Re: [edk2-devel] [PATCH v3 2/3] MdePkg: Support FDT library.

["Chiu, Chasel" <chasel.chiu@intel.com>]

Hello,

Since platform may also define other FDT structures, this EDK2 library may not be able to convert all the FDT structures to little endian.
We might define a generic MACRO in library like CONVERT_FDT_DATA_TO_LITTLE_ENDIAN which can be used for all structure data, but it will be almost like calling SwapBytes** directly.
Any other suggestion?

Thanks,
Chasel


> -----Original Message-----
> From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Michael D
> Kinney
> Sent: Monday, April 24, 2023 10:41 AM
> To: Leif Lindholm <quic_llindhol@quicinc.com>; devel@edk2.groups.io
> Cc: Lin, Benny <benny.lin@intel.com>; Leif Lindholm
> <llindhol@qti.qualcomm.com>; Gao, Liming <gaoliming@byosoft.com.cn>; Liu,
> Zhiguang <zhiguang.liu@intel.com>; Pedro Falcato <pedro.falcato@gmail.com>;
> Kinney, Michael D <michael.d.kinney@intel.com>
> Subject: Re: [edk2-devel] [PATCH v3 2/3] MdePkg: Support FDT library.
> 
> Hi Leif,
> 
> Do you have a proposal or small example on what you want to see
> in the library?
> 
> Mike
> 
> > -----Original Message-----
> > From: Leif Lindholm <quic_llindhol@quicinc.com>
> > Sent: Monday, April 24, 2023 10:29 AM
> > To: devel@edk2.groups.io; Kinney, Michael D <michael.d.kinney@intel.com>
> > Cc: Lin, Benny <benny.lin@intel.com>; Leif Lindholm
> <llindhol@qti.qualcomm.com>; Gao, Liming <gaoliming@byosoft.com.cn>; Liu,
> > Zhiguang <zhiguang.liu@intel.com>; Pedro Falcato
> <pedro.falcato@gmail.com>
> > Subject: Re: [edk2-devel] [PATCH v3 2/3] MdePkg: Support FDT library.
> >
> > Apologies, I was refactoring a git tree and switched off the world :)
> >
> > Well, being a bit late to the party ... my view is it would be
> > preferable if we put the byteswapping in the library.
> >
> > The DT format is *defined* to be big-endian, 32-bit cells. So frankly,
> > I have no problems with pushing responsibility onto individual
> > platforms if they have decided to be "clever" by ignoring that -
> > if that gets rid of a bunch of boilerplate for sensibly behaving platforms.
> >
> > Maybe another excuse for getting
> > https://github.com/tianocore/edk2-
> platforms/blob/master/Silicon/NXP/Library/IoAccessLib/IoAccessLib.c
> > into MdePkg?
> >
> > /
> >     Leif
> >
> > On Thu, Apr 20, 2023 at 16:44:03 +0000, Michael D Kinney wrote:
> > > Hi Leif,
> > >
> > > What is your opinion on FDT being big endian.
> > >
> > > Do we want the lib to help with that aspect, or leave it up to the consumer of
> the lib to
> > > convert as needed?  Seems like an area that could be very error prone if we
> are not
> > > careful.
> > >
> > > Mike
> > >
> > > > -----Original Message-----
> > > > From: Lin, Benny <benny.lin@intel.com>
> > > > Sent: Wednesday, April 19, 2023 9:25 PM
> > > > To: Kinney, Michael D <michael.d.kinney@intel.com>;
> devel@edk2.groups.io
> > > > Cc: Gao, Liming <gaoliming@byosoft.com.cn>; Liu, Zhiguang
> <zhiguang.liu@intel.com>; Pedro Falcato <pedro.falcato@gmail.com>
> > > > Subject: RE: [PATCH v3 2/3] MdePkg: Support FDT library.
> > > >
> > > >
> > > >
> > > > >-----Original Message-----
> > > > >From: Kinney, Michael D <michael.d.kinney@intel.com>
> > > > >Sent: Thursday, April 20, 2023 5:04 AM
> > > > >To: Lin, Benny <benny.lin@intel.com>; devel@edk2.groups.io
> > > > >Cc: Gao, Liming <gaoliming@byosoft.com.cn>; Liu, Zhiguang
> <zhiguang.liu@intel.com>; Pedro Falcato
> > <pedro.falcato@gmail.com>; Kinney,
> > > > Michael D <michael.d.kinney@intel.com>
> > > > >Subject: RE: [PATCH v3 2/3] MdePkg: Support FDT library.
> > > > >
> > > > >Responses below
> > > > >
> > > > >Mike
> > > > >
> > > > >> -----Original Message-----
> > > > >> From: Lin, Benny <benny.lin@intel.com>
> > > > >> Sent: Wednesday, April 19, 2023 10:12 AM
> > > > >> To: Kinney, Michael D <michael.d.kinney@intel.com>;
> > > > >> devel@edk2.groups.io
> > > > >> Cc: Gao, Liming <gaoliming@byosoft.com.cn>; Liu, Zhiguang
> > > > >> <zhiguang.liu@intel.com>; Pedro Falcato <pedro.falcato@gmail.com>
> > > > >> Subject: RE: [PATCH v3 2/3] MdePkg: Support FDT library.
> > > > >>
> > > > >> Please find my feedback below.
> > > > >> We can remove FDT_RESERVE_ENTRY but keep FDT_NODE_HEADER,
> what do you think?
> > > > >>
> > > > >> QQQ
> > > > >> Benny
> > > > >>
> > > > >> >-----Original Message-----
> > > > >> >From: Kinney, Michael D <michael.d.kinney@intel.com>
> > > > >> >Sent: Wednesday, April 19, 2023 11:54 PM
> > > > >> >To: Lin, Benny <benny.lin@intel.com>; devel@edk2.groups.io
> > > > >> >Cc: Gao, Liming <gaoliming@byosoft.com.cn>; Liu, Zhiguang
> > > > >> ><zhiguang.liu@intel.com>; Pedro Falcato <pedro.falcato@gmail.com>;
> > > > >> >Kinney,
> > > > >> Michael D <michael.d.kinney@intel.com>
> > > > >> >Subject: RE: [PATCH v3 2/3] MdePkg: Support FDT library.
> > > > >> >
> > > > >> >A few comments below.
> > > > >> >
> > > > >> >Mike
> > > > >> >
> > > > >> >> -----Original Message-----
> > > > >> >> From: Lin, Benny <benny.lin@intel.com>
> > > > >> >> Sent: Sunday, April 16, 2023 10:35 PM
> > > > >> >> To: devel@edk2.groups.io
> > > > >> >> Cc: Lin, Benny <benny.lin@intel.com>; Kinney, Michael D
> > > > >> >> <michael.d.kinney@intel.com>; Gao, Liming
> > > > >> >> <gaoliming@byosoft.com.cn>; Liu, Zhiguang
> <zhiguang.liu@intel.com>;
> > > > >> >> Pedro Falcato <pedro.falcato@gmail.com>
> > > > >> >> Subject: [PATCH v3 2/3] MdePkg: Support FDT library.
> > > > >> >>
> > > > >> >> From: Benny Lin <benny.lin@intel.com>
> > > > >> >>
> > > > >> >> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4392
> > > > >> >> Add FDT support in EDK2 by submodule 3rd party libfdt
> > > > >> >> (https://github.com/devicetree-org/pylibfdt/tree/main/libfdt)
> > > > >> >> and refer to LibcLib implementation by Pedro.
