Create generic wrapper for primitive returns of GetFirmwareEnvironmen…

…tVariable.
Kytech · Jan 15, 2023 · 9318b08 · 9318b08
1 parent cdf46a8
commit 9318b08
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Showing 3 changed files with 26 additions and 4 deletions.
diff --git a/BootMan.csproj b/BootMan.csproj
@@ -11,6 +11,7 @@
     <UseWinUI>true</UseWinUI>
     <EnableMsixTooling>true</EnableMsixTooling>
     <WindowsPackageType>None</WindowsPackageType>
+    <AllowUnsafeBlocks>True</AllowUnsafeBlocks>
   </PropertyGroup>
 
   <ItemGroup>

diff --git a/Firmware.cs b/Firmware.cs
@@ -13,7 +13,7 @@ public enum FirmwareType
             FirmwareTypeMax,
         }
 
-        private static readonly string EFI_GLOBAL_VARIABLE = "{8BE4DF61-93CA-11D2-AA0D-00E098032B8C}";
+        public static readonly string EFI_GLOBAL_VARIABLE = "{8BE4DF61-93CA-11D2-AA0D-00E098032B8C}";
 
         [DllImport("Kernel32.dll")]
         private static extern bool GetFirmwareType(out FirmwareType firmwareType);
@@ -22,21 +22,33 @@ public enum FirmwareType
         private static extern uint GetFirmwareEnvironmentVariable(
             string lpName,
             string lpGuid,
-            Span<ushort> lpBuffer,
+            byte[] lpBuffer,
             uint nSize
         );
 
         [DllImport("Kernel32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
         private static extern bool SetFirmwareEnvironmentVariable(
             string lpName,
             string lpGuid,
-            Span<ushort> lpBuffer,
+            byte[] lpBuffer,
             uint nSize
         );
 
+        public static unsafe T GetFirmwareEnvironmentVariable<T>(string name, string guid) where T : unmanaged
+        {
+            var buffer = new byte[sizeof(T)];
+            uint size = GetFirmwareEnvironmentVariable(name, guid, buffer, (uint)buffer.Length);
+            if (size == 0)
+            {
+                throw new Exception($"GetFirmwareEnvironmentVariable failed with error code {Marshal.GetLastPInvokeError()}");
+            }
+            return MemoryMarshal.Cast<byte, T>(buffer)[0];
+        }
+
         public static FirmwareType GetFirmwareType()
         {
-            bool success = Firmware.GetFirmwareType(out FirmwareType firmwareType);
+            // TODO: Do error handling to indicate win32 error
+            bool success = GetFirmwareType(out FirmwareType firmwareType);
             return success ? firmwareType : FirmwareType.FirmwareTypeUnknown;
         }
     }

diff --git a/app.manifest b/app.manifest
@@ -2,6 +2,15 @@
 <assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
   <assemblyIdentity version="1.0.0.0" name="BootMan.app"/>
 
+  <!-- TODO: Currently prompting for UAC at beginning, but policy can change to permit regular users, so do admin check at rumtime instead -->
+  <trustInfo xmlns="urn:schemas-microsoft-com:asm.v2">
+    <security>
+      <requestedPrivileges xmlns="urn:schemas-microsoft-com:asm.v3">
+        <requestedExecutionLevel level="requireAdministrator" uiAccess="false" />
+      </requestedPrivileges>
+    </security>
+  </trustInfo>
+
   <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
     <application>
       <!-- Windows 10, version 1809 (10.0; Build 17763) - minimum required version -->