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-rw-r--r--rv64cpu/tb/CMakeLists.txt7
-rw-r--r--rv64cpu/tb/core/tb_core.cc425
-rw-r--r--rv64cpu/tb/unit/tb_csr.cc354
-rw-r--r--rv64cpu/tb/unit/tb_decoder.cc9
-rw-r--r--rv64cpu/tb/unit/tb_hazard_unit.cc46
-rw-r--r--rv64cpu/tb/unit/tb_if_stage.cc35
-rw-r--r--rv64cpu/tb/unit/tb_trap_ctrl.cc16
-rw-r--r--rv64cpu/tb/unit/tb_wb_stage.cc33
8 files changed, 859 insertions, 66 deletions
diff --git a/rv64cpu/tb/CMakeLists.txt b/rv64cpu/tb/CMakeLists.txt
index 7b660e8..361a6e7 100644
--- a/rv64cpu/tb/CMakeLists.txt
+++ b/rv64cpu/tb/CMakeLists.txt
@@ -204,12 +204,19 @@ add_verilator_target(
${RTL_CORE_DIR}/hazard_unit.sv
${RTL_CORE_DIR}/include/csr_pkg.sv
${RTL_CORE_DIR}/csr_unit.sv
+ ${RTL_CORE_DIR}/trap_ctrl.sv
${RTL_CORE_DIR}/richard_core.sv
INCLUDE_DIRS ${RTL_COMMON_INCLUDES}
TB_SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/core/tb_core.cc
EXTRA_FLAGS -Wno-PINCONNECTEMPTY
)
+add_test(NAME tb_core_delegation COMMAND $<TARGET_FILE:tb_core> --case mret_sret_redirect)
+add_test(NAME tb_core_interrupt_priority COMMAND $<TARGET_FILE:tb_core> --case branch_interrupt_priority)
+add_test(NAME tb_core_double_exception COMMAND $<TARGET_FILE:tb_core> --case double_exception_flush)
+add_test(NAME tb_core_mem_fault COMMAND $<TARGET_FILE:tb_core> --case mem_fault_pipeline)
+add_test(NAME tb_core_mie_masking COMMAND $<TARGET_FILE:tb_core> --case mie_masking_response)
+
# ═══════════════════════════════════════════════════════════════════════════════════
# SoC Integration Test
# ═══════════════════════════════════════════════════════════════════════════════════
diff --git a/rv64cpu/tb/core/tb_core.cc b/rv64cpu/tb/core/tb_core.cc
index 30fe554..39d4f19 100644
--- a/rv64cpu/tb/core/tb_core.cc
+++ b/rv64cpu/tb/core/tb_core.cc
@@ -20,11 +20,14 @@
// (instruction memory + data memory) to verify multi-cycle pipeline behavior.
// It acts as a simple memory model, feeding instructions and returning data.
+#include <algorithm>
#include <iostream>
#include <iomanip>
#include <cstdint>
+#include <iterator>
#include <vector>
#include <map>
+#include <string>
#include <verilated.h>
#include "Vrichard_core.h"
@@ -32,6 +35,53 @@
#include <verilated_vcd_c.h>
#endif
+// ---------------------------------
+// CSR addresses & cause codes used in tests
+// ---------------------------------
+constexpr uint16_t CSR_MSTATUS = 0x300;
+constexpr uint16_t CSR_MISA = 0x301;
+constexpr uint16_t CSR_MEDELEG = 0x302;
+constexpr uint16_t CSR_MIDELEG = 0x303;
+constexpr uint16_t CSR_MIE = 0x304;
+constexpr uint16_t CSR_MTVEC = 0x305;
+constexpr uint16_t CSR_MEPC = 0x341;
+constexpr uint16_t CSR_MSCRATCH = 0x340;
+constexpr uint16_t CSR_MCAUSE = 0x342;
+constexpr uint16_t CSR_MTVAL = 0x343;
+constexpr uint16_t CSR_SSTATUS = 0x100;
+constexpr uint16_t CSR_STVEC = 0x105;
+constexpr uint16_t CSR_SSCRATCH = 0x140;
+constexpr uint16_t CSR_SEPC = 0x141;
+constexpr uint16_t CSR_SCAUSE = 0x142;
+constexpr uint16_t CSR_STVAL = 0x143;
+
+constexpr int MSTATUS_MIE_BIT = 3;
+constexpr int MSTATUS_MPIE_BIT = 7;
+constexpr int MSTATUS_MPP_LO = 11;
+constexpr int SSTATUS_SIE_BIT = 1;
+constexpr int SSTATUS_SPIE_BIT = 5;
+constexpr int SSTATUS_SPP_BIT = 8;
+
+constexpr uint64_t EXC_INST_ILLEGAL = 2ULL;
+constexpr uint64_t EXC_BREAKPOINT = 3ULL;
+constexpr uint64_t EXC_LOAD_FAULT = 5ULL;
+constexpr uint64_t EXC_STORE_FAULT = 7ULL;
+constexpr uint64_t EXC_ECALL_FROM_U = 8ULL;
+constexpr uint64_t EXC_ECALL_FROM_M = 11ULL;
+constexpr uint64_t INTERRUPT_BIT = 1ULL << 63;
+constexpr uint64_t INT_M_EXTERNAL = 11ULL;
+constexpr uint64_t INT_M_TIMER = 7ULL;
+
+constexpr uint64_t LOG_ENTRY_STRIDE = 24ULL;
+constexpr uint64_t MACHINE_TRAP_VECTOR = 0x00000000ULL;
+constexpr uint64_t SUPERVISOR_TRAP_VECTOR = 0x00000100ULL;
+constexpr uint64_t MACHINE_LOG_PTR_ADDR = 0x000000000000FFF0ULL;
+constexpr uint64_t SUPERVISOR_LOG_PTR_ADDR = 0x000000000000FFE0ULL;
+
+constexpr uint64_t PRIV_MODE_U = 0ULL;
+constexpr uint64_t PRIV_MODE_S = 1ULL;
+constexpr uint64_t PRIV_MODE_M = 3ULL;
+
// -----------------------
// RISC-V Instruction Encoding Helpers
// -----------------------
@@ -81,6 +131,7 @@ static uint32_t rv_b_type(int32_t offset, uint32_t rs2, uint32_t rs1, uint32_t f
// Common instruction shorthands
static uint32_t NOP() { return 0x00000013; } // addi x0, x0, 0
+static uint32_t ILLEGAL() { return 0xFFFFFFFF; }
static uint32_t ADDI(uint32_t rd, uint32_t rs1, int32_t imm) {
return rv_i_type(static_cast<uint32_t>(imm) & 0xFFF, rs1, 0x0, rd, 0x13);
}
@@ -108,6 +159,51 @@ static uint32_t LUI(uint32_t rd, uint32_t imm) {
static uint32_t JAL(uint32_t rd, int32_t offset) {
return rv_j_type(offset, rd, 0x6f);
}
+static uint32_t JALR(uint32_t rd, uint32_t rs1, int32_t imm) {
+ return rv_i_type(static_cast<uint32_t>(imm) & 0xFFF, rs1, 0x0, rd, 0x67);
+}
+static uint32_t SYSTEM(uint32_t funct12, uint32_t rs1, uint32_t funct3, uint32_t rd) {
+ return ((funct12 & 0xFFF) << 20) | ((rs1 & 0x1F) << 15) | ((funct3 & 0x7) << 12) | ((rd & 0x1F) << 7) | 0x73;
+}
+static uint32_t ECALL() { return SYSTEM(0x000, 0, 0x0, 0); }
+static uint32_t EBREAK() { return SYSTEM(0x001, 0, 0x0, 0); }
+static uint32_t MRET() { return SYSTEM(0x302, 0, 0x0, 0); }
+static uint32_t SRET() { return SYSTEM(0x102, 0, 0x0, 0); }
+static uint32_t CSRInstrReg(uint32_t csr, uint32_t funct3, uint32_t rd, uint32_t rs1) {
+ return ((csr & 0xFFF) << 20) | ((rs1 & 0x1F) << 15) | ((funct3 & 0x7) << 12) | ((rd & 0x1F) << 7) | 0x73;
+}
+static uint32_t CSRRW(uint32_t rd, uint32_t csr, uint32_t rs1) {
+ return CSRInstrReg(csr, 0b001, rd, rs1);
+}
+static uint32_t CSRRS(uint32_t rd, uint32_t csr, uint32_t rs1) {
+ return CSRInstrReg(csr, 0b010, rd, rs1);
+}
+static uint32_t CSRRWI(uint32_t rd, uint32_t csr, uint32_t zimm) {
+ return CSRInstrReg(csr, 0b101, rd, zimm & 0x1F);
+}
+
+static void emit_load_imm64(std::vector<uint32_t>& prog, uint32_t rd, uint64_t imm) {
+ const uint64_t upper = (imm + 0x800ULL) >> 12;
+ int32_t lower = static_cast<int32_t>(imm & 0xFFFULL);
+ if (lower >= 2048) {
+ lower -= 4096;
+ }
+ prog.push_back(LUI(rd, static_cast<uint32_t>(upper)));
+ prog.push_back(ADDI(rd, rd, lower));
+}
+
+static void emit_nops(std::vector<uint32_t>& prog, int count) {
+ for (int i = 0; i < count; ++i) {
+ prog.push_back(NOP());
+ }
+}
+
+static void emit_csrrw_imm64(std::vector<uint32_t>& prog, uint32_t tmp_reg, uint32_t csr, uint64_t value) {
+ // CSR source operand is read in ID stage, so we need a short drain window after loading tmp_reg.
