# MIT License # # Copyright (c) 2023 Neil Webber # # Permission is hereby granted, free of charge, to any person obtaining a copy # of this software and associated documentation files (the "Software"), to deal # in the Software without restriction, including without limitation the rights # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell # copies of the Software, and to permit persons to whom the Software is # furnished to do so, subject to the following conditions: # # The above copyright notice and this permission notice shall be included in # all copies or substantial portions of the Software. # # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE # SOFTWARE. from itertools import chain from types import SimpleNamespace from machine import PDP1170 from pdptraps import PDPTraps import unittest import random class TestMethods(unittest.TestCase): PDPLOGLEVEL = 'INFO' # DISCLAIMER ABOUT TEST CODING PHILOSOPHY: # For the most part, actual PDP-11 machine code is created and # used to establish the test conditions, as this provides additional # (albeit haphazard) testing of the functionality. Occasionally it's # just too much hassle to do that and the pdp object is manipulated # directly via methods/attributes to establish conditions. # There's no rhyme or reason in picking the approach for a given test. # used to create various instances, collects all the options # detail into this one place... @classmethod def make_pdp(cls): return PDP1170(console=False, loglevel=cls.PDPLOGLEVEL) @staticmethod def ioaddr(p, offs): """Given a within-IO-page IO offset, return an IO addr.""" return (offs + p.mmu.iopage_base) & 0o177777 # convenience routine to load word values into physical memory @staticmethod def loadphysmem(p, words, addr): for a, w in enumerate(words, start=(addr >> 1)): p.physmem[a] = w # some of these can't be computed at class definition time, so... @classmethod def usefulconstants(cls): p = cls.make_pdp() # meh, need this for some constants ns = SimpleNamespace() # Kernel instruction space PDR registers ns.KISD0 = cls.ioaddr(p, p.mmu.APR_KERNEL_OFFS) # Kernel data space PDR registers ns.KDSD0 = ns.KISD0 + 0o20 # Kernel instruction space PAR registers ns.KISA0 = ns.KDSD0 + 0o20 # Kernel data space PAR registers ns.KDSA0 = ns.KISA0 + 0o20 # User mode similar ns.UISD0 = cls.ioaddr(p, p.mmu.APR_USER_OFFS) ns.UDSD0 = ns.UISD0 + 0o20 ns.UISA0 = ns.UDSD0 + 0o20 ns.UDSA0 = ns.UISA0 + 0o20 return ns # # Create and return a test machine with a simple memory mapping: # Kernel Instruction space seg 0 points to physical 0 # Kernel Data space segment 0 also points to physical 0 # User instruction space seg 0 points to physical 0o20000 # User Data space seg 0 points to physical 0o40000 # and turns on the MMU # def simplemapped_pdp(self, p=None, addons=[]): if p is None: p = self.make_pdp() cn = self.usefulconstants() # this is a table of instructions that ... # Puts the system stack at 0o20000 (8K) # Puts 0o22222 into physical location 0o20000 # Puts 0o33333 into physical location 0o20002 # Puts 0o44444 into physical location 0o40000 # Sets Kernel Instruction space A0 to point to physical 0 # Sets Kernel Data space A0 to point to the first 8K physical memory # Sets Kernel Data space A7 to point to the IO