> > > > >> >>
> > > > >> >> Cc: Michael D Kinney <michael.d.kinney@intel.com>
> > > > >> >> Cc: Liming Gao <gaoliming@byosoft.com.cn>
> > > > >> >> Cc: Zhiguang Liu <zhiguang.liu@intel.com>
> > > > >> >> Acked-by: Pedro Falcato <pedro.falcato@gmail.com>
> > > > >> >> Signed-off-by: Benny Lin <benny.lin@intel.com>
> > > > >> >> ---
> > > > >> >>  MdePkg/Include/Library/FdtLib.h           | 314
> ++++++++++++++++++++
> > > > >> >>  MdePkg/Library/BaseFdtLib/BaseFdtLib.inf  |  62 ++++
> > > > >> >> MdePkg/Library/BaseFdtLib/BaseFdtLib.uni  |  14 +
> > > > >> >>  MdePkg/Library/BaseFdtLib/FdtLib.c        | 301
> +++++++++++++++++++
> > > > >> >>  MdePkg/Library/BaseFdtLib/LibFdtSupport.h |  99 ++++++
> > > > >> >> MdePkg/Library/BaseFdtLib/LibFdtWrapper.c | 173 +++++++++++
> > > > >> >>  MdePkg/Library/BaseFdtLib/limits.h        |  10 +
> > > > >> >>  MdePkg/Library/BaseFdtLib/stdbool.h       |  10 +
> > > > >> >>  MdePkg/Library/BaseFdtLib/stddef.h        |  10 +
> > > > >> >>  MdePkg/Library/BaseFdtLib/stdint.h        |  10 +
> > > > >> >>  MdePkg/Library/BaseFdtLib/stdlib.h        |  10 +
> > > > >> >>  MdePkg/Library/BaseFdtLib/string.h        |  10 +
> > > > >> >>  MdePkg/MdePkg.ci.yaml                     |  17 +-
> > > > >> >>  MdePkg/MdePkg.dec                         |   4 +
> > > > >> >>  MdePkg/MdePkg.dsc                         |   1 +
> > > > >> >>  15 files changed, 1043 insertions(+), 2 deletions(-)
> > > > >> >>
> > > > >> >> diff --git a/MdePkg/Include/Library/FdtLib.h
> > > > >> >> b/MdePkg/Include/Library/FdtLib.h new file mode 100644 index
> > > > >> >> 0000000000..d59b749c25
> > > > >> >> --- /dev/null
> > > > >> >> +++ b/MdePkg/Include/Library/FdtLib.h
> > > > >> >> @@ -0,0 +1,314 @@
> > > > >> >> +/** @file
> > > > >> >>
> > > > >> >> +  Flattened Device Tree Library.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  Copyright (c) 2023, Intel Corporation. All rights reserved.<BR>
> > > > >> >>
> > > > >> >> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#ifndef FDT_LIB_H_
> > > > >> >>
> > > > >> >> +#define FDT_LIB_H_
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +///
> > > > >> >>
> > > > >> >> +/// Flattened Device Tree definition
> > > > >> >>
> > > > >> >> +///
> > > > >> >>
> > > > >> >> +typedef struct {
> > > > >> >>
> > > > >> >> +  UINT32    Magic;               /* magic word FDT_MAGIC */
> > > > >> >>
> > > > >> >> +  UINT32    TotalSize;           /* total size of DT block */
> > > > >> >>
> > > > >> >> +  UINT32    OffsetDtStruct;      /* offset to structure */
> > > > >> >>
> > > > >> >> +  UINT32    OffsetDtStrings;     /* offset to strings */
> > > > >> >>
> > > > >> >> +  UINT32    OffsetMemRsvmap;     /* offset to memory reserve map
> */
> > > > >> >>
> > > > >> >> +  UINT32    Version;             /* format version */
> > > > >> >>
> > > > >> >> +  UINT32    LastCompVersion;     /* last compatible version */
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  /* version 2 fields below */
> > > > >> >>
> > > > >> >> +  UINT32    BootCpuidPhys;       /* Which physical CPU id we're
> > > > >> >>
> > > > >> >> +                                    booting on */
> > > > >> >>
> > > > >> >> +  /* version 3 fields below */
> > > > >> >>
> > > > >> >> +  UINT32    SizeDtStrings;       /* size of the strings block */
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  /* version 17 fields below */
> > > > >> >>
> > > > >> >> +  UINT32    SizeDtStruct;        /* size of the structure block */
> > > > >> >>
> > > > >> >> +} FDT_HEADER;
> > > > >> >
> > > > >> >I see the macros below use SwapBytes32() on all the fields from this
> > > > >> >structure.  Does this mean this structure is big >endian?  If
> > > > >> that is the case, then the description of this structure and all
> > > > >> individual fields must make that very clear >so any consumer of the
> > > > >> structure knows it does not follow the default endianness of UEFI/PI
> and that consumers >must either use the macros or
> > consumers
> > > > must use SwapBytes32() on their own when using this structure directly.
> > > > >>
> > > > >> Yes, it's big endian. I will complete more descriptions in patch v4.
> > > > >
> > > > >Would it be simpler if we have a lib service that converts the entire header
> from big endian to little endian.
> > > > >That way, the consumer can use the FDT_HEADER directly without any of
> the macros?
> > > > >
> > > > >Also, is the rest of the FDT blob also big endian?
> > > >
> > > > FDT blob format is binary encoding of FDT data with big endian. In addition,
> the consumer will set or get FDT data with FDT
> > blob. We
> > > > can complete more descriptions to warn consumers to be careful if just use
> header struct for mapping and get/set FDT data
> > with FDT
> > > > blob.
> > > >
> > > > For provide lib services that converts between big endian and little endian,
> we can provide a get header function to convert
> > between
> > > > big endian and little endian. However, we also need to consider the
> property value for setting and getting then we can
> > convert in
> > > > wrapper functions.
> > > >
> > > > For example,
> > > >
> > > > INT32
> > > > EFIAPI
> > > > FdtSetProp (
> > > >   IN VOID         *Fdt,
> > > >   IN INT32        NodeOffset,
> > > >   IN CONST CHAR8  *Name,
> > > >   IN CONST VOID   *Value,
> > > >   IN UINT32       Length
> > > >   )
> > > > {
> > > >   return fdt_setprop (Fdt, NodeOffset, Name, Value, (int)Length);
> > > > }
> > > >
> > > > More functions for various byte width.
> > > > INT32
> > > > EFIAPI
> > > > FdtSetProp16 (
> > > >   IN VOID         *Fdt,
> > > >   IN INT32        NodeOffset,
> > > >   IN CONST CHAR8  *Name,
> > > >   IN CONST UINT16   *Value,
> > > >   IN UINT32       Length
> > > >   )
> > > > {
> > > >   return fdt_setprop (Fdt, NodeOffset, Name, SwapBytes16(Value),
> (int)Length);
> > > > }
> > > >
> > > > INT32
> > > > EFIAPI
> > > > FdtSetProp32 (
> > > >   IN VOID         *Fdt,
> > > >   IN INT32        NodeOffset,
> > > >   IN CONST CHAR8  *Name,
> > > >   IN CONST UINT32   *Value,
> > > >   IN UINT32       Length
> > > >   )
> > > > {
> > > >   return fdt_setprop (Fdt, NodeOffset, Name, SwapBytes32(Value),
> (int)Length);
> > > > }
> > > >
> > > > >>
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +typedef struct {
> > > > >> >>
> > > > >> >> +  UINT64    Address;
> > > > >> >>
> > > > >> >> +  UINT64    Size;
> > > > >> >>
> > > > >> >> +} FDT_RESERVE_ENTRY;
> > > > >> >
> > > > >> >
> > > > >> >I do not see this type used anywhere in the lib class or the lib instance.
> > > > >> >Can it be removed?
> > > > >>
> > > > >> I think we can remove it because it might be not used for further usage
> of FDT support.
> > > > >>
> > > > >> >
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +typedef struct {
> > > > >> >>
> > > > >> >> +  UINT32    Tag;
> > > > >> >>
> > > > >> >> +  CHAR8     Name[];
> > > > >> >>
> > > > >> >> +} FDT_NODE_HEADER;
> > > > >> >
> > > > >> >
> > > > >> >I do not see this type used anywhere in the lib class or the lib instance.
> > > > >> >Can it be removed?
> > > > >>
> > > > >> When we need retrieve a node from a FDT blob, we will get a node
> > > > >> offset then we could use the struct to map the node content. It's very
> useful.
> > > > >
> > > > >Please add a comment header for this structure and describe the usage as
> it related to the rest of the FdtLib >services.
> > > >
> > > > I will add descriptions for the usage and remove FDT_RESERVE_ENTRY in
> patch v4.
