EmbeddedPkg: Introduce DT_FIXUP protocol

Proposed by [email protected]:
https://github.com/U-Boot-EFI/EFI_DT_FIXUP_PROTOCOL

Co-authored-by: Heinrich Schuchardt <[email protected]>
Signed-off-by: Dmitrii Merkurev <[email protected]>

Author: dimorinny

EmbeddedPkg/Include/Protocol/DtFixup.h

@@ -0,0 +1,50 @@
+/** @file
+
+  Copyright (c) 2025, Heinrich Schuchardt.
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+/*
+  DT Fix-up Protocol.
+  Lets firmware patch a flattened-device-tree and reserve memory ranges.
+
+  Related docs:
+  https://github.com/U-Boot-EFI/EFI_DT_FIXUP_PROTOCOL
+*/
+
+#ifndef DT_FIXUP_PROTOCOL_H_
+#define DT_FIXUP_PROTOCOL_H_
+
+#include <Uefi/UefiBaseType.h>
+
+//
+// {e617d64c-fe08-46da-f4dc-bbd5870c7300}
+//
+#define DT_FIXUP_PROTOCOL_GUID \
+  { 0xe617d64c, 0xfe08, 0x46da, { 0xf4, 0xdc, 0xbb, 0xd5, 0x87, 0x0c, 0x73, 0x00 } }
+
+#define DT_FIXUP_PROTOCOL_REVISION  0x00010000
+
+typedef struct _DT_FIXUP_PROTOCOL DT_FIXUP_PROTOCOL;
+
+#define DT_FIXUP_APPLY_FIXUPS    0x00000001
+#define DT_FIXUP_RESERVE_MEMORY  0x00000002
+#define DT_FIXUP_ALL             (DT_FIXUP_APPLY_FIXUPS | DT_FIXUP_RESERVE_MEMORY)
+
+typedef
+EFI_STATUS
+(EFIAPI *DT_FIXUP)(
+  IN DT_FIXUP_PROTOCOL *This,
+  IN OUT VOID          *Fdt,
+  IN OUT UINTN         *BufferSize,
+  IN UINT32            Flags
+  );
+
+struct _DT_FIXUP_PROTOCOL {
+  UINT64      Revision;
+  DT_FIXUP    Fixup;
+};
+
+#endif // DT_FIXUP_PROTOCOL_H_