page # Sets User Instruction space A0 to point to physical 0o20000 # sets User Data space D0 to point to physical 0o40000 # and turns on the MMU with I/D sep # # These instructions will be placed at 2K in memory # setup_instructions = ( 0o012706, 0o20000, # put system stack at 8k and works down 0o012737, 0o22222, 0o20000, 0o012737, 0o33333, 0o20002, 0o012737, 0o44444, 0o40000, # point both kernel seg 0 PARs to physical zero 0o005037, cn.KISA0, # CLR $KISA0 0o005037, cn.KDSA0, # CLR $KDSA0 # kernel seg 7 D space PAR to I/O page (at 22-bit location) 0o012737, 0o017760000 >> 6, cn.KDSA0 + (7 * 2), # user I seg 0 to 0o20000, user D seg 0 to 0o40000 0o012737, 0o20000 >> 6, cn.UISA0, 0o012737, 0o40000 >> 6, cn.UDSA0, # set the PDRs for segment zero 0o012703, 0o077406, # MOV #77406,R3 # 77406 = PDR<2:0> = ACF = 0o110 = read/write # PLF<14:8> =0o0774 = full length (128*64 bytes = 8K) 0o010337, cn.KISD0, # MOV R3,KISD0 ... 0o010337, cn.KDSD0, 0o010337, cn.UISD0, 0o010337, cn.UDSD0, # PDR for segment 7 0o010337, cn.KDSD0 + (7 * 2), # set previous mode to USER, keeping current mode KERNEL, pri 7 0o012737, (p.KERNEL << 14) | (p.USER << 12) | (7 << 5), self.ioaddr(p, p.PS_OFFS), # turn on 22-bit mode, unibus mapping, and I/D sep for k & u 0o012737, 0o000065, self.ioaddr(p, p.mmu.MMR3_OFFS), # turn on relocation mode ... yeehah! (MMR0 known zero here) 0o005237, self.ioaddr(p, p.mmu.MMR0_OFFS), # INC MMR0 ) instloc = 0o4000 # 2K self.loadphysmem(p, chain(setup_instructions, addons, (0o0,)), instloc) return p, instloc # these tests end up testing a other stuff too of course, including MMU def test_mfpi(self): # ((r0, ..., rN) results, (instructions)), ... tvecs = ( # r1=2, mfpi (r1) -> r0; expect r0 = 33333 ((0o33333,), (0o012701, 0o02, 0o006511, 0o012600)), # r1=0, mfpi (r1) -> r0; expect r0 = 22222 ((0o22222,), (0o012701, 0o00, 0o006511, 0o012600)), ) for rslts, insts in tvecs: with self.subTest(rslts=rslts, insts=insts): p, pc = self.simplemapped_pdp(addons=insts) p.run(pc=pc) for rN, v in enumerate(rslts): self.assertEqual(p.r[rN], v) def test_mtpi(self): # need an instance just for the constants, meh px = self.make_pdp() tvecs = ( ((0o1717,), (0o012746, 0o1717, 0o006637, 0o02, # turn MMU back off (!) 0o005037, self.ioaddr(px, px.mmu.MMR0_OFFS), 0o013700, 0o20002)), ) for rslts, insts in tvecs: with self.subTest(rslts=rslts, insts=insts): p, pc = self.simplemapped_pdp(addons=insts) p.run(pc=pc) for rN, v in enumerate(rslts): self.assertEqual(p.r[rN], v) def test_add_sub(self): p = self.make_pdp() testvecs = ( # (op0, op1, expected op0 + op1, nzvc, expected op0 - op1, nzvc) # None for nzvc means dont test that (yet/for-now/need to verify) (1, 1, 2, 0, 0, 4), # 1 + 1 = 2(_); 1 - 1 = 0(Z) (1, 32767, 32768, 0o12, 32766, 0), (0, 0, 0, 0o04, 0, 0o04), (32768, 1, 32769, 0o10, 32769, 0o13), (65535, 1, 0, 0o05, 2, 1), ) testloc = 0o10000 add_loc = testloc sub_loc = testloc + 4 p.physmem[add_loc >> 1] = 0o060001 # ADD R0,R1 p.physmem[(add_loc >> 1) + 1] = 0 p.physmem[sub_loc >> 1] = 0o160001 # SUB R0,R1 p.physmem[(sub_loc >> 1) + 1] = 0 for r0, r1, added, a_nzvc, subbed, s_nzvc in testvecs: with self.subTest(r0=r0, r1=r1, op="add"): p.r[0] = r0 p.r[1] = r1 p.run(pc=add_loc) self.assertEqual(p.r[1], added) if a_nzvc is not