281 lines
6.8 KiB
C
281 lines
6.8 KiB
C
#include <stdio.h>
|
|
|
|
/*
|
|
Copyright (c) 2021 Devine Lu Linvega
|
|
|
|
Permission to use, copy, modify, and distribute this software for any
|
|
purpose with or without fee is hereby granted, provided that the above
|
|
copyright notice and this permission notice appear in all copies.
|
|
|
|
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
WITH REGARD TO THIS SOFTWARE.
|
|
*/
|
|
|
|
typedef unsigned char Uint8;
|
|
typedef signed char Sint8;
|
|
typedef unsigned short Uint16;
|
|
typedef signed short Sint16;
|
|
|
|
typedef struct {
|
|
int ptr;
|
|
Uint8 data[65536];
|
|
} Program;
|
|
|
|
typedef struct {
|
|
Uint8 len;
|
|
Uint16 addr;
|
|
char name[64];
|
|
} Label;
|
|
|
|
int labelslen;
|
|
Label labels[256];
|
|
Program p;
|
|
|
|
/* clang-format off */
|
|
|
|
char ops[][4] = {
|
|
"BRK", "NOP", "LIT", "---", "IOR", "IOW", "LDR", "STR",
|
|
"JMP", "JSR", "---", "RTS", "AND", "ORA", "ROL", "ROR",
|
|
"POP", "DUP", "SWP", "OVR", "ROT", "WSR", "RSW", "---",
|
|
"ADD", "SUB", "MUL", "DIV", "EQU", "NEQ", "GTH", "LTH"
|
|
};
|
|
|
|
int scmp(char *a, char *b) { int i = 0; while(a[i] == b[i]) if(!a[i++]) return 1; return 0; } /* string compare */
|
|
int slen(char *s) { int i = 0; while(s[i] && s[++i]) ; return i; } /* string length */
|
|
int sihx(char *s) { int i = 0; char c; while((c = s[i++])) if(!(c >= '0' && c <= '9') && !(c >= 'a' && c <= 'f') && !(c >= 'A' && c <= 'F')) return 0; return 1; } /* string is hexadecimal */
|
|
int shex(char *s) { int n = 0, i = 0; char c; while((c = s[i++])) if(c >= '0' && c <= '9') n = n * 16 + (c - '0'); else if(c >= 'A' && c <= 'F') n = n * 16 + 10 + (c - 'A'); else if(c >= 'a' && c <= 'f') n = n * 16 + 10 + (c - 'a'); return n; } /* string to num */
|
|
char *scpy(char *src, char *dst, int len) { int i = 0; while((dst[i] = src[i]) && i < len - 2) i++; dst[i + 1] = '\0'; return dst; } /* string copy */
|
|
|
|
#pragma mark - Helpers
|
|
|
|
/* clang-format on */
|
|
|
|
#pragma mark - I/O
|
|
|
|
void
|
|
pushbyte(Uint8 b, int lit)
|
|
{
|
|
if(lit)
|
|
pushbyte(0x02, 0);
|
|
p.data[p.ptr++] = b;
|
|
}
|
|
|
|
void
|
|
pushshort(Uint16 s, int lit)
|
|
{
|
|
if(lit)
|
|
pushbyte(0x22, 0);
|
|
pushbyte((s >> 8) & 0xff, 0);
|
|
pushbyte(s & 0xff, 0);
|
|
}
|
|
|
|
Label *
|
|
findlabel(char *s)
|
|
{
|
|
int i;
|
|
for(i = 0; i < labelslen; ++i)
|
|
if(scmp(labels[i].name, s))
|
|
return &labels[i];
|
|
return NULL;
|
|
}
|
|
|
|
Uint8
|
|
findopcode(char *s)
|
|
{
|
|
int i;
|
|
for(i = 0; i < 0x20; ++i) {
|
|
int m = 0;
|
|
char *o = ops[i];
|
|
if(o[0] != s[0] || o[1] != s[1] || o[2] != s[2])