> > > >
> > > > >
> > > > >>
> > > > >> >
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +typedef struct {
> > > > >> >>
> > > > >> >> +  UINT32    Tag;
> > > > >> >>
> > > > >> >> +  UINT32    Length;
> > > > >> >>
> > > > >> >> +  UINT32    NameOffset;
> > > > >> >>
> > > > >> >> +  CHAR8     Data[];
> > > > >> >>
> > > > >> >> +} FDT_PROPERTY;
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#define FDT_GET_HEADER(Fdt, Field)  SwapBytes32(((CONST
> FDT_HEADER
> > > > >> >> +*)(Fdt))->Field)
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#define FDT_MAGIC(Fdt)              (FDT_GET_HEADER(Fdt, Magic))
> > > > >> >>
> > > > >> >> +#define FDT_TOTAL_SIZE(Fdt)         (FDT_GET_HEADER(Fdt,
> TotalSize))
> > > > >> >>
> > > > >> >> +#define FDT_OFFSET_DT_STRUCT(Fdt)   (FDT_GET_HEADER(Fdt,
> OffsetDtStruct))
> > > > >> >>
> > > > >> >> +#define FDT_OFFSET_DT_STRINGS(Fdt)  (FDT_GET_HEADER(Fdt,
> > > > >> >> +OffsetDtStrings))
> > > > >> >>
> > > > >> >> +#define FDT_OFFSET_MEM_RSVMAP(Fdt)  (FDT_GET_HEADER(Fdt,
> > > > >> >> +OffsetMemRsvmap))
> > > > >> >>
> > > > >> >> +#define FDT_VERSION(Fdt)            (FDT_GET_HEADER(Fdt, Version))
> > > > >> >>
> > > > >> >> +#define FDT_LAST_COMP_VERSION(Fdt)  (FDT_GET_HEADER(Fdt,
> > > > >> >> +LastCompVersion))
> > > > >> >>
> > > > >> >> +#define FDT_BOOT_CPUID_PHYS(Fdt)    (FDT_GET_HEADER(Fdt,
> BootCpuidPhys))
> > > > >> >>
> > > > >> >> +#define FDT_SIZE_DT_STRINGS(Fdt)    (FDT_GET_HEADER(Fdt,
> SizeDtStrings))
> > > > >> >>
> > > > >> >> +#define FDT_SIZE_DT_STRUCT(Fdt)     (FDT_GET_HEADER(Fdt,
> SizeDtStruct))
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Verify the header of the Flattened Device Tree
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return Zero for successfully, otherwise failed.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtCheckHeader (
> > > > >> >>
> > > > >> >> +  IN CONST VOID  *Fdt
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Create a empty Flattened Device Tree.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Buffer         The pointer to allocate a pool for FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] BufferSize     The BufferSize to the pool size.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return Zero for successfully, otherwise failed.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +RETURN_STATUS
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtCreateEmptyTree (
> > > > >> >>
> > > > >> >> +  IN VOID   *Buffer,
> > > > >> >>
> > > > >> >> +  IN UINTN  BufferSize
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a offset of next node from the given node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] Offset         The offset to previous node.
> > > > >> >>
> > > > >> >> +  @param[in] Depth          The depth to the level of tree hierarchy.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The offset to next node offset.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtNextNode (
> > > > >> >>
> > > > >> >> +  IN CONST VOID  *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32       Offset,
> > > > >> >>
> > > > >> >> +  IN INT32       *Depth
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a offset of first node under the given node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] Offset         The offset to previous node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The offset to next node offset.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtFirstSubnode (
> > > > >> >>
> > > > >> >> +  IN CONST VOID  *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32       Offset
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a offset of next node from the given node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] Offset         The offset to previous node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The offset to next node offset.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtNextSubnode (
> > > > >> >>
> > > > >> >> +  IN CONST VOID  *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32       Offset
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a offset of first node which includes the given name.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt             The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] ParentOffset    The offset to the node which start find
> under.
> > > > >> >>
> > > > >> >> +  @param[in] Name            The name to search the node with the
> name.
> > > > >> >>
> > > > >> >> +  @param[in] NameLength      The length of the name to check only.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The offset to node offset with given node name.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtSubnodeOffsetNameLen (
> > > > >> >>
> > > > >> >> +  IN CONST VOID   *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32        ParentOffset,
> > > > >> >>
> > > > >> >> +  IN CONST CHAR8  *Name,
> > > > >> >>
> > > > >> >> +  IN INT32        NameLength
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a offset of first node which includes the given property
> name and value.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt             The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] StartOffset     The offset to the starting node to find.
> > > > >> >>
> > > > >> >> +  @param[in] PropertyName    The property name to search the
> node including the named property.
> > > > >> >>
> > > > >> >> +  @param[in] PropertyValue   The property value to check the same
> property value.
> > > > >> >>
> > > > >> >> +  @param[in] PropertyLength  The length of the value in
> PropertValue.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The offset to node offset with given property.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtNodeOffsetByPropValue (
> > > > >> >>
> > > > >> >> +  IN CONST VOID   *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32        StartOffset,
> > > > >> >>
> > > > >> >> +  IN CONST CHAR8  *PropertyName,
> > > > >> >>
> > > > >> >> +  IN CONST VOID   *PropertyValue,
> > > > >> >>
> > > > >> >> +  IN INT32        PropertyLength
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a property with the given name from the given node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] NodeOffset     The offset to the given node.
> > > > >> >>
> > > > >> >> +  @param[in] Name           The name to the property which need be
> searched
> > > > >> >>
> > > > >> >> +  @param[in] Length         The length to the size of the property
> found.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The property to the structure of the found property.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +CONST FDT_PROPERTY *
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtGetProperty (
> > > > >> >>
> > > > >> >> +  IN CONST VOID   *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32        NodeOffset,
> > > > >> >>
> > > > >> >> +  IN CONST CHAR8  *Name,
> > > > >> >>
> > > > >> >> +  IN INT32        *Length
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a offset of first property in the given node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] Offset         The offset to the node which need be
> searched.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The offset to first property offset in the given node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtFirstPropertyOffset (
> > > > >> >>
> > > > >> >> +  IN CONST VOID  *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32       NodeOffset
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a offset of next property from the given property.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] Offset         The offset to previous property.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The offset to next property offset.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtNextPropertyOffset (
> > > > >> >>
> > > > >> >> +  IN CONST VOID  *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32       Offset
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a property from the given offset of the property.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] Offset         The offset to the given offset of the
> property.
> > > > >> >>
> > > > >> >> +  @param[in] Length         The length to the size of the property
> found.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The property to the structure of the given property offset.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +CONST FDT_PROPERTY *
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtGetPropertyByOffset (
> > > > >> >>
> > > > >> >> +  IN CONST VOID  *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32       Offset,
> > > > >> >>
> > > > >> >> +  IN INT32       *Length
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a string by the given string offset.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] StrOffset      The offset to the location in the strings
> block of FDT.
> > > > >> >>
> > > > >> >> +  @param[in] Length         The length to the size of string which need
> be retrieved.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The string to the given string offset.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +CONST CHAR8 *
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtGetString (
> > > > >> >>
> > > > >> >> +  IN CONST VOID  *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32       StrOffset,
> > > > >> >>
> > > > >> >> +  IN INT32       *Length        OPTIONAL
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Add a new node to the FDT.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] ParentOffset   The offset to the node offset which
> want to add in.
> > > > >> >>
> > > > >> >> +  @param[in] Name           The name to name the node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return  The offset to the new node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtAddSubnode (
> > > > >> >>
> > > > >> >> +  IN VOID         *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32        ParentOffset,
> > > > >> >>
> > > > >> >> +  IN CONST CHAR8  *Name
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Add or modify a property in the given node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] NodeOffset     The offset to the node offset which
> want to add in.
> > > > >> >>
> > > > >> >> +  @param[in] Name           The name to name the property.
> > > > >> >>
> > > > >> >> +  @param[in] Value          The value to the property value.
> > > > >> >>
> > > > >> >> +  @param[in] Length         The length to the size of the property.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return  Zero for successfully, otherwise failed.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtSetProp (
> > > > >> >>
> > > > >> >> +  IN VOID         *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32        NodeOffset,
> > > > >> >>
> > > > >> >> +  IN CONST CHAR8  *Name,
> > > > >> >>
> > > > >> >> +  IN CONST VOID   *Value,
> > > > >> >>
> > > > >> >> +  IN UINT32       Length
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#endif /* FDT_LIB_H_ */
> > > > >> >>
> > > > >> >> diff --git a/MdePkg/Library/BaseFdtLib/BaseFdtLib.inf
> > > > >> >> b/MdePkg/Library/BaseFdtLib/BaseFdtLib.inf
> > > > >> >> new file mode 100644
> > > > >> >> index 0000000000..730e568ff6
> > > > >> >> --- /dev/null
> > > > >> >> +++ b/MdePkg/Library/BaseFdtLib/BaseFdtLib.inf
> > > > >> >> @@ -0,0 +1,62 @@
> > > > >> >> +## @file
> > > > >> >>
> > > > >> >> +# Flattened Device Tree Library.