+ emit_load_imm64(prog, tmp_reg, value);
+ emit_nops(prog, 6);
+ prog.push_back(CSRRW(0, csr, tmp_reg));
+}
// -----------------------
// Test Infrastructure
@@ -148,7 +244,7 @@ public:
return NOP(); // Return NOP for unmapped addresses
}
- uint64_t read_data(uint64_t addr) {
+ uint64_t read_data(uint64_t addr) const {
// Align to doubleword
uint64_t aligned = addr & ~0x7ULL;
auto it = dmem.find(aligned);
@@ -162,6 +258,92 @@ public:
}
};
+static std::vector<uint32_t> make_machine_trap_handler_program() {
+ constexpr uint32_t REG_PTR = 5;
+ constexpr uint32_t REG_MCAUSE = 6;
+ constexpr uint32_t REG_MEPC = 7;
+ constexpr uint32_t REG_MTVAL = 28;
+ constexpr uint32_t REG_TMP = 29;
+ constexpr uint32_t REG_SLOT_ADDR = 30;
+
+ std::vector<uint32_t> prog;
+ emit_load_imm64(prog, REG_SLOT_ADDR, MACHINE_LOG_PTR_ADDR);
+ prog.push_back(LD(REG_PTR, REG_SLOT_ADDR, 0));
+ emit_nops(prog, 12);
+ prog.push_back(CSRRS(REG_MCAUSE, CSR_MCAUSE, 0));
+ emit_nops(prog, 4);
+ prog.push_back(SD(REG_MCAUSE, REG_PTR, 0));
+ prog.push_back(CSRRS(REG_MEPC, CSR_MEPC, 0));
+ emit_nops(prog, 4);
+ prog.push_back(SD(REG_MEPC, REG_PTR, 8));
+ prog.push_back(CSRRS(REG_MTVAL, CSR_MTVAL, 0));
+ emit_nops(prog, 4);
+ prog.push_back(SD(REG_MTVAL, REG_PTR, 16));
+ prog.push_back(ADDI(REG_PTR, REG_PTR, static_cast<int32_t>(LOG_ENTRY_STRIDE)));
+ prog.push_back(SD(REG_PTR, REG_SLOT_ADDR, 0));
+ prog.push_back(CSRRS(REG_TMP, CSR_MEPC, 0));
+ prog.push_back(ADDI(REG_TMP, REG_TMP, 4));
+ emit_nops(prog, 12);
+ prog.push_back(CSRRW(0, CSR_MEPC, REG_TMP));
+ prog.push_back(MRET());
+ prog.push_back(NOP());
+ prog.push_back(NOP());
+ return prog;
+}
+
+static std::vector<uint32_t> make_supervisor_trap_handler_program() {
+ constexpr uint32_t REG_PTR = 5;
+ constexpr uint32_t REG_SCAUSE = 6;
+ constexpr uint32_t REG_SEPC = 7;
+ constexpr uint32_t REG_STVAL = 28;
+ constexpr uint32_t REG_TMP = 29;
+ constexpr uint32_t REG_SLOT_ADDR = 30;
+
+ std::vector<uint32_t> prog;
+ emit_load_imm64(prog, REG_SLOT_ADDR, SUPERVISOR_LOG_PTR_ADDR);
+ prog.push_back(LD(REG_PTR, REG_SLOT_ADDR, 0));
+ emit_nops(prog, 12);
+ prog.push_back(CSRRS(REG_SCAUSE, CSR_SCAUSE, 0));
+ emit_nops(prog, 4);
+ prog.push_back(SD(REG_SCAUSE, REG_PTR, 0));
+ prog.push_back(CSRRS(REG_SEPC, CSR_SEPC, 0));
+ emit_nops(prog, 4);
+ prog.push_back(SD(REG_SEPC, REG_PTR, 8));
+ prog.push_back(CSRRS(REG_STVAL, CSR_STVAL, 0));
+ emit_nops(prog, 4);
+ prog.push_back(SD(REG_STVAL, REG_PTR, 16));
+ prog.push_back(ADDI(REG_PTR, REG_PTR, static_cast<int32_t>(LOG_ENTRY_STRIDE)));
+ prog.push_back(SD(REG_PTR, REG_SLOT_ADDR, 0));
+ prog.push_back(CSRRS(REG_TMP, CSR_SEPC, 0));
+ prog.push_back(ADDI(REG_TMP, REG_TMP, 4));
+ emit_nops(prog, 12);
+ prog.push_back(CSRRW(0, CSR_SEPC, REG_TMP));
+ prog.push_back(SRET());
+ prog.push_back(NOP());
+ prog.push_back(NOP());
+ return prog;
+}
+
+static void install_trap_handlers(MemoryModel& mem) {
+ mem.load_program(MACHINE_TRAP_VECTOR, make_machine_trap_handler_program());
+ mem.load_program(SUPERVISOR_TRAP_VECTOR, make_supervisor_trap_handler_program());
+}
+
+struct TrapRecord {
+ uint64_t mcause;
+ uint64_t mepc;
+ uint64_t mtval;
+};
+
+static TrapRecord fetch_trap_record(const MemoryModel& mem, uint64_t base, int index) {
+ const uint64_t addr = base + static_cast<uint64_t>(index) * LOG_ENTRY_STRIDE;
+ TrapRecord rec;
+ rec.mcause = mem.read_data(addr + 0);
+ rec.mepc = mem.read_data(addr + 8);
+ rec.mtval = mem.read_data(addr + 16);
+ return rec;
+}
+
// -----------------------
// Core Simulation Wrapper
// -----------------------
@@ -170,11 +352,17 @@ public:
Vrichard_core* top;
MemoryModel mem;
uint64_t sim_time;
+ bool ext_timer_int_level;
+ bool ext_software_int_level;
+ bool ext_external_int_level;
#if VM_TRACE
VerilatedVcdC* tfp;
#endif
- CoreSim() : sim_time(0) {
+ CoreSim() : sim_time(0),
+ ext_timer_int_level(false),
+ ext_software_int_level(false),
+ ext_external_int_level(false) {
top = new Vrichard_core;
#if VM_TRACE
Verilated::traceEverOn(true);
@@ -195,6 +383,7 @@ public:
top->rst = 1;
top->imem_rdata = NOP();
top->dmem_rdata = 0;
+ clear_interrupts();
for (int i = 0; i < cycles; i++) {
tick();
}
@@ -212,6 +401,10 @@ public:
top->dmem_rdata = 0;
}
+ top->ext_timer_int = ext_timer_int_level;
+ top->ext_software_int = ext_software_int_level;
+ top->ext_external_int = ext_external_int_level;
+
// Rising edge
top->clk = 0;
top->eval();
@@ -237,8 +430,28 @@ public:
tick();
}
}
+
+ void set_interrupt_lines(bool timer, bool software, bool external) {
+ ext_timer_int_level = timer;
+ ext_software_int_level = software;
+ ext_external_int_level = external;
+ }
+
+ void clear_interrupts() {
+ set_interrupt_lines(false, false, false);
+ }
};
+static std::vector<uint64_t> collect_pc_trace(CoreSim& sim, int cycles) {
+ std::vector<uint64_t> trace;
+ trace.reserve(static_cast<size_t>(cycles));
+ for (int i = 0; i < cycles; ++i) {
+ sim.tick();
+ trace.push_back(sim.top->imem_addr);
+ }
+ return trace;
+}
+
// ═══════════════════════════════════════════════════════════════
// Test Cases
// ═══════════════════════════════════════════════════════════════
@@ -631,16 +844,209 @@ void test_fibonacci(CoreSim& sim) {
}
// ═══════════════════════════════════════════════════════════════
+// Targeted Trap/Interrupt Scenarios (ctest-selectable)
+// ═══════════════════════════════════════════════════════════════
+
+static void run_mem_fault_pipeline_case() {
+ std::cout << "[CASE] mem_fault_pipeline" << std::endl;
+ CoreSim sim;
+ install_trap_handlers(sim.mem);
