diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..7e99e36 --- /dev/null +++ b/.gitignore @@ -0,0 +1 @@ +*.pyc \ No newline at end of file diff --git a/README.mdown b/README.mdown index 0076430..9c59a9d 100644 --- a/README.mdown +++ b/README.mdown @@ -2,19 +2,19 @@ A DCPU-16 implementation in Python. See [the spec][0]. -# But what's the goal of this? There's another one already! +# Goal -Well, what's wrong with taking another stab at it? Besides, I personnally felt it was too C-ish, and not pythonic enough (whatever that means, but you should [read][1] [this][2]). I wanted to revive whatever low-level (admittedly limited) ASM knowledge I had (from 6800/68000) and sharpen my Python-fu. The spirit of the thing is to be educative for everyone (including me). +Many high-level implementations looked like C-in-other-language, so let's have a pythonic enough (whatever that means, but you should [read][1] [this][2]) implementation. The spirit of the thing is to be educative for everyone. -# How do I use this? +# Usage -It's meant to be used interactively via the Python REPL as well as programmatically. I might implement a specific ASM REPL at some point. +It's meant to be used interactively via the Python REPL as well as programmatically. A specific ASM REPL might be implemented at some point. An example of a Python REPL session: - >>> from dcpu_16 import CPU + >>> from dcpu_16 import CPU, spec_demo >>> c = CPU(debug=True) - >>> c.load_m() # loads demo program + >>> c.load_m(spec_demo) # loads demo program >>> c.step() # step by one instruction << SET << c.r[0x0] @@ -31,9 +31,9 @@ An example of a Python REPL session: >>> c.dump_r() # get CPU register state as string 'A=0000 B=0000 C=0000 X=0000 Y=0000 Z=0000 I=0000 J=0000 PC=0000 SP=0000 O=0000' -# What is the status of this? +# Status -It's not bug-free yet, the implementation itself is still a WIP and the whole of the spec example does not pass yet. But hey, that's what you get in a few late hours. Fixes coming, I promise. +As of v1.0 the CPU implementation ought to be complete according to DCPU-16 spec v1.1. # Features diff --git a/dcpu_16.py b/dcpu_16.py index 3b25456..b0e60c1 100644 --- a/dcpu_16.py +++ b/dcpu_16.py @@ -1,32 +1,48 @@ +"""DCPU-16 implementation. (c) 2012, Loic Nageleisen + +Spec: http://0x10c.com/doc/dcpu-16.txt + +See LICENSE for licensing information. +""" + + from __future__ import print_function, division + +# DCPU-16 spec version +spec = '1.1' + + +# log tool def log(string): print(" << %s" % string) -#http://0x10c.com/doc/dcpu-16.txt -spec = '1.1' - +# width constants w = 16 -wmask = 2**w-1 - -literals = [l for l in xrange(0, 0x20)] - -opcode_map = {} -valcode_map = {} +wmask = 2**w - 1 +_opcode_map = {} class opcode(object): + """Opcode decorator""" 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 + if len(self.opcode) == 1: + _opcode_map[self.opcode[0]] = _opcode_f + else: + if not self.opcode[0] in _opcode_map.keys(): + _opcode_map[self.opcode[0]] = {} + _opcode_map[self.opcode[0]][self.opcode[1]] = _opcode_f return _opcode_f +_valcode_map = {} class valcode(object): + """Valcode decorator""" def __init__(self, valcode): self.valcode = valcode @@ -36,17 +52,58 @@ class valcode(object): 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) + _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 + _valcode_map[self.valcode] = _valcode_f return _valcode_f +class Register(object): + """Register descriptor""" + def __init__(self, regcode=None): + self.regcode = regcode + + def __get__(self, c, type=None): + if self.regcode is not None: + return c.r[self.regcode] + else: + return self.value + + def __set__(self, c, value): + if self.regcode is not None: + c.r[self.regcode] = value & wmask + else: + self.value = value & wmask + +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 + + @opcode(0x0, 0x01) def JSR(c, a): """pushes the address of the next instruction to the stack, then sets PC to a""" - c.sp = (c.sp - 1) & wmask + c.sp -= 1 c.m[c.sp] = c.pc c.pc = a() @@ -164,35 +221,11 @@ def IFB(c, a, b): 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[0x%01X]" % code - if c.debug: log(v) return v @valcode(range(0x08, 0x10)) @@ -200,7 +233,6 @@ def register(c, code): def register_value(c, code): """[register]""" v = "c.m[c.r[0x%01X]]" % (code-0x07) - if c.debug: log(v) return v @valcode(range(0x10, 0x18)) @@ -208,8 +240,7 @@ def register_value(c, code): def next_word_plus_register_value(c, code): """[next word + register]""" v = "c.m[0x%04X + c.r[0x%01X]]" % (c.m[c.pc], code-0x0F) - if c.debug: log(v) - c.pc = (c.pc + 1) & wmask + c.pc += 1 return v @valcode(0x18) @@ -217,8 +248,7 @@ def next_word_plus_register_value(c, code): def pop(c): """POP / [SP++]""" v = "c.m[0x%04X]" % c.sp - if c.debug: log(v) - c.sp = (c.sp + 1) & wmask + c.sp += 1 return v @valcode(0x19) @@ -226,16 +256,14 @@ def pop(c): def peek(c): """PEEK / [SP]""" v = "c.m[0x%04X]" % c.sp - if c.debug: log(v) return v @valcode(0x1A) @pointerize def push(c): """PUSH / [--SP]""" - c.sp = (c.sp - 1) & wmask + c.sp -= 1 v = "c.m[0x%04X]" % c.sp - if c.debug: log(v) return v @valcode(0x1B) @@ -243,7 +271,6 @@ def push(c): def stack_pointer(c): """stack pointer""" v = "c.sp" - if c.debug: log(v) return v @valcode(0x1C) @@ -251,7 +278,6 @@ def stack_pointer(c): def program_counter(c): """program counter""" v = "c.pc" - if c.debug: log(v) return v @valcode(0x1D) @@ -259,7 +285,6 @@ def program_counter(c): def overflow(c): """overflow""" v = "c.o" - if c.debug: log(v) return v @valcode(0x1E) @@ -267,8 +292,7 @@ def overflow(c): def next_word_value(c): """[next_word]""" v = "c.m[0x%04X]" % c.m[c.pc] - c.pc = (c.pc + 1) & wmask - if c.debug: log(v) + c.pc += 1 return v @valcode(0x1F) @@ -276,8 +300,7 @@ def next_word_value(c): def next_word(c): """next_word (literal)""" v = "c.m[0x%04X]" % c.pc - c.pc = (c.pc + 1) & wmask - if c.debug: log(v) + c.pc += 1 return v @valcode(range(0x20, 0x40)) @@ -285,13 +308,34 @@ def next_word(c): def literal(c, code): """literal value 0x00-0x1F (literal)""" v = "0x%04X" % (code - 0x20) - if c.debug: log(v) return v +class Memory(object): + """array of 16-bit words""" + def __init__(m, debug=False): + m.clear() + + def clear(m): + """clear memory""" + # TODO: (addr, len) memory range to clear + m.w = [0 for _ in xrange(0, 2**w)] + + def __getitem__(m, addr): + """get word at addr""" + return m.w[addr] + + def __setitem__(m, addr, value): + """assignment truncates values to 16-bit words""" + # TODO: multi-word assignment starting at addr when value is list + m.w[addr] = value & wmask + class CPU(object): - def __init__(c, debug=False): + """DCPU-16""" + def __init__(c, memory=Memory(), debug=False): + """If you don't specify memory, CPUs will share the same, default memory object""" + c.m = memory c.clear() c.reset() c.debug = debug @@ -306,107 +350,78 @@ class CPU(object): def clear(c): """clear memory""" - c.m = [0 for _ in xrange(0, 2**w)] - - @property - def a(c): - return c.r[0] - @a.setter - def a(c, val): - c.r[0] = val - - @property - def b(c): - return c.r[1] - @b.setter - def b(c, val): - c.r[1] = val - - @property - def c(c): - return c.r[2] - @c.setter - def c(c, val): - c.r[2] = val - - @property - def x(c): - return c.r[3] - @x.setter - def x(c, val): - c.r[3] = val - - @property - def y(c): - return c.r[4] - @y.setter - def y(c, val): - c.r[4] = val - - @property - def z(c): - return c.r[5] - @z.setter - def z(c, val): - c.r[5] = val - - @property - def i(c): - return c.r[6] - @i.setter - def i(c, val): - c.r[6] = val - - @property - def j(c): - return c.r[7] - @j.setter - def j(c, val): - c.r[7] = val + c.m.clear() + a = Register(0x0) + b = Register(0x1) + c = Register(0x2) + x = Register(0x3) + y = Register(0x4) + z = Register(0x5) + i = Register(0x6) + j = Register(0x7) + pc = Register() + sp = Register() + o = Register() + def _op(c, word): + """dispatch word to op and args""" + opcode = word & 0xF + a_code = word >> 4 & 0x3F + b_code = word >> 10 & 0x3F + try: + op = _opcode_map[opcode] + try: + op = op[a_code] + except TypeError: + args = (c._pointer(a_code), + c._pointer(b_code)) + else: + args = (c._pointer(b_code),) + finally: + if c.debug: + log(' '.join([op.