> > > > >> >>
> > > > >> >> +#
> > > > >> >>
> > > > >> >> +# Copyright (c) 2023, Intel Corporation. All rights reserved.<BR>
> > > > >> >>
> > > > >> >> +#
> > > > >> >>
> > > > >> >> +#  SPDX-License-Identifier: BSD-2-Clause-Patent
> > > > >> >>
> > > > >> >> +#
> > > > >> >>
> > > > >> >> +#
> > > > >> >>
> > > > >> >> +##
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +[Defines]
> > > > >> >>
> > > > >> >> +  INF_VERSION                    = 0x0001001B
> > > > >> >>
> > > > >> >> +  BASE_NAME                      = BaseFdtLib
> > > > >> >>
> > > > >> >> +  MODULE_UNI_FILE                = BaseFdtLib.uni
> > > > >> >>
> > > > >> >> +  FILE_GUID                      = C64DCB01-B037-4FF6-9CF3-
> E8CEC206DE04
> > > > >> >>
> > > > >> >> +  MODULE_TYPE                    = BASE
> > > > >> >>
> > > > >> >> +  VERSION_STRING                 = 1.0
> > > > >> >>
> > > > >> >> +  LIBRARY_CLASS                  = FdtLib
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  DEFINE FDT_LIB_PATH            = libfdt/libfdt
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#
> > > > >> >>
> > > > >> >> +#  VALID_ARCHITECTURES           = IA32 X64
> > > > >> >>
> > > > >> >> +#
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +[Sources]
> > > > >> >>
> > > > >> >> +  FdtLib.c
> > > > >> >>
> > > > >> >> +  LibFdtWrapper.c
> > > > >> >>
> > > > >> >> +  # header Wrapper files
> > > > >> >>
> > > > >> >> +  limits.h
> > > > >> >>
> > > > >> >> +  stdbool.h
> > > > >> >>
> > > > >> >> +  stddef.h
> > > > >> >>
> > > > >> >> +  stdint.h
> > > > >> >>
> > > > >> >> +  stdlib.h
> > > > >> >>
> > > > >> >> +  string.h
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  $(FDT_LIB_PATH)/fdt.c
> > > > >> >>
> > > > >> >> +  $(FDT_LIB_PATH)/fdt.h
> > > > >> >>
> > > > >> >> +  $(FDT_LIB_PATH)/fdt_addresses.c
> > > > >> >>
> > > > >> >> +  $(FDT_LIB_PATH)/fdt_check.c
> > > > >> >>
> > > > >> >> +  $(FDT_LIB_PATH)/fdt_empty_tree.c
> > > > >> >>
> > > > >> >> +  $(FDT_LIB_PATH)/fdt_overlay.c
> > > > >> >>
> > > > >> >> +  $(FDT_LIB_PATH)/fdt_ro.c
> > > > >> >>
> > > > >> >> +  $(FDT_LIB_PATH)/fdt_rw.c
> > > > >> >>
> > > > >> >> +  $(FDT_LIB_PATH)/fdt_strerror.c
> > > > >> >>
> > > > >> >> +  $(FDT_LIB_PATH)/fdt_sw.c
> > > > >> >>
> > > > >> >> +  $(FDT_LIB_PATH)/fdt_wip.c
> > > > >> >>
> > > > >> >> +  $(FDT_LIB_PATH)/libfdt.h
> > > > >> >>
> > > > >> >> +  $(FDT_LIB_PATH)/libfdt_env.h
> > > > >> >>
> > > > >> >> +  $(FDT_LIB_PATH)/libfdt_internal.h
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +[Packages]
> > > > >> >>
> > > > >> >> +  MdePkg/MdePkg.dec
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +[LibraryClasses]
> > > > >> >>
> > > > >> >> +  BaseLib
> > > > >> >>
> > > > >> >> +  BaseMemoryLib
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +[BuildOptions]
> > > > >> >>
> > > > >> >> +  MSFT:*_*_IA32_CC_FLAGS = /wd4146 /wd4245
> > > > >> >>
> > > > >> >> +  MSFT:*_*_X64_CC_FLAGS  = /wd4146 /wd4244 /wd4245 /wd4267
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> diff --git a/MdePkg/Library/BaseFdtLib/BaseFdtLib.uni
> > > > >> >> b/MdePkg/Library/BaseFdtLib/BaseFdtLib.uni
> > > > >> >> new file mode 100644
> > > > >> >> index 0000000000..3f7e45ea6f
> > > > >> >> --- /dev/null
> > > > >> >> +++ b/MdePkg/Library/BaseFdtLib/BaseFdtLib.uni
> > > > >> >> @@ -0,0 +1,14 @@
> > > > >> >> +// /** @file
> > > > >> >>
> > > > >> >> +// Flattened Device Tree Library.
> > > > >> >>
> > > > >> >> +//
> > > > >> >>
> > > > >> >> +// Copyright (c) 2023, Intel Corporation. All rights reserved.<BR>
> > > > >> >>
> > > > >> >> +//
> > > > >> >>
> > > > >> >> +// SPDX-License-Identifier: BSD-2-Clause-Patent
> > > > >> >>
> > > > >> >> +//
> > > > >> >>
> > > > >> >> +// **/
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#string STR_MODULE_ABSTRACT             #language en-US "Instance
> of FDT Library"
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#string STR_MODULE_DESCRIPTION          #language en-US "This
> module provides FDT Library implementation."
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> diff --git a/MdePkg/Library/BaseFdtLib/FdtLib.c
> > > > >> >> b/MdePkg/Library/BaseFdtLib/FdtLib.c
> > > > >> >> new file mode 100644
> > > > >> >> index 0000000000..200a496c7e
> > > > >> >> --- /dev/null
> > > > >> >> +++ b/MdePkg/Library/BaseFdtLib/FdtLib.c
> > > > >> >> @@ -0,0 +1,301 @@
> > > > >> >> +/** @file
> > > > >> >>
> > > > >> >> +  Flattened Device Tree Library.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  Copyright (c) 2023, Intel Corporation. All rights reserved.<BR>
> > > > >> >>
> > > > >> >> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#include <libfdt/libfdt/libfdt.h>
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Verify the header of the Flattened Device Tree
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return Zero for successfully, otherwise failed.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtCheckHeader (
> > > > >> >>
> > > > >> >> +  IN CONST VOID  *Fdt
> > > > >> >>
> > > > >> >> +  )
> > > > >> >>
> > > > >> >> +{
> > > > >> >>
> > > > >> >> +  return fdt_check_header(Fdt);
> > > > >> >>
> > > > >> >> +}
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Create a empty Flattened Device Tree.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Buffer         The pointer to allocate a pool for FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] BufferSize     The BufferSize to the pool size.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return Zero for successfully, otherwise failed.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtCreateEmptyTree (
> > > > >> >>
> > > > >> >> +  IN VOID    *Buffer,
> > > > >> >>
> > > > >> >> +  IN UINT32  BufferSize
> > > > >> >>
> > > > >> >> +  )
> > > > >> >>
> > > > >> >> +{
> > > > >> >>
> > > > >> >> +  return fdt_create_empty_tree (Buffer, (int)BufferSize);
> > > > >> >>
> > > > >> >> +}
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a offset of next node from the given node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] Offset         The offset to previous node.
> > > > >> >>
> > > > >> >> +  @param[in] Depth          The depth to the level of tree hierarchy.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The offset to next node offset.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtNextNode (
> > > > >> >>
> > > > >> >> +  IN CONST VOID  *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32       Offset,
> > > > >> >>
> > > > >> >> +  IN INT32       *Depth
> > > > >> >>
> > > > >> >> +  )
> > > > >> >>
> > > > >> >> +{
> > > > >> >>
> > > > >> >> +  return fdt_next_node (Fdt, Offset, Depth);
> > > > >> >>
> > > > >> >> +}
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a offset of first node under the given node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] Offset         The offset to previous node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The offset to next node offset.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtFirstSubnode (
> > > > >> >>
> > > > >> >> +  IN CONST VOID  *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32       Offset
> > > > >> >>
> > > > >> >> +  )
> > > > >> >>
> > > > >> >> +{
> > > > >> >>
> > > > >> >> +  return fdt_first_subnode (Fdt, Offset);
> > > > >> >>
> > > > >> >> +}
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a offset of next node from the given node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] Offset         The offset to previous node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The offset to next node offset.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtNextSubnode (
> > > > >> >>
> > > > >> >> +  IN CONST VOID  *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32       Offset
> > > > >> >>
> > > > >> >> +  )
> > > > >> >>
> > > > >> >> +{
> > > > >> >>
> > > > >> >> +  return fdt_next_subnode (Fdt, Offset);
> > > > >> >>
> > > > >> >> +}
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a offset of first node which includes the given name.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt             The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] ParentOffset    The offset to the node which start find
> under.
