commit 1612c0df3b7ee10d3509f418d89eacdf701d8a39
parent 1f94d81ac4f15028210db0cf396cdc7ebe3c186e
Author: Brian Swetland <swetland@frotz.net>
Date: Wed, 4 Apr 2012 19:35:18 -0700
a16: an assmbler for the DCPU-16
Work in progress. Support for labels is the next todo.
Diffstat:
| M | Makefile | | | 7 | ++++++- |
| A | a16.c | | | 245 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
2 files changed, 251 insertions(+), 1 deletion(-)
diff --git a/Makefile b/Makefile
@@ -1,6 +1,11 @@
+all: dcpu a16
+
dcpu: dcpu.c
gcc -Wall -o dcpu dcpu.c
+a16: a16.c
+ gcc -Wall -o a16 a16.c
+
clean:
- rm -f dcpu
+ rm -f dcpu a16
diff --git a/a16.c b/a16.c
@@ -0,0 +1,245 @@
+/* Copyright 2012, Brian Swetland. BSD Licensed. Share and Enjoy! */
+/* A DCPU-16 Assembler */
+
+/* DCPU-16 Spec is Copyright 2012 Mojang */
+/* http://0x10c.com/doc/dcpu-16.txt */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdarg.h>
+#include <string.h>
+#include <ctype.h>
+
+typedef uint16_t u16;
+typedef uint32_t u32;
+
+static u16 image[65536] = { 0, };
+static u16 PC = 0;
+static FILE *fin;
+static const char *filename = "";
+static int linenumber = 0;
+
+static char linebuffer[128] = { 0, };
+static char *lineptr = linebuffer;
+static int token;
+static char tstring[128];
+static u16 tnumber;
+
+void die(const char *fmt, ...) {
+ va_list ap;
+ fprintf(stderr,"%s:%d: ", filename, linenumber);
+ va_start(ap, fmt);
+ vfprintf(stderr, fmt, ap);
+ va_end(ap);
+ fprintf(stderr,"\n");
+ if (linebuffer[0])
+ fprintf(stderr,"%s:%d: >> %s <<\n", filename, linenumber, linebuffer);
+ exit(1);
+}
+
+enum tokens {
+ tA, tB, tC, tX, tY, tZ, tI, tJ,
+ tXXX, tSET, tADD, tSUB, tMUL, tDIV, tMOD, tSHL,
+ tSHR, tAND, tBOR, tXOR, tIFE, tIFN, tIFG, tIFB,
+ tJSR,
+ tPOP, tPEEK, tPUSH, tSP, tPC, tO,
+ tCOMMA, tOBRACK, tCBRACK, tCOLON,
+ tSTRING, tNUMBER, tEOF,
+};
+static const char *tnames[] = {
+ "A", "B", "C", "X", "Y", "Z", "I", "J",
+ "XXX", "SET", "ADD", "SUB", "MUL", "DIV", "MOD", "SHL",
+ "SHR", "AND", "BOR", "XOR", "IFE", "IFN", "IFG", "IFB",
+ "JSR",
+ "POP", "PEEK", "PUSH", "SP", "PC", "O",
+ ",", "[", "]", ":",
+ "<STRING>", "<NUMBER>", "<EOF>",
+};
+static const char *rnames[] = {
+ "A", "B", "C", "X", "Y", "Z", "I", "J",
+};
+
+#define LASTKEYWORD tO
+
+int _next(void) {
+ char c;
+nextline:
+ if (!*lineptr) {
+ if (feof(fin)) return tEOF;
+ if (fgets(linebuffer, 128, fin) == 0) return tEOF;
+ lineptr = linebuffer;
+ linenumber++;
+ }
+ while (*lineptr <= ' ') {
+ if (*lineptr == 0) goto nextline;
+ lineptr++;
+ }
+ switch ((c = *lineptr++)) {
+ case ',': return tCOMMA;
+ case '[': return tOBRACK;
+ case ']': return tCBRACK;
+ case ':': return tCOLON;
+ case '/': case ';': *lineptr = 0; goto nextline;
+ default:
+ if (isdigit(c) ||
+ (((c == '+') || (c == '-')) && isdigit(*lineptr))) {
+ tnumber = strtoul(lineptr-1, &lineptr, 0);
+ return tNUMBER;
+ }
+ if (isalpha(c)) {
+ int n;