None: self.assertEqual(p.psw & 0o17, a_nzvc) with self.subTest(r0=r0, r1=r1, op="sub"): p.r[0] = r0 p.r[1] = r1 p.run(pc=sub_loc) self.assertEqual(p.r[1], subbed) if s_nzvc is not None: self.assertEqual(p.psw & 0o17, s_nzvc) def test_bne(self): p = self.make_pdp() loopcount = 0o1000 insts = ( # Program is: # MOV loopcount,R1 # CLR R0 # LOOP: INC R0 # DEC R1 # BNE LOOP # HALT 0o012701, loopcount, 0o005000, 0o005200, 0o005301, 0o001375, 0) instloc = 0o4000 self.loadphysmem(p, insts, instloc) p.run(pc=instloc) self.assertEqual(p.r[0], loopcount) self.assertEqual(p.r[1], 0) def test_cc(self): # various condition code tests p = self.make_pdp() insts = ( # program is: # CLR R0 # BEQ 1f # HALT # 1: CCC # BNE 1f # HALT # 1: DEC R0 # MOV @#05000,R1 ; see discussion below # MOV @#05002,R2 ; see discussion below # CMP R1,R2 # BLE 1f # HALT # 1: DEC R0 # CMP R2,R1 # BGT 1f # HALT # 1: DEC R0 # HALT # # and the program will poke various test cases into locations # 5000 and 5002, with the proviso that 5000 is always the lesser. # # Given that, after running the program R0 should be 65553 0o005000, 0o101401, 0o0, 0o000257, 0o001001, 0, 0o005300, # MOV @#5000 etc 0o013701, 0o5000, 0o013702, 0o5002, # CMP R1,R2 BLE 0o020102, 0o003401, 0, 0o005300, # CMP R2,R1 BGT 0o020201, 0o003001, 0, 0o005300, 0) instloc = 0o4000 self.loadphysmem(p, insts, instloc) # just a convenience so the test data can use neg numbers def s2c(x): return x & 0o177777 for lower, higher in ((0, 1), (s2c(-1), 0), (s2c(-1), 1), (s2c(-32768), 32767), (s2c(-32768), 0), (s2c(-32768), 32767), (17, 42), (s2c(-42), s2c(-17))): p.physmem[0o5000 >> 1] = lower p.physmem[0o5002 >> 1] = higher with self.subTest(lower=lower, higher=higher): p.run(pc=instloc) self.assertEqual(p.r[0], 65533) # probably never a good idea, but ... do some random values for randoms in range(1000): a = random.randint(-32768, 32767) b = random.randint(-32768, 32767) while a == b: b = random.randint(-32768, 32767) if a > b: a, b = b, a p.physmem[0o5000 >> 1] = s2c(a) p.physmem[0o5002 >> 1] = s2c(b) with self.subTest(lower=a, higher=b): p.run(pc=instloc) self.assertEqual(p.r[0], 65533) def test_unscc(self): # more stuff like test_cc but specifically testing unsigned Bxx codes p = self.make_pdp() insts = ( # program is: # CLR R0 # MOV @#05000,R1 ; see discussion below # MOV @#05002,R2 ; see discussion below # CMP R1,R2 # BCS 1f ; BCS same as BLO # HALT # 1: DEC R0 # CMP R2,R1 # BHI 1f # HALT # 1: DEC R0 # HALT # # test values in 5000,5002 .. unsigned and 5002 always higher # # Given that, after running the program R0 should be 65534 0o005000, # MOV @#5000 etc 0o013701, 0o5000, 0o013702, 0o5002, # CMP R1,R2 BCS 0o020102, 0o103401, 0, 0o005300, # CMP R2,R1 BHI 0o020201, 0o101001, 0, 0o005300, 0) instloc = 0o4000 self.loadphysmem(p, insts, instloc) for lower, higher in ((0, 1), (0, 65535), (32768, 65535), (65534, 65535), (32767, 32768), (17, 42)): p.physmem[0o5000 >> 1] = lower p.physmem[0o5002 >> 1] = higher with self.subTest(lower=lower, higher=higher): p.run(pc=instloc) self.assertEqual(p.r[0], 65534) # probably never a good idea, but ... do some random values for randoms in range(1000): a = random.randint(0, 65535) b = random.randint(0, 65535) while a == b: b = random.randint(0, 65535) if