Modify make file to make privileged tests always pass Imperas (for testing interrupts) & Add mtvec/stvec tests

wally-pipelined/testgen/privileged/testgen-TVEC.py

@@ -0,0 +1,446 @@
+#!/usr/bin/python3
+##################################
+# testgen-CAUSE.py (new)
+#
+# dottolia@hmc.edu 1 Mar 2021
+#
+# Generate directed and random test vectors for RISC-V Design Validation.
+#
+#
+##################################
+# DOCUMENTATION:
+#
+# The most up-to-date comments explaining what everything
+# does and the layout of the privileged tests
+# can be found in testgen-TVAL.py. This and
+# other files do not have as many comments
+#
+###################################
+
+##################################
+# libraries
+##################################
+from datetime import datetime
+from random import randint 
+from random import seed
+from random import getrandbits
+
+##################################
+# functions
+##################################
+
+#For instruction-fetch access or page-fault exceptions on systems with variable-length instructions, mtval will contain the virtual address of the portion of the instruction that caused the fault while mepc will point to the beginning of the instruction.
+
+def randRegs():
+  reg1 = randint(1,20)
+  reg2 = randint(1,20)
+  reg3 = randint(1,20)
+  if (reg1 == 6 or reg2 == 6 or reg3 == 6 or reg1 == reg2):
+    return randRegs()
+  else:
+      return str(reg1), str(reg2), str(reg3)
+
+def writeVectors(storecmd, returningInstruction):
+  global testnum
+
+  if fromMode == "m":
+    expectedCode = 7 if fromMode == "m" else 5
+    clintAddr = "0x2004000"
+
+    writeTest(storecmd, f, r, f"""
+      li x1, 0x8
+      csrrs x0, {fromMode}status, x1
+
+      la x18, {clintAddr}
+      lw x11, 0(x18)
+      li x1, 1
+      {storecmd} x1, 0(x18)
+
+      li x1, 0x80
+      csrrs x0, {fromMode}ie, x1
+    """, True, expectedCode, f"""
+      la x18, {clintAddr}
+      {storecmd} x11, 0(x18)
+
+      li x1, 0x80
+      csrrc x0, {fromMode}ie, x1
+    """)
+
+
+  # Illegal Instruction 
+  writeTest(storecmd, f, r, f"""
+    .fill 1, 4, 0
+  """, False, 0)
+
+  # Breakpoint
+  if returningInstruction != "ebreak":
+    writeTest(storecmd, f, r, f"""
+      ebreak
+    """, False, 0)
+
+  # Load Address Misaligned 
+  writeTest(storecmd, f, r, f"""
+    lw x0, 11(x0)
+  """, False, 0)
+
+  # Load Access fault: False, 5
+
+  # Store/AMO address misaligned
+  writeTest(storecmd, f, r, f"""
+    sw x0, 11(x0)
+  """, False, 0)
+
+  # Environment call from u-mode: only for when only M and U mode enabled?
+  # writeTest(storecmd, f, r, f"""
+  #   ecall
+  # """, False, 8, "u")
+  if returningInstruction != "ecall":
+    if fromMode == "u":
+      writeTest(storecmd, f, r, f"""
+        ecall
+      """, False, 0)
+
+    # Environment call from s-mode
+    if fromMode == "s":
+      writeTest(storecmd, f, r, f"""
+        ecall
+      """, False, 0)
+
+    # Environment call from m-mode
+    if fromMode == "m":
+      writeTest(storecmd, f, r, f"""
+        ecall
+      """, False, 0)  
+
+  # Instruction page fault: 12
+  # Load page fault: 13
+  # Store/AMO page fault: 15
+  
+
+  
+
+def writeTest(storecmd, f, r, test, interrupt, code, resetHander = ""):
+  global testnum, storeAddressOffset
+
+  expected = code
+
+  # Boilerplate
+  #
+  # x28 is the address that our trap handler will jump to before returning.