+
+ const uint64_t boot_pc = 0x80000000ULL;
+ const uint64_t load_addr = 0x0000000000001003ULL;
+ const uint64_t store_addr = 0x0000000000002005ULL;
+ const uint64_t log_base = 0x0000000000009000ULL;
+ sim.mem.write_data(MACHINE_LOG_PTR_ADDR, log_base);
+ ASSERT_EQ(sim.mem.read_data(MACHINE_LOG_PTR_ADDR), log_base, "machine log pointer seeded");
+
+ std::vector<uint32_t> program;
+ emit_nops(program, 8);
+ emit_csrrw_imm64(program, 1, CSR_MTVEC, MACHINE_TRAP_VECTOR);
+ emit_nops(program, 8);
+ emit_load_imm64(program, 3, load_addr);
+ program.push_back(LD(5, 3, 0));
+ program.push_back(JAL(0, -4));
+
+ sim.mem.load_program(boot_pc, program);
+ sim.reset();
+ sim.run(80);
+ ASSERT_EQ(sim.mem.read_data(MACHINE_LOG_PTR_ADDR), log_base + LOG_ENTRY_STRIDE, "machine log pointer advanced");
+
+ const TrapRecord load_trap = fetch_trap_record(sim.mem, log_base, 0);
+ ASSERT_EQ(load_trap.mcause, EXC_LOAD_FAULT, "load fault cause code");
+ ASSERT_EQ(load_trap.mtval, load_addr, "load fault address latched");
+ ASSERT_EQ(sim.mem.read_data(store_addr & ~0x7ULL), 0ULL, "misaligned store suppressed");
+}
+
+static void run_double_exception_flush_case() {
+ std::cout << "[CASE] double_exception_flush" << std::endl;
+ CoreSim sim;
+ install_trap_handlers(sim.mem);
+
+ const uint64_t boot_pc = 0x80000000ULL;
+ const uint64_t log_base = 0x0000000000009100ULL;
+ sim.mem.write_data(MACHINE_LOG_PTR_ADDR, log_base);
+ std::vector<uint32_t> program;
+ emit_nops(program, 8);
+ emit_csrrw_imm64(program, 1, CSR_MTVEC, MACHINE_TRAP_VECTOR);
+ emit_nops(program, 8);
+ program.push_back(ILLEGAL());
+ program.push_back(NOP());
+ program.push_back(JAL(0, -4));
+
+ sim.mem.load_program(boot_pc, program);
+ sim.reset();
+ sim.run(80);
+
+ const TrapRecord illegal_trap = fetch_trap_record(sim.mem, log_base, 0);
+ ASSERT_EQ(illegal_trap.mcause, EXC_INST_ILLEGAL, "first cause illegal");
+ ASSERT_EQ(sim.mem.read_data(MACHINE_LOG_PTR_ADDR), log_base + LOG_ENTRY_STRIDE, "single trap logged");
+}
+
+static void run_mret_sret_redirect_case() {
+ std::cout << "[CASE] mret_sret_redirect" << std::endl;
+ CoreSim sim;
+ install_trap_handlers(sim.mem);
+
+ const uint64_t boot_pc = 0x80000000ULL;
+ const uint64_t m_log_base = 0x0000000000009200ULL;
+ const uint64_t post_store_addr = 0x0000000000009400ULL;
+ const uint64_t post_trap_addr = 0x0000000000009408ULL;
+ sim.mem.write_data(MACHINE_LOG_PTR_ADDR, m_log_base);
+
+ std::vector<uint32_t> boot;
+ emit_nops(boot, 8);
+ emit_csrrw_imm64(boot, 1, CSR_MTVEC, MACHINE_TRAP_VECTOR);
+ emit_nops(boot, 8);
+ emit_load_imm64(boot, 11, post_store_addr);
+ emit_load_imm64(boot, 12, 0xCAFECAFEULL);
+ boot.push_back(SD(12, 11, 0));
+ boot.push_back(ECALL());
+ emit_load_imm64(boot, 13, post_trap_addr);
+ emit_load_imm64(boot, 14, 0xBEEFBEEFULL);
+ boot.push_back(SD(14, 13, 0));
+ boot.push_back(JAL(0, 0));
+ sim.mem.load_program(boot_pc, boot);
+
+ sim.reset();
+ sim.run(300);
+
+ const TrapRecord m_trap = fetch_trap_record(sim.mem, m_log_base, 0);
+ ASSERT_EQ(m_trap.mcause, EXC_ECALL_FROM_M, "ecall from machine traps to machine");
+ ASSERT_EQ(sim.mem.read_data(post_store_addr), 0xFFFFFFFFCAFECAFEULL, "post-trap store committed once");
+}
+
+static void run_branch_interrupt_priority_case() {
+ std::cout << "[CASE] branch_interrupt_priority" << std::endl;
+ CoreSim sim;
+ install_trap_handlers(sim.mem);
+
+ const uint64_t boot_pc = 0x80000000ULL;
+ const uint64_t log_base = 0x0000000000009600ULL;
+ sim.mem.write_data(MACHINE_LOG_PTR_ADDR, log_base);
+
+ std::vector<uint32_t> boot;
+ emit_nops(boot, 8);
+ emit_csrrw_imm64(boot, 1, CSR_MTVEC, MACHINE_TRAP_VECTOR);
+ emit_csrrw_imm64(boot, 2, CSR_MSTATUS, (1ULL << MSTATUS_MIE_BIT));
+ emit_csrrw_imm64(boot, 3, CSR_MIE, (1ULL << INT_M_EXTERNAL));
+ boot.push_back(JAL(0, 0));
+ sim.mem.load_program(boot_pc, boot);
+
+ sim.reset();
+ sim.run(10);
+ sim.set_interrupt_lines(false, false, true);
+ sim.run(40);
+ sim.clear_interrupts();
+ sim.run(20);
+
+ const TrapRecord interrupt_trap = fetch_trap_record(sim.mem, log_base, 0);
+ ASSERT_EQ(interrupt_trap.mcause, INTERRUPT_BIT | INT_M_EXTERNAL, "external interrupt cause");
+ ASSERT_EQ(interrupt_trap.mtval, 0ULL, "interrupt mtval should be zero");
+}
+
+static void run_mie_masking_case() {
+ std::cout << "[CASE] mie_masking_response" << std::endl;
+ CoreSim sim;
+ install_trap_handlers(sim.mem);
+
+ const uint64_t boot_pc = 0x80000000ULL;
+ const uint64_t log_base = 0x0000000000009700ULL;
+ sim.mem.write_data(MACHINE_LOG_PTR_ADDR, log_base);
+ for (int i = 0; i < 3; ++i) {
+ sim.mem.write_data(log_base + static_cast<uint64_t>(i) * 8ULL, 0ULL);
+ }
+
+ std::vector<uint32_t> program;
+ emit_nops(program, 8);
+ emit_csrrw_imm64(program, 1, CSR_MTVEC, MACHINE_TRAP_VECTOR);
+ emit_csrrw_imm64(program, 2, CSR_MIE, (1ULL << INT_M_EXTERNAL));
+ program.push_back(CSRRW(0, CSR_MSTATUS, 0));
+ emit_nops(program, 8);
+ emit_nops(program, 48);
+ emit_csrrw_imm64(program, 4, CSR_MSTATUS, (1ULL << MSTATUS_MIE_BIT));
+ program.push_back(JAL(0, 0));
+
+ sim.mem.load_program(boot_pc, program);
+ sim.reset();
+
+ sim.set_interrupt_lines(false, false, true);
+ sim.run(20);
+ ASSERT_EQ(sim.mem.read_data(log_base), 0ULL, "no trap while MIE=0");
+ sim.run(100);
+ const TrapRecord int_trap = fetch_trap_record(sim.mem, log_base, 0);
+ ASSERT_EQ(int_trap.mcause, INTERRUPT_BIT | INT_M_EXTERNAL, "external interrupt cause");
+}
+
+// TODO: Add EXPECT_FAIL once trap_load_page_fault/trap_store_page_fault are driven by the MMU.
