From bae6fb38bd12781257704dc5d1038bc6da8feab3 Mon Sep 17 00:00:00 2001
From: Donald Sebastian Leung <dl@m-labs.hk>
Date: Tue, 28 Jul 2020 14:21:51 +0800
Subject: [PATCH] Add rvfi_imem_check

---
 checks/rvfi_imem_check.py | 88 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)
 create mode 100644 checks/rvfi_imem_check.py

diff --git a/checks/rvfi_imem_check.py b/checks/rvfi_imem_check.py
new file mode 100644
index 0000000..304a988
--- /dev/null
+++ b/checks/rvfi_imem_check.py
@@ -0,0 +1,88 @@
+from nmigen import *
+from nmigen.hdl.ast import *
+
+class rvfi_imem_check(Elaboratable):
+    def __init__(self, RISCV_FORMAL_ILEN=32, RISCV_FORMAL_XLEN=32):
+        self.RISCV_FORMAL_ILEN = RISCV_FORMAL_ILEN
+        self.RISCV_FORMAL_XLEN = RISCV_FORMAL_XLEN
+        self.reset = Signal(1)
+        self.enable = Signal(1)
+        self.imem_addr = Signal(self.RISCV_FORMAL_XLEN)
+        self.imem_data = Signal(16)
+        self.rvfi_valid = Signal(1)
+        self.rvfi_order = Signal(64)
+        self.rvfi_insn = Signal(self.RISCV_FORMAL_ILEN)
+        self.rvfi_trap = Signal(1)
+        self.rvfi_halt = Signal(1)
+        self.rvfi_intr = Signal(1)
+        self.rvfi_mode = Signal(2)
+        self.rvfi_ixl = Signal(2)
+        self.rvfi_rs1_addr = Signal(5)
+        self.rvfi_rs2_addr = Signal(5)
+        self.rvfi_rs1_rdata = Signal(self.RISCV_FORMAL_XLEN)
+        self.rvfi_rs2_rdata = Signal(self.RISCV_FORMAL_XLEN)
+        self.rvfi_rd_addr = Signal(5)
+        self.rvfi_rd_wdata = Signal(self.RISCV_FORMAL_XLEN)
+        self.rvfi_pc_rdata = Signal(self.RISCV_FORMAL_XLEN)
+        self.rvfi_pc_wdata = Signal(self.RISCV_FORMAL_XLEN)
+        self.rvfi_mem_addr = Signal(self.RISCV_FORMAL_XLEN)
+        self.rvfi_mem_rmask = Signal(int(self.RISCV_FORMAL_XLEN // 8))
+        self.rvfi_mem_wmask = Signal(int(self.RISCV_FORMAL_XLEN // 8))
+        self.rvfi_mem_rdata = Signal(self.RISCV_FORMAL_XLEN)
+        self.rvfi_mem_wdata = Signal(self.RISCV_FORMAL_XLEN)
+    def ports(self):
+        input_ports = [
+            self.reset,
+            self.enable,
+            self.rvfi_valid,
+            self.rvfi_order,
+            self.rvfi_insn,
+            self.rvfi_trap,
+            self.rvfi_halt,
+            self.rvfi_intr,
+            self.rvfi_mode,
+            self.rvfi_ixl,
+            self.rvfi_rs1_addr,
+            self.rvfi_rs2_addr,
+            self.rvfi_rs1_rdata,
+            self.rvfi_rs2_rdata,
+            self.rvfi_rd_addr,
+            self.rvfi_rd_wdata,
+            self.rvfi_pc_rdata,
+            self.rvfi_pc_wdata,
+            self.rvfi_mem_addr,
+            self.rvfi_mem_rmask,
+            self.rvfi_mem_wmask,
+            self.rvfi_mem_rdata,
+            self.rvfi_mem_wdata
+        ]
+        output_ports = [
+            self.imem_addr,
+            self.imem_data
+        ]
+        return input_ports + output_ports
+    def elaborate(self, platform):
+        m = Module()
+
+        imem_addr_randval = AnyConst(self.RISCV_FORMAL_XLEN)
+        imem_data_randval = AnyConst(16)
+        m.d.comb += self.imem_addr.eq(imem_addr_randval)
+        m.d.comb += self.imem_data.eq(imem_data_randval)
+
+        pc = Signal(self.RISCV_FORMAL_XLEN)
+        insn = Signal(self.RISCV_FORMAL_ILEN)
+
+        with m.If(self.reset):
+            pass
+        with m.Else():
+            with m.If(self.enable & self.rvfi_valid):
+                m.d.sync += pc.eq(self.rvfi_pc_rdata)
+                m.d.sync += insn.eq(self.rvfi_insn)
+
+                with m.If(pc == self.imem_addr):
+                    m.d.comb += Assert(insn[:16] == self.imem_data)
+
+                with m.If((insn[:2] == 0b11) & (pc + 2 == self.imem_addr)):
+                    m.d.comb += Assert(insn[16:32] == self.imem_data)
+
+        return m