Print OS info to log

Credit to @Maximilian578 for help

Utilities/Log.cpp

@@ -602,6 +602,17 @@ logs::file_listener::file_listener(const std::string& name)
 	file_writer::log(logs::level::always, ver.text.data(), ver.text.size());
 	file_writer::log(logs::level::always, "\n", 1);
 	messages.emplace_back(std::move(ver));
+
+	// Write OS version
+	stored_message os;
+	os.m.ch  = nullptr;
+	os.m.sev = level::notice;
+	os.stamp = 0;
+	os.text = utils::get_OS_version();
+
+	file_writer::log(logs::level::notice, os.text.data(), os.text.size());
+	file_writer::log(logs::level::notice, "\n", 1);
+	messages.emplace_back(std::move(os));
 }
 
 void logs::file_listener::log(u64 stamp, const logs::message& msg, const std::string& prefix, const std::string& _text)

Utilities/sysinfo.cpp

@@ -5,8 +5,11 @@
 
 #ifdef _WIN32
 #include "windows.h"
+#include "sysinfoapi.h"
 #else
 #include <unistd.h>
+#include <sys/utsname.h>
+#include <errno.h>
 #endif
 
 bool utils::has_ssse3()
@@ -153,3 +156,39 @@ std::string utils::get_firmware_version()
 	}
 	return "";
 }
+
+std::string utils::get_OS_version()
+{
+	std::string output = "";
+#ifdef _WIN32
+	// GetVersionEx is deprecated, RtlGetVersion is kernel-mofe only and AnalyticsInfo is UWP only.
+	// So we're forced to read PEB instead to get Windows version info. It's ugly but works.
+
+	const DWORD peb_offset = 0x60;
+	const INT_PTR peb = __readgsqword(peb_offset);
+
+	const DWORD version_major = *reinterpret_cast<const DWORD*>(peb + 0x118);
+	const DWORD version_minor = *reinterpret_cast<const DWORD*>(peb + 0x11c);
+	const WORD build = *reinterpret_cast<const WORD*>(peb + 0x120);
+	// FIXME: What is this thing? Pointer to UTF-16 string? Two bytes of version numbers? Some magic number?
+	const WORD service_pack = *reinterpret_cast<const WORD*>(peb + 0x122);
+	const u64 compatibility_mode = *reinterpret_cast<const u64*>(peb + 0x02C8); // Two DWORDs, major & minor version
+
+	fmt::append(output,
+		"Operating system: Windows, Major: %lu, Minor: %lu, Build: %u, Service Pack: %u, Compatibility mode: %llu",
+		version_major, version_minor, build, service_pack, compatibility_mode);
+#else
+	struct utsname details = {};
+
+	if (!uname(&details))
+	{
+		fmt::append(output, "Operating system: POSIX, Name: %s, Release: %s, Version: %s",
+			details.sysname, details.release, details.version);
+	}
+	else
+	{
+		fmt::append(output, "Operating system: POSIX, Unknown version! (Error: %d)", errno);
+	}
+#endif
+	return output;
+}

Utilities/sysinfo.h

@@ -46,4 +46,6 @@ namespace utils
 	std::string get_system_info();
 
 	std::string get_firmware_version();
+
+	std::string get_OS_version();
 }