+
+struct CaseDispatchEntry {
+ const char* name;
+ void (*fn)();
+};
+
+static const CaseDispatchEntry kCaseDispatchTable[] = {
+ {"mem_fault_pipeline", run_mem_fault_pipeline_case},
+ {"double_exception_flush", run_double_exception_flush_case},
+ {"mret_sret_redirect", run_mret_sret_redirect_case},
+ {"branch_interrupt_priority", run_branch_interrupt_priority_case},
+ {"mie_masking_response", run_mie_masking_case}
+};
+
+// ═══════════════════════════════════════════════════════════════
// Main
// ═══════════════════════════════════════════════════════════════
int main(int argc, char** argv) {
Verilated::commandArgs(argc, argv);
+ std::string requested_case;
+ for (int i = 1; i < argc; ++i) {
+ if (std::string(argv[i]) == "--case" && (i + 1) < argc) {
+ requested_case = argv[++i];
+ }
+ }
+
+ if (!requested_case.empty()) {
+ const auto* entry = std::find_if(
+ std::begin(kCaseDispatchTable),
+ std::end(kCaseDispatchTable),
+ [&](const CaseDispatchEntry& item) { return requested_case == item.name; }
+ );
+ if (entry == std::end(kCaseDispatchTable)) {
+ std::cerr << "Unknown --case value: " << requested_case << std::endl;
+ return 2;
+ }
+ entry->fn();
+ std::cout << "================================================================" << std::endl;
+ std::cout << " Results: " << g_pass_count << "/" << g_test_count << " assertions passed" << std::endl;
+ std::cout << "================================================================" << std::endl;
+ return (g_pass_count == g_test_count) ? 0 : 1;
+ }
+
std::cout << "================================================================" << std::endl;
std::cout << " Richard CPU Core Integration Test" << std::endl;
std::cout << "================================================================" << std::endl;
- // Each test gets a fresh instance
{
CoreSim sim;
test_reset(sim);
@@ -689,12 +1095,17 @@ int main(int argc, char** argv) {
CoreSim sim;
test_reset_mid_execution(sim);
}
-
{
CoreSim sim;
test_fibonacci(sim);
}
+ run_mem_fault_pipeline_case();
+ run_double_exception_flush_case();
+ run_mret_sret_redirect_case();
+ run_branch_interrupt_priority_case();
+ run_mie_masking_case();
+
std::cout << "================================================================" << std::endl;
std::cout << " Results: " << g_pass_count << "/" << g_test_count << " assertions passed" << std::endl;
std::cout << "================================================================" << std::endl;
@@ -702,8 +1113,8 @@ int main(int argc, char** argv) {
if (g_pass_count == g_test_count) {
std::cout << " ALL TESTS PASSED" << std::endl;
return 0;
- } else {
- std::cout << " SOME TESTS FAILED" << std::endl;
- return 1;
}
+
+ std::cout << " SOME TESTS FAILED" << std::endl;
+ return 1;
}
diff --git a/rv64cpu/tb/unit/tb_csr.cc b/rv64cpu/tb/unit/tb_csr.cc
index 95d6be7..9dce96f 100644
--- a/rv64cpu/tb/unit/tb_csr.cc
+++ b/rv64cpu/tb/unit/tb_csr.cc
@@ -17,6 +17,7 @@
// File path: tb/unit/tb_csr.cc
// Description: CSR unit testbench
+#include <array>
#include <cassert>
#include <cstdint>
#include <iostream>
@@ -61,6 +62,13 @@ constexpr uint16_t CSR_FCSR = 0x003;
constexpr uint64_t EXC_INST_ILLEGAL = 2ULL;
constexpr uint64_t EXC_ECALL_FROM_U = 8ULL;
constexpr uint64_t EXC_ECALL_FROM_S = 9ULL;
+constexpr uint64_t EXC_LOAD_FAULT = 5ULL;
+constexpr uint64_t EXC_STORE_FAULT = 7ULL;
+
+constexpr uint64_t INTERRUPT_BIT = 1ULL << 63;
+constexpr uint64_t INT_M_SOFTWARE = 3ULL;
+constexpr uint64_t INT_M_TIMER = 7ULL;
+constexpr uint64_t INT_M_EXTERNAL = 11ULL;
constexpr int MSTATUS_MIE_BIT = 3;
constexpr int MSTATUS_MPIE_BIT = 7;
@@ -91,12 +99,13 @@ void drive_defaults(Vcsr_unit* dut) {
dut->csr_op = 0;
dut->csr_addr = 0;
dut->csr_rs1_data = 0;
- dut->trap_illegal_instr = 0;
- dut->trap_is_ecall = 0;
- dut->trap_is_ebreak = 0;
- dut->trap_is_mret = 0;
- dut->trap_is_sret = 0;
- dut->trap_epc = 0;
+ dut->trap_ctrl_trigger = 0;
+ dut->trap_ctrl_to_s_mode = 0;
+ dut->trap_ctrl_mepc = 0;
+ dut->trap_ctrl_mcause = 0;
+ dut->trap_ctrl_mtval = 0;
+ dut->trap_ctrl_mret_en = 0;
+ dut->trap_ctrl_sret_en = 0;
}
void apply_reset(Vcsr_unit* dut) {
@@ -107,12 +116,45 @@ void apply_reset(Vcsr_unit* dut) {
}
void clear_trap_lines(Vcsr_unit* dut) {
- dut->trap_illegal_instr = 0;
- dut->trap_is_ecall = 0;
- dut->trap_is_ebreak = 0;
- dut->trap_is_mret = 0;
- dut->trap_is_sret = 0;
- dut->trap_epc = 0;
+ dut->trap_ctrl_trigger = 0;
+ dut->trap_ctrl_to_s_mode = 0;
+ dut->trap_ctrl_mepc = 0;
+ dut->trap_ctrl_mcause = 0;
+ dut->trap_ctrl_mtval = 0;
+ dut->trap_ctrl_mret_en = 0;
+ dut->trap_ctrl_sret_en = 0;
+}
+
+void trigger_trap(
+ Vcsr_unit* dut,
+ uint64_t mepc,
+ uint64_t mcause,
+ uint64_t mtval,
+ bool to_s_mode
+) {
+ dut->trap_ctrl_trigger = 1;
+ dut->trap_ctrl_mepc = mepc;
+ dut->trap_ctrl_mcause = mcause;
+ dut->trap_ctrl_mtval = mtval;
+ dut->trap_ctrl_to_s_mode = to_s_mode ? 1 : 0;
+ tick(dut);
+ dut->trap_ctrl_trigger = 0;
+ dut->trap_ctrl_mepc = 0;
+ dut->trap_ctrl_mcause = 0;
+ dut->trap_ctrl_mtval = 0;
+ dut->trap_ctrl_to_s_mode = 0;
+}
+
+void trigger_interrupt(Vcsr_unit* dut, uint64_t mepc, uint64_t int_cause) {
+ trigger_trap(dut, mepc, (INTERRUPT_BIT | int_cause), 0ULL, false);
+}
+
+template <typename Fn>
+void run_csr_scenario(Vcsr_unit* dut, const char* name, Fn&& body) {
+ clear_trap_lines(dut);
+ std::cout << "[RUN] CSR scenario: " << name << std::endl;
+ body(dut);
+ std::cout << "[PASS] CSR scenario: " << name << std::endl;
}
uint64_t read_csr(Vcsr_unit* dut, uint16_t addr) {
@@ -147,9 +189,33 @@ void force_priv_mode_via_mret(Vcsr_unit* dut, uint64_t encoded_mode) {
mstatus &= ~(0x3ULL << MSTATUS_MPP_LO);
mstatus |= (encoded_mode << MSTATUS_MPP_LO);
csr_op(dut, CSR_MSTATUS, CSR_OP_WRITE, mstatus);
- dut->trap_is_mret = 1;
+ dut->trap_ctrl_mret_en = 1;
tick(dut);
- dut->trap_is_mret = 0;
+ dut->trap_ctrl_mret_en = 0;
+}
+
+uint64_t arbitrate_trap_priority(
+ bool ext_external,
+ bool ext_software,
+ bool ext_timer,
+ bool has_sync_exception,
+ uint64_t sync_cause,
+ bool& chose_interrupt
+) {
+ if (ext_external) {
+ chose_interrupt = true;
+ return INTERRUPT_BIT | INT_M_EXTERNAL;
+ }
+ if (ext_software) {
+ chose_interrupt = true;
+ return INTERRUPT_BIT | INT_M_SOFTWARE;
+ }
+ if (ext_timer) {
+ chose_interrupt = true;
+ return INTERRUPT_BIT | INT_M_TIMER;
+ }
+ chose_interrupt = false;
