From eb0eec7b39534b0bec5566ef92985f163e1f7025 Mon Sep 17 00:00:00 2001
From: Mounir IDRASSI <mounir.idrassi@idrix.fr>
Date: Mon, 16 Sep 2024 23:11:37 +0200
Subject: [PATCH] Windows: Fix failed EFI detection on some PCs where BootOrder
 variable is not defined.

we now report that EFI is not support only when GetFirmwareEnvironmentVariable fails with error ERROR_INVALID_FUNCTION.

Proposed by @kriegste on https://github.com/veracrypt/VeraCrypt/issues/360
---
 src/Common/BootEncryption.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Common/BootEncryption.cpp b/src/Common/BootEncryption.cpp
index c9b275dc..bf7a0f64 100644
--- a/src/Common/BootEncryption.cpp
+++ b/src/Common/BootEncryption.cpp
@@ -2636,7 +2636,7 @@ namespace VeraCrypt
 	bool EfiBoot::IsEfiBoot() {
 		DWORD BootOrderLen;
 		BootOrderLen = GetFirmwareEnvironmentVariable(L"BootOrder", EfiVarGuid, tempBuf, sizeof(tempBuf));
-		return BootOrderLen != 0;
+		return (BootOrderLen != 0) || (GetLastError() != ERROR_INVALID_FUNCTION);
 	}
 
 	void EfiBoot::DeleteStartExec(uint16 statrtOrderNum, wchar_t* type) {