add page cache with read-ahead and dirty writeback, file-backed and anonymous mmap with CoW, VAD-based virtual memory replacing the old user region model, PFN database with eviction and reclaim, file identity for cross-open section sharing, FAT32 path cache and per-file cluster chain cache, serial.sys for COM1 keyboard input, xHCI MSI with INTx and polled fallback, PciEnableMsiAuto, waitable input queue, KeWaitForAnyEvent, per-process thread info syscall, expanded kernel stats (PFN/PTE/VAD/file-cache/disk), pool allocation tags, async I/O user buffer locking, file flush on close, add docs.md.

code/drivers/bus/pci/pci.c

@@ -13,6 +13,7 @@
 #include <kernel/mm_virt.h>
 #include <kernel/ke_debug.h>
 #include <kernel/ke_irp.h>
+#include <kernel/ke_irq.h>
 #include <kernel/hal/hal_apic.h>
 
 int _fltused; // MSVC floating-point helper anchor required by printf.obj
@@ -540,7 +541,7 @@ __declspec(dllexport) KSTATUS PciMapBar(DEVICE_OBJECT* pdo, uint8_t index, uint6
         return st;
 
     for (uint64_t off = 0; off < mapLength; off += PAGE_SIZE) {
-        st = MmMapPage(virtBase + (uintptr_t)off, physBase + off, flags, MmMapFailIfPresent);
+        st = MmPteMapPage(virtBase + (uintptr_t)off, physBase + off, flags, MmPteMapFailIfPresent);
         if (!KSUCCESS(st))
             return st;
     }
@@ -659,6 +660,28 @@ __declspec(dllexport) KSTATUS PciEnableMsi(DEVICE_OBJECT* pdo, uint8_t irqSlot)
     return STATUS_SUCCESS;
 }
 
+// Enables a single MSI vector, allocating the nt-lite IRQ slot internally.
+__declspec(dllexport) KSTATUS PciEnableMsiAuto(DEVICE_OBJECT* pdo, uint8_t* outIrqSlot) {
+    PCI_PDO_EXTENSION* ext;
+    if (!outIrqSlot || !PciIsPdo(pdo, &ext))
+        return STATUS_INVALID_PARAMETER;
+
+    if (!PciFindCapability(ext, PCI_CAP_ID_MSI))
+        return STATUS_NOT_SUPPORTED;
+
+    uint8_t irq = 0xFFu;
+    KSTATUS st = KeIrqAllocateMsiVector(&irq);
+    if (!KSUCCESS(st))
+        return st;
+
+    st = PciEnableMsi(pdo, irq);
+    if (!KSUCCESS(st))
+        return st;
+
+    *outIrqSlot = irq;
+    return STATUS_SUCCESS;
+}
+
 // Implements the driver Entry operation.
 KSTATUS DriverEntry(const HAL_API* hal) {
     if (!hal) return STATUS_INVALID_PARAMETER;