+ return has_sync_exception ? sync_cause : 0ULL;
}
int main(int argc, char** argv) {
@@ -190,9 +256,9 @@ int main(int argc, char** argv) {
std::cout << "[PASS] CSRRS/CSRRC honor masks and ignore zero data" << std::endl;
// Read-only CSRs ignore write attempts
- const uint64_t misa_before = read_csr(dut, CSR_MISA);
+ const uint64_t misa_ro_snapshot = read_csr(dut, CSR_MISA);
csr_op(dut, CSR_MISA, CSR_OP_WRITE, 0ULL);
- assert(read_csr(dut, CSR_MISA) == misa_before);
+ assert(read_csr(dut, CSR_MISA) == misa_ro_snapshot);
std::cout << "[PASS] Read-only CSRs reject writes" << std::endl;
// Canonical aliases for cycle/minstret
@@ -209,11 +275,7 @@ int main(int argc, char** argv) {
uint64_t mstatus_cfg = read_csr(dut, CSR_MSTATUS) | (1ULL << MSTATUS_MIE_BIT);
csr_op(dut, CSR_MSTATUS, CSR_OP_WRITE, mstatus_cfg);
const uint64_t instret_pre_trap = read_csr(dut, CSR_MINSTRET);
- dut->trap_illegal_instr = 1;
- dut->trap_epc = 0xDEADULL;
- tick(dut);
- dut->trap_illegal_instr = 0;
- dut->trap_epc = 0;
+ trigger_trap(dut, 0xDEADULL, EXC_INST_ILLEGAL, 0xDEADULL, false);
assert(read_csr(dut, CSR_MINSTRET) == instret_pre_trap);
advance_cycles(dut, 1);
assert(read_csr(dut, CSR_MINSTRET) == instret_pre_trap + 1);
@@ -230,45 +292,37 @@ int main(int argc, char** argv) {
std::cout << "[PASS] Illegal trap updates mepc/mcause/mtval/mstatus" << std::endl;
// mret restore flow
- dut->trap_is_mret = 1;
+ dut->trap_ctrl_mret_en = 1;
tick(dut);
- dut->trap_is_mret = 0;
- const uint64_t mstatus_after_mret = read_csr(dut, CSR_MSTATUS);
- assert(((mstatus_after_mret >> MSTATUS_MIE_BIT) & 1ULL) == 1ULL);
- assert(((mstatus_after_mret >> MSTATUS_MPIE_BIT) & 1ULL) == 1ULL);
- assert(((mstatus_after_mret >> MSTATUS_MPP_LO) & 0x3ULL) == PRIV_ENCODE_U);
+ dut->trap_ctrl_mret_en = 0;
+ const uint64_t mstatus_after_mret_reset = read_csr(dut, CSR_MSTATUS);
+ assert(((mstatus_after_mret_reset >> MSTATUS_MIE_BIT) & 1ULL) == 1ULL);
+ assert(((mstatus_after_mret_reset >> MSTATUS_MPIE_BIT) & 1ULL) == 1ULL);
+ assert(((mstatus_after_mret_reset >> MSTATUS_MPP_LO) & 0x3ULL) == PRIV_ENCODE_U);
std::cout << "[PASS] mret restores interrupt enable bits" << std::endl;
// sret restore flow
uint64_t sstatus_cfg = (1ULL << SSTATUS_SIE_BIT) | (1ULL << SSTATUS_SPP_BIT);
csr_op(dut, CSR_SSTATUS, CSR_OP_WRITE, sstatus_cfg);
- dut->trap_is_sret = 1;
+ dut->trap_ctrl_sret_en = 1;
tick(dut);
- dut->trap_is_sret = 0;
- const uint64_t sstatus_after_sret = read_csr(dut, CSR_SSTATUS);
- assert(((sstatus_after_sret >> SSTATUS_SIE_BIT) & 1ULL) == 0ULL);
- assert(((sstatus_after_sret >> SSTATUS_SPIE_BIT) & 1ULL) == 1ULL);
- assert(((sstatus_after_sret >> SSTATUS_SPP_BIT) & 1ULL) == 0ULL);
+ dut->trap_ctrl_sret_en = 0;
+ const uint64_t sstatus_after_sret_reset = read_csr(dut, CSR_SSTATUS);
+ assert(((sstatus_after_sret_reset >> SSTATUS_SIE_BIT) & 1ULL) == 0ULL);
+ assert(((sstatus_after_sret_reset >> SSTATUS_SPIE_BIT) & 1ULL) == 1ULL);
+ assert(((sstatus_after_sret_reset >> SSTATUS_SPP_BIT) & 1ULL) == 0ULL);
std::cout << "[PASS] sret updates supervisor status bits" << std::endl;
// Ecall causes depend on current privilege mode
force_priv_mode_via_mret(dut, PRIV_ENCODE_S);
- dut->trap_is_ecall = 1;
- dut->trap_epc = 0x600ULL;
- tick(dut);
- dut->trap_is_ecall = 0;
- dut->trap_epc = 0;
+ trigger_trap(dut, 0x600ULL, EXC_ECALL_FROM_S, 0ULL, false);
assert(read_csr(dut, CSR_MCAUSE) == EXC_ECALL_FROM_S);
assert(read_csr(dut, CSR_MTVAL) == 0ULL);
assert(read_csr(dut, CSR_MEPC) == 0x600ULL);
assert(((read_csr(dut, CSR_MSTATUS) >> MSTATUS_MPP_LO) & 0x3ULL) == PRIV_ENCODE_S);
force_priv_mode_via_mret(dut, PRIV_ENCODE_U);
- dut->trap_is_ecall = 1;
- dut->trap_epc = 0x700ULL;
- tick(dut);
- dut->trap_is_ecall = 0;
- dut->trap_epc = 0;
+ trigger_trap(dut, 0x700ULL, EXC_ECALL_FROM_U, 0ULL, false);
assert(read_csr(dut, CSR_MCAUSE) == EXC_ECALL_FROM_U);
assert(read_csr(dut, CSR_MTVAL) == 0ULL);
assert(read_csr(dut, CSR_MEPC) == 0x700ULL);
@@ -279,18 +333,16 @@ int main(int argc, char** argv) {
csr_op(dut, CSR_MEDELEG, CSR_OP_WRITE, 0ULL);
csr_op(dut, CSR_MEDELEG, CSR_OP_SET, (1ULL << EXC_ECALL_FROM_U));
csr_op(dut, CSR_STVEC, CSR_OP_WRITE, 0x4000ULL);
+ assert(read_csr(dut, CSR_MEDELEG) & (1ULL << EXC_ECALL_FROM_U));
force_priv_mode_via_mret(dut, PRIV_ENCODE_U);
- dut->trap_is_ecall = 1;
- dut->trap_epc = 0x900ULL;
- tick(dut);
- dut->trap_is_ecall = 0;
- dut->trap_epc = 0;
+ assert(dut->csr_priv_mode == PRIV_ENCODE_U);
+ trigger_trap(dut, 0x900ULL, EXC_ECALL_FROM_U, 0ULL, true);
+ assert(dut->csr_trap_to_s_mode);
+ assert(dut->csr_trap_vector == 0x4000ULL);
assert(read_csr(dut, CSR_SEPC) == 0x900ULL);
assert(read_csr(dut, CSR_SCAUSE) == EXC_ECALL_FROM_U);
assert(read_csr(dut, CSR_STVAL) == 0ULL);
assert(dut->csr_priv_mode == PRIV_ENCODE_S);
- assert(dut->csr_trap_to_s_mode);
- assert(dut->csr_trap_vector == 0x4000ULL);
std::cout << "[PASS] medeleg routes ecall to supervisor" << std::endl;
force_priv_mode_via_mret(dut, PRIV_ENCODE_M);
@@ -326,6 +378,208 @@ int main(int argc, char** argv) {
assert((read_csr(dut, CSR_FRM) & 0x7ULL) == ((0xABULL >> 5) & 0x7ULL));
std::cout << "[PASS] FCSR/FM/FFLAGS read/write" << std::endl;
+ std::cout << "[INFO] Extending CSR trap coverage" << std::endl;
+
+ run_csr_scenario(dut, "interrupt_priority_matrix", [&](Vcsr_unit* target) {
+ struct PriorityScenario {
+ const char* name;
+ bool ext_external;
+ bool ext_software;
+ bool ext_timer;
+ bool sync_illegal;
+ uint64_t mepc;
+ uint64_t mtval;
+ uint64_t expected_cause;
+ };
+
+ const std::array<PriorityScenario, 5> suite = {{
+ {"external_over_others", true, true, true, true, 0xA000ULL, 0x1111ULL, INTERRUPT_BIT | INT_M_EXTERNAL},
+ {"software_over_timer", false, true, true, true, 0xA040ULL, 0x2222ULL, INTERRUPT_BIT | INT_M_SOFTWARE},
+ {"timer_over_sync", false, false, true, true, 0xA080ULL, 0x3333ULL, INTERRUPT_BIT | INT_M_TIMER},
+ {"interrupt_only", true, false, false, false, 0xA0C0ULL, 0x0ULL, INTERRUPT_BIT | INT_M_EXTERNAL},
+ {"sync_fallback", false, false, false, true, 0xA100ULL, 0x4444ULL, EXC_INST_ILLEGAL}
+ }};
+
+ for (const auto& scenario : suite) {
+ bool chose_interrupt = false;
+ const uint64_t chosen_cause = arbitrate_trap_priority(
+ scenario.ext_external,
+ scenario.ext_software,
+ scenario.ext_timer,
+ scenario.sync_illegal,
+ EXC_INST_ILLEGAL,
