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/user/tests/surface_invalid_rect/surface_invalid_rect.c

@@ -0,0 +1,105 @@
+// Native surface validation test.
+// Exercises invalid parameters and clipped dirty rectangles without depending on windowing.
+
+#include <stdint.h>
+#include <stddef.h>
+#include <string.h>
+#include <ntlite/syscall.h>
+
+#define SURFACE_W 32u
+#define SURFACE_H 24u
+
+static void print(const char* s) {
+    SYS_WRITE_CONSOLE_REQUEST req = { SysSvFromCstr(s) };
+    SysWriteConsole(&req);
+}
+
+static void print_u64(uint64_t v) {
+    char buf[32];
+    int i = 0;
+    if (v == 0) { print("0"); return; }
+    while (v && i < (int)sizeof(buf)) {
+        buf[i++] = (char)('0' + (v % 10));
+        v /= 10;
+    }
+    while (i--) {
+        char c = buf[i];
+        SYS_WRITE_CONSOLE_REQUEST req = { SysSvFromParts(&c, 1) };
+        SysWriteConsole(&req);
+    }
+}
+
+static void exit_now(int code) {
+    for (;;) SysExitProcess(code);
+}
+
+static void fail(const char* msg) {
+    print("surface_invalid_rect: ");
+    print(msg);
+    print("\n");
+    exit_now(1);
+}
+
+static void fail_status(const char* what, uint32_t status) {
+    print("surface_invalid_rect: ");
+    print(what);
+    print(" failed status=");
+    print_u64(status);
+    print("\n");
+    exit_now(1);
+}
+
+static void expect_status(const char* what, uint32_t got, uint32_t expected) {
+    if (got == expected) return;
+    print("surface_invalid_rect: ");
+    print(what);
+    print(" returned ");
+    print_u64(got);
+    print(" expected ");
+    print_u64(expected);
+    print("\n");
+    exit_now(1);
+}
+
+int main(void) {
+    print("surface_invalid_rect: start\n");
+
+    uint32_t bad = 0;
+    uint32_t s = SysCreateSurface(0, SURFACE_H, SYS_SURFACE_FORMAT_XRGB8888, SYS_SURFACE_FLAG_NONE, &bad);
+    expect_status("zero width", s, SYS_STATUS_INVALID_PARAMETER);
+
+    s = SysCreateSurface(SURFACE_W, SURFACE_H, 0x9999u, SYS_SURFACE_FLAG_NONE, &bad);
+    expect_status("bad format", s, SYS_STATUS_NOT_SUPPORTED);
+
+    uint32_t surface = 0;
+    s = SysCreateSurface(SURFACE_W, SURFACE_H, SYS_SURFACE_FORMAT_XRGB8888,
+                         SYS_SURFACE_FLAG_NONE, &surface);
+    if (s != SYS_STATUS_SUCCESS) fail_status("create surface", s);
+
+    void* base = 0;
+    uint32_t pitch = 0;
+    s = SysMapSurface(surface, &base, &pitch);
+    if (s != SYS_STATUS_SUCCESS) fail_status("map surface", s);
+    if (!base || pitch < SURFACE_W * sizeof(uint32_t)) fail("invalid mapping");
+
+    s = SysPresentSurface(surface, 0, 1);
+    expect_status("null rect array with nonzero count", s, SYS_STATUS_INVALID_PARAMETER);
+
+    DISPLAY_RECT rects[SYS_SURFACE_MAX_RECTS + 1];
+    memset(rects, 0, sizeof(rects));
+    s = SysPresentSurface(surface, rects, SYS_SURFACE_MAX_RECTS + 1);
+    expect_status("too many rects", s, SYS_STATUS_INVALID_PARAMETER);
+
+    DISPLAY_RECT clipped = { -8, -8, 24, 24 };
+    s = SysPresentSurface(surface, &clipped, 1);
+    if (s != SYS_STATUS_SUCCESS) fail_status("present clipped rect", s);
+
+    DISPLAY_RECT empty = { 10000, 10000, 16, 16 };
+    s = SysPresentSurface(surface, &empty, 1);
+    if (s != SYS_STATUS_SUCCESS) fail_status("present empty clipped rect", s);
+
+    SysCloseHandle(surface);
+    print("surface_invalid_rect: PASS\n");
+    exit_now(0);
+    return 0;
+}