a value as hex
*/
void _printhexbyte(unsigned char val) {
printchar(hexval2char((val>>4) & 0x0f));
printchar(hexval2char(val & 0x0f));
}
/*
* Fetch, decode and disassemble a VM instruction, then advance the program counter.
*/
void disassemble_instruction()
{
printhex(pc);
print(": ");
_printhexbyte(memory[pc]);
printchar(' ');
switch(memory[pc++]) {
case VM_LDIMM:
case VM_LDAWORDIMM:
case VM_LDABYTEIMM:
case VM_LDRWORDIMM:
case VM_LDRBYTEIMM:
case VM_STAWORDIMM:
case VM_STABYTEIMM:
case VM_STRWORDIMM:
case VM_STRBYTEIMM:
case VM_JMPIMM:
case VM_BRNCHIMM:
case VM_JSRIMM:
_printhexbyte(memory[pc++]);
printchar(' ');
_printhexbyte(memory[pc++]);
print(" ");
print(bytecodenames[memory[pc-3]]);
printchar(' ');
printhex(memory[pc-2] + (memory[pc-1] << 8));
print(" (");
printdec(memory[pc-2] + (memory[pc-1] << 8));
print(")");
break;
case VM_PRMSG:
print("...00 ");
print(bytecodenames[memory[pc-1]]);
print(" \"");
while(memory[pc]) {
printchar(memory[pc++]);
}
++pc;
printchar('"');
break;
default:
print(" ");
if (memory[pc-1] <= VM_KBDLN) {
print(bytecodenames[memory[pc-1]]);
} else {
print("**ILLEGAL**");
}
}
#ifdef A2E
printchar('\r');
#else
printchar('\n');
#endif
};
/*
* Disassemble the program!
*/
void disassemble()
{
while (pc < lastpc) {
disassemble_instruction();
}
}
/*
* Load bytecode into memory[].
*/
void load()
{
FILE *fp;
char ch;
pc = RTPCSTART;
do {
print("\nBytecode file (CR for default)>");
getln((char*)memory, 15);
if (strlen((char*)memory) == 0) {
strcpy((char*)memory, "bytecode");
}
print("Loading '");
print((char*)memory);
print("'\n");
fp = fopen((char*)memory, "r");
} while (!fp);
while (!feof(fp)) {
ch = fgetc(fp);
memory[pc++] = ch;
/* Print dot for each page */
if (pc%0xff == 0) {
printchar('.');
}
}
fclose(fp);
lastpc = pc - 1;
pc = RTPCSTART;
#ifdef A2E
printchar(7);
#endif
}
int main()
{
print("EightBall Disassembler v" VERSIONSTR "\n");
print("(c)Bobbi, 2018\n");
print("Free Software.\n");
print("Licenced under GPL.\n\n");
load();
#ifdef __GNUC__
print(" Done.\n\n");
#endif
#ifdef A2E
videomode(VIDEOMODE_80COL);
clrscr();
#elif defined(CBM)
printchar(147); /* Clear */
#endif
disassemble();
return 0;
}