+ chose_interrupt
+ );
+ assert(chosen_cause == scenario.expected_cause);
+ trigger_trap(
+ target,
+ scenario.mepc,
+ chosen_cause,
+ scenario.sync_illegal ? scenario.mtval : 0ULL,
+ false
+ );
+ const uint64_t mcause = read_csr(target, CSR_MCAUSE);
+ assert(mcause == scenario.expected_cause);
+ assert(read_csr(target, CSR_MEPC) == scenario.mepc);
+ const bool mcause_is_interrupt = (mcause & INTERRUPT_BIT) != 0ULL;
+ assert(mcause_is_interrupt == chose_interrupt);
+ if (scenario.sync_illegal && !mcause_is_interrupt) {
+ assert(read_csr(target, CSR_MTVAL) == scenario.mtval);
+ }
+ assert(target->csr_priv_mode == PRIV_ENCODE_M);
+ }
+ });
+
+ run_csr_scenario(dut, "delegated_multitrap_context", [&](Vcsr_unit* target) {
+ csr_op(target, CSR_MEDELEG, CSR_OP_WRITE, 0ULL);
+ csr_op(target, CSR_MEDELEG, CSR_OP_SET, (1ULL << EXC_ECALL_FROM_U));
+ csr_op(target, CSR_STVEC, CSR_OP_WRITE, 0x4000ULL);
+ csr_op(target, CSR_MTVEC, CSR_OP_WRITE, 0x8000ULL);
+
+ force_priv_mode_via_mret(target, PRIV_ENCODE_S);
+ assert(target->csr_priv_mode == PRIV_ENCODE_S);
+
+ const uint64_t delegated_pc = 0x900ULL;
+ trigger_trap(target, delegated_pc, EXC_ECALL_FROM_U, 0ULL, true);
+ assert(target->csr_trap_to_s_mode);
+ assert(target->csr_trap_vector == 0x4000ULL);
+ assert(read_csr(target, CSR_SEPC) == delegated_pc);
+ assert(read_csr(target, CSR_SCAUSE) == EXC_ECALL_FROM_U);
+ assert(target->csr_priv_mode == PRIV_ENCODE_S);
+
+ const uint64_t machine_pc = 0xA00ULL;
+ trigger_trap(target, machine_pc, EXC_INST_ILLEGAL, 0ULL, false);
+ assert(!target->csr_trap_to_s_mode);
+ assert(target->csr_trap_vector == 0x8000ULL);
+ assert(read_csr(target, CSR_MEPC) == machine_pc);
+ assert(read_csr(target, CSR_SEPC) == delegated_pc);
+ assert(target->csr_priv_mode == PRIV_ENCODE_M);
+ });
+
+ run_csr_scenario(dut, "nested_return_sequence", [&](Vcsr_unit* target) {
+ force_priv_mode_via_mret(target, PRIV_ENCODE_U);
+ csr_op(target, CSR_SSTATUS, CSR_OP_WRITE, (1ULL << SSTATUS_SIE_BIT));
+
+ const uint64_t first_trap_pc = 0xB00ULL;
+ trigger_trap(target, first_trap_pc, EXC_ECALL_FROM_U, 0ULL, true);
+ uint64_t sstatus_snapshot = read_csr(target, CSR_SSTATUS);
+ assert(((sstatus_snapshot >> SSTATUS_SIE_BIT) & 1ULL) == 0ULL);
+ assert(((sstatus_snapshot >> SSTATUS_SPIE_BIT) & 1ULL) == 1ULL);
+ assert(((sstatus_snapshot >> SSTATUS_SPP_BIT) & 1ULL) == 0ULL);
+ assert(read_csr(target, CSR_SEPC) == first_trap_pc);
+
+ target->trap_ctrl_sret_en = 1;
+ tick(target);
+ target->trap_ctrl_sret_en = 0;
+ uint64_t sstatus_after_sret = read_csr(target, CSR_SSTATUS);
+ assert(((sstatus_after_sret >> SSTATUS_SIE_BIT) & 1ULL) == 1ULL);
+ assert(((sstatus_after_sret >> SSTATUS_SPIE_BIT) & 1ULL) == 1ULL);
+ assert(target->csr_priv_mode == PRIV_ENCODE_U);
+
+ // Enable machine interrupts so the subsequent machine trap captures pre-trap MIE=1
+ csr_op(target, CSR_MSTATUS, CSR_OP_SET, (1ULL << MSTATUS_MIE_BIT));
+ const uint64_t second_trap_pc = 0xB80ULL;
+ trigger_trap(target, second_trap_pc, EXC_INST_ILLEGAL, 0ULL, false);
+ uint64_t mstatus_snapshot = read_csr(target, CSR_MSTATUS);
+ assert(((mstatus_snapshot >> MSTATUS_MIE_BIT) & 1ULL) == 0ULL);
+ assert(((mstatus_snapshot >> MSTATUS_MPIE_BIT) & 1ULL) == 1ULL);
+ assert(((mstatus_snapshot >> MSTATUS_MPP_LO) & 0x3ULL) == PRIV_ENCODE_U);
+ assert(read_csr(target, CSR_MEPC) == second_trap_pc);
+
+ target->trap_ctrl_mret_en = 1;
+ tick(target);
+ target->trap_ctrl_mret_en = 0;
+ uint64_t mstatus_after_mret = read_csr(target, CSR_MSTATUS);
+ assert(((mstatus_after_mret >> MSTATUS_MIE_BIT) & 1ULL) == 1ULL);
+ assert(((mstatus_after_mret >> MSTATUS_MPIE_BIT) & 1ULL) == 1ULL);
+ assert(((mstatus_after_mret >> MSTATUS_MPP_LO) & 0x3ULL) == PRIV_ENCODE_U);
+ assert(target->csr_priv_mode == PRIV_ENCODE_U);
+ });
+
+ run_csr_scenario(dut, "illegal_csr_access_guard", [&](Vcsr_unit* target) {
+ force_priv_mode_via_mret(target, PRIV_ENCODE_M);
+ assert(target->csr_priv_mode == PRIV_ENCODE_M);
+ const uint64_t misa_snapshot = read_csr(target, CSR_MISA);
+ target->csr_addr = CSR_MISA;
+ target->csr_op = CSR_OP_WRITE;
+ target->csr_rs1_data = 0x1234ULL;
+ target->csr_req = 1;
+ tick(target);
+ target->csr_req = 0;
+ target->csr_op = 0;
+ target->csr_rs1_data = 0;
+ target->csr_addr = 0;
+ assert(target->csr_illegal_access);
+ assert(read_csr(target, CSR_MISA) == misa_snapshot);
+ assert(!target->csr_trap_to_s_mode);
+ assert(target->csr_priv_mode == PRIV_ENCODE_M);
+ assert(target->csr_trap_vector_next == read_csr(target, CSR_MTVEC));
+ tick(target);
+ assert(!target->csr_illegal_access);
+ });
+
+ run_csr_scenario(dut, "delegation_cross_over", [&](Vcsr_unit* target) {
+ csr_op(target, CSR_MTVEC, CSR_OP_WRITE, 0x1000ULL);
+ csr_op(target, CSR_STVEC, CSR_OP_WRITE, 0x2000ULL);
+ csr_op(target, CSR_MEDELEG, CSR_OP_WRITE, 0ULL);
+ csr_op(target, CSR_MIDELEG, CSR_OP_WRITE, 0ULL);
+
+ struct DelegationProbe {
+ const char* name;
+ bool is_interrupt;
+ uint64_t cause;
+ bool delegate_to_s;
+ uint64_t pc;
+ };
+
+ const std::array<DelegationProbe, 4> probes = {{
+ {"medeleg_set", false, EXC_ECALL_FROM_U, true, 0xD000ULL},
+ {"medeleg_clear", false, EXC_ECALL_FROM_U, false, 0xD040ULL},
+ {"mideleg_set", true, INT_M_TIMER, true, 0xD080ULL},
+ {"mideleg_clear", true, INT_M_TIMER, false, 0xD0C0ULL}
+ }};
+
+ for (const auto& probe : probes) {
+ if (probe.is_interrupt) {
+ const uint64_t mask = (1ULL << probe.cause);
+ if (probe.delegate_to_s) {
+ csr_op(target, CSR_MIDELEG, CSR_OP_SET, mask);
+ } else {
+ csr_op(target, CSR_MIDELEG, CSR_OP_CLEAR, mask);
+ }
+ force_priv_mode_via_mret(target, PRIV_ENCODE_S);
+ trigger_trap(target, probe.pc, (INTERRUPT_BIT | probe.cause), 0ULL, probe.delegate_to_s);
+ if (probe.delegate_to_s) {
+ assert(target->csr_trap_to_s_mode);
+ assert(read_csr(target, CSR_SEPC) == probe.pc);
+ } else {
+ assert(!target->csr_trap_to_s_mode);
+ assert(read_csr(target, CSR_MEPC) == probe.pc);
+ }
+ } else {
+ const uint64_t mask = (1ULL << probe.cause);
+ if (probe.delegate_to_s) {
+ csr_op(target, CSR_MEDELEG, CSR_OP_SET, mask);
+ } else {
+ csr_op(target, CSR_MEDELEG, CSR_OP_CLEAR, mask);
+ }
+ force_priv_mode_via_mret(target, PRIV_ENCODE_U);
+ trigger_trap(target, probe.pc, probe.cause, 0ULL, probe.delegate_to_s);
+ if (probe.delegate_to_s) {
+ assert(target->csr_trap_to_s_mode);
