src/soc/simple/test/test_runner.py

   1 """TestRunner class, runs TestIssuer instructions
   2
   3 related bugs:
   4
   5  * https://bugs.libre-soc.org/show_bug.cgi?id=363
   6  * https://bugs.libre-soc.org/show_bug.cgi?id=686#c51
   7 """
   8 from nmigen import Module, Signal, Cat, ClockSignal
   9 from nmigen.hdl.xfrm import ResetInserter
  10 from copy import copy
  11
  12 # NOTE: to use cxxsim, export NMIGEN_SIM_MODE=cxxsim from the shell
  13 # Also, check out the cxxsim nmigen branch, and latest yosys from git
  14 from nmutil.sim_tmp_alternative import Simulator, Settle
  15
  16 from nmutil.formaltest import FHDLTestCase
  17 from nmutil.gtkw import write_gtkw
  18 from nmigen.cli import rtlil
  19 from openpower.decoder.isa.caller import special_sprs, SVP64State
  20 from openpower.decoder.isa.all import ISA
  21 from openpower.endian import bigendian
  22
  23 from openpower.decoder.power_decoder import create_pdecode
  24 from openpower.decoder.power_decoder2 import PowerDecode2
  25 from soc.regfile.regfiles import StateRegs
  26
  27 from soc.simple.issuer import TestIssuerInternal
  28
  29 from soc.config.test.test_loadstore import TestMemPspec
  30 from soc.simple.test.test_core import (setup_regs, check_regs, check_mem,
  31                                        wait_for_busy_clear,
  32                                        wait_for_busy_hi)
  33 from soc.fu.compunits.test.test_compunit import (setup_tst_memory,
  34                                                  check_sim_memory)
  35 from soc.debug.dmi import DBGCore, DBGCtrl, DBGStat
  36 from nmutil.util import wrap
  37 from soc.experiment.test.test_mmu_dcache import wb_get
  38 from openpower.test.state import TestState, StateRunner
  39
  40
  41 def setup_i_memory(imem, startaddr, instructions):
  42     mem = imem
  43     print("insn before, init mem", mem.depth, mem.width, mem,
  44           len(instructions))
  45     for i in range(mem.depth):
  46         yield mem._array[i].eq(0)
  47     yield Settle()
  48     startaddr //= 4  # instructions are 32-bit
  49     if mem.width == 32:
  50         mask = ((1 << 32)-1)
  51         for ins in instructions:
  52             if isinstance(ins, tuple):
  53                 insn, code = ins
  54             else:
  55                 insn, code = ins, ''
  56             insn = insn & 0xffffffff
  57             yield mem._array[startaddr].eq(insn)
  58             yield Settle()
  59             if insn != 0:
  60                 print("instr: %06x 0x%x %s" % (4*startaddr, insn, code))
  61             startaddr += 1
  62             startaddr = startaddr & mask
  63         return
  64
  65     # 64 bit
  66     mask = ((1 << 64)-1)
  67     for ins in instructions:
  68         if isinstance(ins, tuple):
  69             insn, code = ins
  70         else:
  71             insn, code = ins, ''
  72         insn = insn & 0xffffffff
  73         msbs = (startaddr >> 1) & mask
  74         val = yield mem._array[msbs]
  75         if insn != 0:
  76             print("before set", hex(4*startaddr),
  77                   hex(msbs), hex(val), hex(insn))
  78         lsb = 1 if (startaddr & 1) else 0
  79         val = (val | (insn << (lsb*32)))
  80         val = val & mask
  81         yield mem._array[msbs].eq(val)
  82         yield Settle()
  83         if insn != 0:
  84             print("after  set", hex(4*startaddr), hex(msbs), hex(val))
  85             print("instr: %06x 0x%x %s %08x" % (4*startaddr, insn, code, val))
  86         startaddr += 1
  87         startaddr = startaddr & mask
  88
  89
  90 def set_dmi(dmi, addr, data):
  91     yield dmi.req_i.eq(1)
  92     yield dmi.addr_i.eq(addr)
  93     yield dmi.din.eq(data)
  94     yield dmi.we_i.eq(1)
  95     while True:
  96         ack = yield dmi.ack_o
  97         if ack:
  98             break
  99         yield
 100     yield
 101     yield dmi.req_i.eq(0)
 102     yield dmi.addr_i.eq(0)
 103     yield dmi.din.eq(0)
