From 1eff8b8b5e97a372473043fe3d83cef51d5c2b11 Mon Sep 17 00:00:00 2001
From: Mounir IDRASSI <mounir.idrassi@idrix.fr>
Date: Mon, 23 Apr 2018 00:02:34 +0200
Subject: By default, use Bootmgfw_ms.vc as Windows bootloader since VeraCrypt
 now copies its bootloader to Bootmgfw.efi in order to be compatible with
 machines that always boot on Bootmgfw.efi.

---
 DcsBoot/DcsBoot.c | 75 +++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 51 insertions(+), 24 deletions(-)

diff --git a/DcsBoot/DcsBoot.c b/DcsBoot/DcsBoot.c
index 7eaf41b..664afaa 100644
--- a/DcsBoot/DcsBoot.c
+++ b/DcsBoot/DcsBoot.c
@@ -25,7 +25,8 @@ https://opensource.org/licenses/LGPL-3.0
 
 EFI_GUID          ImagePartGuid;
 EFI_GUID          *gEfiExecPartGuid = &ImagePartGuid;
-CHAR16            *gEfiExecCmdDefault = L"\\EFI\\Microsoft\\Boot\\Bootmgfw.efi";
+CHAR16            *gEfiExecCmdDefault = L"\\EFI\\Microsoft\\Boot\\Bootmgfw_ms.vc";
+CHAR16            *gEfiExecCmdMS = L"\\EFI\\Microsoft\\Boot\\Bootmgfw.efi";
 CHAR16            *gEfiExecCmd = NULL;
 CHAR8             gDoExecCmdMsg[256];
 
@@ -44,7 +45,10 @@ DoExecCmd()
             lockFlags = ConfigReadInt("DcsBmlLockFlags", BML_LOCK_SETVARIABLE | BML_SET_BOOTNEXT | BML_UPDATE_BOOTORDER);
             BmlLock(lockFlags);
 			res = EfiExec(NULL, gEfiExecCmd);
-			AsciiSPrint(gDoExecCmdMsg, sizeof(gDoExecCmdMsg), "\nCan't exec %s start partition %g\n", gEfiExecCmd, gEfiExecPartGuid);
+			if (EFI_ERROR(res))
+				AsciiSPrint(gDoExecCmdMsg, sizeof(gDoExecCmdMsg), "\nCan't exec %s start partition %g\n", gEfiExecCmd, gEfiExecPartGuid);
+			else
+				AsciiSPrint(gDoExecCmdMsg, sizeof(gDoExecCmdMsg), "\nDone exec %s start partition %g\n", gEfiExecCmd, gEfiExecPartGuid);
 		}	else {
 			AsciiSPrint(gDoExecCmdMsg, sizeof(gDoExecCmdMsg), "\nCan't open start partition %g\n", gEfiExecPartGuid);
 		}
@@ -121,6 +125,8 @@ DcsBootMain(
 	UINTN               len;
 	UINT32              attr;
 	BOOLEAN             searchOnESP = FALSE;
+	BOOLEAN             searchMsOnESP = FALSE;
+	EFI_GUID          *pEfiExecPartBackup = NULL;
 //	EFI_INPUT_KEY       key;
 
 	InitBio();
@@ -169,6 +175,8 @@ DcsBootMain(
 	if (EFI_ERROR(res)) {
 		gEfiExecPartGuid = &ImagePartGuid;
 	}
+	
+	pEfiExecPartBackup = gEfiExecPartGuid;
 
 	res = EfiGetVar(L"DcsExecCmd", NULL, &gEfiExecCmd, &len, &attr);
 	if (EFI_ERROR(res)) {
@@ -177,6 +185,9 @@ DcsBootMain(
 
 	searchOnESP = CompareGuid(gEfiExecPartGuid, &ImagePartGuid) &&
 		EFI_ERROR(FileExist(NULL, gEfiExecCmd));
+		
+	searchMsOnESP = CompareGuid(gEfiExecPartGuid, &ImagePartGuid) &&
+		EFI_ERROR(FileExist(NULL, gEfiExecCmdMS));
 