+  # This is where we can do our actual tests. After we're done computing and storing
+  # what we want, we jump to x27, which continues with the trap handling code (look at the _j_x_trap_... labels)
+  # 
+  lines = f"""
+    la x28, _jtest{testnum}
+    j _jdo{testnum}
+
+    _jtest{testnum}:
+    nop
+    {resetHander}
+    jr x27
+
+    _jdo{testnum}:
+    li x25, 0xDEADBEA7
+    {test}
+  """
+
+  # We expect x25 to be 0 always. This is because of the code we wrote at the begining
+  # of this function
+  
+  # Store the expected value of x25 to memory and in the .reference_output file
+  lines += f"""
+    {storecmd} x25, {testnum * wordsize}(x6)
+  """
+
+  f.write(lines)
+  if (xlen == 32):
+    line = formatrefstr.format(expected)+"\n"
+  else:
+    line = formatrefstr.format(expected % 2**32)+"\n" + formatrefstr.format(expected >> 32) + "\n"
+  r.write(line)
+  testnum = testnum+1
+
+##################################
+# main body
+##################################
+
+author = "dottolia@hmc.edu"
+xlens = [32, 64]
+testCount = 16;
+
+# setup
+# Change this seed to a different constant value for every test
+seed(0xC363DAEB9193AB45) # make tests reproducible
+
+# generate files for each test
+for xlen in xlens:
+  formatstrlen = str(int(xlen/4))
+  formatstr = "0x{:0" + formatstrlen + "x}" # format as xlen-bit hexadecimal number
+  formatrefstr = "{:08x}" # format as xlen-bit hexadecimal number with no leading 0x
+  if (xlen == 32):
+    storecmd = "sw"
+    wordsize = 4
+  else:
+    storecmd = "sd"
+    wordsize = 8
+
+  # testMode can be m, s, and u. User mode traps are deprecated, so this should likely just be ["m", "s"]
+  for testMode in ["m", "s"]:
+    imperaspath = "../../../imperas-riscv-tests/riscv-test-suite/rv" + str(xlen) + "p/"
+    basename = "WALLY-" + testMode.upper() + "TVEC"
+    fname = imperaspath + "src/" + basename + ".S"
+    refname = imperaspath + "references/" + basename + ".reference_output"
+    testnum = 0
+    storeAddressOffset = 0
+
+    # print custom header part
+    f = open(fname, "w")
+    r = open(refname, "w")
+    line = "///////////////////////////////////////////\n"
+    f.write(line)
+    lines="// "+fname+ "\n// " + author + "\n"
+    f.write(lines)
+    line ="// Created " + str(datetime.now()) 
+    f.write(line)
+
+    # insert generic header
+    h = open("../testgen_header.S", "r")
+    for line in h:  
+      f.write(line)
+
+    # We need to leave at least one bit in medeleg unset so that we have a way to get
+    # back to machine mode when the tests are complete (otherwise we'll only ever be able
+    # to get up to supervisor mode). 
+    #
+    # So, we define a returning instruction which will be used to cause the exception that
+    # brings us into machine mode. The bit for this returning instruction is NOT set in
+    # medeleg. However, this also means that we can't test that instruction. So, we have
+    # two different returning instructions.
+    #
+    # Current code is written to only support ebreak and ecall.
+    #
+    # For testgen-TVAL, we don't need to test ebreak, so we can use that as the sole
+    # returning instruction. For others, like testgen-CAUSE, we'll need to put
+    # both ebreak and ecall here.
+    for returningInstruction in ["ebreak"]:
+
+      # All registers used:
+      # x30: set to 1 if we should return to & stay in machine mode after trap, 0 otherwise
+      # ...
+      # x28: address trap handler should jump to for the test
+      # x27: address the test should return to after the test
+      # ...
+      # x25: value to write to memory
+      # ...
+      # x20: intermediate value in trap handler. Don't overwrite this!
+      # x19: mtvec old value
+      # x18: medeleg old value
+      # x17: sedeleg old value (currently unused — user mode traps deprecated)
+      # x16: mideleg old value
+      # ...
+      # x10 - x14 can be freely written
+      # ...
+      # x7: copy of x6. Increment this instead of using an offset on x6.
+      #     this allows us to create more than 2048/wordlen tests.
+      #     This is the address we write results to
+      # x6: Starting address we should write expected results to
+      # ...
+      # x1 - x5 can be freely written  
+
+
+
+      # Set up x7 and store old value of mtvec
+      lines = f"""
+        add x7, x6, x0
+        csrr x19, mtvec
+      """
+
+      # Not used — user mode traps are deprecated
+      if testMode == "u":
+        lines += f"""
+          csrr x17, sedeleg
+          li x9, {"0b1100000000" if testMode == "u" else "0b0000000000"}
+          csrs sedeleg, x9
+          """
+
+      # Code that will jump to the test (x28 is set in writeTest above)
+      testJumpCode = f"""
+        auipc x27, 0
+        addi x27, x27, 12
+        jr x28
+      """
+
+      beforeCode = ""
+      for i in range(0, 16):
+        beforeCode+=f"""
+          nop
+          nop
+          li x25, {i}
+          j _j_m_trap_end_{returningInstruction}
+        """
+
+        ########
+        ####### FIXME: wally is causing exception code 1 when you put non 4-bit aligned into mtvec. Bad wally.
+        ########
+
+      # Code for handling traps in different modes
+      # Some comments are inside of the below strings (prefixed with a #, as you might expected)
+      lines += f"""
+        # Reset x30 to 0 so we can run the tests. We'll set this to 1 when tests are completed so we stay in machine mode
+        li x30, 0
+
+        # Set up 
+        la x1, _j_m_trap_{returningInstruction}
+        addi x1, 1
+        csrw mtvec, x1
+        la x1, _j_s_trap_{returningInstruction}
+        csrw stvec, x1
+        la x1, _j_u_trap_{returningInstruction}
+        # csrw utvec, x1 # user mode traps are not supported
+
+        # Start the tests!
