from __future__ import print_function, division def log(string): print(" << %s" % string) #http://0x10c.com/doc/dcpu-16.txt spec = '1.1' w = 16 wmask = 2**w-1 literals = [l for l in xrange(0, 0x20)] opcode_map = {} valcode_map = {} class opcode(object): def __init__(self, *opcode): self.opcode = opcode def __call__(self, f): _opcode_f = f _opcode_f.opcode = self.opcode opcode_map[self.opcode] = _opcode_f return _opcode_f class valcode(object): def __init__(self, valcode): self.valcode = valcode def __call__(self, f): _valcode_f = f _valcode_f.valcode = self.valcode try: for code in self.valcode: # currify with (bound) code valcode_map[code] = lambda c, code=code: _valcode_f(c, code) valcode_map[code].__name__ = '%s(code=0x%02X)' % (_valcode_f.__name__, code) except TypeError: valcode_map[self.valcode] = _valcode_f return _valcode_f @opcode(0x0, 0x01) def JSR(c, a): """pushes the address of the next instruction to the stack, then sets PC to a""" #pushnext c.pc = c[a] @opcode(0x1) def SET(c, a, b): """sets a to b""" c[a] = c[b] @opcode(0x2) def ADD(c, a, b): """sets a to a+b, sets O to 0x0001 if there's an overflow""" res = (c[a] + c[b]) if res > wmask: c.o = 0x0001 res = res & wmask c[a] = res @opcode(0x3) def SUB(c, a, b): """sets a to a-b, sets O to 0xFFFF if there's an underflow""" res = (c[a] - c[b]) if res & (wmask+1): c.o = 0xFFFF res = res & wmask c[a] = res @opcode(0x4) def MUL(c, a, b): """sets a to a*b, sets O to ((a*b)>>16)&0xFFFF""" res = (c[a] * c[b]) c.o = ((c[a] * c[b]) >> w) & wmask res = res & wmask c[a] = res @opcode(0x5) def DIV(c, a, b): """sets a to a/b, sets O to ((a<<16)/b)&0xFFFF""" res = c[a] / c[b] c.o = ((c[a] << w) / c[b]) & wmask c[a] = res @opcode(0x6) def MOD(c, a, b): """sets a to a%b. if b==0, sets a to 0 instead""" if c[b]==0: res = 0 else: res = c[a] % c[b] c[a] = res @opcode(0x7) def SHL(c, a, b): """sets a to a<>16)&0xFFFF""" res = (c[a] << c[b]) c.o = ((c[a] << c[b]) >> w) & wmask res = res & wmask c[a] = res @opcode(0x8) def SHR(c, a, b): """sets a to a>>b. sets O to ((a>>16)>>b)&0xFFFF""" res = (c[a] >> c[b]) c.o = ((c[a] >> w) >> c[b]) & wmask res = res & wmask c[a] = res @opcode(0x9) def AND(c, a, b): """sets a to a&b""" res = c[a] & c[b] c[a] = res @opcode(0xA) def BOR(c, a, b): """sets a to a|b""" res = c[a] | c[b] c[a] = res @opcode(0xB) def XOR(c, a, b): """sets a to a^b""" res = c[a] ^ c[b] c[a] = res @opcode(0xC) def IFE(c, a, b): """performs next instruction only if a==b""" if c[a] == c[b]: c.skip = True @opcode(0xD) def IFN(c, a, b): """performs next instruction only if a!=b""" if c[a] != c[b]: c.skip = True @opcode(0xE) def IFG(c, a, b): """performs next instruction only if a>b""" if c[a] > c[b]: c.skip = True @opcode(0xF) def IFB(c, a, b): """performs next instruction only if (a&b)!=0""" if (c[a] & c[b]) != 0: c.skip = True def make_pointer(c, codestr): """creates a pointer func that evaluates codestr""" def getter(c=c): return eval("%s" % codestr) def setter(data, c=c): exec("%s = %r" % (codestr, data)) in {}, {'c': c, 'data': data} pointer = getter pointer.codestr = codestr pointer.set = setter return pointer def pointerize(f): """wraps a function that generates a codestr to create a pointer""" if f.func_code.co_argcount == 1: ptrz = lambda c: make_pointer(c, f(c)) elif f.func_code.co_argcount == 2: ptrz = lambda c, code: make_pointer(c, f(c, code)) else: raise Exception('%s has too many arguments' % f.