 104     yield dmi.we_i.eq(0)
 105     yield
 106
 107
 108 def get_dmi(dmi, addr):
 109     yield dmi.req_i.eq(1)
 110     yield dmi.addr_i.eq(addr)
 111     yield dmi.din.eq(0)
 112     yield dmi.we_i.eq(0)
 113     while True:
 114         ack = yield dmi.ack_o
 115         if ack:
 116             break
 117         yield
 118     yield  # wait one
 119     data = yield dmi.dout  # get data after ack valid for 1 cycle
 120     yield dmi.req_i.eq(0)
 121     yield dmi.addr_i.eq(0)
 122     yield dmi.we_i.eq(0)
 123     yield
 124     return data
 125
 126
 127 def run_hdl_state(dut, test, issuer, pc_i, svstate_i, instructions):
 128     """run_hdl_state - runs a TestIssuer nmigen HDL simulation
 129     """
 130
 131     imem = issuer.imem._get_memory()
 132     core = issuer.core
 133     dmi = issuer.dbg.dmi
 134     pdecode2 = issuer.pdecode2
 135     l0 = core.l0
 136     hdl_states = []
 137
 138     # establish the TestIssuer context (mem, regs etc)
 139
 140     pc = 0  # start address
 141     counter = 0  # test to pause/start
 142
 143     yield from setup_i_memory(imem, pc, instructions)
 144     yield from setup_tst_memory(l0, test.mem)
 145     yield from setup_regs(pdecode2, core, test)
 146
 147     # set PC and SVSTATE
 148     yield pc_i.eq(pc)
 149     yield issuer.pc_i.ok.eq(1)
 150
 151     # copy initial SVSTATE
 152     initial_svstate = copy(test.svstate)
 153     if isinstance(initial_svstate, int):
 154         initial_svstate = SVP64State(initial_svstate)
 155     yield svstate_i.eq(initial_svstate.value)
 156     yield issuer.svstate_i.ok.eq(1)
 157     yield
 158
 159     print("instructions", instructions)
 160
 161     # run the loop of the instructions on the current test
 162     index = (yield issuer.cur_state.pc) // 4
 163     while index < len(instructions):
 164         ins, code = instructions[index]
 165
 166         print("hdl instr: 0x{:X}".format(ins & 0xffffffff))
 167         print(index, code)
 168
 169         if counter == 0:
 170             # start the core
 171             yield
 172             yield from set_dmi(dmi, DBGCore.CTRL,
 173                                1<<DBGCtrl.START)
 174             yield issuer.pc_i.ok.eq(0) # no change PC after this
 175             yield issuer.svstate_i.ok.eq(0) # ditto
 176             yield
 177             yield
 178
 179         counter = counter + 1
 180
 181         # wait until executed
 182         while not (yield issuer.insn_done):
 183             yield
 184
 185         yield Settle()
 186
 187         index = (yield issuer.cur_state.pc) // 4
 188
 189         terminated = yield issuer.dbg.terminated_o
 190         print("terminated", terminated)
 191
 192         if index < len(instructions):
 193             # Get HDL mem and state
 194             state = yield from TestState("hdl", core, dut,
 195                                          code)
 196             hdl_states.append(state)
 197
 198         if index >= len(instructions):
 199             print ("index over, send dmi stop")
 200             # stop at end
 201             yield from set_dmi(dmi, DBGCore.CTRL,
 202                                1<<DBGCtrl.STOP)
 203             yield
 204             yield
 205
 206         terminated = yield issuer.dbg.terminated_o
 207         print("terminated(2)", terminated)
 208         if terminated:
 209             break
 210
 211     return hdl_states
 212
 213
 214 def run_sim_state(dut, test, simdec2, instructions, gen, insncode):
 215     """run_sim_state - runs an ISACaller simulation
 216     """
 217
 218     sim_states = []
 219
 220     # set up the Simulator (which must track TestIssuer exactly)
 221     sim = ISA(simdec2, test.regs, test.sprs, test.cr, test.mem,
 222               test.msr,
 223               initial_insns=gen, respect_pc=True,
 224               disassembly=insncode,
 225               bigendian=bigendian,
 226               initial_svstate=test.svstate)
 227