> > > > >> >>
> > > > >> >> +  @param[in] Name            The name to search the node with the
> name.
> > > > >> >>
> > > > >> >> +  @param[in] NameLength      The length of the name to check only.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The offset to node offset with given node name.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtSubnodeOffsetNameLen (
> > > > >> >>
> > > > >> >> +  IN CONST VOID   *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32        ParentOffset,
> > > > >> >>
> > > > >> >> +  IN CONST CHAR8  *Name,
> > > > >> >>
> > > > >> >> +  IN INT32        NameLength
> > > > >> >>
> > > > >> >> +  )
> > > > >> >>
> > > > >> >> +{
> > > > >> >>
> > > > >> >> +  return fdt_subnode_offset_namelen (Fdt, ParentOffset, Name,
> > > > >> >> + NameLength);
> > > > >> >>
> > > > >> >> +}
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a offset of first node which includes the given property
> name and value.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt             The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] StartOffset     The offset to the starting node to find.
> > > > >> >>
> > > > >> >> +  @param[in] PropertyName    The property name to search the
> node including the named property.
> > > > >> >>
> > > > >> >> +  @param[in] PropertyValue   The property value to check the same
> property value.
> > > > >> >>
> > > > >> >> +  @param[in] PropertyLength  The length of the value in
> PropertValue.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The offset to node offset with given property.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtNodeOffsetByPropValue (
> > > > >> >>
> > > > >> >> +  IN CONST VOID   *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32        StartOffset,
> > > > >> >>
> > > > >> >> +  IN CONST CHAR8  *PropertyName,
> > > > >> >>
> > > > >> >> +  IN CONST VOID   *PropertyValue,
> > > > >> >>
> > > > >> >> +  IN INT32        PropertyLength
> > > > >> >>
> > > > >> >> +  )
> > > > >> >>
> > > > >> >> +{
> > > > >> >>
> > > > >> >> +  return fdt_node_offset_by_prop_value (Fdt, StartOffset,
> > > > >> >> + PropertyName, PropertyValue, PropertyLength);
> > > > >> >>
> > > > >> >> +}
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a property with the given name from the given node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] NodeOffset     The offset to the given node.
> > > > >> >>
> > > > >> >> +  @param[in] Name           The name to the property which need be
> searched
> > > > >> >>
> > > > >> >> +  @param[in] Length         The length to the size of the property
> found.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The property to the structure of the found property.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +CONST struct fdt_property *
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtGetProperty (
> > > > >> >>
> > > > >> >> +  IN CONST VOID   *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32        NodeOffset,
> > > > >> >>
> > > > >> >> +  IN CONST CHAR8  *Name,
> > > > >> >>
> > > > >> >> +  IN INT32        *Length
> > > > >> >>
> > > > >> >> +  )
> > > > >> >>
> > > > >> >> +{
> > > > >> >>
> > > > >> >> +  return fdt_get_property (Fdt, NodeOffset, Name, Length);
> > > > >> >>
> > > > >> >> +}
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a offset of first property in the given node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] NodeOffset     The offset to the node which need be
> searched.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The offset to first property offset in the given node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtFirstPropertyOffset (
> > > > >> >>
> > > > >> >> +  IN CONST VOID  *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32       NodeOffset
> > > > >> >>
> > > > >> >> +  )
> > > > >> >>
> > > > >> >> +{
> > > > >> >>
> > > > >> >> +  return fdt_first_property_offset (Fdt, NodeOffset);
> > > > >> >>
> > > > >> >> +}
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a offset of next property from the given property.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] Offset         The offset to previous property.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The offset to next property offset.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtNextPropertyOffset (
> > > > >> >>
> > > > >> >> +  IN CONST VOID  *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32       Offset
> > > > >> >>
> > > > >> >> +  )
> > > > >> >>
> > > > >> >> +{
> > > > >> >>
> > > > >> >> +  return fdt_next_property_offset (Fdt, Offset);
> > > > >> >>
> > > > >> >> +}
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a property from the given offset of the property.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] Offset         The offset to the given offset of the
> property.
> > > > >> >>
> > > > >> >> +  @param[in] Length         The length to the size of the property
> found.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The property to the structure of the given property offset.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +CONST struct fdt_property *
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtGetPropertyByOffset (
> > > > >> >>
> > > > >> >> +  IN CONST VOID  *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32       Offset,
> > > > >> >>
> > > > >> >> +  IN INT32       *Length
> > > > >> >>
> > > > >> >> +  )
> > > > >> >>
> > > > >> >> +{
> > > > >> >>
> > > > >> >> +  return fdt_get_property_by_offset (Fdt, Offset, Length);
> > > > >> >>
> > > > >> >> +}
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Returns a string by the given string offset.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] StrOffset      The offset to the location in the strings
> block of FDT.
> > > > >> >>
> > > > >> >> +  @param[in] Length         The length to the size of string which need
> be retrieved.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return The string to the given string offset.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +CONST CHAR8 *
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtGetString (
> > > > >> >>
> > > > >> >> +  IN CONST VOID  *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32       StrOffset,
> > > > >> >>
> > > > >> >> +  IN INT32       *Length        OPTIONAL
> > > > >> >>
> > > > >> >> +  )
> > > > >> >>
> > > > >> >> +{
> > > > >> >>
> > > > >> >> +  return fdt_get_string (Fdt, StrOffset, Length);
> > > > >> >>
> > > > >> >> +}
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Add a new node to the FDT.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] ParentOffset   The offset to the node offset which
> want to add in.
> > > > >> >>
> > > > >> >> +  @param[in] Name           The name to name the node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return  The offset to the new node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtAddSubnode (
> > > > >> >>
> > > > >> >> +  IN VOID         *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32        ParentOffset,
> > > > >> >>
> > > > >> >> +  IN CONST CHAR8  *Name
> > > > >> >>
> > > > >> >> +  )
> > > > >> >>
> > > > >> >> +{
> > > > >> >>
> > > > >> >> +  return fdt_add_subnode (Fdt, ParentOffset, Name);
> > > > >> >>
> > > > >> >> +}
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +/**
> > > > >> >>
> > > > >> >> +  Add or modify a property in the given node.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @param[in] Fdt            The pointer to FDT blob.
> > > > >> >>
> > > > >> >> +  @param[in] NodeOffset     The offset to the node offset which
> want to add in.
> > > > >> >>
> > > > >> >> +  @param[in] Name           The name to name the property.
> > > > >> >>
> > > > >> >> +  @param[in] Value          The value to the property value.
