#include /* 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 { char name[64], params[16][64]; Uint8 len, length[16], size; } Macro; typedef struct { Uint8 len, offset; Uint16 addr; char name[64]; Macro *macro; } Label; int macroslen; Macro macros[256]; 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 scin(char *s, char c) { int i = 0; while(s[i]) if(s[i++] == c) return i - 1; return -1; } /* string char index */ int scmp(char *a, char *b, int len) { int i = 0; while(a[i] == b[i] && i < len) 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); } Macro * findmacro(char *s) { int i; for(i = 0; i < macroslen; ++i) if(scmp(macros[i].name, s, 64)) return ¯os[i]; return NULL; } Label * findlabel(char *s) { int i, rng = scin(s, '.'); char name[64]; scpy(s, name, rng > 0 ? rng + 1 : 64); for(i = 0; i < labelslen; ++i) if(scmp(labels[i].name, name, 64)) return &labels[i]; return NULL; } Uint16 findlabeladdr(char *s) { int i, o = 0; char *param; Label *l = findlabel(s); if(scin(s, '.') < 1) return l->addr; param = s + scin(s, '.') + 1; for(i = 0; i < l->macro->len; ++i) { if(scmp(l->macro->params[i], param, 64)) return l->addr + o; o += l->macro->length[i]; } printf("Warning %s.%s[%s]\n", l->name, param, l->macro->name); return 0; } Uint8 findlabellen(char *s) { int i; char *param; Label *l = findlabel(s); if(scin(s, '.') < 1) return l->len; param = s + scin(s, '.') + 1; for(i = 0; i < l->macro->len; ++i) if(scmp(l->macro->params[i], param, 64)) return l->macro->length[i]; printf("Warning %s.%s[%s]\n", l->name, param, l->macro->name); return 0; } 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 makemacro(char *name, FILE *f) { Uint8 mode = 0; Macro *m; char wv[64]; if(findmacro(name)) return error("Macro duplicate", name); if(sihx(name)) return error("Macro name is hex number", name); if(findopcode(name)) return error("Macro name is invalid", name); m = ¯os[macroslen++]; scpy(name, m->name, 64); while(fscanf(f, "%s", wv)) { if(wv[0] == '{') continue; if(wv[0] == '}') break; if(mode == 0) scpy(wv, m->params[m->len], 64); else { m->length[m->len] = shex(wv); m->size += m->length[m->len]; m->len++; } mode = !mode; } printf("New macro: %s[%d:%d]\n", name, m->len, m->size); return 1; } int makelabel(char *name, Uint16 addr, Uint8 len, Macro *m) { 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); if(m) l->macro = m; 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, 0); } int makevariable(char *id, Uint16 *addr, FILE *f) { char wv[64]; Uint8 origin, len; Macro *m = NULL; fscanf(f, "%s", wv); origin = *addr; if((m = findmacro(wv))) len = m->size; else len = shex(wv); *addr += len; return makelabel(id, origin, len, m); } int skipblock(char *w, int *cap, char a, char b) { if(w[0] == b) { *cap = 0; return 1; } if(w[0] == a) *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, cbits = 0; Uint16 addr = 0; char w[64]; printf("Pass 1\n"); while(fscanf(f, "%s", w) == 1) { if(skipblock(w, &ccmnt, '(', ')')) continue; if(skipstring(w, &cstrg, &addr)) continue; if(skipblock(w, &cbits, '[', ']')) addr += w[0] != '[' && w[0] != ']' ? 2 : 0; else if(w[0] == '@') { if(!makelabel(w + 1, addr, 0, NULL)) 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(!makemacro(w + 1, 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", 4)) 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, cbits = 0, cmacro = 0; char w[64]; printf("Pass 2\n"); while(fscanf(f, "%s", w) == 1) { Uint8 op = 0; Label *l; if(w[0] == '@') continue; if(w[0] == '&') continue; if(skipblock(w, &ccmnt, '(', ')')) continue; if(skipblock(w, &cmacro, '{', '}')) continue; if(capturestring(w, &cstrg)) continue; /* clang-format off */ if(skipblock(w, &cbits, '[', ']')) { if(w[0] != '[' && w[0] != ']') { pushshort(shex(w), 0); } } else if(w[0] == '|') p.ptr = shex(w + 1); else if((op = findopcode(w)) || scmp(w, "BRK", 4)) 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(findlabeladdr(w+1), 1); pushbyte(findopcode(findlabellen(w+1) == 2? "STR2" : "STR"), 0); } else if(w[0] == '~' && (l = findlabel(w + 1)) && l->len){ pushshort(findlabeladdr(w+1), 1); pushbyte(findopcode(findlabellen(w+1) == 2 ? "LDR2" : "LDR"), 0); } else if((l = findlabel(w + 1))) pushshort(findlabeladdr(w+1), 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; }