1 files changed, 58 insertions, 0 deletions
diff --git a/test/test_vmm.cc b/test/test_vmm.cc
new file mode 100644
index 0000000..635e3f3
--- /dev/null
+++ b/test/test_vmm.cc
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (C) 2026 Richard Qin */
+
+/*
+ * Boot Self-Test: VMM and Address Translation
+ */
+
+#include <lume/selftest.h>
+#include <lume/klog.h>
+#include <lume/config.h>
+#include <lume/addr.h>
+#include <lume/vmm.h>
+#include <lume/pmm.h>
+#include <arch/config.h>
+
+namespace {
+constexpr uint64 kUartBase = 0x10000000ULL;
+constexpr uint64 kPageOffsetMask = kPageSize - 1;
+}
+
+void selftest_vmm() {
+    st_begin("vmm: virtual/physical address translation");
+    {
+        PhysAddr pa = pmm_get_mem_base();
+        VirtAddr va = pa_to_va(pa);
+        ST_ASSERT_EQ(va.raw, arch::g_direct_map_base + pa.raw);
+        ST_ASSERT_EQ(va_to_pa(va).raw, pa.raw);
+
+        Pfn p = pa_to_pfn(pa);
+        ST_ASSERT_EQ(p.raw, pa.raw / kPageSize);
+        ST_ASSERT_EQ(pfn_to_pa(p).raw, pa.raw);
+    }
+    st_pass();
+
+    st_begin("vmm: page alignment macros");
+    {
+        uint64 base = pmm_get_mem_base().raw;
+        uint64 addr = base + kPageOffsetMask;
+        ST_ASSERT_EQ(page_align_down(addr), base);
+        ST_ASSERT_EQ(page_align_up(addr),   base + kPageSize);
+        ST_ASSERT_EQ(page_align_down(base), base);
+        ST_ASSERT_EQ(page_align_up(base),   base);
+    }
+    st_pass();
+
+    st_begin("vmm: mapping kernel MMIO (driver API)");
+    {
+        /* Use UART MMIO address (0x10000000 on RISC-V virt).
+         * Must NOT use pmm_get_mem_base() — that's PMP-protected firmware. */
+        uint64 mmio_pa = kUartBase;
+        vmm_map_kernel_mmio(mmio_pa, kPageSize);
+        
+        // Verify it doesn't crash and address is reachable in higher half
+        uint64 va = pa_to_va(phys_addr(mmio_pa)).raw;
+        ST_ASSERT(va >= arch::g_direct_map_base);
+    }
+    st_pass();
+}