> > > > >> >>
> > > > >> >> +  @param[in] Length         The length to the size of the property.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  @return  Zero for successfully, otherwise failed.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +INT32
> > > > >> >>
> > > > >> >> +EFIAPI
> > > > >> >>
> > > > >> >> +FdtSetProp (
> > > > >> >>
> > > > >> >> +  IN VOID         *Fdt,
> > > > >> >>
> > > > >> >> +  IN INT32        NodeOffset,
> > > > >> >>
> > > > >> >> +  IN CONST CHAR8  *Name,
> > > > >> >>
> > > > >> >> +  IN CONST VOID   *Value,
> > > > >> >>
> > > > >> >> +  IN UINT32       Length
> > > > >> >>
> > > > >> >> +  )
> > > > >> >>
> > > > >> >> +{
> > > > >> >>
> > > > >> >> +  return fdt_setprop (Fdt, NodeOffset, Name, Value, (int)Length);
> > > > >> >>
> > > > >> >> +}
> > > > >> >>
> > > > >> >> diff --git a/MdePkg/Library/BaseFdtLib/LibFdtSupport.h
> > > > >> >> b/MdePkg/Library/BaseFdtLib/LibFdtSupport.h
> > > > >> >> new file mode 100644
> > > > >> >> index 0000000000..e738f4ded4
> > > > >> >> --- /dev/null
> > > > >> >> +++ b/MdePkg/Library/BaseFdtLib/LibFdtSupport.h
> > > > >> >> @@ -0,0 +1,99 @@
> > > > >> >> +/** @file
> > > > >> >>
> > > > >> >> +  Root include file of C runtime library to support building the
> > > > >> >> + third-party
> > > > >> >>
> > > > >> >> +  libfdt library.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  Copyright (c) 2023, Intel Corporation. All rights reserved.<BR>
> > > > >> >>
> > > > >> >> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#ifndef FDT_LIB_SUPPORT_H_
> > > > >> >>
> > > > >> >> +#define FDT_LIB_SUPPORT_H_
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#include <Base.h>
> > > > >> >>
> > > > >> >> +#include <Library/BaseLib.h>
> > > > >> >>
> > > > >> >> +#include <Library/BaseMemoryLib.h>
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +typedef UINT8    uint8_t;
> > > > >> >>
> > > > >> >> +typedef UINT16   uint16_t;
> > > > >> >>
> > > > >> >> +typedef INT32    int32_t;
> > > > >> >>
> > > > >> >> +typedef UINT32   uint32_t;
> > > > >> >>
> > > > >> >> +typedef UINT64   uint64_t;
> > > > >> >>
> > > > >> >> +typedef UINTN    uintptr_t;
> > > > >> >>
> > > > >> >> +typedef UINTN    size_t;
> > > > >> >>
> > > > >> >> +typedef BOOLEAN  bool;
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#define true   (1 == 1)
> > > > >> >>
> > > > >> >> +#define false  (1 == 0)
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +//
> > > > >> >>
> > > > >> >> +// Definitions for global constants used by libfdt library
> > > > >> >> +routines
> > > > >> >>
> > > > >> >> +//
> > > > >> >>
> > > > >> >> +#define INT_MAX          0x7FFFFFFF      /* Maximum (signed) int value
> */
> > > > >> >>
> > > > >> >> +#define INT32_MAX        0x7FFFFFFF      /* Maximum (signed) int32
> value */
> > > > >> >>
> > > > >> >> +#define UINT32_MAX       0xFFFFFFFF      /* Maximum unsigned int32
> value */
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +//
> > > > >> >>
> > > > >> >> +// Function prototypes of libfdt Library routines
> > > > >> >>
> > > > >> >> +//
> > > > >> >>
> > > > >> >> +void *
> > > > >> >>
> > > > >> >> +memset     (
> > > > >> >>
> > > > >> >> +  void *,
> > > > >> >>
> > > > >> >> +  int,
> > > > >> >>
> > > > >> >> +  size_t
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +int
> > > > >> >>
> > > > >> >> +memcmp      (
> > > > >> >>
> > > > >> >> +  const void *,
> > > > >> >>
> > > > >> >> +  const void *,
> > > > >> >>
> > > > >> >> +  size_t
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +int
> > > > >> >>
> > > > >> >> +strcmp      (
> > > > >> >>
> > > > >> >> +  const char *,
> > > > >> >>
> > > > >> >> +  const char *
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +char *
> > > > >> >>
> > > > >> >> +strchr     (
> > > > >> >>
> > > > >> >> +  const char *,
> > > > >> >>
> > > > >> >> +  int
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +char *
> > > > >> >>
> > > > >> >> +strrchr    (
> > > > >> >>
> > > > >> >> +  const char *,
> > > > >> >>
> > > > >> >> +  int
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +unsigned long
> > > > >> >>
> > > > >> >> +strtoul     (
> > > > >> >>
> > > > >> >> +  const char *,
> > > > >> >>
> > > > >> >> +  char **,
> > > > >> >>
> > > > >> >> +  int
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +char *
> > > > >> >>
> > > > >> >> +strcpy (
> > > > >> >>
> > > > >> >> +  char        *strDest,
> > > > >> >>
> > > > >> >> +  const char  *strSource
> > > > >> >>
> > > > >> >> +  );
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +//
> > > > >> >>
> > > > >> >> +// Macros that directly map functions to BaseLib, BaseMemoryLib,
> > > > >> >> +and DebugLib functions
> > > > >> >>
> > > > >> >> +//
> > > > >> >>
> > > > >> >> +#define memcpy(dest, source, count)         CopyMem(dest,source,
> (UINTN)(count))
> > > > >> >>
> > > > >> >> +#define memset(dest, ch, count)             SetMem(dest,
> (UINTN)(count),(UINT8)(ch))
> > > > >> >>
> > > > >> >> +#define memchr(buf, ch, count)              ScanMem8(buf,
> (UINTN)(count),(UINT8)ch)
> > > > >> >>
> > > > >> >> +#define memcmp(buf1, buf2, count)           (int)(CompareMem(buf1,
> buf2, (UINTN)(count)))
> > > > >> >>
> > > > >> >> +#define memmove(dest, source, count)        CopyMem(dest, source,
> (UINTN)(count))
> > > > >> >>
> > > > >> >> +#define strlen(str)                         (size_t)(AsciiStrLen(str))
> > > > >> >>
> > > > >> >> +#define strnlen(str, count)                 (size_t)(AsciiStrnLenS(str, count))
> > > > >> >>
> > > > >> >> +#define strncpy(strDest, strSource, count)  AsciiStrnCpyS(strDest,
> > > > >> >> +MAX_STRING_SIZE, strSource, (UINTN)count)
> > > > >> >>
> > > > >> >> +#define strcat(strDest, strSource)          AsciiStrCatS(strDest,
> MAX_STRING_SIZE, strSource)
> > > > >> >>
> > > > >> >> +#define strcmp(string1, string2, count)     (int)(AsciiStrCmp(string1,
> string2))
> > > > >> >>
> > > > >> >> +#define strncmp(string1, string2, count)    (int)(AsciiStrnCmp(string1,
> string2, (UINTN)(count)))
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#endif /* FDT_LIB_SUPPORT_H_ */
> > > > >> >>
> > > > >> >> diff --git a/MdePkg/Library/BaseFdtLib/LibFdtWrapper.c
> > > > >> >> b/MdePkg/Library/BaseFdtLib/LibFdtWrapper.c
> > > > >> >> new file mode 100644
> > > > >> >> index 0000000000..772bba4839
> > > > >> >> --- /dev/null
> > > > >> >> +++ b/MdePkg/Library/BaseFdtLib/LibFdtWrapper.c
> > > > >> >> @@ -0,0 +1,173 @@
> > > > >> >> +/** @file
> > > > >> >>
> > > > >> >> +  ISO C implementations of strchr, strrchr and strtoul.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  Copyright (c) 2023, Intel Corporation. All rights reserved.<BR>
> > > > >> >>
> > > > >> >> +  Copyright (c) 2023 Pedro Falcato All rights reserved.
> > > > >> >>
> > > > >> >> +  SPDX-License-Identifier: BSD-2-Clause-Patent
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#include <Base.h>
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#define ULONG_MAX        0xFFFFFFFF      /* Maximum unsigned long
> value */
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +// Very quick notes:
> > > > >> >>
> > > > >> >> +// We only go through the string once for both functions
> > > > >> >>
> > > > >> >> +// They are minimal implementations (not speed optimized) of ISO C
> > > > >> >> +semantics
> > > > >> >>
> > > > >> >> +// strchr and strrchr also include the null terminator as part of
> > > > >> >> +the string
> > > > >> >>
> > > > >> >> +// so the code gets a bit clunky to handle that case specifically.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +char *
> > > > >> >>
> > > > >> >> +strchr (
> > > > >> >>
> > > > >> >> +  const char  *Str,
> > > > >> >>
> > > > >> >> +  int         Char
> > > > >> >>
> > > > >> >> +  )
> > > > >> >>
> > > > >> >> +{
> > > > >> >>
> > > > >> >> +  char  *S;
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  S = (char *)Str;
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  for ( ; ; S++) {
> > > > >> >>
> > > > >> >> +    if (*S == Char) {
> > > > >> >>
> > > > >> >> +      return S;
> > > > >> >>
> > > > >> >> +    }
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +    if (*S == '\0') {
> > > > >> >>
> > > > >> >> +      return NULL;
> > > > >> >>
> > > > >> >> +    }
> > > > >> >>
> > > > >> >> +  }
> > > > >> >>
> > > > >> >> +}
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +char *
> > > > >> >>
> > > > >> >> +strrchr (
> > > > >> >>
> > > > >> >> +  const char  *Str,
> > > > >> >>
> > > > >> >> +  int         Char
> > > > >> >>
> > > > >> >> +  )
> > > > >> >>
> > > > >> >> +{
> > > > >> >>
> > > > >> >> +  char  *S, *last;
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  S    = (char *)Str;
> > > > >> >>
> > > > >> >> +  last = NULL;
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  for ( ; ; S++) {
> > > > >> >>
> > > > >> >> +    if (*S == Char) {
> > > > >> >>
> > > > >> >> +      last = S;
> > > > >> >>
> > > > >> >> +    }
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +    if (*S == '\0') {
> > > > >> >>
> > > > >> >> +      return last;
> > > > >> >>
> > > > >> >> +    }
> > > > >> >>
> > > > >> >> +  }
> > > > >> >>
> > > > >> >> +}
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +STATIC
> > > > >> >>