     // Clear DcsExecPartGuid before execute OS to avoid problem in VirtualBox with reboot.
     EfiSetVar(L"DcsExecPartGuid", NULL, NULL, 0, EFI_VARIABLE_BOOTSERVICE_ACCESS);
@@ -187,34 +198,50 @@ DcsBootMain(
 	InitBio();
 	res = InitFS();
 
-	// Default load of bootmgfw?
-	if (searchOnESP) {
-		// gEfiExecCmd is not found on start partition. Try from ESP
-		EFI_BLOCK_IO_PROTOCOL *bio = NULL;
-		EFI_PARTITION_TABLE_HEADER *gptHdr = NULL;
-		EFI_PARTITION_ENTRY        *gptEntry = NULL;
-		HARDDRIVE_DEVICE_PATH hdp;
-		EFI_HANDLE disk;
-		if (!EFI_ERROR(res = EfiGetPartDetails(gFileRootHandle, &hdp, &disk))) {
-			if ((bio = EfiGetBlockIO(disk)) != NULL) {
-				if (!EFI_ERROR(res = GptReadHeader(bio, 1, &gptHdr)) &&
-					!EFI_ERROR(res = GptReadEntryArray(bio, gptHdr, &gptEntry))) {
-					UINT32 i;
-					for (i = 0; i < gptHdr->NumberOfPartitionEntries; ++i) {
-						if (CompareGuid(&gptEntry[i].PartitionTypeGUID, &gEfiPartTypeSystemPartGuid)) {
-							// select ESP GUID
-							CopyGuid(gEfiExecPartGuid, &gptEntry[i].UniquePartitionGUID);
-							res = DoExecCmd();
-							if(EFI_ERROR(res)) continue;
+	while (1)
+	{
+		// Default load of bootmgfw?
+		if (searchOnESP) {
+			// gEfiExecCmd is not found on start partition. Try from ESP
+			EFI_BLOCK_IO_PROTOCOL *bio = NULL;
+			EFI_PARTITION_TABLE_HEADER *gptHdr = NULL;
+			EFI_PARTITION_ENTRY        *gptEntry = NULL;
+			HARDDRIVE_DEVICE_PATH hdp;
+			EFI_HANDLE disk;
+			if (!EFI_ERROR(res = EfiGetPartDetails(gFileRootHandle, &hdp, &disk))) {
+				if ((bio = EfiGetBlockIO(disk)) != NULL) {
+					if (!EFI_ERROR(res = GptReadHeader(bio, 1, &gptHdr)) &&
+						!EFI_ERROR(res = GptReadEntryArray(bio, gptHdr, &gptEntry))) {
+						UINT32 i;
+						for (i = 0; i < gptHdr->NumberOfPartitionEntries; ++i) {
+							if (CompareGuid(&gptEntry[i].PartitionTypeGUID, &gEfiPartTypeSystemPartGuid)) {
+								// select ESP GUID
+								CopyGuid(gEfiExecPartGuid, &gptEntry[i].UniquePartitionGUID);
+								res = DoExecCmd();
+								if(EFI_ERROR(res)) continue;
+							}
 						}
 					}
 				}
 			}
+		}	else {
+			res = DoExecCmd();
 		}
-	}	else {
-		res = DoExecCmd();
+		
+		if(EFI_ERROR(res))
+		{
+			if (0 == StrCmp (gEfiExecCmd, gEfiExecCmdDefault))
+			{
+				gEfiExecCmd = gEfiExecCmdMS;
+				searchOnESP = searchMsOnESP;
+				gEfiExecPartGuid = pEfiExecPartBackup;
+			}
+			else
+				break;
+		}
+		else
+			break;
 	}
-
 	ERR_PRINT(L"%a\nStatus -  %r", gDoExecCmdMsg, res);
 	EfiCpuHalt();
    return EFI_INVALID_PARAMETER;
-- 
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