 228     # run the loop of the instructions on the current test
 229     index = sim.pc.CIA.value//4
 230     while index < len(instructions):
 231         ins, code = instructions[index]
 232
 233         print("sim instr: 0x{:X}".format(ins & 0xffffffff))
 234         print(index, code)
 235
 236         # set up simulated instruction (in simdec2)
 237         try:
 238             yield from sim.setup_one()
 239         except KeyError:  # instruction not in imem: stop
 240             break
 241         yield Settle()
 242
 243         # call simulated operation
 244         print("sim", code)
 245         yield from sim.execute_one()
 246         yield Settle()
 247         index = sim.pc.CIA.value//4
 248
 249         # get sim register and memory TestState, add to list
 250         state = yield from TestState("sim", sim, dut, code)
 251         sim_states.append(state)
 252
 253     return sim_states
 254
 255
 256 class SimRunner(StateRunner):
 257     def __init__(self, dut, m, pspec):
 258         self.dut = dut
 259
 260         regreduce_en = pspec.regreduce_en == True
 261         self.simdec2 = simdec2 = PowerDecode2(None, regreduce_en=regreduce_en)
 262         m.submodules.simdec2 = simdec2  # pain in the neck
 263
 264
 265 class HDLRunner(StateRunner):
 266     def __init__(self, dut, m, pspec):
 267         self.dut = dut
 268         #hard_reset = Signal(reset_less=True)
 269         self.issuer = TestIssuerInternal(pspec)
 270         # use DMI RESET command instead, this does actually work though
 271         #issuer = ResetInserter({'coresync': hard_reset,
 272         #                        'sync': hard_reset})(issuer)
 273         m.submodules.issuer = self.issuer
 274         self.dmi = self.issuer.dbg.dmi
 275
 276
 277 class TestRunner(FHDLTestCase):
 278     def __init__(self, tst_data, microwatt_mmu=False, rom=None,
 279                         svp64=True, run_hdl=True, run_sim=True):
 280         super().__init__("run_all")
 281         self.test_data = tst_data
 282         self.microwatt_mmu = microwatt_mmu
 283         self.rom = rom
 284         self.svp64 = svp64
 285         self.run_hdl = run_hdl
 286         self.run_sim = run_sim
 287
 288     def run_all(self):
 289         m = Module()
 290         comb = m.d.comb
 291         if self.microwatt_mmu:
 292             ldst_ifacetype = 'test_mmu_cache_wb'
 293         else:
 294             ldst_ifacetype = 'test_bare_wb'
 295         imem_ifacetype = 'test_bare_wb'
 296
 297         pspec = TestMemPspec(ldst_ifacetype=ldst_ifacetype,
 298                              imem_ifacetype=imem_ifacetype,
 299                              addr_wid=48,
 300                              mask_wid=8,
 301                              imem_reg_wid=64,
 302                              # wb_data_width=32,
 303                              use_pll=False,
 304                              nocore=False,
 305                              xics=False,
 306                              gpio=False,
 307                              regreduce=True,
 308                              svp64=self.svp64,
 309                              mmu=self.microwatt_mmu,
 310                              reg_wid=64)
 311
 312         ###### SETUP PHASE #######
 313         # StateRunner.setup_for_test()
 314
 315         if self.run_hdl:
 316             hdlrun = HDLRunner(self, m, pspec)
 317
 318         if self.run_sim:
 319             simrun = SimRunner(self, m, pspec)
 320
 321         # run core clock at same rate as test clock
 322         intclk = ClockSignal("coresync")
 323         comb += intclk.eq(ClockSignal())
 324
 325         if self.run_hdl:
 326
 327             pc_i = Signal(32)
 328             svstate_i = Signal(64)
 329
 330             comb += hdlrun.issuer.pc_i.data.eq(pc_i)
 331             comb += hdlrun.issuer.svstate_i.data.eq(svstate_i)
 332
 333         # nmigen Simulation - everything runs around this, so it
 334         # still has to be created.