a > b: a, b = b, a p.physmem[0o5000 >> 1] = a p.physmem[0o5002 >> 1] = b with self.subTest(lower=a, higher=b): p.run(pc=instloc) self.assertEqual(p.r[0], 65534) def test_ash1(self): # this code sequence taken from Unix startup, it's not really # much of a test. insts = (0o012702, 0o0122451, # mov #122451,R2 0o072227, 0o0177772, # ash -6,R2 0o042702, 0o0176000, # bic #0176000,R2 0) # R2 should be 1224 p = self.make_pdp() instloc = 0o4000 self.loadphysmem(p, insts, instloc) p.run(pc=instloc) self.assertEqual(p.r[2], 0o1224) def test_br(self): # though the bug has been fixed, this is a test of whether # all branch offset values work correctly. Barn door shut... p = self.make_pdp() # the idea is a block of INC R0 instructions # followed by a halt, then a spot for a branch # then a block of INC R1 instructions followed by a halt # # By tweaking the BR instruction (different forward/back offsets) # and starting execution at the BR, the result on R0 and R1 # will show if the correct branch offset was effected. # # NOTE: 0o477 (branch offset -1) is a tight-loop branch to self # and that case is tested separately. # insts = [0o5200] * 300 # 300 INC R0 instructions insts += [0] # 1 HALT instruction insts += [0o477] # BR instruction .. see below # want to know where in memory this br will is brspot = len(insts) - 1 insts += [0o5201] * 300 # 300 INC R1 instructions insts += [0] # 1 HALT instruction # put that mess into memory at an arbitrary spot baseloc = 0o10000 for a, w in enumerate(insts, start=(baseloc >> 1)): p.physmem[a] = w # test the negative offsets: # Set R0 to 65535 (-1) # Set R1 to 17 # -1 is a special case, that's the tight loop and not tested here # -2 reaches the HALT instruction only, R0 will remain 65535 # -3 reaches back to one INC R0, R0 will be 0 # -4 reaches back two INC R0's, R0 will be 1 # and so on # 0o400 | offset starting at 0o376 will be the BR -2 case expected_R0 = 65535 for offset in range(0o376, 0o200, -1): p.physmem[(baseloc >> 1) + brspot] = (0o400 | offset) p.r[0] = 65535 p.r[1] = 17 # note the 2* because PC is an addr vs physmem word index p.run(pc=baseloc + (2*brspot)) with self.subTest(offset=offset): self.assertEqual(p.r[0], expected_R0) self.assertEqual(p.r[1], 17) expected_R0 = (expected_R0 + 1) & 0o177777 # and the same sort of test but with forward branching expected_R1 = 42 + 300 for offset in range(0, 0o200): p.physmem[(baseloc >> 1) + brspot] = (0o400 | offset) p.r[0] = 17 p.r[1] = 42 # note the 2* because PC is an addr vs physmem word index p.run(pc=baseloc + (2*brspot)) with self.subTest(offset=offset): self.assertEqual(p.r[0], 17) self.assertEqual(p.r[1], expected_R1) expected_R1 = (expected_R1 - 1) & 0o177777 def test_trap(self): # test some traps p = self.make_pdp() # put a handlers for different traps into memory # starting at location 0o10000 (4K). This just knows # that each handler is 3 words long, the code being: # MOV something,R4 # RTT # # where the "something" changes with each handler. handlers_addr = 0o10000 handlers = ( 0o012704, 0o4444, 0o000006, # for vector 0o004 0o012704, 0o1010, 0o000006, # for vector 0o010 0o012704, 0o3030, 0o000006, # for vector 0o030 0o012704, 0o3434, 0o000006 # for vector 0o034 ) self.loadphysmem(p, handlers, handlers_addr) # and