__name__) ptrz.__name__ = 'ptr_to_%s' % f.__name__ ptrz.__doc__ = f.__doc__ return ptrz @valcode(range(0x00, 0x08)) @pointerize def register(c, code): """register""" v = "c.r[%r]" % code log(v) return v @valcode(range(0x08, 0x10)) @pointerize def register_value(c, code): """[register]""" v = "c.m[c.r[%r-0x07]]" % code log(v) return v @valcode(range(0x10, 0x18)) @pointerize def next_word_plus_register_value(c, code): """[next word + register]""" v = "c.m[%r + %r-0x0f]" % (c.m[c.pc], code) log(v) c.pc += 1 return v @valcode(0x18) @pointerize def pop(c): """POP / [SP++]""" v = "c.m[%r]" % c.sp log(v) c.sp += 1 return v @valcode(0x19) @pointerize def peek(c): """PEEK / [SP]""" v = "c.m[%r]" % c.sp log(v) return v @valcode(0x1A) @pointerize def push(c): """PUSH / [--SP]""" c.sp -= 1 v = "c.m[%r]" % c.sp log(v) return v @valcode(0x1B) @pointerize def stack_pointer(c): """stack pointer""" v = "c.sp" log(v) return v @valcode(0x1C) @pointerize def program_counter(c): """program counter""" v = "c.pc" log(v) return v @valcode(0x1D) @pointerize def overflow(c): """overflow""" v = "c.o" log(v) return v @valcode(0x1E) @pointerize def next_word_value(c): """[next_word]""" v = "c.m[%r]" % c.m[c.pc] c.pc += 1 log(v) return v @valcode(0x1F) @pointerize def next_word(c): """next_word (literal)""" v = "c.m[%r]" % c.pc c.pc += 1 log(v) return v @valcode(range(0x20, 0x40)) @pointerize def literal(c, code): """literal value 0x00-0x1F (literal)""" v = "%r" % (code - 0x20) log(v) return v class CPU(object): def __init__(c, debug=False): c.clear() c.reset() c.debug = debug def reset(c): """reset CPU""" c.r = [0 for _ in xrange(0, 8)] c.pc = 0x0000 c.sp = 0x0000 c.o = 0x0000 c.skip = False def clear(c): """clear memory""" c.m = [0 for _ in xrange(0, 2**w)] def _pointer(c, code): """get pointer to value code""" try: return valcode_map[code](c) except KeyError: raise Exception("Invalid value code") def __getitem__(c, code): """get pointer to value""" return c._pointer(code)() def __setitem__(c, code, value): """set value at pointer""" c._pointer(code).set(value) def step(c): """start handling [PC]""" word = c.m[c.pc] c.pc += 1 opcode = word & 0xF try: op = opcode_map[(opcode,)] log(op.__name__) except KeyError: raise Exception('Invalid opcode %01X at PC=%04X' % (opcode, c.pc)) a = word >> 4 & 0x3F b = word >> 10 & 0x3F if c.skip: c.skip = False else: op(c, a, b) if c.debug: log(c.dump_r()) def dump_r(c): """human-readable register status""" return " ".join( "%s=%04X" % (["A", "B", "C", "X", "Y", "Z", "I", "J", "PC", "SP", "O", ][i], (c.r + [c.pc, c.sp, c.o])[i]) for i in range(11)) def load_m(c, io=None): """load data in memory""" # TODO: load from io object data = [ 0x7c01, 0x0030, 0x7de1, 0x1000, 0x0020, 0x7803, 0x1000, 0xc00d, 0x7dc1, 0x001a, 0xa861, 0x7c01, 0x2000, 0x2161, 0x2000, 0x8463, 0x806d, 0x7dc1, 0x000d, 0x9031, 0x7c10, 0x0018, 0x7dc1, 0x001a, 0x9037, 0x61c1, 0x7dc1, 0x001a, 0x0000, 0x0000, 0x0000, 0x0000, ] for i in xrange(len(data)): c.m[i] = data[i] def dump_m(c, io): """dump memory data""" # TODO: save to io object pass