+ char *x = tstring;
+ lineptr--;
+ while (isalnum(*lineptr))
+ *x++ = tolower(*lineptr++);
+ *x = 0;
+ for (n = 0; n <= LASTKEYWORD; n++)
+ if (!strcasecmp(tnames[n], tstring))
+ return n;
+ return tSTRING;
+ }
+ die("illegal character '%c'", c);
+ return tEOF;
+ }
+}
+
+int next(void) {
+ token = _next();
+ //fprintf(stderr,"%3d %s\n", token, tnames[token]);
+ return token;
+}
+
+void expect(int t) {
+ if (next() != t)
+ die("expecting %s, found %s", tnames[t], tnames[token]);
+}
+
+int assemble_operand(void) {
+ int n;
+ next();
+ switch (token) {
+ case tA: case tB: case tC: case tX:
+ case tY: case tZ: case tI: case tJ:
+ return token & 7;
+ case tPOP: return 0x18;
+ case tPEEK: return 0x19;
+ case tPUSH: return 0x1a;
+ case tSP: return 0x1b;
+ case tPC: return 0x1c;
+ case tO: return 0x1d;
+ case tNUMBER:
+ image[PC++] = tnumber;
+ return 0x1f;
+ default:
+ if (token != tOBRACK)
+ die("expected [");
+ }
+ next();
+ switch (token) {
+ case tA: case tB: case tC: case tX:
+ case tY: case tZ: case tI: case tJ:
+ n = token & 7;
+ next();
+ if (token == tCBRACK) {
+ return n | 0x08;
+ } else if (token == tCOMMA) {
+ expect(tNUMBER); // handle labels
+ image[PC++] = tnumber;
+ expect(tCBRACK);
+ return n | 0x10;
+ } else {
+ die("invalid operand");
+ }
+ //case tSTRING:
+ // handle labels
+ case tNUMBER:
+ image[PC++] = tnumber;
+ next();
+ if (token == tCBRACK) {
+ return 0x1e;
+ } else if ((token >= tA) && (token <= tJ)) {
+ return 0x10 | (token & 7);
+ } else {
+ die("invalid operand");
+ }
+ default:
+ die("invalid operand");
+ }
+ return 0;
+}
+
+void assemble_binop(int op) {
+ int pc = PC++;
+ int a, b;
+ a = assemble_operand();
+ expect(tCOMMA);
+ b = assemble_operand();
+ image[pc] = op | (a << 4) | (b << 10);
+}
+
+void assemble(const char *fn) {
+ fin = fopen(fn, "r");
+ filename = fn;
+ linenumber = 0;
+ if (!fin) die("cannot read file");
+
+ for (;;) {
+ next();
+ switch (token) {
+ case tEOF:
+ goto done;
+ case tCOLON:
+ expect(tSTRING);
+ //setlabel(tstring, PC);
+ continue;
+ case tSET: case tADD: case tSUB: case tMUL:
+ case tDIV: case tMOD: case tSHL: case tSHR:
+ case tAND: case tBOR: case tXOR: case tIFE:
+ case tIFN: case tIFG: case tIFB:
+ assemble_binop(token - tXXX);
+ continue;
+ default:
+ die("unexpected: %s", tnames[token]);
+ }
+ }
+done:
+ fclose(fin);
+}
+
+void emit(const char *fn) {
+ FILE *fp;
+ int n;
+ filename = fn;
+ linenumber = 0;
+ fp = fopen(fn, "w");
+ if (!fp) die("cannot write file");
+ for (n = 0; n < PC; n++)
+ fprintf(fp, "%04x\n", image[n]);
+ fclose(fp);
+}
+
+int main(int argc, char **argv) {
+ const char *outfn = "out.hex";
+
+ while (argc > 1) {
+ argc--;
+ argv++;
+ if (argv[0][0] == '-') {
+ if (!strcmp(argv[0],"-o")) {
+ if (argc > 1) {
+ outfn = argv[1];
+ argc--;
+ argv++;
+ continue;
+ }
+ }
+ die("unknown option: %s", argv[0]);
+ }
+ assemble(argv[0]);
+ }
+
+ emit(outfn);
+ return 0;
+}
+
