From dfd6c73a212f8cf6b32ce74807de9a08a87f0b79 Mon Sep 17 00:00:00 2001

From: Peter Jones <pjones@redhat.com>

Date: Fri, 31 Jan 2014 10:30:24 -0500

Subject: [PATCH 18/19] [fallback] For HD() device paths, use just the media

 node and later.

UEFI 2.x section 3.1.2 provides for "short-form device path", where the

first element specified is a "hard drive media device path", so that you

can move a disk around on different buses without invalidating your

device path.  Fallback has not been using this option, though in most

cases efibootmgr has.

Note that we still keep the full device path, because LoadImage()

isn't necessarily the layer where HD() works - one some systems BDS is

responsible for resolving the full path and passes that to LoadImage()

instead.  So we have to do LoadImage() with the full path.

---

 fallback.c | 103 ++++++++++++++++++++++++++++++++++++++++++++++---------------

 1 file changed, 78 insertions(+), 25 deletions(-)

diff --git a/fallback.c b/fallback.c

index ba864ee..a12bb74 100644

--- a/fallback.c

+++ b/fallback.c

@@ -15,6 +15,27 @@

 EFI_LOADED_IMAGE *this_image = NULL;

 static EFI_STATUS

+FindSubDevicePath(EFI_DEVICE_PATH *In, UINT8 Type, UINT8 SubType,

+		  EFI_DEVICE_PATH **Out)

+{

+	EFI_DEVICE_PATH *dp = In;

+	if (!In || !Out)

+		return EFI_INVALID_PARAMETER;

+

+	for (dp = In; !IsDevicePathEnd(dp); dp = NextDevicePathNode(dp)) {

+		if (DevicePathType(dp) == Type &&

+				DevicePathSubType(dp) == SubType) {

+			*Out = DuplicateDevicePath(dp);

+			if (!*Out)

+				return EFI_OUT_OF_RESOURCES;

+			return EFI_SUCCESS;

+		}

+	}

+	*Out = NULL;

+	return EFI_NOT_FOUND;

+}

+

+static EFI_STATUS

 get_file_size(EFI_FILE_HANDLE fh, UINTN *retsize)

 {

 	EFI_STATUS rc;

@@ -93,7 +114,9 @@ make_full_path(CHAR16 *dirname, CHAR16 *filename, CHAR16 **out, UINT64 *outlen)

 {

 	UINT64 len;

-	len = StrLen(dirname) + StrLen(filename) + StrLen(L"\\EFI\\\\") + 2;

+	len = StrLen(L"\\EFI\\") + StrLen(dirname)

+	    + StrLen(L"\\") + StrLen(filename)

+	    + 2;

 	CHAR16 *fullpath = AllocateZeroPool(len*sizeof(CHAR16));

 	if (!fullpath) {

@@ -119,7 +142,8 @@ VOID *first_new_option_args = NULL;

 UINTN first_new_option_size = 0;

 EFI_STATUS

-add_boot_option(EFI_DEVICE_PATH *dp, CHAR16 *filename, CHAR16 *label, CHAR16 *arguments)

+add_boot_option(EFI_DEVICE_PATH *hddp, EFI_DEVICE_PATH *fulldp,

+		CHAR16 *filename, CHAR16 *label, CHAR16 *arguments)

 {

 	static int i = 0;

 	CHAR16 varname[] = L"Boot0000";

@@ -136,24 +160,31 @@ add_boot_option(EFI_DEVICE_PATH *dp, CHAR16 *filename, CHAR16 *label, CHAR16 *ar

 		void *var = LibGetVariable(varname, &global);

 		if (!var) {

 			int size = sizeof(UINT32) + sizeof (UINT16) +

-				StrLen(label)*2 + 2 + DevicePathSize(dp) +

-				StrLen(arguments) * 2 + 2;

+				StrLen(label)*2 + 2 + DevicePathSize(hddp) +

+				StrLen(arguments) * 2;

 			CHAR8 *data = AllocateZeroPool(size);

 			CHAR8 *cursor = data;

 			*(UINT32 *)cursor = LOAD_OPTION_ACTIVE;

 			cursor += sizeof (UINT32);

-			*(UINT16 *)cursor = DevicePathSize(dp);

+			*(UINT16 *)cursor = DevicePathSize(hddp);

 			cursor += sizeof (UINT16);

 			StrCpy((CHAR16 *)cursor, label);

 			cursor += StrLen(label)*2 + 2;

-			CopyMem(cursor, dp, DevicePathSize(dp));

-			cursor += DevicePathSize(dp);

+			CopyMem(cursor, hddp, DevicePathSize(hddp));

+			cursor += DevicePathSize(hddp);

 			StrCpy((CHAR16 *)cursor, arguments);

 			Print(L"Creating boot entry \"%s\" with label \"%s\" "

 					L"for file \"%s\"\n",

 				varname, label, filename);

+

+			if (!first_new_option) {

+				first_new_option = DuplicateDevicePath(fulldp);