+ assert(read_csr(target, CSR_SEPC) == probe.pc);
+ } else {
+ assert(!target->csr_trap_to_s_mode);
+ assert(read_csr(target, CSR_MEPC) == probe.pc);
+ }
+ }
+
+ const uint64_t expected_vector = probe.delegate_to_s ? read_csr(target, CSR_STVEC)
+ : read_csr(target, CSR_MTVEC);
+ assert(target->csr_trap_vector == expected_vector);
+ }
+ });
+
std::cout << "----------------------------------\n";
std::cout << "All CSR unit tests passed!\n";
std::cout << "----------------------------------\n";
diff --git a/rv64cpu/tb/unit/tb_decoder.cc b/rv64cpu/tb/unit/tb_decoder.cc
index aa6788c..25a3d69 100644
--- a/rv64cpu/tb/unit/tb_decoder.cc
+++ b/rv64cpu/tb/unit/tb_decoder.cc
@@ -39,7 +39,8 @@ static int fail_count = 0;
} \
} while(0)
-void decode(Vdecoder* dut, uint32_t instr, const char* name) {
+void decode(Vdecoder* dut, uint32_t instr, const char* name, uint8_t priv_mode = 3) {
+ dut->priv_mode = priv_mode & 0x3;
dut->instr = instr;
dut->eval();
test_count++;
@@ -233,6 +234,10 @@ int main(int argc, char** argv) {
CHECK(dut, reg_write_en, 1, "CSRRW");
CHECK(dut, illegal_instr,0, "CSRRW");
+ decode(dut, 0x300110F3, "CSRRW x1, mstatus, x2 (U-mode)", 0);
+ CHECK(dut, illegal_instr,1, "CSRRW U-mode illegal");
+ CHECK(dut, is_csr, 0, "CSRRW U-mode is_csr cleared");
+
// 20. ECALL
// all-zero fields + opcode=1110011
decode(dut, 0x00000073, "ECALL");
@@ -256,7 +261,7 @@ int main(int argc, char** argv) {
// 23. SRET
// funct7=0001000 rs2=00010 rs1=00000 funct3=000 rd=00000 op=1110011
- decode(dut, 0x10200073, "SRET");
+ decode(dut, 0x10200073, "SRET", 1);
CHECK(dut, is_sret, 1, "SRET");
CHECK(dut, reg_write_en, 0, "SRET");
diff --git a/rv64cpu/tb/unit/tb_hazard_unit.cc b/rv64cpu/tb/unit/tb_hazard_unit.cc
index 69ebab9..d43ccc5 100644
--- a/rv64cpu/tb/unit/tb_hazard_unit.cc
+++ b/rv64cpu/tb/unit/tb_hazard_unit.cc
@@ -42,9 +42,13 @@ void reset(Vhazard_unit* dut) {
dut->ex_reg_write_en = 0;
dut->ex_is_load = 0;
dut->ex_branch_taken = 0;
+ dut->ex_branch_target = 0;
dut->mem_rd_addr = 0;
dut->mem_reg_write_en = 0;
dut->mem_stall_req = 0;
+ dut->trap_flush_req = 0;
+ dut->trap_pc_sel = 0;
+ dut->trap_target_pc = 0;
dut->wb_rd_addr = 0;
dut->wb_reg_write_en = 0;
dut->eval();
@@ -69,6 +73,8 @@ int main(int argc, char** argv) {
check(dut->id_ex_flush_en == 0, "NoHazard_NoIDEXFlush");
check(dut->id_ex_stall_en == 0, "NoHazard_NoIDEXStall");
check(dut->ex_mem_stall_en == 0, "NoHazard_NoEXMEMStall");
+ check(dut->pc_redirect_sel == 0, "NoHazard_NoRedirect");
+ check(dut->pc_redirect_is_trap == 0, "NoHazard_NoTrapRedirect");
// -----------------------
// 2. Forward A from MEM stage
@@ -231,11 +237,15 @@ int main(int argc, char** argv) {
// -----------------------
reset(dut);
dut->ex_branch_taken = 1;
+ dut->ex_branch_target = 0x400;
dut->eval();
check(dut->if_id_flush_en == 1, "Branch_IFID_Flush");
check(dut->id_ex_flush_en == 1, "Branch_IDEX_Flush");
check(dut->if_stall_en == 0, "Branch_IF_NoStall");
check(dut->if_id_stall_en == 0, "Branch_IFID_NoStall");
+ check(dut->pc_redirect_sel == 1, "Branch_Redirect_Valid");
+ check(dut->pc_redirect_is_trap == 0, "Branch_Redirect_NotTrap");
+ check(dut->pc_redirect_target == 0x400, "Branch_Redirect_Target");
// -----------------------
// 15. Branch overrides load-use stall
@@ -282,12 +292,48 @@ int main(int argc, char** argv) {
// -----------------------
reset(dut);
dut->ex_branch_taken = 1;
+ dut->ex_branch_target = 0x410;
dut->mem_stall_req = 1;
dut->eval();
check(dut->if_id_flush_en == 1, "Branch_MemStall_IFID_Flush");
check(dut->id_ex_flush_en == 1, "Branch_MemStall_IDEX_Flush");
check(dut->if_stall_en == 0, "Branch_MemStall_IF_NoStall");
+ // -----------------------
+ // 19. Trap redirect overrides branch and stalls
+ // -----------------------
+ reset(dut);
+ dut->trap_pc_sel = 1;
+ dut->trap_flush_req = 1;
+ dut->trap_target_pc = 0x800;
+ dut->ex_branch_taken = 1;
+ dut->ex_branch_target = 0x900;
+ dut->mem_stall_req = 1;
+ dut->eval();
+ check(dut->pc_redirect_sel == 1, "Trap_Redirect_Valid");
+ check(dut->pc_redirect_is_trap == 1, "Trap_Redirect_IsTrap");
+ check(dut->pc_redirect_target == 0x800, "Trap_Redirect_Target");
+ check(dut->if_id_flush_en == 1, "Trap_Flush_IFID");
+ check(dut->id_ex_flush_en == 1, "Trap_Flush_IDEX");
+ check(dut->if_stall_en == 0, "Trap_Clears_IF_Stall");
+ check(dut->if_id_stall_en == 0, "Trap_Clears_IFID_Stall");
+ check(dut->id_ex_stall_en == 0, "Trap_Clears_IDEX_Stall");
+ check(dut->ex_mem_stall_en == 0, "Trap_Clears_EXMEM_Stall");
+
+ // -----------------------
+ // 20. Trap flush overrides load-use stall even without redirect
+ // -----------------------
+ reset(dut);
+ dut->trap_flush_req = 1;
+ dut->ex_is_load = 1;
+ dut->ex_rd_addr = 4;
+ dut->id_rs1_addr = 4;
+ dut->eval();
+ check(dut->if_id_flush_en == 1, "TrapFlush_IFID");
+ check(dut->id_ex_flush_en == 1, "TrapFlush_IDEX");
+ check(dut->if_stall_en == 0, "TrapFlush_NoIFStall");
+ check(dut->if_id_stall_en == 0, "TrapFlush_NoIFIDStall");
+
std::cout << "----------------------------------" << std::endl;
std::cout << "\033[32mAll " << pass_count << " tests passed!\033[0m" << std::endl;
std::cout << "----------------------------------" << std::endl;
diff --git a/rv64cpu/tb/unit/tb_if_stage.cc b/rv64cpu/tb/unit/tb_if_stage.cc
index ebb888a..f0110c9 100644
--- a/rv64cpu/tb/unit/tb_if_stage.cc
+++ b/rv64cpu/tb/unit/tb_if_stage.cc
@@ -51,8 +51,9 @@ int main(int argc, char** argv) {
// --- 1. Init / Reset ---
dut->stall_en = 0;
- dut->ex_branch_taken = 0;
- dut->ex_branch_target = 0;
+ dut->pc_redirect_sel = 0;
+ dut->pc_redirect_target = 0;
+ dut->pc_redirect_is_trap = 0;
dut->rst = 1;
tick(dut);
@@ -78,13 +79,14 @@ int main(int argc, char** argv) {
check_pc(0x8000000CULL, dut->if_pc, "Release_Stall_Normal_Increment");
// --- 4. Branch Taken ---
- dut->ex_branch_taken = 1;
- dut->ex_branch_target = 0x80000100ULL;
+ dut->pc_redirect_sel = 1;
+ dut->pc_redirect_is_trap = 0;
+ dut->pc_redirect_target = 0x80000100ULL;
tick(dut);
check_pc(0x80000100ULL, dut->if_pc, "Branch_Taken_Updates_PC");
// Return to normal
- dut->ex_branch_taken = 0;
+ dut->pc_redirect_sel = 0;
tick(dut);
check_pc(0x80000104ULL, dut->if_pc, "Post_Branch_Normal_Increment");
@@ -92,8 +94,9 @@ int main(int argc, char** argv) {
// If a branch is taken but the pipeline is stalled, the PC should freeze.