 335         sim = Simulator(m)
 336         sim.add_clock(1e-6)
 337
 338         def process():
 339
 340             ###### PREPARATION PHASE AT START OF RUNNING #######
 341             # StateRunner.setup_during_test()
 342
 343             if self.run_hdl:
 344                 # start in stopped
 345                 yield from set_dmi(hdlrun.dmi, DBGCore.CTRL, 1<<DBGCtrl.STOP)
 346                 yield
 347
 348             # get each test, completely reset the core, and run it
 349
 350             for test in self.test_data:
 351
 352                 with self.subTest(test.name):
 353
 354                     ###### PREPARATION PHASE AT START OF TEST #######
 355                     # StateRunner.prepare_for_test()
 356
 357                     if self.run_hdl:
 358                         # set up bigendian (TODO: don't do this, use MSR)
 359                         yield hdlrun.issuer.core_bigendian_i.eq(bigendian)
 360                         yield Settle()
 361
 362                         yield
 363                         yield
 364                         yield
 365                         yield
 366
 367                     print(test.name)
 368                     program = test.program
 369                     print("regs", test.regs)
 370                     print("sprs", test.sprs)
 371                     print("cr", test.cr)
 372                     print("mem", test.mem)
 373                     print("msr", test.msr)
 374                     print("assem", program.assembly)
 375                     gen = list(program.generate_instructions())
 376                     insncode = program.assembly.splitlines()
 377                     instructions = list(zip(gen, insncode))
 378
 379                     ###### RUNNING OF EACH TEST #######
 380                     # StateRunner.step_test()
 381
 382                     # Run two tests (TODO, move these to functions)
 383                     # * first the Simulator, collate a batch of results
 384                     # * then the HDL, likewise
 385                     #   (actually, the other way round because running
 386                     #    Simulator somehow modifies the test state!)
 387                     # * finally, compare all the results
 388
 389                     ##########
 390                     # 1. HDL
 391                     ##########
 392                     if self.run_hdl:
 393                         hdl_states = yield from run_hdl_state(self, test,
 394                                                               hdlrun.issuer,
 395                                                               pc_i, svstate_i,
 396                                                               instructions)
 397
 398                     ##########
 399                     # 2. Simulator
 400                     ##########
 401
 402                     if self.run_sim:
 403                         sim_states = yield from run_sim_state(self, test,
 404                                                           simrun.simdec2,
 405                                                           instructions, gen,
 406                                                           insncode)
 407
 408                     ###### COMPARING THE TESTS #######
 409
 410                     ###############
 411                     # 3. Compare
 412                     ###############
 413
 414                     if self.run_sim:
 415                         last_sim = copy(sim_states[-1])
 416                     elif self.run_hdl:
 417                         last_sim = copy(hdl_states[-1])
 418                     else:
 419                         last_sim = None # err what are you doing??
 420
 421                     if self.run_hdl and self.run_sim:
 422                         for simstate, hdlstate in zip(sim_states, hdl_states):
 423                             simstate.compare(hdlstate)     # register check
 424                             simstate.compare_mem(hdlstate) # memory check
 425
 426                     if self.run_hdl:
 427                         print ("hdl_states")
 428                         for state in hdl_states:
 429                             print (state)
 430
 431                     if self.run_sim:
 432                         print ("sim_states")
 433                         for state in sim_states:
 434                             print (state)
 435
 436                     # compare against expected results
 437                     if test.expected is not None:
 438                         # have to put these in manually
 439                         test.expected.to_test = test.expected
 440                         test.expected.dut = self
 441                         test.expected.state_type = "expected"
 442                         test.expected.code = 0
 443                         # do actual comparison, against last item
 444                         last_sim.compare(test.expected)
 445
 446                     if self.run_hdl and self.run_sim:
 447                         self.assertTrue(len(hdl_states) == len(sim_states),
 448                                     "number of instructions run not the same")
 449
 450                 ###### END OF A TEST #######
 451                 # StateRunner.end_test()
 452
 453                 if self.run_hdl:
 454                     # stop at end
 455                     yield from set_dmi(hdlrun.dmi, DBGCore.CTRL, 1<<DBGCtrl.STOP)
 456                     yield
 457                     yield
 458
 459                     # TODO, here is where the static (expected) results
 460                     # can be checked: register check (TODO, memory check)
 461                     # see https://bugs.libre-soc.org/show_bug.cgi?id=686#c51
 462                     # yield from check_regs(self, sim, core, test, code,
 463                     #                       >>>expected_data<<<)
 464
 465                     # get CR
 466                     cr = yield from get_dmi(hdlrun.dmi, DBGCore.CR)
 467                     print("after test %s cr value %x" % (test.name, cr))
 468
 469                     # get XER
 470                     xer = yield from get_dmi(hdlrun.dmi, DBGCore.XER)
 471                     print("after test %s XER value %x" % (test.name, xer))
 472
 473                     # test of dmi reg get
 474                     for int_reg in range(32):
 475                         yield from set_dmi(hdlrun.dmi, DBGCore.GSPR_IDX, int_reg)
 476                         value = yield from get_dmi(hdlrun.dmi, DBGCore.GSPR_DATA)
 477
 478                         print("after test %s reg %2d value %x" %
 479                               (test.name, int_reg, value))
 480
 481                     # pull a reset
 482                     yield from set_dmi(hdlrun.dmi, DBGCore.CTRL, 1<<DBGCtrl.RESET)
 483                     yield
 484
 485         ###### END OF EVERYTHING (but none needs doing, still call fn) #######
 486         # StateRunner.cleanup()
 487
 488         styles = {
 489             'dec': {'base': 'dec'},
 490             'bin': {'base': 'bin'},
 491             'closed': {'closed': True}
 492         }
 493
 494         traces = [
 495             'clk',
 496             ('state machines', 'closed', [
 497                 'fetch_pc_i_valid', 'fetch_pc_o_ready',
 498                 'fetch_fsm_state',
 499                 'fetch_insn_o_valid', 'fetch_insn_i_ready',
 500                 'pred_insn_i_valid', 'pred_insn_o_ready',
 501                 'fetch_predicate_state',
 502                 'pred_mask_o_valid', 'pred_mask_i_ready',
 503                 'issue_fsm_state',
 504                 'exec_insn_i_valid', 'exec_insn_o_ready',
 505                 'exec_fsm_state',
 506                 'exec_pc_o_valid', 'exec_pc_i_ready',
 507                 'insn_done', 'core_stop_o', 'pc_i_ok', 'pc_changed',
 508                 'is_last', 'dec2.no_out_vec']),
 509             {'comment': 'fetch and decode'},
 510             (None, 'dec', [
 511                 'cia[63:0]', 'nia[63:0]', 'pc[63:0]',
 512                 'cur_pc[63:0]', 'core_core_cia[63:0]']),
 513             'raw_insn_i[31:0]',
 514             'raw_opcode_in[31:0]', 'insn_type', 'dec2.dec2_exc_happened',
 515             ('svp64 decoding', 'closed', [
 516                 'svp64_rm[23:0]', ('dec2.extra[8:0]', 'bin'),
 517                 'dec2.sv_rm_dec.mode', 'dec2.sv_rm_dec.predmode',
 518                 'dec2.sv_rm_dec.ptype_in',
 519                 'dec2.sv_rm_dec.dstpred[2:0]', 'dec2.sv_rm_dec.srcpred[2:0]',
 520                 'dstmask[63:0]', 'srcmask[63:0]',
 521                 'dregread[4:0]', 'dinvert',
 522                 'sregread[4:0]', 'sinvert',
 523                 'core.int.pred__addr[4:0]', 'core.int.pred__data_o[63:0]',
 524                 'core.int.pred__ren']),
 525             ('register augmentation', 'dec', 'closed', [
 526                 {'comment': 'v3.0b registers'},
 527                 'dec2.dec_o.RT[4:0]',
 528                 'dec2.dec_a.RA[4:0]',
