Improved checks for QEMU's ACPI device signature

auxiliary/boot_logo_hasher.cpp

@@ -0,0 +1,77 @@
+/**
+ * ██╗   ██╗███╗   ███╗ █████╗ ██╗    ██╗ █████╗ ██████╗ ███████╗
+ * ██║   ██║████╗ ████║██╔══██╗██║    ██║██╔══██╗██╔══██╗██╔════╝
+ * ██║   ██║██╔████╔██║███████║██║ █╗ ██║███████║██████╔╝█████╗
+ * ╚██╗ ██╔╝██║╚██╔╝██║██╔══██║██║███╗██║██╔══██║██╔══██╗██╔══╝
+ *  ╚████╔╝ ██║ ╚═╝ ██║██║  ██║╚███╔███╔╝██║  ██║██║  ██║███████╗
+ *   ╚═══╝  ╚═╝     ╚═╝╚═╝  ╚═╝ ╚══╝╚══╝ ╚═╝  ╚═╝╚═╝  ╚═╝╚══════╝
+ *
+ *  C++ VM detection library
+ *
+ * ===============================================================
+ *
+ *  This program computes a CRC32 checksum of boot logo images
+ *  via hardware‐accelerated intrinsics in 8-byte chunks.
+ *
+ * ===============================================================
+ *
+ *  - Made by: @Requiem (https://github.com/NotRequiem)
+ *  - Repository: https://github.com/kernelwernel/VMAware
+ *  - License: MIT
+ */
+
+#include <immintrin.h>
+#include <fstream>
+#include <vector>
+#include <iostream>
+#include <cstdint>
+
+static inline uint32_t crc32c_bmp(const char* filename) {
+    std::ifstream in{ filename, std::ios::binary | std::ios::ate };
+    if (!in) return 0;
+    auto size = in.tellg();
+    in.seekg(0, std::ios::beg);
+
+    std::vector<uint8_t> buf(static_cast<size_t>(size));
+    in.read(reinterpret_cast<char*>(buf.data()), size);
+
+    // offset in BMP header (bytes 10–13)
+    uint32_t offset = *reinterpret_cast<uint32_t*>(buf.data() + 10);
+    uint8_t* bmp = buf.data() + offset;
+    size_t  len = buf.size() - offset;
+
+#if defined(_M_X64) || defined(__x86_64__)
+    uint64_t crc64 = 0xFFFFFFFFull;
+    auto     q64 = len / 8;
+    auto const* p64 = reinterpret_cast<uint64_t const*>(bmp);
+    for (size_t i = 0; i < q64; ++i)
+        crc64 = _mm_crc32_u64(crc64, p64[i]);
+
+    uint32_t crc = static_cast<uint32_t>(crc64);
+    auto const* tail = reinterpret_cast<uint8_t const*>(p64 + q64);
+    for (size_t i = 0, r = len & 7; i < r; ++i)
+        crc = _mm_crc32_u8(crc, tail[i]);
+#else
+    uint32_t crc = 0xFFFFFFFFu;
+    auto     q32 = len / 4;
+    auto const* p32 = reinterpret_cast<uint32_t const*>(bmp);
+    for (size_t i = 0; i < q32; ++i)
+        crc = _mm_crc32_u32(crc, p32[i]);
+
+    auto const* tail = reinterpret_cast<uint8_t const*>(p32 + q32);
+    for (size_t i = 0, r = len & 3; i < r; ++i)
+        crc = _mm_crc32_u8(crc, tail[i]);
+#endif
+
+    return crc ^ 0xFFFFFFFFu;
+}
+
+int main(int argc, char** argv) {
+    for (int i = 1; i < argc; ++i) {
+        uint32_t h = crc32c_bmp(argv[i]);
+        std::cout << argv[i]
+            << ": 0x" << std::hex << std::uppercase << h
+            << std::dec << "\n";
+    }
+    return 0;
+}