feat: add self-tests for Trap/IRQ subsystem functionality

1 files changed, 197 insertions, 0 deletions

diff --git a/na/test/test_trap.cc b/na/test/test_trap.cc
new file mode 100644
index 0000000..c91948a
--- /dev/null
+++ b/na/test/test_trap.cc
@@ -0,0 +1,197 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (C) 2026 Richard Qin */
+
+/*
+ * Boot self-tests for the Trap/IRQ subsystem.
+ *
+ * Tests MD→MI translation, IrqManager register/dispatch/unregister,
+ * and stvec installation verification.
+ */
+
+#include <lume/types.h>
+#include <lume/selftest.h>
+#include <lume/trap.h>
+#include <lume/irq.h>
+#include <lume/errno.h>
+#include <lume/console.h>
+#include <arch/trap.h>
+
+TrapCause trap_translate_scause(uint64 scause);
+
+/* ========================================================================
+ * IrqManager test helpers
+ * ======================================================================== */
+
+static volatile uint32 g_test_irq_fired = 0;
+static volatile void*  g_test_irq_arg   = nullptr;
+
+static void test_irq_handler(uint32 irq, void* arg)
+{
+    g_test_irq_fired = irq;
+    g_test_irq_arg   = arg;
+}
+
+/* ========================================================================
+ * Test cases
+ * ======================================================================== */
+
+static bool test_stvec_installed() {
+    uint64 vec = arch::trap::get_vector();
+    return vec != 0;
+}
+
+static bool test_scause_exception_translation() {
+    /* Verify all exception causes map correctly */
+    bool ok = true;
+    ok = ok && (trap_translate_scause(EXC_LOAD_PAGE_FAULT)   == TrapCause::PageFaultLoad);
+    ok = ok && (trap_translate_scause(EXC_STORE_PAGE_FAULT)  == TrapCause::PageFaultStore);
+    ok = ok && (trap_translate_scause(EXC_INST_PAGE_FAULT)   == TrapCause::PageFaultExec);
+    ok = ok && (trap_translate_scause(EXC_ECALL_FROM_U)      == TrapCause::Syscall);
+    ok = ok && (trap_translate_scause(EXC_ILLEGAL_INST)      == TrapCause::IllegalInst);
+    ok = ok && (trap_translate_scause(EXC_BREAKPOINT)        == TrapCause::Breakpoint);
+    ok = ok && (trap_translate_scause(EXC_LOAD_ACCESS_FAULT) == TrapCause::AccessFault);
+    ok = ok && (trap_translate_scause(EXC_INST_MISALIGNED)   == TrapCause::AlignFault);
+    return ok;
+}
+
+static bool test_scause_interrupt_translation() {
+    bool ok = true;
+    ok = ok && (trap_translate_scause(SCAUSE_INTERRUPT | IRQ_S_TIMER)    == TrapCause::IrqTimer);
+    ok = ok && (trap_translate_scause(SCAUSE_INTERRUPT | IRQ_S_SOFTWARE) == TrapCause::IrqSoftware);
+    ok = ok && (trap_translate_scause(SCAUSE_INTERRUPT | IRQ_S_EXTERNAL) == TrapCause::IrqExternal);
+    ok = ok && (trap_translate_scause(SCAUSE_INTERRUPT | 99)             == TrapCause::Unknown);
+    return ok;
+}
+
+static bool test_scause_unknown() {
+    /* ecall from S-mode should map to Unknown (we only handle U-mode ecall) */
+    return trap_translate_scause(EXC_ECALL_FROM_S) == TrapCause::Unknown;
+}
+
+static bool test_irqmanager_register_dispatch() {
+    IrqManager mgr;
+    mgr.init();
+
+    g_test_irq_fired = 0;
+    g_test_irq_arg = nullptr;
+
+    int dummy_arg = 42;
+    int ret = mgr.register_handler(10, test_irq_handler, &dummy_arg);
+    if (ret != 0) return false;
+
+    /* Dispatch IRQ 10 — handler should be called */
+    mgr.dispatch(10);
+
+    if (g_test_irq_fired != 10) return false;
+    if (g_test_irq_arg != &dummy_arg) return false;
+
+    return true;
+}
+
+static bool test_irqmanager_unregister() {
+    IrqManager mgr;
+    mgr.init();
+
+    g_test_irq_fired = 0;
+
+    mgr.register_handler(5, test_irq_handler, nullptr);
+    mgr.unregister_handler(5);
+
+    /* Dispatch after unregister — handler should NOT be called */
+    mgr.dispatch(5);
+
+    return g_test_irq_fired == 0;
+}
+
+static bool test_irqmanager_double_register() {
+    IrqManager mgr;
+    mgr.init();
+
+    int ret1 = mgr.register_handler(7, test_irq_handler, nullptr);
+    int ret2 = mgr.register_handler(7, test_irq_handler, nullptr);
+
+    return ret1 == 0 && ret2 == -EBUSY;
+}
+
+static bool test_irqmanager_invalid_irq() {
+    IrqManager mgr;
+    mgr.init();
+
+    int ret = mgr.register_handler(999, test_irq_handler, nullptr);
+    return ret == -EINVAL;
+}
+
+static bool test_irqmanager_has_handler() {
+    IrqManager mgr;
+    mgr.init();
+
+    if (mgr.has_handler(10)) return false;  /* not yet registered */
+
+    mgr.register_handler(10, test_irq_handler, nullptr);
+    if (!mgr.has_handler(10)) return false;  /* now registered */
+
+    mgr.unregister_handler(10);
+    if (mgr.has_handler(10)) return false;  /* unregistered */
+
+    return true;
+}
+
+static bool test_irqmanager_spurious_dispatch() {
+    IrqManager mgr;
+    mgr.init();
+
+    g_test_irq_fired = 0;
+
+    /* Dispatch an unregistered IRQ — should not crash or fire */
+    mgr.dispatch(0);
+    mgr.dispatch(63);
+
+    return g_test_irq_fired == 0;
+}
+
+/* ========================================================================
+ * Test runner
+ * ======================================================================== */
+
+void selftest_trap()
+{
+    st_begin("trap: stvec is installed");
+    ST_ASSERT(test_stvec_installed());
+    st_pass();
+
+    st_begin("trap: scause exception translation");
+    ST_ASSERT(test_scause_exception_translation());
+    st_pass();
+
+    st_begin("trap: scause interrupt translation");
+    ST_ASSERT(test_scause_interrupt_translation());
+    st_pass();
+
+    st_begin("trap: scause unknown (ecall from S)");
+    ST_ASSERT(test_scause_unknown());
+    st_pass();
+
+    st_begin("trap: IrqManager register/dispatch");
+    ST_ASSERT(test_irqmanager_register_dispatch());
+    st_pass();
+
+    st_begin("trap: IrqManager unregister");
+    ST_ASSERT(test_irqmanager_unregister());
+    st_pass();
+
+    st_begin("trap: IrqManager double register");
+    ST_ASSERT(test_irqmanager_double_register());
+    st_pass();
+
+    st_begin("trap: IrqManager invalid IRQ");
+    ST_ASSERT(test_irqmanager_invalid_irq());
+    st_pass();
+
+    st_begin("trap: IrqManager has_handler");
+    ST_ASSERT(test_irqmanager_has_handler());
+    st_pass();
+
+    st_begin("trap: IrqManager spurious dispatch");
+    ST_ASSERT(test_irqmanager_spurious_dispatch());
+    st_pass();
+}