Compatibility for EFI Device Paths

Some EFI device paths have an ending node with type 0xFF instead of the usual 0x7F. Since 0xFF is not a valid type for UEFI, gfxutil should assume that it is an end type. gfxutil.xscheme has an example device path.
acidanthera · Jun 5, 2021 · 0b636b9 · 0b636b9
1 parent 7bd92cc
commit 0b636b9
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Showing 4 changed files with 32 additions and 1 deletion.
diff --git a/edk2misc.c b/edk2misc.c
@@ -134,6 +134,22 @@ typedef struct {
 } PATCHED_SASEX_DEVICE_PATH;
 
 
+BOOLEAN
+EFIAPI
+OldIsDevicePathEndType (
+  IN CONST VOID  *Node
+);
+
+BOOLEAN
+EFIAPI
+IsDevicePathEndType (
+  IN CONST VOID  *Node
+  )
+{
+  ASSERT (Node != NULL);
+  return (BOOLEAN) ((DevicePathType (Node) & EFI_DP_TYPE_MASK) == END_DEVICE_PATH_TYPE);
+}
+
 VOID
 OldDevPathToTextSasEx (
 	IN OUT POOL_PRINT *Str,
@@ -327,6 +343,10 @@ const DEVICE_NODE_TO_SIZE NodeSize[] = {
 	{BBS_DEVICE_PATH       , BBS_BBS_DP                       , psize(Bbs)                       , 0, 0 },
 	{END_DEVICE_PATH_TYPE  , END_INSTANCE_DEVICE_PATH_SUBTYPE , psize(DevPath)                   , 0, 0 },
 	{END_DEVICE_PATH_TYPE  , END_ENTIRE_DEVICE_PATH_SUBTYPE   , psize(DevPath)                   , 0, 0 },
+	{EFI_DP_TYPE_UNPACKED +
+	 END_DEVICE_PATH_TYPE  , END_INSTANCE_DEVICE_PATH_SUBTYPE , psize(DevPath)                   , 0, 0 },
+	{EFI_DP_TYPE_UNPACKED +
+	 END_DEVICE_PATH_TYPE  , END_ENTIRE_DEVICE_PATH_SUBTYPE   , psize(DevPath)                   , 0, 0 },
 	{0                     , 0                                , psize(DevPath)                   , 1, 1 },
 };
 
@@ -377,6 +397,9 @@ void VerifyDevicePathNodeSizes(VOID * DevicePath) {
 		}
 
 		if (IsDevicePathEnd (Node)) {
+			if (!OldIsDevicePathEndType (Node)) {
+				fprintf(stderr, "End node at offset %ld has type 0xFF which is valid for EFI but not UEFI.\n", (void*)Node-(void*)DevicePath);
+			}
 			break;
 		}
 		Node = NextDevicePathNode (Node);

diff --git a/edk2misc.h b/edk2misc.h
@@ -7,6 +7,10 @@
 
 #include "UefiDevicePathLib.h"
 
+#define EFI_DP_TYPE_MASK                    0x7F
+#define EFI_DP_TYPE_UNPACKED                0x80
+
+
 EFI_STATUS
 EFIAPI
 UefiBootServicesTableLibConstructor (void);

diff --git a/efidevp.c b/efidevp.c
@@ -104,7 +104,7 @@ int OutputDevicePathUtilFromText(void* asciitextpath, unsigned long asciitextpat
 			{
 				int nodelen = node->Length[0] | node->Length[1] << 8;
 				bytepathlen += nodelen;
-				if (node->Type == END_DEVICE_PATH_TYPE && node->SubType == END_ENTIRE_DEVICE_PATH_SUBTYPE) break;
+				if ((node->Type & EFI_DP_TYPE_MASK) == END_DEVICE_PATH_TYPE && node->SubType == END_ENTIRE_DEVICE_PATH_SUBTYPE) break;
 				node = (EFI_DEVICE_PATH_PROTOCOL *)((UINT8*)node + nodelen);
 			}
 			PrintMem (bytepath, bytepathlen);

diff --git a/gfxutil.xcodeproj/xcshareddata/xcschemes/gfxutil.xcscheme b/gfxutil.xcodeproj/xcshareddata/xcschemes/gfxutil.xcscheme
@@ -67,6 +67,10 @@
             argument = "02010c00d041030a0000000001010600001b0101060000000316100001000000000000000000000004012a0002000000062c0100000000004d7d000100000000e7f9c0ca664da545b0bd10a52e34ec5d020204032400f7fc74be7c0bf349914701f4042e68426c5c2fe7555cc34aaabf0209eb2185077fff0400"
             isEnabled = "YES">
          </CommandLineArgument>
+         <CommandLineArgument
+            argument = "04061400CA98B835A9B6CE498C72904735CC49B7FFFF04007074616C380000000000000000000000000000000000000000000000000000000000000000000000"
+            isEnabled = "YES">
+         </CommandLineArgument>
          <CommandLineArgument
             argument = "-vsn -o xml -i bin deviceproperties.bin deviceproperties.plist"
             isEnabled = "NO">