cvw/tests/testgen/privileged/testgen-TVAL.py

375 lines
11 KiB
Python
Executable File

#!/usr/bin/env python3
##################################
# testgen-TVAL.py
#
# dottolia@hmc.edu 1 Mar 2021
#
# Generate directed and random test vectors for RISC-V Design Validation.
#
##################################
# DOCUMENTATION:
#
# Most of the comments explaining what everything
# does and the layout of the privileged tests
# can be found in this file
#
###################################
##################################
# libraries
##################################
from datetime import datetime
from random import randint
from random import seed
from random import getrandbits
##################################
# functions
##################################
def writeVectors(storecmd):
global testnum
# Illegal Instruction
writeTest(storecmd, f, r, f"""
.fill 1, 4, 0
""", f"""
li x23, 0
""")
val = (randint(0, 200) * 2) + 1
# Load Address Misaligned
writeTest(storecmd, f, r, f"""
lw x0, {val}(x0)
""", f"""
li x23, {val}
""")
val = (randint(0, 200) * 2) + 1
# Store Address Misaligned
writeTest(storecmd, f, r, f"""
sw x0, {val}(x0)
""", f"""
li x23, {val}
""")
def writeTest(storecmd, f, r, test, expected, mode = "m", resetHander = ""):
global testnum, storeAddressOffset
# The code we actually change for our test
lines = f"""
{expected}
csrr x25, {testMode}tval
sub x25, x25, x23
"""
# 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}:
{lines}
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
expected = 0
# Store the expected value of x25 to memory and in the .reference_output file
lines += f"""
{storecmd} x25, 0(x7)
addi x7, x7, {wordsize}
"""
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 = 32;
# 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() + "TVAL"
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
# ...
# x4 & x5 can be freely written
# x3 — DO NOT WRITE ANY NON-ZERO VALUE TO THIS — test exits on ecall if x3 = 1 (x3 is gp)
# x1 & x2 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
"""
# 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}
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}:
{testJumpCode if testMode == "m" else "li x25, 0xBAD00003"}
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 x31, mstatus, x1
li x1, 0b0100000000000
csrrs x31, 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 x31, 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)
# 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
{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()