> > > > >> >> +int
> > > > >> >>
> > > > >> >> +__isspace (
> > > > >> >>
> > > > >> >> +  int  ch
> > > > >> >>
> > > > >> >> +  )
> > > > >> >>
> > > > >> >> +{
> > > > >> >>
> > > > >> >> +  // basic ASCII ctype.h:isspace(). Not efficient
> > > > >> >>
> > > > >> >> +  return ch == '\r' || ch == '\n' || ch == ' ' || ch == '\t' || ch
> > > > >> >> + == '\v' || ch == '\f';
> > > > >> >>
> > > > >> >> +}
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +unsigned long
> > > > >> >>
> > > > >> >> +strtoul (
> > > > >> >>
> > > > >> >> +  const char  *Nptr,
> > > > >> >>
> > > > >> >> +  char        **EndPtr,
> > > > >> >>
> > > > >> >> +  int         Base
> > > > >> >>
> > > > >> >> +  )
> > > > >> >>
> > > > >> >> +{
> > > > >> >>
> > > > >> >> +  BOOLEAN        Negate;
> > > > >> >>
> > > > >> >> +  BOOLEAN        Overflow;
> > > > >> >>
> > > > >> >> +  unsigned long  Val;
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  Negate   = FALSE;
> > > > >> >>
> > > > >> >> +  Overflow = FALSE;
> > > > >> >>
> > > > >> >> +  Val      = 0;
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  // Reject bad numeric bases
> > > > >> >>
> > > > >> >> +  if ((Base < 0) || (Base == 1) || (Base > 36)) {
> > > > >> >>
> > > > >> >> +    return 0;
> > > > >> >>
> > > > >> >> +  }
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  // Skip whitespace
> > > > >> >>
> > > > >> >> +  while (__isspace (*Nptr)) {
> > > > >> >>
> > > > >> >> +    Nptr++;
> > > > >> >>
> > > > >> >> +  }
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  // Check for + or - prefixes
> > > > >> >>
> > > > >> >> +  if (*Nptr == '-') {
> > > > >> >>
> > > > >> >> +    Negate = TRUE;
> > > > >> >>
> > > > >> >> +    Nptr++;
> > > > >> >>
> > > > >> >> +  } else if (*Nptr == '+') {
> > > > >> >>
> > > > >> >> +    Nptr++;
> > > > >> >>
> > > > >> >> +  }
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  // Consume the start, autodetecting base if needed
> > > > >> >>
> > > > >> >> +  if ((Nptr[0] == '0') && ((Nptr[1] == 'x') || (Nptr[1] == 'X'))
> > > > >> >> + && ((Base == 0) || (Base == 16))) {
> > > > >> >>
> > > > >> >> +    // Hex
> > > > >> >>
> > > > >> >> +    Nptr += 2;
> > > > >> >>
> > > > >> >> +    Base  = 16;
> > > > >> >>
> > > > >> >> +  } else if ((Nptr[0] == '0') && ((Nptr[1] == 'b') || (Nptr[1] ==
> > > > >> >> + 'B')) && ((Base == 0) || (Base == 2))) {
> > > > >> >>
> > > > >> >> +    // Binary (standard pending C23)
> > > > >> >>
> > > > >> >> +    Nptr += 2;
> > > > >> >>
> > > > >> >> +    Base  = 2;
> > > > >> >>
> > > > >> >> +  } else if ((Nptr[0] == '0') && ((Base == 0) || (Base == 8))) {
> > > > >> >>
> > > > >> >> +    // Octal
> > > > >> >>
> > > > >> >> +    Nptr++;
> > > > >> >>
> > > > >> >> +    Base = 8;
> > > > >> >>
> > > > >> >> +  } else {
> > > > >> >>
> > > > >> >> +    if (Base == 0) {
> > > > >> >>
> > > > >> >> +      // Assume decimal
> > > > >> >>
> > > > >> >> +      Base = 10;
> > > > >> >>
> > > > >> >> +    }
> > > > >> >>
> > > > >> >> +  }
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  while (TRUE) {
> > > > >> >>
> > > > >> >> +    int            Digit;
> > > > >> >>
> > > > >> >> +    char           C;
> > > > >> >>
> > > > >> >> +    unsigned long  NewVal;
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +    C     = *Nptr;
> > > > >> >>
> > > > >> >> +    Digit = -1;
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +    if ((C >= '0') && (C <= '9')) {
> > > > >> >>
> > > > >> >> +      Digit = C - '0';
> > > > >> >>
> > > > >> >> +    } else if ((C >= 'a') && (C <= 'z')) {
> > > > >> >>
> > > > >> >> +      Digit = C - 'a' + 10;
> > > > >> >>
> > > > >> >> +    } else if ((C >= 'A') && (C <= 'Z')) {
> > > > >> >>
> > > > >> >> +      Digit = C - 'A' + 10;
> > > > >> >>
> > > > >> >> +    }
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +    if ((Digit == -1) || (Digit >= Base)) {
> > > > >> >>
> > > > >> >> +      // Note that this case also handles the \0
> > > > >> >>
> > > > >> >> +      if (EndPtr) {
> > > > >> >>
> > > > >> >> +        *EndPtr = (char *)Nptr;
> > > > >> >>
> > > > >> >> +      }
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +      break;
> > > > >> >>
> > > > >> >> +    }
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +    NewVal = Val * Base + Digit;
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +    if (NewVal < Val) {
> > > > >> >>
> > > > >> >> +      // Overflow
> > > > >> >>
> > > > >> >> +      Overflow = TRUE;
> > > > >> >>
> > > > >> >> +    }
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +    Val = NewVal;
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +    Nptr++;
> > > > >> >>
> > > > >> >> +  }
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  if (Negate) {
> > > > >> >>
> > > > >> >> +    Val = -Val;
> > > > >> >>
> > > > >> >> +  }
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  if (Overflow) {
> > > > >> >>
> > > > >> >> +    Val = ULONG_MAX;
> > > > >> >>
> > > > >> >> +  }
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +  // TODO: We're lacking errno here.
> > > > >> >>
> > > > >> >> +  return Val;
> > > > >> >>
> > > > >> >> +}
> > > > >> >>
> > > > >> >> diff --git a/MdePkg/Library/BaseFdtLib/limits.h
> > > > >> >> b/MdePkg/Library/BaseFdtLib/limits.h
> > > > >> >> new file mode 100644
> > > > >> >> index 0000000000..f6cf8d5702
> > > > >> >> --- /dev/null
> > > > >> >> +++ b/MdePkg/Library/BaseFdtLib/limits.h
> > > > >> >> @@ -0,0 +1,10 @@
> > > > >> >> +/** @file
> > > > >> >>
> > > > >> >> +  Include file to support building the third-party libfdt library.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +Copyright (c) 2023, Intel Corporation. All rights reserved.<BR>
> > > > >> >>
> > > > >> >> +SPDX-License-Identifier: BSD-2-Clause-Patent
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#include <LibFdtSupport.h>
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> diff --git a/MdePkg/Library/BaseFdtLib/stdbool.h
> > > > >> >> b/MdePkg/Library/BaseFdtLib/stdbool.h
> > > > >> >> new file mode 100644
> > > > >> >> index 0000000000..f6cf8d5702
> > > > >> >> --- /dev/null
> > > > >> >> +++ b/MdePkg/Library/BaseFdtLib/stdbool.h
> > > > >> >> @@ -0,0 +1,10 @@
> > > > >> >> +/** @file
> > > > >> >>
> > > > >> >> +  Include file to support building the third-party libfdt library.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +Copyright (c) 2023, Intel Corporation. All rights reserved.<BR>
> > > > >> >>
> > > > >> >> +SPDX-License-Identifier: BSD-2-Clause-Patent
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#include <LibFdtSupport.h>
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> diff --git a/MdePkg/Library/BaseFdtLib/stddef.h
> > > > >> >> b/MdePkg/Library/BaseFdtLib/stddef.h
> > > > >> >> new file mode 100644
> > > > >> >> index 0000000000..f6cf8d5702
> > > > >> >> --- /dev/null
> > > > >> >> +++ b/MdePkg/Library/BaseFdtLib/stddef.h
> > > > >> >> @@ -0,0 +1,10 @@
> > > > >> >> +/** @file
> > > > >> >>
> > > > >> >> +  Include file to support building the third-party libfdt library.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +Copyright (c) 2023, Intel Corporation. All rights reserved.<BR>
> > > > >> >>
> > > > >> >> +SPDX-License-Identifier: BSD-2-Clause-Patent
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#include <LibFdtSupport.h>
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> diff --git a/MdePkg/Library/BaseFdtLib/stdint.h
> > > > >> >> b/MdePkg/Library/BaseFdtLib/stdint.h
> > > > >> >> new file mode 100644
> > > > >> >> index 0000000000..f6cf8d5702
> > > > >> >> --- /dev/null
> > > > >> >> +++ b/MdePkg/Library/BaseFdtLib/stdint.h
> > > > >> >> @@ -0,0 +1,10 @@
> > > > >> >> +/** @file
> > > > >> >>
> > > > >> >> +  Include file to support building the third-party libfdt library.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +Copyright (c) 2023, Intel Corporation. All rights reserved.<BR>
> > > > >> >>
> > > > >> >> +SPDX-License-Identifier: BSD-2-Clause-Patent
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#include <LibFdtSupport.h>
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> diff --git a/MdePkg/Library/BaseFdtLib/stdlib.h
> > > > >> >> b/MdePkg/Library/BaseFdtLib/stdlib.h
> > > > >> >> new file mode 100644
> > > > >> >> index 0000000000..f6cf8d5702
> > > > >> >> --- /dev/null
> > > > >> >> +++ b/MdePkg/Library/BaseFdtLib/stdlib.h
> > > > >> >> @@ -0,0 +1,10 @@
> > > > >> >> +/** @file
> > > > >> >>
> > > > >> >> +  Include file to support building the third-party libfdt library.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +Copyright (c) 2023, Intel Corporation. All rights reserved.<BR>
> > > > >> >>
> > > > >> >> +SPDX-License-Identifier: BSD-2-Clause-Patent
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#include <LibFdtSupport.h>
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> diff --git a/MdePkg/Library/BaseFdtLib/string.h
> > > > >> >> b/MdePkg/Library/BaseFdtLib/string.h
> > > > >> >> new file mode 100644
> > > > >> >> index 0000000000..f6cf8d5702
> > > > >> >> --- /dev/null
> > > > >> >> +++ b/MdePkg/Library/BaseFdtLib/string.h
> > > > >> >> @@ -0,0 +1,10 @@
> > > > >> >> +/** @file
> > > > >> >>
> > > > >> >> +  Include file to support building the third-party libfdt library.