+        j _j_t_begin_{returningInstruction}
+
+        # Machine mode traps
+        _j_m_trap_{returningInstruction}:
+        {beforeCode}
+
+        _j_m_trap_end_{returningInstruction}:
+        {testJumpCode}
+
+        csrrs x20, mepc, x0
+        addi x20, x20, 4
+        csrrw x0, mepc, x20
+        bnez x30, _j_all_end_{returningInstruction}
+        mret
+
+        # Supervisor mode traps
+        _j_s_trap_{returningInstruction}:
+        {testJumpCode if testMode == "s" else "li x25, 0xBAD00001"}
+
+        csrrs x20, sepc, x0
+        addi x20, x20, 4
+        csrrw x0, sepc, x20
+        bnez x30, _j_goto_machine_mode_{returningInstruction}
+        sret
+
+        # Unused: user mode traps are no longer supported
+        _j_u_trap_{returningInstruction}:
+        {testJumpCode if testMode == "u" else "li x25, 0xBAD00000"}
+
+        csrrs x20, uepc, x0
+        addi x20, x20, 4
+        csrrw x0, uepc, x20
+        bnez x30, _j_goto_supervisor_mode_{returningInstruction}
+        uret
+
+        # Currently unused. Just jumps to _j_goto_machine_mode. If you actually
+        # want to implement this, you'll likely need to reset sedeleg here
+        # and then cause an exception with {returningInstruction} (based on my intuition. Try that first, but I could be missing something / just wrong)
+        _j_goto_supervisor_mode_{returningInstruction}:
+        j _j_goto_machine_mode_{returningInstruction}
+
+        _j_goto_machine_mode_{returningInstruction}:
+        li x30, 1 # This will cause us to branch to _j_all_end_{returningInstruction} in the machine trap handler, which we'll get into by invoking...
+        {returningInstruction} # ... this instruction!
+
+        # Run the actual tests!
+        _j_t_begin_{returningInstruction}:
+      """
+
+      fromModeOptions = ["m", "s", "u"] if testMode == "m" else (["s", "u"] if testMode == "s" else ["u"])
+
+      # We don't want to delegate our returning instruction. Otherwise, we'll have no way of getting
+      # back to machine mode at the end! (and we need to be in machine mode to complete the tests)
+      medelegMask = "0b1111111111110111" if returningInstruction == "ebreak" else "0b1111000011111111"
+
+      # Set medeleg and mideleg
+      lines += f"""
+        csrr x18, medeleg
+        li x9, {medelegMask if testMode == "s" or testMode == "u" else "0"}
+        csrw medeleg, x9
+
+        csrr x16, mideleg
+        li x9, {"0xffffffff" if testMode == "s" or testMode == "u" else "0"}
+        csrw mideleg, x9
+      """
+
+      f.write(lines)
+
+      for fromMode in fromModeOptions:
+        lines = ""
+        
+        # Code to bring us down to supervisor mode
+        if fromMode == "s" or fromMode == "u":
+          lines += f"""
+            li x1, 0b110000000000
+            csrrc x28, mstatus, x1
+            li x1, 0b0100000000000
+            csrrs x28, mstatus, x1
+
+            auipc x1, 0
+            addi x1, x1, 16 # x1 is now right after the mret instruction
+            csrw mepc, x1
+            mret
+
+            # We're now in supervisor mode...
+          """
+
+        # Code to bring us down to user mode
+        if fromMode == "u":
+          lines += f"""
+
+          li x1, 0b110000000000
+          csrrc x28, sstatus, x1
+
+          auipc x1, 0
+          addi x1, x1, 16 # x1 is now right after the sret instruction
+          csrw sepc, x1
+          sret
+
+          # We're now in user mode...
+          """
+
+        f.write(lines)
+        for i in range(0,testCount):
+          writeVectors(storecmd, returningInstruction)
+
+
+      # Very end of test. Bring us back up to machine mode
+      # We set x30 to 1, which will cause us to branch to _j_all_end in the
+      # machine mode trap handler, before executing the mret instruction. This will
+      # make us stay in machine mode.
+      #
+      # If we're currently in user mode, this will first bump us up to the supervisor mode
+      # trap handler, which will call returningInstruction again before it's sret instruction,
+      # bumping us up to machine mode
+      #
+      # Get into the trap handler by running returningInstruction (either an ecall or ebreak) 
+      f.write(f"""
+        li x30, 1
+        li gp, 0
+        {returningInstruction}
+        _j_all_end_{returningInstruction}:
+
+        # Reset trap handling csrs to old values
+        csrw mtvec, x19
+        csrw medeleg, x18
+        csrw mideleg, x16
+      """)
+
+    # print footer
+    h = open("../testgen_footer.S", "r")
+    for line in h:  
+      f.write(line)
+
+    # Finish
+    lines = ".fill " + str(testnum) + ", " + str(wordsize) + ", -1\n"
+    lines = lines + "\nRV_COMPLIANCE_DATA_END\n" 
+    f.write(lines)
+    f.close()
+    r.close()
+
+
+
+
+