__name__] + [arg.codestr for arg in args])) + except KeyError: + raise Exception('Invalid opcode %s at PC=%04X' % (["%02X"%x for x in opcode], c.pc)) + return op, args def _pointer(c, code): - """get pointer to value code""" + """get pointer to valcode""" try: - return valcode_map[code](c) + return _valcode_map[code](c) except KeyError: - raise Exception("Invalid value code") + raise Exception("Invalid valcode") def __getitem__(c, code): - """get pointer to value""" + """get value of valcode""" return c._pointer(code)() def __setitem__(c, code, value): - """set value at pointer""" + """set value at valcode""" c._pointer(code).set(value) def step(c): """start handling [PC]""" word = c.m[c.pc] - c.pc = (c.pc + 1) & wmask - if (word & 0xF) > 0: - opcode = (word & 0xF,) - a = c._pointer(word >> 4 & 0x3F) - b = c._pointer(word >> 10 & 0x3F) - args = (a, b) - elif (word >> 4 & 0x3F) > 0: - opcode = (0x0, word >> 4 & 0x3F) - a = c._pointer(word >> 10 & 0x3F) - args = (a, ) - else: - raise Exception('Invalid opcode %s at PC=%04X' % (["%02X"%x for x in opcode], c.pc)) - try: - op = opcode_map[opcode] - if c.debug: log(op.__name__) - except KeyError: - raise Exception('Invalid opcode %s at PC=%04X' % (["%02X"%x for x in opcode], c.pc)) + c.pc += 1 + op, args = c._op(word) if c.skip: c.skip = False + if c.debug: log("Skipped") else: op(c, *args) if c.debug: log(c.dump_r()) + def run(c): + """step until PC is constant""" + last_pc = 0xFFFF + last_sp = 0xFFFF + while c.pc != last_pc or c.sp != last_sp: + last_pc = c.pc + last_sp = c.sp + c.step() + log("Infinite loop") + def dump_r(c): """human-readable register status""" return " ".join( "%s=%04X" % @@ -418,15 +433,9 @@ class CPU(object): (c.r + [c.pc, c.sp, c.o])[i]) for i in range(11)) - def load_m(c, io=None): + def load_m(c, data=None, 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] @@ -436,3 +445,9 @@ class CPU(object): pass +spec_demo = [ + 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, +] diff --git a/test.py b/test.py index 5232f5e..640601c 100644 --- a/test.py +++ b/test.py @@ -190,6 +190,7 @@ class TestInstructions(unittest.TestCase): self.assertEqual(c.sp, 0xFFFF) self.assertEqual(c.m[0xFFFF], 0xBEEF) + class TestCPU(unittest.TestCase): """CPU behavior""" @@ -232,7 +233,95 @@ class TestCPU(unittest.TestCase): for r in c.m: self.assertEqual(r, 0) +class TestCPUWithPrograms(unittest.TestCase): + def setUP(self): + pass + + def test_spec_demo(self): + c = CPU() + 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, + ] + c.load_m(data=data) + + self.assertEqual(c.pc, 0) + c.step() # SET A, 0x30 + self.assertEqual(c.a, 0x30) + + self.assertEqual(c.pc, 2) + c.step() # SET [0x1000], 0x20 + self.assertEqual(c.m[0x1000], 0x20) + + self.assertEqual(c.pc, 5) + c.step() # SUB A, [0x1000] + self.assertEqual(c.a, 0x10) + + self.assertEqual(c.pc, 7) + c.step() # IFN A, 0x10 + self.assertEqual(c.pc, 8) + self.assertEqual(c.skip, True) + + c.step() # skip SET PC, crash + self.assertEqual(c.skip, False) + + self.assertEqual(c.pc, 10) + c.step() # SET I, 10 + self.assertEqual(c.i, 0x0A) + + self.assertEqual(c.pc, 11) + c.step() # SET A, 0x2000 + self.assertEqual(c.a, 0x2000) + + for i in range(10, 0, -1): + self.assertEqual(c.pc, 13) + c.step() # SET [0x2000+I], [A] + self.assertEqual(c.m[0x2000+i], 0x0) + + self.assertEqual(c.pc, 15) + c.step() # SUB I, 1 + self.assertEqual(c.i, i-1) + + self.assertEqual(c.pc, 16) + c.step() # IFN I, 0 + self.assertEqual(c.skip, i-1==0) + + self.assertEqual(c.pc, 17) + c.step() # SET PC, loop (with skip if c.i==0) + + self.assertEqual(c.pc, 19) + c.step() # SET X, 0x4 + self.assertEqual(c.x, 0x4) + + self.assertEqual(c.pc, 20) + c.step() # JSR testsub + self.assertEqual(c.sp, 0xFFFF) + self.assertEqual(c.m[0xFFFF], 22) + + self.assertEqual(c.pc, 24) + c.step() # SHL X, 4 + self.assertEqual(c.x, 0x40) + + self.assertEqual(c.pc, 25) + c.step() # SET PC, POP + + self.assertEqual(c.pc, 22) + c.step() # SET PC, crash + + self.assertEqual(c.pc, 26) + c.step() # SET PC, crash + + self.assertEqual(c.pc, 26) + # endless loop + if __name__ == '__main__': - suite = unittest.TestLoader().loadTestsFromNames(['test.TestInstructions', 'test.TestCPU']) + cases = [ + 'test.TestInstructions', + 'test.TestCPU', + 'test.TestCPUWithPrograms' + ] + suite = unittest.TestLoader().loadTestsFromNames(cases) unittest.TextTestRunner(verbosity=2).run(suite)