just jam the vectors in place p.physmem[2] = handlers_addr # vector 0o004 p.physmem[3] = 0 # new PSW, stay in kernel mode p.physmem[4] = handlers_addr + 6 # each handler above was 6 bytes p.physmem[5] = 0 p.physmem[12] = handlers_addr + 12 # vector 0o30 (EMT) p.physmem[13] = 0 p.physmem[14] = handlers_addr + 18 # vector 0o34 (TRAP) p.physmem[15] = 0 # (tnum, insts) testvectors = ( # this will reference an odd address, trap 4 (0o4444, ( # establish reasonable stack pointer (at 8K) 0o012706, 0o20000, # CLR R3 and R4 so will know if they get set to something 0o005003, 0o005004, # put 0o1001 into R0 0o012700, 0o1001, # and reference it ... boom! 0o011001, # show that the RTT got to here by putting magic into R3 0o012703, 0o123456)), # this will execute a reserved instruction trap 10 (0o1010, ( # establish reasonable stack pointer (at 8K) 0o012706, 0o20000, # CLR R3 and R4 so will know if they get set to something 0o005003, 0o005004, # 0o007777 is a reserved instruction ... boom! 0o007777, # show that the RTT got to here by putting magic into R3 0o012703, 0o123456)), # this will execute an EMT instruction (0o3030, ( # establish reasonable stack pointer (at 8K) 0o012706, 0o20000, # CLR R3 and R4 so will know if they get set to something 0o005003, 0o005004, # EMT #42 0o104042, # show that the RTT got to here by putting magic into R3 0o012703, 0o123456)), # this will execute an actual TRAP instruction (0o3434, ( # establish reasonable stack pointer (at 8K) 0o012706, 0o20000, # CLR R3 and R4 so will know if they get set to something 0o005003, 0o005004, # TRAP #17 0o104417, # show that the RTT got to here by putting magic into R3 0o012703, 0o123456)), ) for R4, insts in testvectors: self.loadphysmem(p, insts, 0o3000) p.run(pc=0o3000) self.assertEqual(p.r[3], 0o123456) self.assertEqual(p.r[4], R4) def test_trapcodes(self): # a more ambitious testing of TRAP which verifies all # available TRAP instruction codes work p = self.make_pdp() # poke the TRAP vector info directly in p.physmem[14] = 0o10000 # vector 0o34 (TRAP) --> 0o10000 p.physmem[15] = 0 # this trap handler puts the trap # into R3 handler = ( # the saved PC is at the top of the stack ... get it 0o011600, # MOV (SP),R0 # get the low byte of the instruction which is the trap code # note that the PC points after the TRAP instruction so # MOVB -2(R0),R3 0o116003, 0o177776, # RTT 6) self.loadphysmem(p, handler, 0o10000) # just bash a stack pointer directly in p.r[6] = 0o20000 # 8K and working down for i in range(256): insts = ( 0o104400 | i, # TRAP #i 0o010301, # MOV R3,R1 just to show RTT worked 0) self.loadphysmem(p, insts, 0o30000) p.run(pc=0o30000) self.assertEqual(p.r[3], p.r[1]) # because the machine code did MOVB, values over 127 get # sign extended, so take that into consideration if i > 127: trapexpected = 0xFF00 | i else: trapexpected = i self.assertEqual(p.r[1], trapexpected) # test_mmu_1 .. test_mmu_N .. a variety of MMU tests. # # Any of the other tests that use simplemapped_pdp() implicitly # test some aspects of the MMU but these are more targeted tests. # NOTE: it's a lot easier to test via the methods than via writing # elaborate PDP-11 machine code so that's what these do. def test_mmu_1(self): # test the page length field support p = self.make_pdp() # using ED=0 (segments grow upwards), create a (bizarre!) # user DSPACE mapping where the the first segment has length 0, # the second has 16, the third has 32 ... etc and then check # that that valid addresses map correctly and invalid ones fault # correctly. NOTE that there are subtle semantics to the so-called # "page length field" ... in a page that grows upwards, a plf of # zero means that to be INVALID the block number has to be greater # than zero (therefore "zero" length really means 64 bytes of # validity) and there is a similar off-by-one semantic to ED=1 # downward pages. The test understands this. cn = self.usefulconstants() for segno in range(8): p.mmu.wordRW(cn.UDSA0 + (segno*2), (8192 * segno) >> 6) pln = segno * 16 p.mmu.wordRW(cn.UDSD0 + (segno*2), (pln << 8) | 0o06) # enable user I/D separation p.mmu.MMR3 |= 0o01 # turn on the MMU! p.mmu.MMR0 = 1 for segno in range(8): basea = segno * 8192 maxvalidoffset = 63 + ((segno * 64) * 16) for o in range(8192): if o <= maxvalidoffset: _ = p.mmu.v2p(basea + o, p.USER, p.mmu.DSPACE, p.mmu.CYCLE.READ) else: with self.assertRaises(PDPTraps.MMU): _ = p.mmu.v2p(basea + o, p.USER, p.mmu.DSPACE, p.mmu.CYCLE.READ) def test_mmu_2(self): # same test as _1 but with ED=1 so segments grow downwards # test the page length field support p = self.make_pdp() cn = self.usefulconstants() for segno in range(8): p.mmu.wordRW(cn.UDSA0 + (segno*2), (8192 * segno) >> 6) pln = 0o177 - (segno * 16) p.mmu.wordRW(cn.UDSD0 + (segno*2), (pln << 8) | 0o16) # enable user I/D separation p.mmu.MMR3 |= 0o01 # turn on the MMU! p.mmu.MMR0 = 1 for segno in range(8): basea = segno * 8192 minvalidoffset = 8192 - (64 + ((segno * 64) * 16)) for o in range(8192): if o >= minvalidoffset: _ = p.mmu.v2p(basea + o, p.USER, p.mmu.DSPACE, p.mmu.CYCLE.READ) else: with self.assertRaises(PDPTraps.MMU): _ = p.mmu.v2p(basea + o, p.USER, p.mmu.DSPACE, p.mmu.CYCLE.READ) def test_ubmap(self): p = self.make_pdp() ubmaps = self.ioaddr(p, p.ub.UBMAP_OFFS) # code paraphrased from UNIX startup, creates a mapping pattern # that the rest of the code expects (and fiddles upper bits) # So ... test that. for i in range(0, 62, 2): p.mmu.wordRW(ubmaps + (2 * i), i << 12 & 0o1777777) p.mmu.wordRW(ubmaps + (2 * (i + 1)), 0) # XXX there is no real test yet because the UBMAPs # are all just dummied up right now # this is not a unit test, invoke it using timeit etc def speed_test_setup(self, *, loopcount=10000, mmu=True, inst=None): p, pc = self.simplemapped_pdp() # the returned pdp is loaded with instructions for setting up # the mmu; only do them if that's what is wanted if mmu: p.run(pc=pc) # by default the instruction being timed will be MOV R1,R0 # but other instructions could be used. MUST ONLY BE ONE WORD if inst is None: inst = 0o010100 # now load the test timing loop... 9 MOV R1,R0 instructions # and an SOB for looping (so 10 instructions per loop) insts = (0o012704, loopcount, # loopcount into R4 inst, inst, inst, inst, inst, inst, inst, inst, inst, 0o077412, # SOB R4 back to first inst 0) # HALT instloc = 0o4000 for a2, w in enumerate(insts): p.mmu.wordRW(instloc + (2 * a2), w) return p, instloc def speed_test_run(self, p, instloc): p.run(pc=instloc) if __name__ == "__main__": unittest.main()