101 lines
4.6 KiB
C
101 lines
4.6 KiB
C
#include "uxn.h"
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#include <stdio.h>
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/*
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Copyright (u) 2022-2023 Devine Lu Linvega, Andrew Alderwick, Andrew Richards
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Permission to use, copy, modify, and distribute this software for any
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purpose with or without fee is hereby granted, provided that the above
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copyright notice and this permission notice appear in all copies.
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THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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WITH REGARD TO THIS SOFTWARE.
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*/
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/* a,b,c: general use. m2: byte/short mode flag.
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tsp: macro temp stack ptr. ksp: "keep" mode copy of stack ptr. sp: ptr to stack ptr.
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x,y: macro in params. o: macro out param. */
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#define HALT(c) { return uxn_halt(u, instr, (c), pc - 1); }
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#define JUMP(x) { if(m2) pc = (x); else pc += (Sint8)(x); }
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#define PUSH8(x) { if(s->ptr == 0xff) HALT(2) s->dat[s->ptr++] = (x); }
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#define PUSH16(x) { if((tsp = s->ptr) >= 0xfe) HALT(2) t = (x); s->dat[tsp] = t >> 8; s->dat[tsp + 1] = t; s->ptr = tsp + 2; }
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#define PUSH(x) { if(m2) { PUSH16(x) } else { PUSH8(x) } }
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#define POP8(o) { if(*sp == 0x00) HALT(1) o = s->dat[--*sp]; }
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#define POP16(o) { if((tsp = *sp) <= 0x01) HALT(1) o = s->dat[tsp - 1] | (s->dat[tsp - 2] << 8); *sp = tsp - 2; }
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#define POP(o) { if(m2) { POP16(o) } else { POP8(o) } }
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#define POKE(x, y) { if(m2) { t = (y); u->ram[(x)] = t >> 8; u->ram[(x) + 1] = t; } else { u->ram[(x)] = (y); } }
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#define PEEK16(o, x) { o = (u->ram[(x)] << 8) | u->ram[(x) + 1]; }
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#define PEEK(o, x) { if(m2) PEEK16(o, x) else o = u->ram[(x)]; }
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#define DEO(a, b) { u->dev[(a)] = (b); if((deo_mask[(a) >> 4] >> ((a) & 0xf)) & 0x1) uxn_deo(u, (a)); }
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#define DEI(a, b) { a = ((dei_mask[(b) >> 4] >> ((b) & 0xf)) & 0x1) ? uxn_dei(u, (b)) : u->dev[(b)]; }
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int
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uxn_eval(Uxn *u, Uint16 pc)
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{
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Uint8 instr, opcode, m2, ksp, tsp, *sp;
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Uint16 a, b, c, t;
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Stack *s;
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if(!pc || u->dev[0x0f]) return 0;
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for(;;) {
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instr = u->ram[pc++];
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opcode = instr & 0x1f;
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/* 2 Mode */ m2 = instr & 0x20;
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/* r Mode */ s = instr & 0x40 ? &u->rst : &u->wst;
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/* k Mode */ if(instr & 0x80) { ksp = s->ptr; sp = &ksp; } else sp = &s->ptr;
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switch(opcode - (!opcode * (instr >> 5))) {
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/* Immediate */
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case -0x0: /* BRK */ return 1;
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case -0x1: /* JCI */ POP8(b) if(!b) { pc += 2; break; } /* fall through */
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case -0x2: /* JMI */ PEEK16(a, pc) pc += a + 2; break;
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case -0x3: /* JSI */ s = &u->rst; PUSH16(pc + 2) PEEK16(a, pc) pc += a + 2; break;
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case -0x4: /* LIT */
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case -0x6: /* LITr */ a = u->ram[pc++]; PUSH8(a) break;
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case -0x5: /* LIT2 */
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case -0x7: /* LIT2r */ PEEK16(a, pc) PUSH16(a) pc += 2; break;
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/* ALU */
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case 0x01: /* INC */ POP(a) PUSH(a + 1) break;
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case 0x02: /* POP */ POP(a) break;
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case 0x03: /* NIP */ POP(a) POP(b) PUSH(a) break;
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case 0x04: /* SWP */ POP(a) POP(b) PUSH(a) PUSH(b) break;
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case 0x05: /* ROT */ POP(a) POP(b) POP(c) PUSH(b) PUSH(a) PUSH(c) break;
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case 0x06: /* DUP */ POP(a) PUSH(a) PUSH(a) break;
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case 0x07: /* OVR */ POP(a) POP(b) PUSH(b) PUSH(a) PUSH(b) break;
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case 0x08: /* EQU */ POP(a) POP(b) PUSH8(b == a) break;
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case 0x09: /* NEQ */ POP(a) POP(b) PUSH8(b != a) break;
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case 0x0a: /* GTH */ POP(a) POP(b) PUSH8(b > a) break;
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case 0x0b: /* LTH */ POP(a) POP(b) PUSH8(b < a) break;
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case 0x0c: /* JMP */ POP(a) JUMP(a) break;
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case 0x0d: /* JCN */ POP(a) POP8(b) if(b) JUMP(a) break;
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case 0x0e: /* JSR */ POP(a) s = (instr & 0x40) ? &u->wst : &u->rst; PUSH16(pc) JUMP(a) break;
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case 0x0f: /* STH */ POP(a) s = (instr & 0x40) ? &u->wst : &u->rst; PUSH(a) break;
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case 0x10: /* LDZ */ POP8(a) PEEK(b, a) PUSH(b) break;
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case 0x11: /* STZ */ POP8(a) POP(b) POKE(a, b) break;
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case 0x12: /* LDR */ POP8(a) PEEK(b, pc + (Sint8)a) PUSH(b) break;
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case 0x13: /* STR */ POP8(a) POP(b) POKE(pc + (Sint8)a, b) break;
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case 0x14: /* LDA */ POP16(a) PEEK(b, a) PUSH(b) break;
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case 0x15: /* STA */ POP16(a) POP(b) POKE(a, b) break;
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case 0x16: /* DEI */ POP8(a) if(m2){ DEI(b, a) DEI(c, a + 1) PUSH16((b << 8) | c) } else { DEI(b, a) PUSH8(b) } break;
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case 0x17: /* DEO */ POP8(a) if(m2){ POP(b) DEO(a, b >> 8) DEO(a + 1, b) } else { POP8(b) DEO(a, b) } break;
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case 0x18: /* ADD */ POP(a) POP(b) PUSH(b + a) break;
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case 0x19: /* SUB */ POP(a) POP(b) PUSH(b - a) break;
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case 0x1a: /* MUL */ POP(a) POP(b) PUSH((Uint32)b * a) break;
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case 0x1b: /* DIV */ POP(a) POP(b) if(!a) HALT(3) PUSH(b / a) break;
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case 0x1c: /* AND */ POP(a) POP(b) PUSH(b & a) break;
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case 0x1d: /* ORA */ POP(a) POP(b) PUSH(b | a) break;
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case 0x1e: /* EOR */ POP(a) POP(b) PUSH(b ^ a) break;
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case 0x1f: /* SFT */ POP8(a) POP(b) PUSH(b >> (a & 0x0f) << ((a & 0xf0) >> 4)) break;
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}
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}
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}
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int
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uxn_boot(Uxn *u, Uint8 *ram)
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{
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Uint32 i;
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char *cptr = (char *)u;
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for(i = 0; i < sizeof(*u); i++)
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cptr[i] = 0;
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u->ram = ram;
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return 1;
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} |