feat: add boot self-tests for various kernel components

- Implemented a self-test runner in `selftest.cc` to invoke all test suites.
- Added tests for atomic operations in `test_atomic.cc`, covering construction, store/load, exchange, arithmetic, and compare-and-swap.
- Created tests for the Flattened Device Tree (FDT) in `test_fdt.cc`, verifying node access and compatibility queries.
- Developed a comprehensive Physical Memory Manager (PMM) test suite in `test_pmm.cc`, including allocation, deallocation, reference counting, and boundary conditions.
- Implemented Red-Black Tree tests in `test_rbtree.cc`, validating insertion, deletion, and iteration.
- Added Slab Allocator tests in `test_slab.cc`, covering various allocation sizes, edge cases, and operator overloads.
- Created Spinlock tests in `test_spinlock.cc`, ensuring proper locking behavior and interrupt state preservation.
- Developed Virtual Memory Area (VMA) tests in `test_vma.cc`, validating region mapping, unmapping, and fault handling.
- Added tests for Virtual Memory Management (VMM) in `test_vmm.cc`, verifying address translation and page alignment.

1 files changed, 61 insertions, 0 deletions

diff --git a/na/test/test_vmm.cc b/na/test/test_vmm.cc
new file mode 100644
index 0000000..cd76140
--- /dev/null
+++ b/na/test/test_vmm.cc
@@ -0,0 +1,61 @@
+/* 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/addr.h>
+#include <lume/vmm.h>
+#include <arch/config.h>
+
+/* Assuming pmap namespace is accessible or we can test basic structures */
+
+void selftest_vmm() {
+    st_begin("vmm: virtual/physical address translation");
+    {
+        uint64 pa = 0x80000000ULL;
+        uint64 va = pa_to_va(pa);
+        ST_ASSERT_EQ(va, 0xFFFFFFC080000000ULL);
+        ST_ASSERT_EQ(va_to_pa(va), pa);
+        
+        uint64 pfn = pa_to_pfn(pa);
+        ST_ASSERT_EQ(pfn, 0x80000ULL);
+        ST_ASSERT_EQ(pfn_to_pa(pfn), pa);
+        
+        ST_ASSERT(is_kernel_va(va));
+        ST_ASSERT(!is_kernel_va(pa));
+        
+        ST_ASSERT_EQ(ensure_pa(va), pa);
+        ST_ASSERT_EQ(ensure_pa(pa), pa);
+        
+        ST_ASSERT_EQ(ensure_va(va), va);
+        ST_ASSERT_EQ(ensure_va(pa), va);
+    }
+    st_pass();
+
+    st_begin("vmm: page alignment macros");
+    {
+        uint64 addr = 0x80000FFFULL;
+        ST_ASSERT_EQ(page_align_down(addr), 0x80000000ULL);
+        ST_ASSERT_EQ(page_align_up(addr),   0x80001000ULL);
+        ST_ASSERT_EQ(page_align_down(0x80000000ULL), 0x80000000ULL);
+        ST_ASSERT_EQ(page_align_up(0x80000000ULL),   0x80000000ULL);
+    }
+    st_pass();
+
+    st_begin("vmm: mapping kernel MMIO (driver API)");
+    {
+        // Map 4KB of MMIO at 0x10001000 (UART is at 0x10000000)
+        vmm_map_kernel_mmio(0x10001000, 0x1000);
+        
+        // Verify it doesn't crash and address is reachable in higher half
+        uint64 va = pa_to_va(0x10001000);
+        ST_ASSERT(is_kernel_va(va));
+        
+        // We can't safely dereference it here without knowing QEMU layout perfectly,
+        // but vmm_init should have mapped it.
+    }
+    st_pass();
+}