+				first_new_option_args = arguments;

+				first_new_option_size = StrLen(arguments) * sizeof (CHAR16);

+			}

+

 			rc = uefi_call_wrapper(RT->SetVariable, 5, varname,

 				&global, EFI_VARIABLE_NON_VOLATILE |

 					 EFI_VARIABLE_BOOTSERVICE_ACCESS |

@@ -254,7 +285,10 @@ add_to_boot_list(EFI_FILE_HANDLE fh, CHAR16 *dirname, CHAR16 *filename, CHAR16 *

 	if (EFI_ERROR(rc))

 		return rc;

-	EFI_DEVICE_PATH *dph = NULL, *dpf = NULL, *dp = NULL;

+	EFI_DEVICE_PATH *dph = NULL;

+	EFI_DEVICE_PATH *file = NULL;

+	EFI_DEVICE_PATH *full_device_path = NULL;

+	EFI_DEVICE_PATH *dp = NULL;

 	dph = DevicePathFromHandle(this_image->DeviceHandle);

 	if (!dph) {

@@ -262,19 +296,31 @@ add_to_boot_list(EFI_FILE_HANDLE fh, CHAR16 *dirname, CHAR16 *filename, CHAR16 *

 		goto err;

 	}

-	dpf = FileDevicePath(fh, fullpath);

-	if (!dpf) {

+	file = FileDevicePath(fh, fullpath);

+	if (!file) {

 		rc = EFI_OUT_OF_RESOURCES;

 		goto err;

 	}

-	dp = AppendDevicePath(dph, dpf);

-	if (!dp) {

+	full_device_path = AppendDevicePath(dph, file);

+	if (!full_device_path) {

 		rc = EFI_OUT_OF_RESOURCES;

 		goto err;

 	}

+	rc = FindSubDevicePath(full_device_path,

+				MEDIA_DEVICE_PATH, MEDIA_HARDDRIVE_DP, &dp;;

+	if (EFI_ERROR(rc)) {

+		if (rc == EFI_NOT_FOUND) {

+			dp = full_device_path;

+		} else {

+			rc = EFI_OUT_OF_RESOURCES;

+			goto err;

+		}

+	}

+

 #ifdef DEBUG_FALLBACK

+	{

 	UINTN s = DevicePathSize(dp);

 	int i;

 	UINT8 *dpv = (void *)dp;

@@ -287,20 +333,16 @@ add_to_boot_list(EFI_FILE_HANDLE fh, CHAR16 *dirname, CHAR16 *filename, CHAR16 *

 	CHAR16 *dps = DevicePathToStr(dp);

 	Print(L"device path: \"%s\"\n", dps);

-#endif

-	if (!first_new_option) {

-		CHAR16 *dps = DevicePathToStr(dp);

-		Print(L"device path: \"%s\"\n", dps);

-		first_new_option = DuplicateDevicePath(dp);

-		first_new_option_args = arguments;

-		first_new_option_size = StrLen(arguments) * sizeof (CHAR16);

 	}

+#endif

-	add_boot_option(dp, fullpath, label, arguments);

+	add_boot_option(dp, full_device_path, fullpath, label, arguments);

 err:

-	if (dpf)

-		FreePool(dpf);

+	if (file)

+		FreePool(file);

+	if (full_device_path)

+		FreePool(full_device_path);

 	if (dp)

 		FreePool(dp);

 	if (fullpath)

@@ -629,8 +671,19 @@ try_start_first_option(EFI_HANDLE parent_image_handle)

 			       first_new_option, NULL, 0,

 			       &image_handle);

 	if (EFI_ERROR(rc)) {

-		Print(L"LoadImage failed: %d\n", rc);

-		uefi_call_wrapper(BS->Stall, 1, 2000000);

+		CHAR16 *dps = DevicePathToStr(first_new_option);

+		UINTN s = DevicePathSize(first_new_option);

+		int i;

+		UINT8 *dpv = (void *)first_new_option;

+		Print(L"LoadImage failed: %d\nDevice path: \"%s\"\n", rc, dps);

+		for (i = 0; i < s; i++) {

+			if (i > 0 && i % 16 == 0)

+				Print(L"\n");

+			Print(L"%02x ", dpv[i]);

+		}

+		Print(L"\n");

+

+		uefi_call_wrapper(BS->Stall, 1, 500000000);

 		return rc;

 	}

@@ -644,7 +697,7 @@ try_start_first_option(EFI_HANDLE parent_image_handle)

 	rc = uefi_call_wrapper(BS->StartImage, 3, image_handle, NULL, NULL);

 	if (EFI_ERROR(rc)) {

 		Print(L"StartImage failed: %d\n", rc);

-		uefi_call_wrapper(BS->Stall, 1, 2000000);

+		uefi_call_wrapper(BS->Stall, 1, 500000000);

 	}

 	return rc;

 }

-- 

1.8.5.3