 529                 'dec2.dec_b.RB[4:0]',
 530                 ('Rdest', [
 531                     'dec2.o_svdec.reg_in[4:0]',
 532                     ('dec2.o_svdec.spec[2:0]', 'bin'),
 533                     'dec2.o_svdec.reg_out[6:0]']),
 534                 ('Rsrc1', [
 535                     'dec2.in1_svdec.reg_in[4:0]',
 536                     ('dec2.in1_svdec.spec[2:0]', 'bin'),
 537                     'dec2.in1_svdec.reg_out[6:0]']),
 538                 ('Rsrc1', [
 539                     'dec2.in2_svdec.reg_in[4:0]',
 540                     ('dec2.in2_svdec.spec[2:0]', 'bin'),
 541                     'dec2.in2_svdec.reg_out[6:0]']),
 542                 {'comment': 'SVP64 registers'},
 543                 'dec2.rego[6:0]', 'dec2.reg1[6:0]', 'dec2.reg2[6:0]'
 544             ]),
 545             {'comment': 'svp64 context'},
 546             'core_core_vl[6:0]', 'core_core_maxvl[6:0]',
 547             'core_core_srcstep[6:0]', 'next_srcstep[6:0]',
 548             'core_core_dststep[6:0]',
 549             {'comment': 'issue and execute'},
 550             'core.core_core_insn_type',
 551             (None, 'dec', [
 552                 'core_rego[6:0]', 'core_reg1[6:0]', 'core_reg2[6:0]']),
 553             'issue_i', 'busy_o',
 554             {'comment': 'dmi'},
 555             'dbg.dmi_req_i', 'dbg.dmi_ack_o',
 556             {'comment': 'instruction memory'},
 557             'imem.sram.rdport.memory(0)[63:0]',
 558             {'comment': 'registers'},
 559             # match with soc.regfile.regfiles.IntRegs port names
 560             'core.int.rp_src1.memory(0)[63:0]',
 561             'core.int.rp_src1.memory(1)[63:0]',
 562             'core.int.rp_src1.memory(2)[63:0]',
 563             'core.int.rp_src1.memory(3)[63:0]',
 564             'core.int.rp_src1.memory(4)[63:0]',
 565             'core.int.rp_src1.memory(5)[63:0]',
 566             'core.int.rp_src1.memory(6)[63:0]',
 567             'core.int.rp_src1.memory(7)[63:0]',
 568             'core.int.rp_src1.memory(9)[63:0]',
 569             'core.int.rp_src1.memory(10)[63:0]',
 570             'core.int.rp_src1.memory(13)[63:0]'
 571         ]
 572
 573         # PortInterface module path varies depending on MMU option
 574         if self.microwatt_mmu:
 575             pi_module = 'core.ldst0'
 576         else:
 577             pi_module = 'core.fus.ldst0'
 578
 579         traces += [('ld/st port interface', {'submodule': pi_module}, [
 580             'oper_r__insn_type',
 581             'ldst_port0_is_ld_i',
 582             'ldst_port0_is_st_i',
 583             'ldst_port0_busy_o',
 584             'ldst_port0_addr_i[47:0]',
 585             'ldst_port0_addr_i_ok',
 586             'ldst_port0_addr_ok_o',
 587             'ldst_port0_exc_happened',
 588             'ldst_port0_st_data_i[63:0]',
 589             'ldst_port0_st_data_i_ok',
 590             'ldst_port0_ld_data_o[63:0]',
 591             'ldst_port0_ld_data_o_ok',
 592             'exc_o_happened',
 593             'cancel'
 594         ])]
 595
 596         if self.microwatt_mmu:
 597             traces += [
 598                 {'comment': 'microwatt_mmu'},
 599                 'core.fus.mmu0.alu_mmu0.illegal',
 600                 'core.fus.mmu0.alu_mmu0.debug0[3:0]',
 601                 'core.fus.mmu0.alu_mmu0.mmu.state',
 602                 'core.fus.mmu0.alu_mmu0.mmu.pid[31:0]',
 603                 'core.fus.mmu0.alu_mmu0.mmu.prtbl[63:0]',
 604                 {'comment': 'wishbone_memory'},
 605                 'core.fus.mmu0.alu_mmu0.dcache.stb',
 606                 'core.fus.mmu0.alu_mmu0.dcache.cyc',
 607                 'core.fus.mmu0.alu_mmu0.dcache.we',
 608                 'core.fus.mmu0.alu_mmu0.dcache.ack',
 609                 'core.fus.mmu0.alu_mmu0.dcache.stall,'
 610             ]
 611
 612         write_gtkw("issuer_simulator.gtkw",
 613                    "issuer_simulator.vcd",
 614                    traces, styles, module='top.issuer')
 615
 616         # add run of instructions
 617         sim.add_sync_process(process)
 618
 619         # optionally, if a wishbone-based ROM is passed in, run that as an
 620         # extra emulated process
 621         if self.rom is not None:
 622             dcache = core.fus.fus["mmu0"].alu.dcache
 623             default_mem = self.rom
 624             sim.add_sync_process(wrap(wb_get(dcache, default_mem, "DCACHE")))
 625
 626         with sim.write_vcd("issuer_simulator.vcd"):
 627             sim.run()