|
|
continue;
|
|
while(s[3 + m]) {
|
|
if(s[3 + m] == '2') i |= (1 << 5); /* mode: short */
|
|
if(s[3 + m] == 'S') i |= (1 << 6); /* mode: signed */
|
|
if(s[3 + m] == '?') i |= (1 << 7); /* mode: conditional */
|
|
m++;
|
|
}
|
|
return i;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#pragma mark - Parser
|
|
|
|
int
|
|
error(char *name, char *id)
|
|
{
|
|
printf("Error: %s[%s]\n", name, id);
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
makelabel(char *name, Uint16 addr, Uint8 len)
|
|
{
|
|
Label *l;
|
|
if(findlabel(name))
|
|
return error("Label duplicate", name);
|
|
if(sihx(name))
|
|
return error("Label name is hex number", name);
|
|
if(findopcode(name))
|
|
return error("Label name is invalid", name);
|
|
l = &labels[labelslen++];
|
|
l->addr = addr;
|
|
l->len = len;
|
|
scpy(name, l->name, 64);
|
|
printf("New label: %s, at 0x%02x[%d]\n", l->name, l->addr, l->len);
|
|
return 1;
|
|
}
|
|
|
|
int
|
|
makeconst(char *id, FILE *f)
|
|
{
|
|
char wv[64];
|
|
fscanf(f, "%s", wv);
|
|
return makelabel(id, shex(wv), 1);
|
|
}
|
|
|
|
int
|
|
makevariable(char *id, Uint16 *addr, FILE *f)
|
|
{
|
|
char wv[64];
|
|
Uint8 origin;
|
|
fscanf(f, "%s", wv);
|
|
origin = *addr;
|
|
*addr += shex(wv);
|
|
return makelabel(id, origin, shex(wv));
|
|
}
|
|
|
|
int
|
|
skipcomment(char *w, int *cap)
|
|
{
|
|
if(w[0] == ')') {
|
|
*cap = 0;
|
|
return 1;
|
|
}
|
|
if(w[0] == '(') *cap = 1;
|
|
if(*cap) return 1;
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
skipstring(char *w, int *cap, Uint16 *addr)
|
|
{
|
|
if(w[0] == '"') {
|
|
if(*cap)
|
|
*addr += 1;
|
|
*cap = !(*cap);
|
|
return 1;
|
|
}
|
|
if(*cap) {
|
|
*addr += slen(w) + 1;
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
capturestring(char *w, int *cap)
|
|
{
|
|
if(w[0] == '"') {
|
|
if(*cap)
|
|
pushbyte(0x00, 0);
|
|
*cap = !(*cap);
|
|
return 1;
|
|
}
|
|
if(*cap) {
|
|
int i;
|
|
for(i = 0; i < slen(w); ++i)
|
|
pushbyte(w[i], 0);
|
|
pushbyte(' ', 0);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
pass1(FILE *f)
|
|
{
|
|
int ccmnt = 0, cstrg = 0;
|
|
Uint16 addr = 0;
|
|
char w[64];
|
|
while(fscanf(f, "%s", w) == 1) {
|
|
if(skipcomment(w, &ccmnt)) continue;
|
|
if(skipstring(w, &cstrg, &addr)) continue;
|
|
if(w[0] == '@') {
|
|
if(!makelabel(w + 1, addr, 0))
|
|
return error("Pass1 failed", w);
|
|
} else if(w[0] == ';') {
|
|
if(!makevariable(w + 1, &addr, f))
|
|
return error("Pass1 failed", w);
|
|
} else if(w[0] == ':') {
|
|
if(!makeconst(w + 1, f))
|
|
return error("Pass1 failed", w);
|
|
} else if(findopcode(w) || scmp(w, "BRK"))
|
|
addr += 1;