// However, if the stall clears later, the branch target should theoretically be taken.
// In our RV64 simple pipeline design, stall_en freezes the PC reg completely.
- dut->ex_branch_taken = 1;
- dut->ex_branch_target = 0x80000200ULL;
+ dut->pc_redirect_sel = 1;
+ dut->pc_redirect_is_trap = 0;
+ dut->pc_redirect_target = 0x80000200ULL;
dut->stall_en = 1;
tick(dut);
check_pc(0x80000104ULL, dut->if_pc, "Stall_Overrides_Branch_Target_Load");
@@ -102,6 +105,24 @@ int main(int argc, char** argv) {
tick(dut);
check_pc(0x80000200ULL, dut->if_pc, "Branch_Target_Loaded_After_Stall_Clears");
+ // --- 6. Trap redirect overrides stall ---
+ dut->pc_redirect_sel = 0;
+ dut->pc_redirect_is_trap = 0;
+ dut->pc_redirect_target = 0;
+
+ dut->stall_en = 1;
+ dut->pc_redirect_sel = 1;
+ dut->pc_redirect_is_trap = 1;
+ dut->pc_redirect_target = 0x80000300ULL;
+ tick(dut);
+ check_pc(0x80000300ULL, dut->if_pc, "Trap_Overrides_Stall");
+
+ dut->stall_en = 0;
+ dut->pc_redirect_sel = 0;
+ dut->pc_redirect_is_trap = 0;
+ tick(dut);
+ check_pc(0x80000304ULL, dut->if_pc, "Resume_After_Trap");
+
std::cout << "----------------------------------" << std::endl;
std::cout << "\033[32mAll tests passed!\033[0m" << std::endl;
std::cout << "----------------------------------" << std::endl;
diff --git a/rv64cpu/tb/unit/tb_trap_ctrl.cc b/rv64cpu/tb/unit/tb_trap_ctrl.cc
index 142d743..1708598 100644
--- a/rv64cpu/tb/unit/tb_trap_ctrl.cc
+++ b/rv64cpu/tb/unit/tb_trap_ctrl.cc
@@ -28,6 +28,8 @@ namespace {
constexpr uint64_t EXC_INST_ILLEGAL = 2ULL;
constexpr uint64_t EXC_ECALL_FROM_S = 9ULL;
constexpr uint64_t EXC_LOAD_PAGE_FAULT= 13ULL;
+constexpr uint64_t EXC_LOAD_FAULT = 5ULL;
+constexpr uint64_t EXC_STORE_FAULT = 7ULL;
constexpr uint64_t INT_M_SOFTWARE = 3ULL;
constexpr uint64_t INT_M_TIMER = 7ULL;
@@ -125,6 +127,20 @@ int main(int argc, char** argv) {
check(dut->trap_mcause == EXC_LOAD_PAGE_FAULT, "PageFault_Mcause");
check(dut->trap_mtval == 0xBADC0FFEE0ULL, "PageFault_Mtval");
+ drive_defaults(dut);
+ dut->trap_load_fault = 1;
+ dut->trap_bad_addr = 0xABCDEF0010ULL;
+ dut->eval();
+ check(dut->trap_mcause == EXC_LOAD_FAULT, "LoadFault_Mcause");
+ check(dut->trap_mtval == 0xABCDEF0010ULL, "LoadFault_Mtval");
+
+ drive_defaults(dut);
+ dut->trap_store_fault = 1;
+ dut->trap_bad_addr = 0xABCDEF0020ULL;
+ dut->eval();
+ check(dut->trap_mcause == EXC_STORE_FAULT, "StoreFault_Mcause");
+ check(dut->trap_mtval == 0xABCDEF0020ULL, "StoreFault_Mtval");
+
// ---------------------------------------------------------------------
// 2) Interrupt priority + delegation to supervisor
// ---------------------------------------------------------------------
diff --git a/rv64cpu/tb/unit/tb_wb_stage.cc b/rv64cpu/tb/unit/tb_wb_stage.cc
index 0f228ee..3f6bedb 100644
--- a/rv64cpu/tb/unit/tb_wb_stage.cc
+++ b/rv64cpu/tb/unit/tb_wb_stage.cc
@@ -58,12 +58,17 @@ int main(int argc, char** argv) {
dut->mem_wb_rs1_rdata = 0x99;
dut->mem_wb_rs1_addr = 1;
dut->mem_wb_imm = 0x123;
+ dut->mem_wb_instr = 0xDEADBEEFu;
dut->mem_wb_illegal_instr = 0;
dut->mem_wb_is_ecall = 0;
dut->mem_wb_is_ebreak = 0;
dut->mem_wb_is_mret = 0;
dut->mem_wb_is_sret = 0;
+ dut->mem_wb_load_fault = 0;
+ dut->mem_wb_store_fault = 0;
+ dut->mem_wb_fault_addr = 0;
dut->csr_rdata = 0x0;
+ dut->csr_illegal_access = 0;
tick(dut);
@@ -118,9 +123,37 @@ int main(int argc, char** argv) {
check(dut->trap_is_mret == 1, "Trap_MRET");
check(dut->trap_is_sret == 1, "Trap_SRET");
check(dut->trap_epc == 0x80000000, "Trap_EPC");
+ check(dut->trap_bad_instr == 0xDEADBEEFu, "Trap_BadInstr_Payload");
check(dut->wb_reg_write_en == 0, "Trap_Gates_RegWriteEn");
check(dut->csr_req == 0, "Trap_Gates_CSR_Req");
+ // 7. CSR illegal access should raise an illegal-instr trap
+ dut->mem_wb_illegal_instr = 0;
+ dut->mem_wb_is_ecall = 0;
+ dut->mem_wb_is_ebreak = 0;
+ dut->csr_illegal_access = 1;
+ tick(dut);
+ check(dut->trap_illegal_instr == 1, "CSR_Illegal_Raises_Trap");
+ check(dut->wb_reg_write_en == 0, "CSR_Illegal_Kills_Write");
+
+ // 8. Load/store faults propagate to trap outputs and block writeback
+ dut->csr_illegal_access = 0;
+ dut->mem_wb_load_fault = 1;
+ dut->mem_wb_fault_addr = 0x80000010ULL;
+ tick(dut);
+ check(dut->trap_load_fault == 1, "LoadFault_AssertsTrap");
+ check(dut->trap_bad_addr == 0x80000010ULL, "LoadFault_PassesAddress");
+ check(dut->wb_reg_write_en == 0, "LoadFault_KillsWrite");
+
+ dut->mem_wb_load_fault = 0;
+ dut->mem_wb_store_fault = 1;
+ dut->mem_wb_fault_addr = 0x80000020ULL;
+ tick(dut);
+ check(dut->trap_store_fault == 1, "StoreFault_AssertsTrap");
+ check(dut->trap_bad_addr == 0x80000020ULL, "StoreFault_PassesAddress");
+
+ dut->mem_wb_store_fault = 0;
+
std::cout << "----------------------------------" << std::endl;
std::cout << "\033[32mAll " << pass_count << " tests passed!\033[0m" << std::endl;
std::cout << "----------------------------------" << std::endl;