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +Copyright (c) 2023, Intel Corporation. All rights reserved.<BR>
> > > > >> >>
> > > > >> >> +SPDX-License-Identifier: BSD-2-Clause-Patent
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +**/
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> +#include <LibFdtSupport.h>
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >> diff --git a/MdePkg/MdePkg.ci.yaml b/MdePkg/MdePkg.ci.yaml
> index
> > > > >> >> 6ba85ebe61..f039daccdb 100644
> > > > >> >> --- a/MdePkg/MdePkg.ci.yaml
> > > > >> >> +++ b/MdePkg/MdePkg.ci.yaml
> > > > >> >> @@ -2,7 +2,7 @@
> > > > >> >>  # CI configuration for MdePkg
> > > > >> >>
> > > > >> >>  #
> > > > >> >>
> > > > >> >>  # Copyright (c) Microsoft Corporation
> > > > >> >>
> > > > >> >> -# Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
> > > > >> >>
> > > > >> >> +# Copyright (c) 2023, Intel Corporation. All rights reserved.<BR>
> > > > >> >>
> > > > >> >>  # Copyright (c) 2021, Arm Limited. All rights reserved.<BR>
> > > > >> >>
> > > > >> >>  # Copyright (c) 2023, Loongson Technology Corporation Limited. All
> > > > >> >> rights reserved.<BR>
> > > > >> >>
> > > > >> >>  # SPDX-License-Identifier: BSD-2-Clause-Patent
> > > > >> >>
> > > > >> >> @@ -67,7 +67,8 @@
> > > > >> >>              "Include/Library/PcdLib.h",
> > > > >> >>
> > > > >> >>              "Include/Library/SafeIntLib.h",
> > > > >> >>
> > > > >> >>              "Include/Protocol/DebugSupport.h",
> > > > >> >>
> > > > >> >> -            "Test/UnitTest/Library/BaseSafeIntLib/TestBaseSafeIntLib.c"
> > > > >> >>
> > > > >> >> +
> > > > >> >> + "Test/UnitTest/Library/BaseSafeIntLib/TestBaseSafeIntLib.c",
> > > > >> >>
> > > > >> >> +            "Library/BaseFdtLib"
> > > > >> >>
> > > > >> >>          ]
> > > > >> >>
> > > > >> >>      },
> > > > >> >>
> > > > >> >>      ## options defined ci/Plugin/CompilerPlugin
> > > > >> >>
> > > > >> >> @@ -164,5 +165,17 @@
> > > > >> >>          "ExtendWords": [],           # words to extend to the dictionary for
> this package
> > > > >> >>
> > > > >> >>          "IgnoreStandardPaths": [],   # Standard Plugin defined paths that
> should be ignore
> > > > >> >>
> > > > >> >>          "AdditionalIncludePaths": [] # Additional paths to spell
> > > > >> >> check (wildcards supported)
> > > > >> >>
> > > > >> >> +    },
> > > > >> >>
> > > > >> >> +    # options defined in .pytool/Plugin/UncrustifyCheck
> > > > >> >>
> > > > >> >> +    "UncrustifyCheck": {
> > > > >> >>
> > > > >> >> +        "IgnoreFiles": [
> > > > >> >>
> > > > >> >> +            "Library/BaseFdtLib/libfdt",
> > > > >> >>
> > > > >> >> +            "Library/BaseFdtLib/limits.h",
> > > > >> >>
> > > > >> >> +            "Library/BaseFdtLib/stdbool.h",
> > > > >> >>
> > > > >> >> +            "Library/BaseFdtLib/stddef.h",
> > > > >> >>
> > > > >> >> +            "Library/BaseFdtLib/stdint.h",
> > > > >> >>
> > > > >> >> +            "Library/BaseFdtLib/stdlib.h",
> > > > >> >>
> > > > >> >> +            "Library/BaseFdtLib/string.h"
> > > > >> >>
> > > > >> >> +        ]
> > > > >> >>
> > > > >> >>      }
> > > > >> >>
> > > > >> >>  }
> > > > >> >>
> > > > >> >> diff --git a/MdePkg/MdePkg.dec b/MdePkg/MdePkg.dec index
> > > > >> >> e70182bf7f..9804a7a6bd 100644
> > > > >> >> --- a/MdePkg/MdePkg.dec
> > > > >> >> +++ b/MdePkg/MdePkg.dec
> > > > >> >> @@ -289,6 +289,10 @@
> > > > >> >>    #
> > > > >> >>
> > > > >> >>    ArmTrngLib|Include/Library/ArmTrngLib.h
> > > > >> >>
> > > > >> >>
> > > > >> >>
> > > > >> >> +  ##  @libraryclass  Provides APIs for third-party library libfdt.
> > > > >> >>
> > > > >> >> +  #
> > > > >> >>
> > > > >> >> +  FdtLib|Include/Library/FdtLib.h
> > > > >> >>
> > > > >> >> +
> > > > >> >>
> > > > >> >>  [LibraryClasses.IA32, LibraryClasses.X64, LibraryClasses.AARCH64]
> > > > >> >>
> > > > >> >>    ##  @libraryclass  Provides services to generate random number.
> > > > >> >>
> > > > >> >>    #
> > > > >> >>
> > > > >> >> diff --git a/MdePkg/MdePkg.dsc b/MdePkg/MdePkg.dsc index
> > > > >> >> 152c02991a..b38c863812 100644
> > > > >> >> --- a/MdePkg/MdePkg.dsc
> > > > >> >> +++ b/MdePkg/MdePkg.dsc
> > > > >> >> @@ -137,6 +137,7 @@
> > > > >> >>
> > > > >> >>
> MdePkg/Library/SmmCpuRendezvousLibNull/SmmCpuRendezvousLibNull.inf
> > > > >> >>
> > > > >> >>
> > > > >> >>
> > > > >> >>    MdePkg/Library/JedecJep106Lib/JedecJep106Lib.inf
> > > > >> >>
> > > > >> >> +  MdePkg/Library/BaseFdtLib/BaseFdtLib.inf
> > > > >> >>
> > > > >> >>
> > > > >> >>
> > > > >> >>  [Components.IA32, Components.X64, Components.ARM,
> > > > >> >> Components.AARCH64]
> > > > >> >>
> > > > >> >>    #
> > > > >> >>
> > > > >> >> --
> > > > >> >> 2.39.1.windows.1
> > > > >
> > > > >
> > >
> > >
> > >
> > >
> > >
> 
> 
> 
>