|
|
else {
|
|
switch(w[0]) {
|
|
case '|': addr = shex(w + 1); break;
|
|
case '=': addr += 4; break; /* STR helper */
|
|
case '~': addr += 4; break; /* LDR helper */
|
|
case ',': addr += 3; break;
|
|
case '.': addr += (slen(w + 1) == 2 ? 1 : 2); break;
|
|
case '+': /* signed positive */
|
|
case '-': /* signed negative */
|
|
case '#': addr += (slen(w + 1) == 2 ? 2 : 3); break;
|
|
default: return error("Unknown label in first pass", w);
|
|
}
|
|
}
|
|
}
|
|
rewind(f);
|
|
return 1;
|
|
}
|
|
|
|
int
|
|
pass2(FILE *f)
|
|
{
|
|
int ccmnt = 0, cstrg = 0;
|
|
char w[64];
|
|
while(fscanf(f, "%s", w) == 1) {
|
|
Uint8 op = 0;
|
|
Label *l;
|
|
if(w[0] == '@') continue;
|
|
if(skipcomment(w, &ccmnt)) continue;
|
|
if(capturestring(w, &cstrg)) continue;
|
|
/* clang-format off */
|
|
if(w[0] == '|') p.ptr = shex(w + 1);
|
|
else if((op = findopcode(w)) || scmp(w, "BRK")) pushbyte(op, 0);
|
|
else if(w[0] == ':') fscanf(f, "%s", w);
|
|
else if(w[0] == ';') fscanf(f, "%s", w);
|
|
else if(w[0] == '.' && sihx(w + 1) && slen(w + 1) == 2) pushbyte(shex(w + 1), 0);
|
|
else if(w[0] == '.' && sihx(w + 1) && slen(w + 1) == 4) pushshort(shex(w + 1), 0);
|
|
else if(w[0] == '#' && sihx(w + 1) && slen(w + 1) == 2) pushbyte(shex(w + 1), 1);
|
|
else if(w[0] == '#' && sihx(w + 1) && slen(w + 1) == 4) pushshort(shex(w + 1), 1);
|
|
else if(w[0] == '+' && sihx(w + 1) && slen(w + 1) == 2) pushbyte((Sint8)shex(w + 1), 1);
|
|
else if(w[0] == '+' && sihx(w + 1) && slen(w + 1) == 4) pushshort((Sint16)shex(w + 1), 1);
|
|
else if(w[0] == '-' && sihx(w + 1) && slen(w + 1) == 2) pushbyte((Sint8)(shex(w + 1) * -1), 1);
|
|
else if(w[0] == '-' && sihx(w + 1) && slen(w + 1) == 4) pushshort((Sint16)(shex(w + 1) * -1), 1);
|
|
else if(w[0] == '=' && (l = findlabel(w + 1)) && l->len){ pushshort(l->addr, 1); pushbyte(findopcode(l->len == 2 ? "STR2" : "STR"),0); }
|
|
else if(w[0] == '~' && (l = findlabel(w + 1)) && l->len){ pushshort(l->addr, 1); pushbyte(findopcode(l->len == 2 ? "LDR2" : "LDR"),0); }
|
|
else if((l = findlabel(w + 1))) pushshort(l->addr, w[0] == ',');
|
|
else return error("Unknown label in second pass", w);
|
|
/* clang-format on */
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
int
|
|
main(int argc, char *argv[])
|
|
{
|
|
FILE *f;
|
|
if(argc < 3)
|
|
return error("Input", "Missing");
|
|
if(!(f = fopen(argv[1], "r")))
|
|
return error("Open", "Failed");
|
|
if(!pass1(f) || !pass2(f))
|
|
return error("Assembly", "Failed");
|
|
fwrite(p.data, sizeof(p.data), 1, fopen(argv[2], "wb"));
|
|
fclose(f);
|
|
printf("Assembled %s.\n\n", argv[2]);
|
|
return 0;
|
|
}
|