Add register checks

This commit is contained in:
Donald Sebastian Leung 2020-08-20 11:10:33 +08:00
parent 2383706012
commit 2a9ddf0868
3 changed files with 94 additions and 0 deletions

62
rvfi/checks/reg_check.py Normal file
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@ -0,0 +1,62 @@
from nmigen import *
from nmigen.asserts import *
"""
Register Check
"""
class RegCheck(Elaboratable):
def __init__(self, RISCV_FORMAL_XLEN):
# Core-specific constants
self.RISCV_FORMAL_XLEN = RISCV_FORMAL_XLEN
# Input ports
self.reset = Signal(1)
self.check = Signal(1)
self.rvfi_valid = Signal(1)
self.rvfi_order = Signal(64)
self.rvfi_rs1_addr = Signal(5)
self.rvfi_rs1_rdata = Signal(self.RISCV_FORMAL_XLEN)
self.rvfi_rs2_addr = Signal(5)
self.rvfi_rs2_rdata = Signal(self.RISCV_FORMAL_XLEN)
self.rvfi_rd_addr = Signal(5)
self.rvfi_rd_wdata = Signal(self.RISCV_FORMAL_XLEN)
def ports(self):
input_ports = [
self.reset,
self.check,
self.rvfi_valid,
self.rvfi_order,
self.rvfi_rs1_addr,
self.rvfi_rs1_rdata,
self.rvfi_rs2_addr,
self.rvfi_rs2_rdata,
self.rvfi_rd_addr,
self.rvfi_rd_wdata
]
return input_ports
def elaborate(self, platform):
m = Module()
insn_order = AnyConst(64)
register_index = AnyConst(5)
register_shadow = Signal(self.RISCV_FORMAL_XLEN, reset=0)
register_written = Signal(1, reset=0)
with m.If(self.reset):
m.d.sync += register_shadow.eq(0)
m.d.sync += register_written.eq(0)
with m.Else():
with m.If(self.check):
m.d.comb += Assume(self.rvfi_valid)
m.d.comb += Assume(insn_order == self.rvfi_order)
with m.If(register_written & (register_index == self.rvfi_rs1_addr)):
m.d.comb += Assert(register_shadow == self.rvfi_rs1_rdata)
with m.If(register_written & (register_index == self.rvfi_rs2_addr)):
m.d.comb += Assert(register_shadow == self.rvfi_rs2_rdata)
with m.Else():
with m.If(self.rvfi_valid & (self.rvfi_order < insn_order) & (register_index == self.rvfi_rd_addr)):
m.d.sync += register_shadow.eq(self.rvfi_rd_wdata)
m.d.sync += register_written.eq(1)
return m

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@ -0,0 +1,28 @@
from nmigen import *
from ..core import *
from nmigen.test.utils import *
from ....checks.reg_check import *
class RegSpec(Elaboratable):
def elaborate(self, platform):
m = Module()
m.submodules.cpu = cpu = Minerva(with_rvfi=True)
m.submodules.reg_spec = reg_spec = RegCheck(RISCV_FORMAL_XLEN=32)
m.d.comb += reg_spec.reset.eq(0)
m.d.comb += reg_spec.check.eq(1)
m.d.comb += reg_spec.rvfi_valid.eq(cpu.rvfi.valid)
m.d.comb += reg_spec.rvfi_order.eq(cpu.rvfi.order)
m.d.comb += reg_spec.rvfi_rs1_addr.eq(cpu.rvfi.rs1_addr)
m.d.comb += reg_spec.rvfi_rs1_rdata.eq(cpu.rvfi.rs1_rdata)
m.d.comb += reg_spec.rvfi_rs2_addr.eq(cpu.rvfi.rs2_addr)
m.d.comb += reg_spec.rvfi_rs2_rdata.eq(cpu.rvfi.rs2_rdata)
m.d.comb += reg_spec.rvfi_rd_addr.eq(cpu.rvfi.rd_addr)
m.d.comb += reg_spec.rvfi_rd_wdata.eq(cpu.rvfi.rd_wdata)
return m
class RegTestCase(FHDLTestCase):
def verify(self):
self.assertFormal(RegSpec(), mode="bmc", depth=12, engine="smtbmc --nopresat")

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@ -3,6 +3,7 @@ from .test.test_cache import *
from .test.test_instructions import * from .test.test_instructions import *
from .test.test_pc_forward import * from .test.test_pc_forward import *
from .test.test_pc_backward import * from .test.test_pc_backward import *
from .test.test_register import *
from .test.test_units_divider import * from .test.test_units_divider import *
from .test.test_units_multiplier import * from .test.test_units_multiplier import *
@ -56,5 +57,8 @@ PcFwdTestCase().verify()
print("Verifying PC backward checks ...") print("Verifying PC backward checks ...")
PcBwdTestCase().verify() PcBwdTestCase().verify()
print("Verifying register checks ...")
RegTestCase().verify()
print("Testing multiplier and divider ...") print("Testing multiplier and divider ...")
unittest.main() unittest.main()